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Ciais G, Massin V, Tibbo M, Dardenne T, Abdellaoui M, Ricón J, Antoni M, Laumonerie P. Stress shielding following radial head arthroplasty: the impact of preoperative bone quality. J Shoulder Elbow Surg 2024:S1058-2746(24)00302-1. [PMID: 38697508 DOI: 10.1016/j.jse.2024.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/21/2024] [Accepted: 03/03/2024] [Indexed: 05/05/2024]
Abstract
INTRODUCTION We sought to assess if the medullary diameter to cortical width ratio (MD:CW), canal flair index (CFI), and canal fill (CF) of the proximal radius were associated with the presence of Stress shielding (SS) after a MoPyC radial head arthroplasty (RHA). MATERIAL & METHOD We conducted a retrospective, international, multicenter (4 centers) study. A total of 100 radial head arthroplasties in 64 women and 36 men with a mean age of 58.40 years ±14.90 (range, 25.00; 91.00) were included. Radiographic measurements, including MD:CW, CFI, CF, and postoperative SS were captured at a mean follow-up of 3.9 years ±2.8 (range, 0.5-11). RESULTS Stress shielding was identified in 60 patients. Mean preoperative MD:CW, CFI, and CF were 0.55 ±0.09, 1.05 ±0.18 and 0.79±0.11, respectively. The presence of SS was significantly associated with MD:CW (aOR=13.66; p=0.001), and expansion of the stem (aOR=3.78; p=0.001). The amount of the SS was significantly correlated with expansion of the stem (aβ 4.58; p<0.001). CONCLUSIONS Our study found that MD:CW was an independent risk factor of SS after Mopyc RHA. Patients with longer and larger diameter (auto-expansion) Mopyc stems were also at significantly increased risk of SS. Further studies involving multiple implants designs are needed to confirm the preliminary observations presented in the current study.
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Affiliation(s)
- Grégoire Ciais
- Department of Orthopedic Surgery, Clinique Jouvenet, Paris, France
| | - Valentin Massin
- Department of Orthopedic Surgery, La Timone hospital, Marseille, France
| | - Meagan Tibbo
- Department of Orthopedic Surgery, Mayo Clinic, Phoenix, AZ, USA
| | - Theopol Dardenne
- Department of Orthopedic Surgery, Pellegrin hospital, Bordeaux, France
| | | | - Javier Ricón
- Department of Orthopedic Surgery, Vega Baja, Orihuela, Spain
| | - Maxime Antoni
- Department of Orthopedic Surgery, Clinique de l'orangerie, Strasbourg, France
| | - Pierre Laumonerie
- Department of Orthopedic Surgery, Pellegrin hospital, Bordeaux, France.
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Panaite T, Savin C, Olteanu ND, Karvelas N, Romanec C, Vieriu RM, Balcos C, Baltatu MS, Benchea M, Achitei D, Zetu I. Heat Treatment's Vital Role: Elevating Orthodontic Mini-Implants for Superior Performance and Longevity-Pilot Study. Dent J (Basel) 2024; 12:103. [PMID: 38668015 PMCID: PMC11049007 DOI: 10.3390/dj12040103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/01/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Orthodontic mini-implants are devices used for anchorage in various orthodontic treatments. We conducted a pilot study which aimed to observe preliminary trends regarding the impact of heat treatment on the elastic modulus of Ti6Al4V alloy and stainless steel 316L mini-implants. The initial phase involved testing the impact of heat treatment on the mechanical properties of Ti6Al4V alloy and stainless steel 316L mini-implants. MATERIAL AND METHODS Ten self-drilling mini-implants sourced from two distinct manufacturers (Jeil Medical Corporation® and Leone®) with dimensions of 2.0 mm diameter and 10 mm length were tested. They were separated into two material groups: Ti6Al4V and 316L. Using the CETRUMT-2 microtribometer equipment, indentation testing was conducted employing a diamond-tipped Rockwell penetrator at a constant force of 4.5 N. RESULTS Slight differences were observed in the elastic modulus of the Ti6Al4V alloy (103.99 GPa) and stainless steel 316L (203.20 GPa) compared to natural bone. The higher elastic moduli of these materials indicate that they are stiffer, which could potentially lead to stress-shielding phenomena and bone resorption. Heat treatment resulted in significant changes in mechanical properties, including elastic modulus reductions of approximately 26.14% for Ti6Al4V and 24.82% for 316L, impacting their performance in orthodontic applications. CONCLUSION Understanding the effects of heat treatment on these alloys is crucial for optimizing their biomechanical compatibility and longevity in orthodontic treatment. To fully evaluate the effects of heat treatment on mini-implants and to refine their design and efficacy in clinical practice, further research is needed.
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Affiliation(s)
- Tinela Panaite
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Carmen Savin
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Nicolae Daniel Olteanu
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Nikolaos Karvelas
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Cristian Romanec
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Raluca-Maria Vieriu
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Carina Balcos
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
| | - Madalina Simona Baltatu
- Faculty of Materials Science and Engineering, “Gheorghe Asachi” Technical University of Iasi, 41 “D. Mangeron” Street, 700050 Iasi, Romania;
| | - Marcelin Benchea
- Faculty of Mechanical Engineering, “Gheorghe Asachi” Technical University of Iasi, Blvd. Dimitrie Mangeron, No. 61–63, 700050 Iasi, Romania;
| | - Dragos Achitei
- Department of Technologies and Equipments for Materials Processing, Faculty of Materials Science and Engineering, Gheorghe Asachi Technical University of Iaşi, Blvd. Mangeron, No. 51, 700050 Iasi, Romania;
| | - Irina Zetu
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Gr. T. Popa” University of Medicine and Pharmacy, 16 Universitatii Str., 700115 Iasi, Romania; (T.P.); (N.D.O.); (N.K.); (R.-M.V.); (C.B.); (I.Z.)
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Hitchon S, Soltanmohammadi P, Milner JS, Holdsworth D, Willing R. Porous versus solid shoulder implants in humeri of different bone densities: A finite element analysis. J Orthop Res 2024. [PMID: 38520665 DOI: 10.1002/jor.25840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 03/09/2024] [Accepted: 03/12/2024] [Indexed: 03/25/2024]
Abstract
Porous metallic prosthesis components can now be manufactured using additive manufacturing techniques, and may prove beneficial for promoting bony ingrowth, for accommodating drug delivery systems, and for reducing stress shielding. Using finite element modeling techniques, 36 scenarios (three porous stems, three bone densities, and four held arm positions) were analysed to assess the viability of porous humeral stems for use in total shoulder arthroplasty, and their resulting mechanobiological impact on the surrounding humerus bone. All three porous stems were predicted to experience stresses below the yield strength of Ti6Al4V (880 MPa) and to be capable of withstanding more than 10 million cycles of each loading scenario before failure. There was an indication that within an 80 mm region of the proximal humerus, there would be a reduction in bone resorption as stem porosity increased. Overall, this study shows promise that these porous structures are mechanically viable for incorporation into permanent shoulder prostheses to combat orthopedic infections.
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Affiliation(s)
- Sydney Hitchon
- School of Biomedical Engineering, Western University, London, Ontario, Canada
- Bone and Joint Institute, Western University, London, Ontario, Canada
| | | | - Jaques S Milner
- Robarts Research Institute, Western University, London, Ontario, Canada
| | - David Holdsworth
- Bone and Joint Institute, Western University, London, Ontario, Canada
- Robarts Research Institute, Western University, London, Ontario, Canada
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Ryan Willing
- School of Biomedical Engineering, Western University, London, Ontario, Canada
- Bone and Joint Institute, Western University, London, Ontario, Canada
- Department of Mechanical and Materials Engineering, Western University, London, Ontario, Canada
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Stoddart JC, Garner A, Tuncer M, Amis AA, Cobb J, van Arkel RJ. Load transfer in bone after partial, multi-compartmental, and total knee arthroplasty. Front Bioeng Biotechnol 2024; 12:1274496. [PMID: 38524193 PMCID: PMC10957574 DOI: 10.3389/fbioe.2024.1274496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/24/2024] [Indexed: 03/26/2024] Open
Abstract
Introduction: Arthroplasty-associated bone loss remains a clinical problem: stiff metallic implants disrupt load transfer to bone and, hence, its remodeling stimulus. The aim of this research was to analyze how load transfer to bone is affected by different forms of knee arthroplasty: isolated partial knee arthroplasty (PKA), compartmental arthroplasty [combined partial knee arthroplasty (CPKA), two or more PKAs in the same knee], and total knee arthroplasty (TKA). Methods: An experimentally validated subject-specific finite element model was analyzed native and with medial unicondylar, lateral unicondylar, patellofemoral, bi-unicondylar, medial bicompartmental, lateral bicompartmental, tricompartmental, and total knee arthroplasty. Three load cases were simulated for each: gait, stair ascent, and sit-to-stand. Strain shielding and overstraining were calculated from the differences between the native and implanted states. Results: For gait, the TKA femoral component led to mean strain shielding (30%) more than three times higher than that of PKA (4%-7%) and CPKA (5%-8%). Overstraining was predicted in the proximal tibia (TKA 21%; PKA/CPKA 0%-6%). The variance in the distribution for TKA was an order of magnitude greater than for PKA/CPKA, indicating less physiological load transfer. Only the TKA-implanted femur was sensitive to the load case: for stair ascent and gait, almost the entire distal femur was strain-shielded, whereas during sit-to-stand, the posterior femoral condyles were overstrained. Discussion: TKA requires more bone resection than PKA and CPKA. These finite element analyses suggest that a longer-term benefit for bone is probable as partial and multi-compartmental knee procedures lead to more natural load transfer compared to TKA. High-flexion activity following TKA may be protective of posterior condyle bone resorption, which may help explain why bone loss affects some patients more than others. The male and female bone models used for this research are provided open access to facilitate future research elsewhere.
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Affiliation(s)
- Jennifer C. Stoddart
- Biomechanics Group, Department of Mechanical Engineering, Imperial College London, London, United Kingdom
| | - Amy Garner
- Msk Lab, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
- Dunhill Medical Trust and Royal College of Surgeons of England Joint Research Fellowship, London, United Kingdom
- Nuffield Orthopaedic Centre, Oxford Universities NHS Trust, Oxford, United Kingdom
| | | | - Andrew A. Amis
- Biomechanics Group, Department of Mechanical Engineering, Imperial College London, London, United Kingdom
| | - Justin Cobb
- Msk Lab, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Richard J. van Arkel
- Biomechanics Group, Department of Mechanical Engineering, Imperial College London, London, United Kingdom
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Swart A, Hamouda A, Pennington Z, Lakomkin N, Mikula AL, Martini ML, Shafi M, Subramaniam T, Sebastian AS, Freedman BA, Nassr AN, Fogelson JL, Elder BD. Significant Reduction in Bone Density as Measured by Hounsfield Units in Patients with Ankylosing Spondylitis or Diffuse Idiopathic Skeletal Hyperostosis. J Clin Med 2024; 13:1430. [PMID: 38592686 PMCID: PMC10932308 DOI: 10.3390/jcm13051430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/05/2024] [Accepted: 02/27/2024] [Indexed: 04/10/2024] Open
Abstract
Background: Multisegmental pathologic autofusion occurs in patients with ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH). It may lead to reduced vertebral bone density due to stress shielding. Methods: This study aimed to determine the effects of autofusion on bone density by measuring Hounsfield units (HU) in the mobile and immobile spinal segments of patients with AS and DISH treated at a tertiary care center. The mean HU was calculated for five distinct regions-cranial adjacent mobile segment, cranial fused segment, mid-construct fused segment, caudal fused segment, and caudal adjacent mobile segment. Means for each region were compared using paired-sample t-tests. Multivariable regression was used to determine independent predictors of mid-fused segment HUs. Results: One hundred patients were included (mean age 76 ± 11 years, 74% male). The mean HU for the mid-construct fused segment (100, 95% CI [86, 113]) was significantly lower than both cranial and caudal fused segments (174 and 108, respectively; both p < 0.001), and cranial and caudal adjacent mobile segments (195 and 115, respectively; both p < 0.001). Multivariable regression showed the mid-construct HUs were predicted by history of smoking (-30 HU, p = 0.009). Conclusions: HUs were significantly reduced in the middle of long-segment autofusion, which was consistent with stress shielding. Such shielding may contribute to the diminution of vertebral bone integrity in AS/DISH patients and potentially increased fracture risk.
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Affiliation(s)
- Alexander Swart
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Abdelrahman Hamouda
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Zach Pennington
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Nikita Lakomkin
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Anthony L. Mikula
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Michael L. Martini
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Mahnoor Shafi
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | | | - Arjun S. Sebastian
- Department of Orthopedic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Brett A. Freedman
- Department of Orthopedic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Ahmad N. Nassr
- Department of Orthopedic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Jeremy L. Fogelson
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
| | - Benjamin D. Elder
- Department of Neurologic Surgery, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA
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Giannicola G, Amura A, Prigent S, Zoccali C, Sessa P. Stress Shielding around Press-Fit Radial Head Arthroplasty: Proposal for a New Classification System Based on the Analysis of 97 Patients with a Mid-Term Follow-Up and a Review of the Literature. Healthcare (Basel) 2024; 12:396. [PMID: 38338281 PMCID: PMC10855405 DOI: 10.3390/healthcare12030396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/25/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024] Open
Abstract
Stress shielding (SS) around press-fit radial head arthroplasty (RHA) was recently reported as a cause of a new type of proximal radial neck resorption (PRNR). Very few studies have analyzed this phenomenon. No comprehensive classification is currently available. We thus decided to clinically and radiographically analyze 97 patients who underwent a press-fit RHA and who were followed up for a mean period of 72 months (range: 2-14 years). PRNR in the four quadrants of the radial neck was assessed. We designed a novel SS classification based on (1) the degree of resorption of the length of the radial neck and (2) the number of neck quadrants involved on the axial plane. The mean PRNR (mPRNR) was calculated as the mean resorption in the four quadrants. mPRNR was classified as mild (<3 mm), moderate (3 to 6 mm), and severe (>6 mm). Eighty-four percent of the patients presented PRNR. mPRNR was mild in 33% of the patients, moderate in 54%, and severe in 13%. In total, 6% of the patients with mild mPRNR displayed resorption in one quadrant, 18% displayed resorption in two quadrants, 4% displayed resorption in three quadrants, and 72% displayed resorption in four quadrants. All four quadrants were always involved in moderate or severe mPRNR, with no significant differences being detected between quadrants (p = 0.568). mPRNR has no apparent effect on the clinical results, complications, or RHA survival in the medium term. However, longer-term studies are needed to determine the effects of varying degrees of PRNR on implant failure.
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Affiliation(s)
- Giuseppe Giannicola
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, “Sapienza” University of Rome, Piazzale Aldo Moro 3, 00185 Rome, Italy; (G.G.); (S.P.); (C.Z.)
| | - Andrea Amura
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, “Sapienza” University of Rome, Piazzale Aldo Moro 3, 00185 Rome, Italy; (G.G.); (S.P.); (C.Z.)
| | - Sebastien Prigent
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, “Sapienza” University of Rome, Piazzale Aldo Moro 3, 00185 Rome, Italy; (G.G.); (S.P.); (C.Z.)
| | - Carmine Zoccali
- Department of Anatomical, Histological, Forensic Medicine and Orthopedics Sciences, “Sapienza” University of Rome, Piazzale Aldo Moro 3, 00185 Rome, Italy; (G.G.); (S.P.); (C.Z.)
| | - Pasquale Sessa
- Department of Orthopedics and Traumatology, A.O. San Camillo-Forlanini, Circonvallazione Gianicolense 87, 00100 Rome, Italy
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Kazemirad S, Yazdi MA. The assessment of implant shape-dependent failure mechanisms in primary total hip arthroplasty using finite element analysis. Comput Methods Biomech Biomed Engin 2024:1-14. [PMID: 38247427 DOI: 10.1080/10255842.2023.2301676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024]
Abstract
The three mechanisms known to be responsible for the failure of uncemented femoral stems in primary total hip arthroplasty (THA) are the stress shielding, excessive bone-implant interface stress, and excessive initial micromotion. Since implant designers usually have to sacrifice two mechanisms to improve the other one, the aim of this study was to assess which of them plays a more important role in the failure of uncemented stems. Two hip implant stems which are widely used in the primary THA and their mid-term clinical outcomes are available, were selected. Then, the amount of the three failure mechanisms created by each stem during the normal walking gait cycle was determined for a 70 kg female patient using the finite element method. The results indicated that the stem with better clinical outcome induced an average of 36.6% less stress shielding in the proximal regions of femur bone compared with the other stem. However, the maximum bone-implant interface stress and maximum initial micromotion were, respectively, 30 and 155% higher for the stem with better clinical outcomes. It was therefore concluded that the stress shielding has a more significant impact on the mid-term life of uncemented stems. However, care must be taken to ensure that the other two failure mechanisms do not exceed a certain threshold. It was also observed that the thinner and shorter stem created a smaller amount of stress shielding in the femur bone. The outcomes of this study can be used to design new hip implant stems that can potentially last longer.
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Affiliation(s)
- Siavash Kazemirad
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
| | - Mohammad Ali Yazdi
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
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Zhang C, Wen P, Xu Y, Fu Z, Ren G. Exploring Advanced Functionalities of Carbon Fiber-Graded PEEK Composites as Bone Fixation Plates Using Finite Element Analysis. Materials (Basel) 2024; 17:414. [PMID: 38255583 PMCID: PMC10817601 DOI: 10.3390/ma17020414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024]
Abstract
This study aims to address the challenges associated with conventional metallic bone fixation plates in biomechanical applications, such as stainless steel and titanium alloys, including stress shielding, allergic reactions, corrosion resistance, and interference with medical imaging. The use of materials with a low elastic modulus is regarded as an effective approach to overcome these problems. In this study, the impact of different types of chopped carbon fiber-reinforced polyether ether ketone (CCF/PEEK) functionally graded material (FGM) bone plates on stress shielding under static and instantaneous dynamic loading was explored using finite element analysis (FEA). The FGM bone plate models were established using ABAQUS and the user's subroutine USDFLD and VUSDFLD, and each model was established with an equivalent overall elastic modulus and distinctive distributions. The results revealed that all FGM bone plates exhibited lower stress shielding effects compared to metal bone plates. Particularly, the FGM plate with an elastic modulus gradually increased from the centre to both sides and provided maximum stress stimulation and the most uniform stress distribution within the fractured area. These findings offer crucial insights for designing implantable medical devices that possess enhanced mechanical adaptability.
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Affiliation(s)
- Chenggong Zhang
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK;
| | - Pihua Wen
- Institute of Aeronautics and Astronautics, School of Infrastructure Engineering, Nanchang University, Nanchang 330031, China
| | - Yigeng Xu
- School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield MK43 0AL, UK;
| | - Zengxiang Fu
- Faculty of Life Science, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Guogang Ren
- School of Physics, Engineering and Computer Science, University of Hertfordshire, Hatfield AL10 9AB, UK
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Montemaggi P, Lo EY, Ouseph A, Lund J, Krishnan SG. Cementless reverse total shoulder arthroplasty implantation with humeral matchstick autograft augmentation: early radiographic outcomes. J Shoulder Elbow Surg 2024:S1058-2746(24)00022-3. [PMID: 38218403 DOI: 10.1016/j.jse.2023.11.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/14/2023] [Accepted: 11/19/2023] [Indexed: 01/15/2024]
Abstract
BACKGROUND Humeral-sided complications account for up to 21% of all revision reverse total shoulder arthroplasty (RTSA) surgeries. Stress shielding with large bulky stems can lead to proximal bone resorption per Wolff law, complicating further surgeries. Previously published studies suggest that lowering the metaphyseal implant fill ratio can lead to fewer adaptive radiographic changes and decreased bone resorption. Inspired by these studies, cementless primary RTSA implantation technique with humeral matchstick autografts was proposed to augment cementless humeral constructs, foster the use of a smaller size stem, and create primary stability of the humeral implant even in osteoporotic or in-between size medullary canals. In this study, retrospective review of this cementless RTSA technique with short-term radiographic evaluation was performed. METHODS Forty-six nonconsecutive patients underwent primary RTSA with a short-stem cementless prosthesis (Stryker Ascend Flex) augmented by matchstick bone grafting from January to July 2020. Patient demographics were recorded, and follow-up radiographs were retrospectively reviewed to assess metaphyseal fill ratios and incidence of stress shielding at minimum 1-year follow-up. Discrepancies between templated and final stem sizes were recorded, along with all intraoperative and postoperative complications. RESULTS Of the 46 patients originally identified, there were 5 men and 41 women with a mean age of 71 years (standard deviation [SD] 7, range 53-88). Mean templated stem size was 4 (SD 2, range 1-8), whereas the mean final implant size was 2 (SD 1, range 1-3). Mean fill ratios were 0.76 (SD 0.06, range 0.54-0.89) along the metaphysis and 0.67 (SD 0.09, range 0.49-0.83) along the diaphysis. There were no intraoperative humeral fractures from implantation. All patients were available for radiographic follow-up with a mean of 19 months (SD 8, range 12-40). There were 3 cases (7%) of proximal humeral stress shielding, with average fill ratios of 0.857 and 0.807 in the metaphysis and diaphysis, respectively. There were 3 patients (7%) who underwent revision surgeries for baseplate failure and periprosthetic humeral fracture. There were no cases of early humeral loosening. DISCUSSION Matchstick autograft humeral augmentation is a simple, promising surgical technique with low intraoperative complication rates and good short-term radiographic outcomes. When the implant fill ratio is successfully reduced, there is a possible lower risk of humeral stress shielding. The authors believe this technique can help maximize implant stability in cementless shoulder arthroplasty and preserve humeral bone stock for future revision surgeries.
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Affiliation(s)
| | - Eddie Y Lo
- The Shoulder Center Research, Baylor Scott and White Research Institute, Dallas, TX, USA; The Shoulder Service, Baylor University Medical Center, Baylor Scott and White Health, Dallas, TX, USA.
| | - Alvin Ouseph
- The Shoulder Center Research, Baylor Scott and White Research Institute, Dallas, TX, USA; The Shoulder Service, Baylor University Medical Center, Baylor Scott and White Health, Dallas, TX, USA
| | - Julia Lund
- The Shoulder Center Research, Baylor Scott and White Research Institute, Dallas, TX, USA; The Shoulder Service, Baylor University Medical Center, Baylor Scott and White Health, Dallas, TX, USA
| | - Sumant G Krishnan
- The Shoulder Center Research, Baylor Scott and White Research Institute, Dallas, TX, USA; The Shoulder Service, Baylor University Medical Center, Baylor Scott and White Health, Dallas, TX, USA
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Zhao SC, Zhang HJ, Li Y. Cold granular targets slow the bulk freezing of an impacting droplet. Proc Natl Acad Sci U S A 2024; 121:e2311930121. [PMID: 38175861 PMCID: PMC10786308 DOI: 10.1073/pnas.2311930121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 11/20/2023] [Indexed: 01/06/2024] Open
Abstract
When making contact with an undercooled target, a drop freezes. The colder the target is, the more rapid the freezing is supposed to be. In this research, we explore the impact of droplets on cold granular material. As the undercooling degree increases, the bulk freezing of the droplet is delayed by at least an order of magnitude. The postponement of the overall solidification is accompanied by substantial changes in dynamics, including the spreading-retraction process, satellite drop generation, and cratering in the target. The solidification of the wetted pores in the granular target primarily causes these effects. The freezing process over the pore dimension occurs rapidly enough to match the characteristic timescales of impact dynamics at moderate undercooling degrees. As a result, the hydrophilic impact appears "hydrophobic," and the dimension of the solidified droplet shrinks. A monolayer of cold grains on a surface can reproduce these consequences. Our research presents a potential approach to regulate solidified morphology for subfreezing drop impacts. It additionally sheds light on the impact scenario of strong coupling between the dynamics and solidification.
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Affiliation(s)
- Song-Chuan Zhao
- Department of Engineering Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi’an Jiaotong University, Xi’an710049, China
| | - Hao-Jie Zhang
- Department of Engineering Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi’an Jiaotong University, Xi’an710049, China
| | - Yudong Li
- Department of Engineering Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi’an Jiaotong University, Xi’an710049, China
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11
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Zhai Y, Zhang H, Liu T, Zou C, Zhou C. Mechanical property of Ti6Al4V cylindrical porous structure for dental implants fabricated by selective laser melting. Comput Methods Biomech Biomed Engin 2024:1-19. [PMID: 38178700 DOI: 10.1080/10255842.2023.2300686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/03/2023] [Indexed: 01/06/2024]
Abstract
The commonly used titanium alloy dental implants currently apply solid structures. However, issues such as stress shielding and stress concentration may arise due to the significant difference in elastic modulus between the implant and host. In order to address these problems, this paper proposes five porous structures based on the Gibson-Ashby theoretical model. We utilized selective laser melting technology to shape a porous structure using Ti-6Al-4V material precisely. The mechanical properties of the porous structure were verified through simulation and compression experiments. The optimal porous structure, which best matched the human bone, was a circular ring structure with a pillar diameter of 0.6 mm and a layer height of 2 mm. The stress and strain of the porous implant on the surrounding cortical and cancellous bone under different biting conditions were studied to verify the effectiveness of the optimal circular ring porous structure in alleviating stress shielding in both standard and osteoporotic bone conditions. The results confirm that the circular ring porous structure meets implant requirements and provides a theoretical basis for clinical dental implantation.
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Affiliation(s)
- Yun Zhai
- Department of Mechanical Engineering, Dalian Jiaotong University, Dalian, China
| | - Hao Zhang
- Department of Mechanical Engineering, Dalian Jiaotong University, Dalian, China
| | - Tong Liu
- Department of Mechanical Engineering, Dalian Jiaotong University, Dalian, China
| | - Cong Zou
- Department of Stomatology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Changchun Zhou
- National Engineering Research Centre for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu, China
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12
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Vegas A, Cannon D, Lewis S, Glener J, Mekkawy KL, Rodriguez HC, Schodlbauer DF, Levy JC. Impact of humeral stem length on calcar resorption in anatomic total shoulder arthroplasty. J Shoulder Elbow Surg 2024; 33:130-138. [PMID: 37419442 DOI: 10.1016/j.jse.2023.05.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/08/2023] [Accepted: 05/28/2023] [Indexed: 07/09/2023]
Abstract
BACKGROUND Use of standard-length anatomic total shoulder (TSA) humeral stems has been associated with high rates of medial calcar bone loss. Calcar bone loss has been attributed to stress shielding, debris-induced osteolysis, and undiagnosed infection. Short stem and canal-sparing humeral components may provide more optimal stress distribution and thus lower rates of calcar bone loss related to stress shielding. The purpose of this study is to determine whether implant length will affect the rate and severity of medial calcar resorption. METHODS A retrospective review was performed on TSA patients treated with three different-length humeral implants (canal-sparing, short, and standard-length designs). Patients were matched 1:1:1 based on both gender and age (±4 years), resulting in 40 patients per cohort. Radiographic changes in medial calcar bone were evaluated and graded on a 4-point scale, from the initial postoperative radiographs to those at 3 months, 6 months, and 12 months. RESULTS The presence of any degree of medial calcar resorption demonstrated an overall rate of 73.3% at one year. At 3 months, calcar resorption was observed in 20% of the canal-sparing cohort, while the short and standard designs demonstrated resorption in 55% and 52.5%, respectively (P = .002). At 12 months, calcar resorption was seen in 65% of the canal-sparing design, while both the short and standard designs had a 77.5% rate of resorption (P = .345). The severity of calcar resorption for the canal-sparing cohort was significantly lower at all time points when compared to the short stem (3 months, P = .004; 6 months, P = .003; 12 months, P = .004) and at 3 months when compared to the standard-length stem (P = .009). CONCLUSION Patients treated with canal-sparing TSA humeral components have significantly lower rates of early calcar resorption with less severe bone loss when compared to patients treated using short and standard-length designs.
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Affiliation(s)
- Austin Vegas
- Department of Orthopedic Surgery, Larkin Community Hospital, South Miami, FL, USA
| | - Dylan Cannon
- Department of Orthopaedic Surgery, Oklahoma University, Oklahoma City, OK, USA
| | - Steven Lewis
- Holy Cross Orthopedic Institute, Fort Lauderdale, FL, USA
| | - Julie Glener
- Holy Cross Orthopedic Institute, Fort Lauderdale, FL, USA
| | | | - Hugo C Rodriguez
- Department of Orthopedic Surgery, Larkin Community Hospital, South Miami, FL, USA
| | - Daniel F Schodlbauer
- Levy Shoulder Center at Paley Orthopedic and Spine Institute, Boca Raton, FL, USA
| | - Jonathan C Levy
- Levy Shoulder Center at Paley Orthopedic and Spine Institute, Boca Raton, FL, USA.
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13
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Yabusaki Y, Asai K, Hisakado H, Takano N. Effect of short stem alignment on initial fixation, stress transfer, and failure risk. Technol Health Care 2024; 32:117-130. [PMID: 37302047 DOI: 10.3233/thc-220591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND Short stems are advantageous for revision as they preserve autogenous bone. At present, the method of short-stem installation is determined based on the surgeon's experience. OBJECTIVE To provide the guideline for installing a short stem, we aimed to investigate the alignment effect on the initial fixation of the stem, stress transfer, and the risk of failure numerically. METHODS Models in which the caput-collum-diaphyseal (CCD) angle and flexion angle were hypothetically changed based on the two clinical cases of hip osteoarthritis were analyzed using the non-linear finite element method. RESULTS The medial settlement of the stem increased in the varus model and decreased in the valgus model. With varus alignment, the stresses acting on the femur were high in the distal to the femoral neck. In contrast, the stresses in the proximal to the femoral neck tend to be higher with valgus alignment, although the difference in the femur stress between varus and valgus alignment was slight. CONCLUSION Both initial fixation and stress transmission are lower when the device was placed in the valgus model than in the actual surgical case. In order to obtain initial fixation and suppress stress shielding, it is essential to extend the contact area between the medial portion of the stem and the femur along the bone axis, and to ensure adequate contact between the lateral portion of the stem tip and the femur.
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Affiliation(s)
- Yumie Yabusaki
- Department of Mechanical Engineering, Kanazawa Institute of Technology, Hakusan, Japan
| | - Kenji Asai
- Department of Mechanical Engineering, Kanazawa Institute of Technology, Hakusan, Japan
| | | | - Noriyuki Takano
- Integrated Technology Research Center of Medical Science and Engineering, Kanazawa Institute of Technology, Hakusan, Japan
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14
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Hijazi KM, Dixon SJ, Armstrong JE, Rizkalla AS. Titanium Alloy Implants with Lattice Structures for Mandibular Reconstruction. Materials (Basel) 2023; 17:140. [PMID: 38203994 PMCID: PMC10779528 DOI: 10.3390/ma17010140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 11/30/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024]
Abstract
In recent years, the field of mandibular reconstruction has made great strides in terms of hardware innovations and their clinical applications. There has been considerable interest in using computer-aided design, finite element modelling, and additive manufacturing techniques to build patient-specific surgical implants. Moreover, lattice implants can mimic mandibular bone's mechanical and structural properties. This article reviews current approaches for mandibular reconstruction, their applications, and their drawbacks. Then, we discuss the potential of mandibular devices with lattice structures, their development and applications, and the challenges for their use in clinical settings.
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Affiliation(s)
- Khaled M. Hijazi
- School of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON N6A 3K7, Canada
- Bone and Joint Institute, The University of Western Ontario, London, ON N6G 2V4, Canada
| | - S. Jeffrey Dixon
- Bone and Joint Institute, The University of Western Ontario, London, ON N6G 2V4, Canada
- Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Jerrold E. Armstrong
- Division of Oral and Maxillofacial Surgery, Department of Otolaryngology Head and Neck Surgery, Henry Ford Hospital, Detroit, MI 48202, USA
| | - Amin S. Rizkalla
- School of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON N6A 3K7, Canada
- Bone and Joint Institute, The University of Western Ontario, London, ON N6G 2V4, Canada
- Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
- Chemical and Biochemical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON N6A 5B9, Canada
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15
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Sanaei R, Pagel CN, Ayodele BA, Lozanovski B, Beths T, Leary M, Shidid D, Kastrati E, Elambasseril J, Bühner U, Williamson T, Ryan S, Brandt M. Reducing the prosthesis modulus by inclusion of an open space lattice improves osteogenic response in a sheep model of extraarticular defect. Front Bioeng Biotechnol 2023; 11:1301454. [PMID: 38130824 PMCID: PMC10733966 DOI: 10.3389/fbioe.2023.1301454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
Introduction: Stress shielding is a common complication following endoprosthetic reconstruction surgery. The resulting periprosthetic osteopenia often manifests as catastrophic fractures and can significantly limit future treatment options. It has been long known that bone plates with lower elastic moduli are key to reducing the risk of stress shielding in orthopedics. Inclusion of open space lattices in metal endoprostheses is believed to reduce the prosthesis modulus potentially improving stress shielding. However, no in vivo data is currently available to support this assumption in long bone reconstruction. This manuscript aims to address this hypothesis using a sheep model of extraarticular bone defect. Methods: Initially, CT was used to create a virtual resection plan of the distal femoral metaphyses and to custom design endoprostheses specific to each femur. The endoprostheses comprised additively manufactured Ti6Al4V-ELI modules that either had a solid core with a modulus of ∼120 GPa (solid implant group) or an open space lattice core with unit cells that had a modulus of 3-6 GPa (lattice implant group). Osteotomies were performed using computer-assisted navigation followed by implantations. The periprosthetic, interfacial and interstitial regions of interest were evaluated by a combination of micro-CT, back-scattered scanning electron microscopy (BSEM), as well as epifluorescence and brightfield microscopy. Results: In the periprosthetic region, mean pixel intensity (a proxy for tissue mineral density in BSEM) in the caudal cortex was found to be higher in the lattice implant group. This was complemented by BSEM derived porosity being lower in the lattice implant group in both caudal and cranial cortices. In the interfacial and interstitial regions, most pronounced differences were observed in the axial interfacial perimeter where the solid implant group had greater bone coverage. In contrast, the lattice group had a greater coverage in the cranial interfacial region. Conclusion: Our findings suggest that reducing the prosthesis modulus by inclusion of an open-space lattice in its design has a positive effect on bone material and morphological parameters particularly within the periprosthetic regions. Improved mechanics appears to also have a measurable effect on the interfacial osteogenic response and osteointegration.
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Affiliation(s)
- Reza Sanaei
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Charles Neil Pagel
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Babatunde A. Ayodele
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Bill Lozanovski
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
| | - Thierry Beths
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Martin Leary
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
| | - Darpan Shidid
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
| | - Endri Kastrati
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
- Stryker Australia Pty Ltd., St Leonards, NSW, Australia
| | - Joe Elambasseril
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
| | | | - Tom Williamson
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
- Stryker Australia Pty Ltd., St Leonards, NSW, Australia
| | - Stewart Ryan
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC, Australia
| | - Milan Brandt
- RMIT Centre for Additive Manufacturing, RMIT University, Carlton, VIC, Australia
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16
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Diez Sánchez B, Barco R, Antuña SA. Radial head replacement for acute complex elbow instability: a long-term comparative cohort study of 2 implant designs. J Shoulder Elbow Surg 2023; 32:2581-2589. [PMID: 37619928 DOI: 10.1016/j.jse.2023.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 07/11/2023] [Accepted: 07/21/2023] [Indexed: 08/26/2023]
Abstract
BACKGROUND Radial head fractures not amenable to reconstruction should be treated by radial head replacement (RHR) when there is associated elbow or forearm instability. There are multiple RHR designs with different philosophies, but 2 of the most commonly used implants include the anatomic press-fit radial head system and the loose-fit metallic spacer. There is little information available specifically comparing the long-term clinical and radiographic outcomes of these 2 systems. The objective of this study was to compare the long-term clinical and radiologic outcomes of 2 RHR designs in the context of complex acute elbow instability. MATERIALS AND METHODS Ninety-five patients with an average age of 54 years (range, 21-87 years) underwent an acute RHR (46 press-fit Acumed anatomic and 49 loose-fit Evolve metallic spacer) and were prospectively followed for an average of 61 months (range, 24-157 months). There were 34 terrible triads; 36 isolated RH fractures with medial, lateral, or longitudinal instability; and 25 RH fractures associated with a proximal ulnar fracture. Clinical outcome and disability were evaluated with the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score, and the Disabilities of the Arm, Shoulder, and Hand (DASH) score. Pain and satisfaction were assessed using a visual analog scale. Radiographic analysis included presence of loosening, bone loss, and overstuffing related to the RHR. RESULTS Eight patients with an anatomic RHR (2 with overstuffing, 3 for stiffness, and 3 with loose implants) and 1 patient with a spacer (with stiffness) required implant removal. There were no significant differences between spacer RHR and anatomic RHR in arc of motion (120° vs. 113°, P = .14), pain relief (1 vs. 1.7, P = .135), MEPS (94 vs. 88; P = .07), Oxford Elbow Score (42.3 vs. 42.2, P = .4), or DASH score (12.2 vs. 14.4, P = .5). However, patients with a spacer RHR were significantly more satisfied (9 vs. 7.7; P = .004) than those with an anatomic implant. Radiographically, 19 anatomic implants had significant proximal bone loss and 10 showed complete lucent lines around the stem. Lucent lines were common around the spacer RHR. These radiographic changes were not always related to worse clinical outcomes. CONCLUSION Both the anatomic and spacer RHR designs can provide good clinical long-term outcomes. However, patients with a spacer showed a higher degree of satisfaction and those with an anatomic press-fit RHR had a higher revision rate, with radiographic changes that warrant continued follow-up.
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Affiliation(s)
| | - Raúl Barco
- Upper Limb Unit, Hospital Universitario La Paz, Madrid, Spain
| | - Samuel A Antuña
- Upper Limb Unit, Hospital Universitario La Paz, Madrid, Spain.
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17
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Tavakoli A, Spangenberg GW, Reeves JM, Faber KJ, Langohr GDG. The effect of humeral head positioning and incomplete backside contact on bone stresses following total shoulder arthroplasty with a short humeral stem. J Shoulder Elbow Surg 2023; 32:1988-1998. [PMID: 37230287 DOI: 10.1016/j.jse.2023.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/27/2023] [Accepted: 04/05/2023] [Indexed: 05/27/2023]
Abstract
BACKGROUND The use of uncemented humeral stems in total shoulder arthroplasty (TSA) is known to be associated with stress shielding. This may be decreased with smaller stems that are well-aligned and do not fill the intramedullary canal; however, the effect of humeral head positioning and incomplete head backside contact has not yet been investigated. The purpose of this study was to quantify the effect of changes in humeral head position and incomplete head backside contact on bone stresses and expected bone response following reconstruction. METHODS Three-dimensional finite element models of 8 cadaveric humeri were generated, which were then virtually reconstructed with a short-stem implant. An optimally sized humeral head was then positioned in both a superolateral and inferomedial position for each specimen that was in full contact with the humeral resection plane. Additionally, for the inferomedial position, 2 incomplete humeral head backside contact conditions were simulated whereby contact was defined between only the superior or inferior half of the backside of the humeral head and the resection plane. Trabecular properties were assigned based on computed tomography attenuation and cortical bone was applied uniform properties. Loads representing 45° and 75° of abduction were then applied, and the resulting differentials in bone stress versus the corresponding intact state and the expected time-zero bone response were determined and compared. RESULTS The superolateral position reduced resorbing potential in the lateral cortex and increased resorbing potential in the lateral trabecular bone, while the inferomedial position produced the same effects but in the medial quadrant. For the inferomedial position, full backside contact with the resection plane was best in terms of changes in bone stress and expected bone response, although a small region of the medial cortex did experience no load transfer. The implant-bone load transfer of the inferior contact condition was concentrated at the midline of the backside of the humeral head, leaving the medial aspect largely unloaded as a result of the lack of lateral backside support. DISCUSSION This study shows that inferomedial humeral head positioning loads the medial cortex at the cost of unloading the medial trabecular bone, with the same occurring for the superolateral position except that the lateral cortex is loaded at the cost of unloading the lateral trabecular bone. Inferomedial positioned heads also were predisposed to humeral head lift-off from the medial cortex, which may increase the risk of calcar stress shielding. For the inferomedial head position, full contact between the implant and resection plane was preferable.
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Affiliation(s)
- Amir Tavakoli
- Department of Mechanical Engineering, Western University, London, ON, Canada; The Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Hospital, London, ON, Canada
| | - Gregory W Spangenberg
- Department of Mechanical Engineering, Western University, London, ON, Canada; The Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Hospital, London, ON, Canada
| | - Jacob M Reeves
- The Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Hospital, London, ON, Canada; Department of Surgery, Western University, London, ON, Canada
| | - Kenneth J Faber
- The Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Hospital, London, ON, Canada; Department of Surgery, Western University, London, ON, Canada
| | - G Daniel G Langohr
- Department of Mechanical Engineering, Western University, London, ON, Canada; The Roth | McFarlane Hand and Upper Limb Centre, St. Joseph's Hospital, London, ON, Canada; Department of Surgery, Western University, London, ON, Canada.
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18
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Togher CJ, Thompson JM, Perkins JM, Berlet GC, Hyer CF. A Study of Tibial Cyst Formation in Modular Stemmed Total Ankle Arthroplasty: Exploring a Possible Relationship to Smooth and Porous Coating on the Stem Segments. J Foot Ankle Surg 2023; 62:756-763. [PMID: 37100341 DOI: 10.1053/j.jfas.2023.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 02/01/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023]
Abstract
Vertical fixation through stemmed components has been a successful strategy in total ankle arthroplasty. Research in hip replacement surgery has demonstrated increased rates of stress shielding, aseptic loosening, thigh pain, and cystic formation around stemmed femoral implants extensively coated with porous surfaces. While some ankle prostheses have integrated porous coating technology with stemmed tibial implants, there is little to no research investigating the potential negative effects of bone bonding to the tibial stems and possible impact on tibial cyst formation. We performed a retrospective cohort study comparing the incidence of periprosthetic tibial cyst formation in smooth versus fully porous-coated stemmed tibial implants after undergoing total ankle implant arthroplasty. Radiographs were compared for postoperative rates of tibial cyst formation and bone bonding to the tibial stems. Relative risk for reoperation between the smooth and porous-coated implants was investigated. The smooth-stem group showed no incidence of tibial cyst formation nor signs of significant bone bonding to the tibial stems; however, the follow-up matched porous-coated group showed a rate of 63% of cystic formation with associated evidence of bone bonding on final radiographic follow-up (p < .01). Relative risk for reoperation was 0.74. Despite a higher incidence of tibial cyst formation in the stemmed ankle arthroplasty groups with porous coating, reoperation rates were similar. We theorize that the proximal bonding to the porous stem surface could impact the distal stems and result in the observed increase in cyst formation.
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Affiliation(s)
- Cody J Togher
- Fellow, Orthopedic Foot & Ankle Center, Worthington, OH.
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19
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Galteri G, Cristofolini L. In vitro and in silico methods for the biomechanical assessment of osseointegrated transfemoral prostheses: a systematic review. Front Bioeng Biotechnol 2023; 11:1237919. [PMID: 37662439 PMCID: PMC10469938 DOI: 10.3389/fbioe.2023.1237919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 08/08/2023] [Indexed: 09/05/2023] Open
Abstract
The amputee population according to the World-Health-Organization is about 40 million. However, there is a high abandon rate of socket prostheses for the lower limb (25%-57%). The direct connection between the external prosthesis and the patient's bone makes osseointegrated prostheses for transfemoral amputees advantageous (e.g., improvement of the motor control) compared to socket prostheses, which are currently the gold standard. However, similarly to other uncemented prostheses, the osseointegrated ones are at risk of aseptic loosening and adverse bone remodelling caused by stress-shielding. The preclinical assessment of these prostheses has already been evaluated using different methods which did not provide unanimous and comparable evidence. To compare data from different investigations, a clear and detailed overview of the methods used to assess the performance is necessary. In this review 17 studies investigating the primary stability, stress shielding and stress concentration of osseointegrated transfemoral prostheses are examined. Primary stability consists in the biomechanical stability upon implant insertion. Primary stability is assessed measuring extraction force (either with a pull-out or a push-out test) and micromotion at the interface between the implant and the host bone with LVDT (in vitro test) or numerical models. Stress-shielding causes adaptive changes in the bone density around metal implants, and thus in the bone strength and stiffness. Stress-shielding is assessed with strain gauges or numerical models measuring the load transfer and the strain distribution on the surface of the femur, and between the implant and the bone respectively. Stress concentration can lead to the formation of cracks inside the bone, resulting in fractures. The stress concentration is assessed measuring the load transfer and the strain energy density at the interface between the implant and the bone, using numerical models. As a result, a global view and consensus about the methods are missing from all these tests. Indeed, different setup and loading scenario were used in the in vitro test, while different model parameters (e.g., bone properties) were used in the numerical models. Once the preclinical assessment method is established, it would be important to define thresholds and acceptance criteria for each of the possible failure scenarios investigated.
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Affiliation(s)
| | - Luca Cristofolini
- Department of Industrial Engineering, School of Engineering and Architecture, Alma Mater Studiorum-University of Bologna, Bologna, Italy
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20
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Galas A, Banci L, Innocenti B. The Effects of Different Femoral Component Materials on Bone and Implant Response in Total Knee Arthroplasty: A Finite Element Analysis. Materials (Basel) 2023; 16:5605. [PMID: 37629896 PMCID: PMC10456576 DOI: 10.3390/ma16165605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023]
Abstract
Due to the high stiffness of the biomaterials used in total knee arthroplasty, stress shielding can lead to decreased periprosthetic bone mineral density and bone resorption. As different materials and 3D-printed highly porous surfaces are available for knee femoral components from the industry nowadays, this study aimed to compare the effects of two same-design cruciate-retaining femoral components, made with CoCr and titanium alloy, respectively, on periprosthetic bone stresses through a finite element model of the implanted knee in order to evaluate the induced stress shielding. Moreover, the effect of the cementless highly porous surface of the titanium implant was analyzed in comparison to the cemented interface of the CoCr implant. The von Mises stresses were analyzed in different periprosthetic regions of interest of the femur with different configurations and knee flexion angles. The titanium component induced higher bone stresses in comparison with the CoCr component, mostly in the medial compartment at higher knee flexion angles; therefore, the CoCr component led to more stress shielding. The model was revealed to be effective in describing the effects of different femoral component materials on bone stress, highlighting how a cementless, highly porous titanium femoral component might lead to less stress shielding in comparison to a cemented CoCr implant with significant clinical relevance and reduced bone resorption after total knee arthroplasty.
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Affiliation(s)
- Allegra Galas
- LaBS, Department of Chemistry, Materials and Chemical Engineering “G. Natta”, Politecnico di Milano, 20133 Milan, Italy
| | - Lorenzo Banci
- Clinical Department, Permedica Orthopaedics, 23807 Merate, Italy;
| | - Bernardo Innocenti
- BEAMS Department (Bio Electro and Mechanical Systems), École Polytechnique de Bruxelles, Université Libre de Bruxelles, 1050 Bruxelles, Belgium
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21
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Nemes-Károly I, Szebényi G. Reliable Methods for Classification, Characterization, and Design of Cellular Structures for Patient-Specific Implants. Materials (Basel) 2023; 16:ma16114146. [PMID: 37297280 DOI: 10.3390/ma16114146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/12/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023]
Abstract
In our research, our goal was to develop a characterization method that can be universally applied to periodic cell structures. Our work involved the accurate tuning of the stiffness properties of cellular structure components that can significantly reduce the number of revision surgeries. Up to date porous, cellular structures provide the best possible osseointegration, while stress shielding and micromovements at the bone-implant interface can be reduced by implants with elastic properties equivalent to bone tissue. Furthermore, it is possible to store a drug inside implants with a cellular structure, for which we have also prepared a viable model. In the literature, there is currently no established uniform stiffness sizing procedure for periodic cellular structures but also no uniform designation to identify the structures. A uniform marking system for cellular structures was proposed. We developed a multi-step exact stiffness design and validation methodology. The method consists of a combination of FE (Finite Element) simulations and mechanical compression tests with fine strain measurement, which are finally used to accurately set the stiffness of components. We succeeded in reducing the stiffness of test specimens designed by us to a level equivalent to that of bone (7-30 GPa), and all of this was also validated with FE simulation.
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Affiliation(s)
- István Nemes-Károly
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
| | - Gábor Szebényi
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
- MTA-BME Lendület Lightweight Polymer Composites Research Group, Műegyetem rkp. 3, H-1111 Budapest, Hungary
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22
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López Galiano IC, Echeverry-Mejía J, Ortiz JG, Zambrano HR, Juha M. Design of titanium uncemented femoral stems for hip prosthesis suitable for the Colombian young adult population. Comput Methods Biomech Biomed Engin 2023:1-11. [PMID: 37145102 DOI: 10.1080/10255842.2023.2205978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The increase of revision surgeries in hip replacement procedure in Colombian young adult population can be addressed by a new design of femoral stem that reduces stress shielding. A new femoral stem was designed using topology optimization as a design aid to reduce the mass in the femoral stem and its overall stiffness, combined with the theoretical, computational, and experimental assessment of the new design that complies with a static and fatigue safety factor greater than one. The new femoral stem design can be used as a design tool to reduce the number of revision surgeries caused by stress shielding.
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Affiliation(s)
- Iván Camilo López Galiano
- Doctorado en Ingeniería, Facultad de Ingeniería, Universidad de La Sabana, Campus Universitario del Puente del Común, Chía, Cundinamarca, Colombia
- Human Centered Design (HCD) Research Group, Universidad de La Sabana, Campus Universitario del Puente del Común, Chía, Cundinamarca, Colombia
| | - Julián Echeverry-Mejía
- Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Campus Aguascalientes, Los Pocitos, Aguascalientes, México
| | - Juan Guillermo Ortiz
- Clínica Universidad de La Sabana, Campus Universitario del Puente del Común, Chía, Cundinamarca, Colombia
| | - Habib R Zambrano
- Departamento de Ingeniería Mecánica, Grupo GIMYP, Universidad del Norte, Barranquilla, Colombia
| | - Mario Juha
- Energy, Materials and Environment (GEMA) Research Group, Universidad de La Sabana, Campus Universitario del Puente del Común, Chía, Cundinamarca, Colombia
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23
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Maeda T, Nakano M, Nakamura Y, Momose T, Sobajima A, Takahashi J, Nakata K, Nawata M. Relationship between Stress Shielding and Optimal Femoral Canal Contact Regions for Short, Tapered-Wedge Stem Analyzed by 2D and 3D Systems in Total Hip Arthroplasty. J Clin Med 2023; 12:jcm12093138. [PMID: 37176578 PMCID: PMC10179674 DOI: 10.3390/jcm12093138] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/18/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
Although tapered-wedge short stem has been widely employed with its availability for minimally invasive surgeries in total hip arthroplasty (THA), post-operative stress shielding matter remains unresolved in cementless procedures. This study aimed to clarify the most optimal femoral canal contact regions of the stem design taking stress shielding incidence into consideration. This investigation included 60 joints from 60 patients (mean age at operation: 65.9 years), of which follow-up duration after primary THA had been more than 2 years. Frequencies of spot welds, subsidence, and stress shielding were examined 2 years after surgery. The most suitable femoral canal contact regions were evaluated by plain radiograph (2D) and 3D-computed tomography analyses according to Nakata's division for fitting manners. Spot welds were observed in 38 cases (63.3%), and no subsidence case was seen. Respective number of stress shielding cases, based on Engh's classification, categorized as degree 0, 1, and 2, were 2 (3.3%), 31 (51.7%), and 27 (45.0%), while no cases for degree 3 or 4 were found. When assessed by 3D fitting analysis, 27 cases of stress shielding degree 2 were constituted by 13/42 cases of mediolateral (ML) fit, 2/4 cases of flare fit, and 12/14 cases of multi point fit. In 42 cases of ML fitting, stem contact rate of the most proximedial region in stress shielding degree 0 and 1 was significantly higher compared to stress shielding degree 2 cases. Meanwhile, the rates of distal regions were significantly lower or absent in stress shielding degree 0 and 1 cases. The initial fixation of this stem design was very good in our cohort regardless of fitting manners. This study successfully revealed that ML fitting with femoral component, especially the most proximedial calcar site restricted fitting, would be optimal for reducing stress shielding occurrence in cementless short, tapered-wedge stem THA. Thus, the ideal stem contact region should be considered during THA procedures in light of the reduction of stress shielding development.
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Affiliation(s)
- Takashi Maeda
- Department of Orthopaedic Surgery, Marunouchi Hospital, Matsumoto 390-8601, Japan
| | - Masaki Nakano
- Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Yukio Nakamura
- Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Takashige Momose
- Department of Orthopaedic Surgery, Marunouchi Hospital, Matsumoto 390-8601, Japan
| | - Atsushi Sobajima
- Department of Orthopaedic Surgery, Marunouchi Hospital, Matsumoto 390-8601, Japan
| | - Jun Takahashi
- Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
| | - Katsuya Nakata
- Department of Orthopaedic Surgery, JCHO Osaka Hospital, Fukushima-ku, Osaka 553-0003, Japan
| | - Masashi Nawata
- Department of Orthopaedic Surgery, Marunouchi Hospital, Matsumoto 390-8601, Japan
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24
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Abstract
Implant failure is due to stress shielding and interface micromotion. The application of porous structures in the femoral implant has a great effect on reducing stress shielding and improving the stability of the bone-implant interface. The performance of femoral stems with triply periodic minimal surface (TPMS) structures, IWP, and Gyroid structures was evaluated using finite element analysis. We studied the stress shielding phenomenon of the porous femoral stem based on the ability of stress transfer to the femur. The micromotion at the bone-implant interface was explored for different porous femoral stems. The effect of gradient structure design was investigated in the axial direction of the stem. These gradient designs involved a stem with an increasing volume fraction in the axial direction (IAGS) and a decreasing volume fraction along the stem (DAGS). The results showed that the axial stiffness of the stem has a direct effect on stress shielding and an inverse relation to bone-implant micromotion. The finite element analysis results inferred that bone resorption is higher in the stems with IWP structure than in Gyroid at the same volume fraction. Axially graded stems transfer higher stress to the femur than homogenous porous stems. DAGS design of IWP and Gyroid and IAGS Gyroid increased the stress on the proximal-medial of the femur. Homogeneous porous stems with high porosity (80% porosity for IWP and 70% porosity for Gyroid) and DAGS design exhibited low stress shielding and controlled bone-implant interface micromotion within an acceptable range for bone ingrowth.
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Affiliation(s)
- Neda Rahmat
- Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
| | - Javad Kadkhodapour
- Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
| | - Mohammdreza Arbabtafti
- Department of Mechanical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
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25
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Xiao Z, Wu L, Wu W, Tang R, Dai J, Zhu D. Multi-Scale Topology Optimization of Femoral Stem Structure Subject to Stress Shielding Reduce. Materials (Basel) 2023; 16:3151. [PMID: 37109987 PMCID: PMC10143993 DOI: 10.3390/ma16083151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 06/19/2023]
Abstract
Hip replacement femoral implants are made of substantial materials that all have stiffness considerably higher than that of bone, which can cause significant bone resorption secondary to stress shielding and lead to severe complications. The topology optimization design method based on the uniform distribution of material micro-structure density can form a continuous mechanical transmission route, which can better solve the problem of reducing the stress shielding effect. A multi-scale parallel topology optimization method is proposed in this paper and a topological structure of type B femoral stem is derived. Using the traditional topology optimization method (Solid Isotropic Material with Penalization, SIMP), a topological structure of type A femoral stem is also derived. The sensitivity of the two kinds of femoral stems to the change of load direction is compared with the variation amplitude of the structural flexibility of the femoral stem. Furthermore, the finite element method is used to analyze the stress of type A and type B femoral stem under multiple conditions. Simulation and experimental results show that the average stress of type A and type B femoral stem on the femur are 14.80 MPa, 23.55 MPa, 16.94 MPa and 10.89 MPa, 20.92 MPa, 16.50 MPa, respectively. For type B femoral stem, the average error of strain is -1682με and the average relative error is 20.3% at the test points on the medial side and the mean error of strain is 1281με and the mean relative error is 19.5% at the test points on the outside.
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26
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Al-Hajaj Z, Avval PT, Bougherara H. Computational prediction of the long-term behavior of the femoral density after THR using the Silent Hip stem. Comput Methods Biomech Biomed Engin 2023; 26:373-382. [PMID: 35436164 DOI: 10.1080/10255842.2022.2064712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Aseptic loosening due to the progressive periprosthetic bone resorption following total hip replacement is a crucial concern, that causes complications and failure of the arthroplasty surgery. The mismatch in stiffness between the hip implant and the surrounding femoral bone is one of the key factors leading to bone density resorption. This paper aimed to investigate the long-term response of the femoral bone after THR using the Silent Hip stem. For this purpose, a validated thermodynamic-based computational model was used to compute the change in bone density before and after THR. This model incorporated essential factors involved in bone remodeling process, such as mechanical loading, and biochemical affinities. The results of the numerical simulations using 3D finite element analysis were analyzed in five zones of interest qualitatively and quantitatively. Bone density predictions showed notable bone resorption in cervical areas, specifically in zone 1 and zone 5 of -18.7% and -14%, respectively. Conversely, bone formation was observed in the greater trochanter area (zone 2) of +25%. Stress shielding seemed to occur at cervical area due to the reduction in the mechanical loading in this region. Based on the quantitative analysis of the bone density distribution throughout the femoral bone, it appears that the Silent Hip stem achieved less bone resorption compared to conventional hip stem designs reported in the literature, which could be used for active patients.
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Affiliation(s)
- Zainab Al-Hajaj
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada.,Department of Mechanical Engineering, Australian College of Kuwait, Safat, Kuwait
| | - Pouria Tavakkoli Avval
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada.,Wearable, Interactive, and Mobile Technologies Access Centre in Health, Centennial College, Toronto, ON, Canada
| | - Habiba Bougherara
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada
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27
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Vale J, Pinto LV, Barros B, Diniz S, Rodrigues F, Marques M, Belinha J, Vilaça A. Total knee arthroplasty coronal alignment and tibial base stress-a new numerical evaluation. Porto Biomed J 2023; 8:e208. [PMID: 37152633 PMCID: PMC10158898 DOI: 10.1097/j.pbj.0000000000000208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/07/2023] [Indexed: 05/09/2023] Open
Abstract
Background Total knee arthroplasty (TKA) is one of the most frequently performed orthopedic procedures. The correct positioning and alignment of the components significantly affects prosthesis survival. Considering the current controversy regarding the target of postoperative alignment of TKA, this study evaluated the tension at tibial component interface using two numerical methods. Methods The stress of the prosthesis/bone interface of the proximal tibial component was evaluated using two numerical methods: the finite element method (FEM) and the new meshless method: natural neighbor radial point interpolation method (NNRPIM). The construction of the model was based on Zimmers NexGen LPS-Flex Mobile® prosthesis and simulated the forces by using a free-body diagram. Results Tibiofemoral mechanical axis (TFMA) for which a higher number of nodes are under optimal mechanical tension is between 1° valgus 2° varus. For values outside the interval, there are regions under the tibial plate at risk of bone absorption. At the extremities of the tibial plate of the prosthesis, both medial and lateral, independent of the alignment, are under a low stress. In all nodes evaluated for all TFMA, the values of the effective stresses were higher in the NNRPIM when compared with the FEM. Conclusion Through this study, we can corroborate that the optimal postoperative alignment is within the values that are currently considered of 0 ± 3° varus. It was verified that the meshless methods obtain smoother and more conservative results, which may make them safer when transposed to the clinical practice.
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Affiliation(s)
- João Vale
- Department of Orthopaedics, Centro Hospitalar do Universitário do Porto, Porto, Portugal
- Corresponding author: Department of Orthopaedics, Centro Hospitalar do Universitário do Porto, Largo Professor Abel Salazar, 4099-001, Porto, Portugal. E-mail address: (João Vale)
| | - Luisa V. Pinto
- Department of Physical and Medicine Rehabilitation, Centro Hospitalar de Entre o Douro e Vouga, Santa Maria da Feira, Portugal
| | - Bianca Barros
- Department of Orthopaedics, Centro Hospitalar do Universitário do Porto, Porto, Portugal
| | - Sara Diniz
- Department of Orthopaedics, Centro Hospitalar do Universitário do Porto, Porto, Portugal
| | - Filipe Rodrigues
- Department of Orthopaedics, Centro Hospitalar do Universitário do Porto, Porto, Portugal
| | - Marco Marques
- Institute of Science and Innovation in Mechanical and Industrial Engineering, INEGI, Porto, Portugal
| | - Jorge Belinha
- Department of Mechanical Engineering, School of Engineering, Polytechnic of Porto, ISEP, Porto, Portugal
| | - Adélio Vilaça
- Department of Orthopaedics, Centro Hospitalar do Universitário do Porto, Porto, Portugal
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28
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Bigach SD, Kolevar MP, Moore RD, Adavi P, Rimnac CM, Kraay MJ. Dual-Energy X-Ray Absorptiometry (DEXA) Evaluation of the Bone Remodeling Effects of a Low-Modulus Composite Hip Stem After 2 Decades of Follow-Up. HSS J 2023; 19:69-76. [PMID: 36776510 PMCID: PMC9837405 DOI: 10.1177/15563316221108182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/06/2022] [Indexed: 02/14/2023]
Abstract
Background: The Epoch FullCoat Hip Stem (Zimmer) was an isoelastic composite femoral stem developed to address stem stiffness concerns. Purpose: We sought to evaluate the long-term bone mineral density (BMD) of a cohort of patients who underwent total hip arthroplasty (THA) using the Epoch isoelastic stem and having more than 2-decade follow-up. Methods: We conducted a retrospective chart review of all patients who were study subjects at our institution in a multicenter prospective trial for the Food and Drug Administration of the Epoch implant in the mid-1990s. Through this, we identified 16 patients who had dual-energy X-ray absorptiometry (DEXA) scans, with which we could determine BMD preoperatively and at 3 points postoperatively. Of these, 5 agreed to participate in the study (the others were deceased, unable or declined to participate, or were lost to follow-up) with mean follow-up of 22 years. These participants underwent clinical and radiographic evaluation consisting of a Harris hip score, anteroposterior (AP) pelvis and AP and lateral hip X-rays, and DEXA evaluation of both hips. BMD in the 7 Gruen zones at last follow-up was compared with immediate postoperative and 2-year follow-up. Results: At last follow-up, all stems were well-fixed with signs of extensive osteointegration. In proximal Gruen zones 1 and 7, patients underwent a decrease in BMD with more modest losses in Gruen zone 1. All patients demonstrated an increase in BMD in zones 2 through 6 at latest follow-up, except for 1 patient in Gruen zone 6. BMD changes were not limited to the first 2 years of follow-up. Conclusion: This small follow-up cohort study found excellent long-term clinical results, no plain radiographic signs of notable stress shielding, and general maintenance of BMD at a follow-up of over 20 years for this isoelastic stem. Long-term bone remodeling after implantation of the isoelastic stem resulted in increased BMD in Gruen zones 2 through 6, suggesting that composite implant designs may still have a role in THA.
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Affiliation(s)
- Stephen D. Bigach
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Matthew P. Kolevar
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Rebecca D. Moore
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, OH, USA
| | - Pranav Adavi
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, OH, USA
| | - Clare M. Rimnac
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, OH, USA
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Matthew J. Kraay
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, OH, USA
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29
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Naghavi SA, Tamaddon M, Garcia-Souto P, Moazen M, Taylor S, Hua J, Liu C. A novel hybrid design and modelling of a customised graded Ti-6Al-4V porous hip implant to reduce stress-shielding: An experimental and numerical analysis. Front Bioeng Biotechnol 2023; 11:1092361. [PMID: 36777247 PMCID: PMC9910359 DOI: 10.3389/fbioe.2023.1092361] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/10/2023] [Indexed: 01/27/2023] Open
Abstract
Stress shielding secondary to bone resorption is one of the main causes of aseptic loosening, which limits the lifespan of hip prostheses and exacerbates revision surgery rates. In order to minimise post-hip replacement stress variations, this investigation proposes a low-stiffness, porous Ti6Al4V hip prosthesis, developed through selective laser melting (SLM). The stress shielding effect and potential bone resorption properties of the porous hip implant were investigated through both in vitro quasi-physiological experimental assays, together with finite element analysis. A solid hip implant was incorporated in this investigation for contrast, as a control group. The stiffness and fatigue properties of both the solid and the porous hip implants were measured through compression tests. The safety factor of the porous hip stem under both static and dynamic loading patterns was obtained through simulation. The porous hip implant was inserted into Sawbone/PMMA cement and was loaded to 2,300 N (compression). The proposed porous hip implant demonstrated a more natural stress distribution, with reduced stress shielding (by 70%) and loss in bone mass (by 60%), when compared to a fully solid hip implant. Solid and porous hip stems had a stiffness of 2.76 kN/mm and 2.15 kN/mm respectively. Considering all daily activities, the porous hip stem had a factor of safety greater than 2. At the 2,300 N load, maximum von Mises stresses on the hip stem were observed as 112 MPa on the medial neck and 290 MPa on the distal restriction point, whereby such values remained below the endurance limit of 3D printed Ti6Al4V (375 MPa). Overall, through the strut thickness optimisation process for a Ti6Al4V porous hip stem, stress shielding and bone resorption can be reduced, therefore proposing a potential replacement for the generic solid implant.
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Affiliation(s)
- Seyed Ataollah Naghavi
- Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, Royal National Orthopaedic Hospital, University College London, Stanmore, United Kingdom
| | - Maryam Tamaddon
- Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, Royal National Orthopaedic Hospital, University College London, Stanmore, United Kingdom
| | - Pilar Garcia-Souto
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Mehran Moazen
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Stephen Taylor
- Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, Royal National Orthopaedic Hospital, University College London, Stanmore, United Kingdom
| | - Jia Hua
- School of Science and Technology, Middlesex University, London, United Kingdom
| | - Chaozong Liu
- Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, Royal National Orthopaedic Hospital, University College London, Stanmore, United Kingdom,*Correspondence: Chaozong Liu,
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30
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Li Y, Li H, Lai Q, Xue R, Zhu K, Deng Y. Finite element analysis of 3D-printed personalized titanium plates for mandibular angle fracture. Comput Methods Biomech Biomed Engin 2023; 26:78-89. [PMID: 35587215 DOI: 10.1080/10255842.2022.2047952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This paper discussed the size of 3 D-printed personalized titanium plates that can gain maximum stability of mandibular fracture and minimize stress shielding through finite element analysis. A 3 D virtual model of mandible with mandibular angle fracture was created from the CT data of patient. 3 D-printed personalized titanium plates varying in length and thickness were designed, and finite element analysis was performed under different loading conditions and fracture healing periods. After that, the stress distribution and deformation of the mandible with gonial fracture could be observed, and the stress shielding rate could be obtained. Finally, SPSS21.0 was used for statistical analysis. The results of finite element analysis indicated that as the thickness of titanium plates and the healing time decreased, the maximum displacement increased, under a certain condition in which the pore size, the width, the hole distance and the bridge spacing were 2.0 mm, 4.0 mm, 6.0 mm, 12.0 mm, respectively. What's more, in this condition, the thicker the titanium plate and the shorter the healing time were, the higher the stress shielding was at central occlusion. When the thickness of the personalized 3 D-printed titanium plate was 1.0 mm, the maximum displacement tended to be stable and the stress shielding was minimized. It can not only improve the bone stability after tension band fixation, but also minimize the stress shielding, which is expected to expand the indications of tension band fixation.
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Affiliation(s)
- Yan Li
- The Second Hospital of Shandong University, Jinan, People's Republic of China.,Department of Dermatology, Jinan Central Hospital, Shandong University, Jinan, Shandong Province, People's Republic of China
| | - Hui Li
- The Second Hospital of Shandong University, Jinan, People's Republic of China
| | - Qingguo Lai
- Department of Oral and Maxillofacial Surgery, The Second Hospital of Shandong University, Jinan, Shandong Province, People's Republic of China.,Research Center of 3D Printing in Stomatology of Shandong University, Shandong University, Shandong Province, People's Republic of China
| | - Runqi Xue
- Department of Oral and Maxillofacial Surgery, The Second Hospital of Shandong University, Jinan, Shandong Province, People's Republic of China
| | - Kaiwen Zhu
- Department of Oral and Maxillofacial Surgery, The Second Hospital of Shandong University, Jinan, Shandong Province, People's Republic of China
| | - Yanwei Deng
- Department of Oral and Maxillofacial Surgery, The Second Hospital of Shandong University, Jinan, Shandong Province, People's Republic of China
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31
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Naghavi SA, Lin C, Sun C, Tamaddon M, Basiouny M, Garcia-Souto P, Taylor S, Hua J, Li D, Wang L, Liu C. Stress Shielding and Bone Resorption of Press-Fit Polyether-Ether-Ketone (PEEK) Hip Prosthesis: A Sawbone Model Study. Polymers (Basel) 2022; 14:4600. [PMID: 36365594 PMCID: PMC9657056 DOI: 10.3390/polym14214600] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/22/2022] [Accepted: 10/25/2022] [Indexed: 09/23/2023] Open
Abstract
Stress shielding secondary to bone resorption is one of the main causes of aseptic loosening, which limits the lifespan of the hip prostheses and increases the rates of revision surgery. This study proposes a low stiffness polyether-ether-ketone (PEEK) hip prostheses, produced by fused deposition modelling to minimize the stress difference after the hip replacement. The stress shielding effect and the potential bone resorption of the PEEK implant was investigated through both experimental tests and FE simulation. A generic Ti6Al4V implant was incorporated in this study to allow fair comparison as control group. Attributed to the low stiffness, the proposed PEEK implant showed a more natural stress distribution, less stress shielding (by 104%), and loss in bone mass (by 72%) compared with the Ti6Al4V implant. The stiffness of the Ti6Al4V and the PEEK implant were measured through compression tests to be 2.76 kN/mm and 0.276 kN/mm. The factor of safety for the PEEK implant in both static and dynamic loading scenarios were obtained through simulation. Most of the regions in the PEEK implant were tested to be safe (FoS larger than 1) in terms of representing daily activities (2300 N), while the medial neck and distal restriction point of the implant attracts large von Mises stress 82 MPa and 76 MPa, respectively, and, thus, may possibly fail during intensive activities by yield and fatigue. Overall, considering the reduction in stress shielding and bone resorption in cortical bone, PEEK could be a promising material for the patient-specific femoral implants.
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Affiliation(s)
- Seyed Ataollah Naghavi
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK
| | - Churun Lin
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - Changning Sun
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK
- State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
- National Medical Products Administration (NMPA), Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices, Xi’an Jiaotong University, Xi’an 710054, China
| | - Maryam Tamaddon
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK
| | - Mariam Basiouny
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK
| | - Pilar Garcia-Souto
- Medical Physics & Biomedical Engineering, University College London, London WC1E 6BT, UK
| | - Stephen Taylor
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK
| | - Jia Hua
- School of Science and Technology, Middlesex University, London NW4 4BT, UK
| | - Dichen Li
- State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
- National Medical Products Administration (NMPA), Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices, Xi’an Jiaotong University, Xi’an 710054, China
| | - Ling Wang
- State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
- National Medical Products Administration (NMPA), Key Laboratory for Research and Evaluation of Additive Manufacturing Medical Devices, Xi’an Jiaotong University, Xi’an 710054, China
| | - Chaozong Liu
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK
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Pareatumbee P, Zainul-Abidin S, Yew A, Chou SM, Howe TS, Koh JSB, Tan MH. Effect of implant length variations on stress shielding in proximal humeral replacement after tumor excision under torsion: Finite element study. J Orthop Res 2022; 41:1139-1147. [PMID: 36200541 DOI: 10.1002/jor.25456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 09/01/2022] [Accepted: 10/01/2022] [Indexed: 02/04/2023]
Abstract
The proximal humerus is the most common site of occurrence of primary bone tumors in the upper limb. Endoprosthetic replacement is deemed as the preferred reconstructive option following primary resection of bone tumors. However, it has been also associated with complications such as stress shielding and aseptic loosening compromising prosthetic survival. Our objective was to conduct a finite element (FE) study to investigate the effect of varying endoprosthesis length on bone stresses as well as to quantify the extent of stress shielding across the bone length (BL) in a humerus-prosthesis assembly for proximal humeral replacement after tumor excision thereby allowing us to identify the optimal implant length with best biomechanical performance. FE models of the intact humerus and humerus-prosthesis assemblies were established where they were loaded at the elbow joint under torsion with the glenohumeral joint fixed to represent twisting. After dividing the bone into individual slices consisting of 5% BL, the maximum cortical and cancellous principal, von Mises and shear bone stresses were calculated. To measure the level of stress shielding, the percentage stress change from the intact state was evaluated across each slice. Similar stress patterns were observed between the intact state and shorter endoprosthesis compared to the longer endoprostheses. Our findings illustrated the possibility of stress shielding occurring under torsional forces with its effect increasing with implant lengthening. To conclude, we believe that using a shorter prosthesis may substantially diminish the risk of potential implant failure due to stress shielding.
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Affiliation(s)
- Pivatidevi Pareatumbee
- Singhealth-Duke NUS Musculoskeletal Sciences Academic Clinical Program, Singapore General Hospital, Singapore, Singapore
| | - Suraya Zainul-Abidin
- Singhealth-Duke NUS Musculoskeletal Sciences Academic Clinical Program, Singapore General Hospital, Singapore, Singapore.,Department of Orthopedic Surgery, Singapore General Hospital, Singapore, Singapore.,Division of Musculoskeletal Sciences, Singapore General Hospital, Singapore, Singapore
| | - Andy Yew
- Singhealth-Duke NUS Musculoskeletal Sciences Academic Clinical Program, Singapore General Hospital, Singapore, Singapore.,Division of Musculoskeletal Sciences, Singapore General Hospital, Singapore, Singapore
| | - Siaw M Chou
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore
| | - Tet Sen Howe
- Singhealth-Duke NUS Musculoskeletal Sciences Academic Clinical Program, Singapore General Hospital, Singapore, Singapore.,Department of Orthopedic Surgery, Singapore General Hospital, Singapore, Singapore.,Division of Musculoskeletal Sciences, Singapore General Hospital, Singapore, Singapore
| | - Joyce S B Koh
- Singhealth-Duke NUS Musculoskeletal Sciences Academic Clinical Program, Singapore General Hospital, Singapore, Singapore.,Department of Orthopedic Surgery, Singapore General Hospital, Singapore, Singapore.,Division of Musculoskeletal Sciences, Singapore General Hospital, Singapore, Singapore
| | - Mann Hong Tan
- Singhealth-Duke NUS Musculoskeletal Sciences Academic Clinical Program, Singapore General Hospital, Singapore, Singapore.,Department of Orthopedic Surgery, Singapore General Hospital, Singapore, Singapore.,Division of Musculoskeletal Sciences, Singapore General Hospital, Singapore, Singapore
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33
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Brogren E, Abramo A, Tägil M. Bone Remodeling after Ulna Head Replacement in Distal Radioulnar Joint Arthroplasty: A Radiographic Comparison between a Partial and a Total Ulna Head Concept. J Wrist Surg 2022; 11:425-432. [PMID: 36339080 PMCID: PMC9633151 DOI: 10.1055/s-0041-1742098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/17/2021] [Indexed: 11/08/2022]
Abstract
Background Ulna head arthroplasty has become an eligible solution for injury or disease in the distal radioulnar joint. Bone resorption beneath the prosthetic head is often reported, but mechanism poorly understood. Purpose The aims were to evaluate bone remodeling and radiological instability in two conceptually different distal radioulnar joint arthroplasties: the total and the partial ulna head replacement. Patients and Methods We conducted a retrospective radiographic assessment of 51 ulna head arthroplasties; 26 Herbert ulna (total ulna head replacement) and 25 First Choice (partial ulna head replacement), to analyze periprosthetic bone resorption and radiologic instability. Intraoperative/immediate postoperative and 1-year radiographs were reviewed by two independent assessors. The radiographic follow-up averaged 13 (10-17) months. The size of the stem in relation to the diameter of the ulna (filling ratio) was measured on the intraoperative/immediate postoperative radiographs. Bone resorption beneath the collar of the prothesis was measured on the 1-year radiographs and expressed as a bone resorption index (BRI) between the length of the resorption and the length of the implant stem. Radiological stability was measured on both the preoperative and the 1-year lateral radiographs. Results The total ulna head prothesis presented with more extensive bone resorption beneath the prosthetic head than the partial ulna head prothesis at 1-year post surgery ( p <0.001). The filling ratio did not influence the 1-year bone resorption and there was no difference regarding radiological instability between the two prosthetic designs. Conclusion The pattern of bone adaptions after an ulna head prothesis may differ due to design and concept of the prosthesis.
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Affiliation(s)
- Elisabeth Brogren
- Department of Hand Surgery, Skåne University Hospital, Malmö, Sweden
- Department of Translational Medicine, Lund University, Lund, Sweden
| | - Antonio Abramo
- Department of Hand Surgery, Skåne University Hospital, Malmö, Sweden
- Department of Translational Medicine, Lund University, Lund, Sweden
| | - Magnus Tägil
- Department of Orthopedics, Skåne University Hospital, Malmö, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
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Tavakoli A, Spangenberg G, Reeves JM, Faber KJ, Langohr GDG. Humeral short stem varus-valgus alignment affects bone stress. J Orthop Res 2022; 40:2169-2178. [PMID: 34914123 DOI: 10.1002/jor.25239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/25/2021] [Accepted: 12/04/2021] [Indexed: 02/04/2023]
Abstract
The use of uncemented humeral stems in total shoulder arthroplasty (TSA) is associated with stress shielding. Shorter length stems have shown to decrease stress shielding; however, the effect of stem varus-valgus alignment is currently not known. The purpose of this study was to quantify the effect of short stem distal humeral endosteal contact due to varus-valgus angulation on bone stresses after TSA. Three-dimensional models of eight male cadaveric humeri were constructed from computed tomography data. Bone models were reconstructed with a short stem humeral component implant in three positions (standard, varus, and valgus). Modeling was performed at 45° and 75° of abduction and the resulting differentials in bone stress compared to the intact state and the expected time-zero bone response were determined. In cortical and trabecular bone, the standard position (STD) altered bone stress less than the valgus (VAL) and varus (VAR) positions relative to the intact state. For both cortical (p = 0.033) and trabecular (p = 0.012) bone, the VAL position produced a larger volume of bone with resorbing potential compared to the STD position.
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Affiliation(s)
- Amir Tavakoli
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada
- Roth McFarlane Hand and Upper Limb Center, St. Joseph's Health Care London, London, Ontario, Canada
| | - Gregory Spangenberg
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada
- Roth McFarlane Hand and Upper Limb Center, St. Joseph's Health Care London, London, Ontario, Canada
| | - Jacob M Reeves
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada
- Roth McFarlane Hand and Upper Limb Center, St. Joseph's Health Care London, London, Ontario, Canada
| | - Kenneth J Faber
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada
- Roth McFarlane Hand and Upper Limb Center, St. Joseph's Health Care London, London, Ontario, Canada
| | - G Daniel G Langohr
- Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario, Canada
- Roth McFarlane Hand and Upper Limb Center, St. Joseph's Health Care London, London, Ontario, Canada
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35
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Knight KM, King GE, Palcsey SL, Suda A, Liang R, Moalli PA. Mesh Deformation: a mechanism underlying polypropylene prolapse mesh complications in vivo. Acta Biomater 2022; 148:323-335. [PMID: 35671876 DOI: 10.1016/j.actbio.2022.05.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 05/12/2022] [Accepted: 05/31/2022] [Indexed: 12/12/2022]
Abstract
Polypropylene meshes used in pelvic organ prolapse (POP) repair are hampered by complications. Most POP meshes are highly unstable after tensioning ex vivo, as evidenced by marked deformations (pore collapse and wrinkling) that result in altered structural properties and material burden. By intentionally introducing collapsed pores and wrinkles into a mesh that normally has open pores and remains relatively flat after implantation, we reproduce mesh complications in vivo. To do this, meshes were implanted onto the vagina of rhesus macaques in nondeformed (flat) vs deformed (pore collapse +/- wrinkles) configurations and placed on tension. Twelve weeks later, animals with deformed meshes had two complications, 1) mesh exposure through the vaginal epithelium, and 2) myofibroblast proliferation with fibrosis - a mechanism of pain. The overarching response to deformed mesh was vaginal thinning associated with accelerated apoptosis, reduced collagen content, increased proteolysis, deterioration of mechanical integrity, and loss of contractile function consistent with stress shielding - a precursor to mesh exposure. Regional differences were observed, however, with some areas demonstrating myofibroblast proliferation and matrix deposition. Variable mechanical cues imposed by deformed meshes likely induce these two disparate responses. Utilizing meshes associated with uniform stresses on the vagina by remaining flat with open pores after tensioning is critical to improving outcomes. STATEMENT OF SIGNIFICANCE: Pain and exposure are the two most reported complications associated with the use of polypropylene mesh in urogynecologic procedures. Most meshes have unstable geometries as evidenced by pore collapse and wrinkling after tensioning ex vivo, recapitulating what is observed in meshes excised from women with complications in vivo. We demonstrate that collapsed pores and wrinkling results in two distinct responses 1) mesh exposure associated with tissue degradation and atrophy and 2) myofibroblast proliferation and matrix deposition consistent with fibrosis, a tissue response associated with pain. In conclusion, mesh deformation leads to areas of tissue degradation and myofibroblast proliferation, the likely mechanisms of mesh exposure and pain, respectively. These data corroborate that mesh implantation in a flat configuration with open pores is a critical factor for reducing complications in mesh-augmented surgeries.
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Affiliation(s)
- Katrina M Knight
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA; Magee-Womens Research Institute, Pittsburgh, PA.
| | | | | | - Amanda Suda
- School of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Rui Liang
- Magee-Womens Research Institute, Pittsburgh, PA; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA
| | - Pamela A Moalli
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA; Division of Urogynecology and Reconstructive Pelvic Surgery, Magee-Womens Hospital of the University of Pittsburgh, Pittsburgh, PA
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36
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Bendich I, Lawrie CM, Riegler V, Barrack RL, Nunley RM. The Impact of Component Design and Fixation on Stress Shielding After Modern Total Knee Arthroplasty. J Arthroplasty 2022; 37:S221-S225. [PMID: 35249788 DOI: 10.1016/j.arth.2022.01.074] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/09/2022] [Accepted: 01/24/2022] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Total knee arthroplasty (TKA) tibial baseplate thickness, metallurgy, and implant fixation with cement may influence stress shielding. The purpose of the present study is to compare bone mineral density of 2 cemented and press-fit TKA designs with differing tibial baseplate thicknesses and metallurgy over a 2-year period to assess for changes in stress shielding. METHODS One-hundred one TKAs were performed in this Institutional Review Board-approved, prospective study. There were 4 cohorts: DePuy Attune cemented and press-fit, and Stryker Triathlon cemented and press-fit. The Attune tibial baseplate was thicker; both cemented tibial and femoral components were cobalt-chromium. The DePuy Attune press-fit had a cobalt-chromium sintered bead porous coating while the Stryker Triathlon was 3-dimensional printed highly porous titanium alloy. All patients had quantitative dual-energy X-ray absorptiometry scans performed at baseline (4-6 weeks postoperatively) and at 1 and 2 years postoperatively. Stress shielding was evaluated by comparing percent change in bone mineral density in 11 radiographic zones over 2 years. RESULTS Over a 2-year period, there were no differences in stress shielding on the tibial side in either cemented or press-fit between Stryker Triathlon and DePuy Attune; however, there were differences on the femoral side. The press-fit tibial components of the Stryker Triathlon and DePuy Attune had either similar or less stress shielding over a 2-year period compared to their cemented counterparts. CONCLUSION This study comparing 2 TKA implants with differing tibial tray thickness did not find significant differences in tibial stress shielding between designs. There was a difference in stress shielding on the femoral side between designs, suggesting that longer term follow-up is warranted.
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Affiliation(s)
- Ilya Bendich
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO
| | - Charles M Lawrie
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO
| | - Venessa Riegler
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO
| | - Robert L Barrack
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO
| | - Ryan M Nunley
- Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, MO
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Li Y, Fei H, Wang J, Li T, Feng Y, Huan Y. The Regularity of Stress Shielding in Internal Fixation Characterized by Hydromechanics. J Biomech Eng 2022; 144:1122990. [PMID: 34729598 DOI: 10.1115/1.4052884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Indexed: 11/08/2022]
Abstract
Stress shielding is an important factor in the internal fixation of a fracture. To explore the regularity of stress shielding in internal fixation, a simplified model of a comminuted femoral shaft fracture bridged by a locking plate was established and finite element analysis was performed to analyze the load distribution between the plate and femur from the proximal end of the femur to the fracture line and investigate the stress shielding degree of the plate on the bone. The stress, deformation, and axial compressive force distribution of four internal fixation schemes under compression were obtained, and the stress shielding degrees on each section was calculated. To compare the regularity of stress shielding and flow distribution, the relationship between the compressive force increment and stress shielding degree was established. The normalized curves of compressive force increment with the plate section position were compared with the flow distribution in a Z-type manifold, a parallel pipe system similar to an internal fixation system in structure and working characteristics. For quantitative comparison, the similarity between normalized curves of the compressive force increment and simulated flow distribution was calculated. The regularity of load distribution along the section position of the plate was similar to the flow distribution in the Z-type manifold. Therefore, the flow distribution pattern of the Z-type manifold can be used to characterize the regularity of load distribution in internal fixation. This study provided a new method to characterize the stress shielding degree of a locking plate on bone.
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Affiliation(s)
- Yu Li
- State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Han Fei
- Department of Traumatic Orthopedics, Beijing Jishuitan Hospital, Beijing 100035, China
| | - Jun Wang
- State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ting Li
- Department of Traumatic Orthopedics, Beijing Jishuitan Hospital, Beijing 100035, China
| | - Yihui Feng
- State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yong Huan
- State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China; Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
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38
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Nguyen DM, Murawski CD, Fu FH, Kaufmann RA. Stress Shielding of Ligaments Using Nonabsorbable Suture Augmentation May Influence the Biology of Ligament Healing. J Hand Surg Am 2022; 47:275-8. [PMID: 34716057 DOI: 10.1016/j.jhsa.2021.09.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 07/31/2021] [Accepted: 09/17/2021] [Indexed: 02/02/2023]
Abstract
Nonabsorbable suture augmentation of ligament reconstruction has seen an increase in use over the past several years with the goal of protecting the newly reconstructed ligament while allowing early rehabilitation for a potential earlier return to activity and sport. By spanning the joint with a durable nonabsorbable suture, this construct shares the stress and load seen by the reconstructed ligament, thereby protecting it from forces that could result in an early failure during the early ligamentization phase of the tendon graft. However, stress shielding of the ligament via nonabsorbable suture augmentation is also a double-edged sword, as a reduction in the stress and load seen by the ligament during this healing phase may ultimately have an impact on the final strength and composition of the reconstructed ligament. Although the long-term effects of this stress shielding have yet to be studied or reported in human subjects, multiple biomechanical and animal studies have demonstrated overall changes in architecture, tensile strength, and mechanical properties of a stress-shielded autograft ligament reconstruction.
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Halvorson RT, Lalchandani GR, Cherches MF, Petit LM, Lattanza L, Lee NH, Kandemir U. Interobserver and Intraobserver Reliability of Classification Systems for Radiographic Complications After Radial Head Arthroplasty. J Hand Surg Am 2022; 48:513.e1-513.e8. [PMID: 35181176 DOI: 10.1016/j.jhsa.2021.11.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 09/21/2021] [Accepted: 11/12/2021] [Indexed: 02/02/2023]
Abstract
PURPOSE Although several classifications are used to assess radiographs following radial head arthroplasty (RHA), including the Popovic classification for radiolucency, the Chanlalit classification for stress shielding (SS), the Brooker classification for heterotopic ossification (HO), and the Broberg-Morrey classification for radiocapitellar arthritis, little is known about the reliability of these classification systems. The purpose of this study was to determine the interobserver and intraobserver reliability of these classifications. METHODS Six orthopedic surgeons at various levels of training reviewed elbow radiographs of 20 patients who underwent RHA and classified them according to the Popovic, Chanlalit, Brooker, and Broberg-Morrey classifications for radiolucency, SS, HO, and RHA, respectively. Four weeks after initial review, radiographic reviews were repeated. Reliability was measured using the Fleiss kappa and the intraclass correlation coefficient. Agreement was interpreted as none (<0), slight (0.01-0.2), fair (0.21-0.4), moderate (0.41-0.6), substantial (0.61-0.8), and almost perfect (0.81-1) based on agreement among attending surgeons. RESULTS Among fellowship-trained attending surgeons, interobserver reliability was slight for SS (Chanlalit) and the categorical interpretation of radiolucency (Popovic), fair for radiocapitellar arthritis (Broberg-Morrey) and HO (Brooker), and substantial for the ordinal interpretation of radiolucency (Popovic). Residents had a higher interobserver reliability than attending physicians when using the Brooker classification. Mean intraobserver reliability was fair for SS (Chanlalit) and the categorical interpretation of radiolucency (Popovic), moderate for HO (Brooker) and radiocapitellar arthritis (Broberg-Morrey), and almost perfect for the ordinal interpretation of radiolucency (Popovic). Trainees had higher intraobserver reliability than attending surgeons using the SS (Chanlalit) classification. CONCLUSIONS The number of Popovic zones is reliable for communication between physicians, but caution should be taken with the Brooker, Chanlalit, Broberg-Morrey, and categorical interpretation of the Popovic classifications. All the classifications had better intraobserver than interobserver reliability. CLINICAL RELEVANCE Reliability of classification systems for radiographic complications after RHA is less than substantial except the number of zones of radiolucency; therefore, caution is required when drawing conclusions based on these classifications.
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Affiliation(s)
- Ryan T Halvorson
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA
| | - Gopal R Lalchandani
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA
| | - Matthew F Cherches
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA
| | - Logan M Petit
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT
| | - Lisa Lattanza
- Department of Orthopaedics and Rehabilitation, Yale School of Medicine, New Haven, CT
| | - Nicolas H Lee
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA
| | - Utku Kandemir
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA.
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Chao L, Jiao C, Liang H, Xie D, Shen L, Liu Z. Analysis of Mechanical Properties and Permeability of Trabecular-Like Porous Scaffold by Additive Manufacturing. Front Bioeng Biotechnol 2022; 9:779854. [PMID: 34993188 PMCID: PMC8724551 DOI: 10.3389/fbioe.2021.779854] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/17/2021] [Indexed: 11/13/2022] Open
Abstract
Human bone cells live in a complex environment, and the biomimetic design of porous structures attached to implants is in high demand. Porous structures based on Voronoi tessellation with biomimetic potential are gradually used in bone repair scaffolds. In this study, the mechanical properties and permeability of trabecular-like porous scaffolds with different porosity levels and average apertures were analyzed. The mechanical properties of bone-implant scaffolds were evaluated using finite element analysis and a mechanical compression experiment, and the permeability was studied by computational fluid dynamics. Finally, the attachment of cells was observed by confocal fluorescence microscope. The results show that the performance of porous structures can be controlled by the initial design of the microstructure and tissue morphology. A good structural design can accurately match the performance of the natural bone. The study of mechanical properties and permeability of the porous structure can help address several problems, including stress shielding and bone ingrowth in existing biomimetic bone structures, and will also promotes cell adhesion, migration, and eventual new bone attachment.
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Affiliation(s)
- Long Chao
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Chen Jiao
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Huixin Liang
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China.,Jiangsu Engineering Research Center for 3D Bioprinting, Nanjing, China
| | - Deqiao Xie
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Lida Shen
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Zhidong Liu
- College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
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Abstract
Cementless femoral stems are prone to stress shielding of the femoral bone, which is caused by a mismatch in stiffness between the femoral stem and femur. This can cause bone resorption and resultant loosening of the implant. It is possible to reduce the stress shielding by using a femoral stem with porous structures and lower stiffness. A porous structure also provides a secondary function of allowing bone ingrowth, thus improving the long-term stability of the prosthesis. Furthermore, due to the advent of additive manufacturing (AM) technology, it is possible to fabricate femoral stems with internal porous lattices. Several review articles have discussed porous structures, mainly focusing on the geometric design, mechanical properties and influence on bone ingrowth. However, the safety and effectiveness of porous femoral stems depend not only on the characteristic of porous structure but also on the macro design of the femoral stem; for example, the distribution of the porous structure, the stem geometric shape, the material, and the manufacturing process. This review focuses on porous femoral stems, including the porous structure, macro geometric design of the stem, performance evaluation, research methods used for designing and evaluating the femoral stems, materials and manufacturing techniques. In addition, this review will evaluate whether porous femoral stems can reduce stress shielding and increase bone ingrowth, in addition to analyzing their shortcomings and related risks and providing ideas for potential design improvements.
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Affiliation(s)
- Bolun Liu
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Huizhi Wang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Ningze Zhang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Min Zhang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Cheng-Kung Cheng
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.,School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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Mohandes Y, Tahani M, Rouhi G. Osteosynthesis of diaphyseal tibia fracture with locking compression plates: A numerical investigation using Taguchi and ANOVA. Int J Numer Method Biomed Eng 2021; 37:e3528. [PMID: 34486240 DOI: 10.1002/cnm.3528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
Performance of the locking compression plate (LCP) is a multifactorial function. The control parameters of plating, such as geometries, material properties, and physical constraints of the LCP components, affect basic functions associated with the bone fixation, including the extent of stress shielding and subsequent bone remodeling, strength and stability of the bone-LCP construct, and performance of secondary bone healing. The main objectives of this research were as follows: (1) to find the appropriate values of control parameters of an LCP construct to achieve the optimized performance throughout bone healing; and (2) to unravel relationships between LCP parameters and the LCP's performance. Different values for the plate/screw modulus of elasticity (E), plate width (W), plate thickness (T), screw diameter (D), bone-plate offset (O), and screw configuration (C), as six control parameters, were considered at five different levels. Taguchi method was adopted to create trial combinations of control parameters and determining the best set of parameters, which can optimize the overall performance of the LCP. All design cases were analyzed using the finite element method. The optimal set of control parameters consisting of 150 GPa, 12 mm, 4 mm, 5.5 mm, 2 mm, and 123,678 were determined for E, W, T, D, O, and C, respectively. Furthermore, ANOVA was used to rank the most influential parameters on each function of the LCP fixation. In the overall performance of the LCP fixation, E, D, T, C, W, and O showed a contribution percentage of 46%, 22%, 10%, 11%, 8%, and 3%, respectively.
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Affiliation(s)
- Yousof Mohandes
- Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Masoud Tahani
- Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Gholamreza Rouhi
- Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
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Tan N, van Arkel RJ. Topology Optimisation for Compliant Hip Implant Design and Reduced Strain Shielding. Materials (Basel) 2021; 14:7184. [PMID: 34885337 PMCID: PMC8658148 DOI: 10.3390/ma14237184] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/01/2021] [Accepted: 11/22/2021] [Indexed: 01/12/2023]
Abstract
Stiff total hip arthroplasty implants can lead to strain shielding, bone loss and complex revision surgery. The aim of this study was to develop topology optimisation techniques for more compliant hip implant design. The Solid Isotropic Material with Penalisation (SIMP) method was adapted, and two hip stems were designed and additive manufactured: (1) a stem based on a stochastic porous structure, and (2) a selectively hollowed approach. Finite element analyses and experimental measurements were conducted to measure stem stiffness and predict the reduction in stress shielding. The selectively hollowed implant increased peri-implanted femur surface strains by up to 25 percentage points compared to a solid implant without compromising predicted strength. Despite the stark differences in design, the experimentally measured stiffness results were near identical for the two optimised stems, with 39% and 40% reductions in the equivalent stiffness for the porous and selectively hollowed implants, respectively, compared to the solid implant. The selectively hollowed implant's internal structure had a striking resemblance to the trabecular bone structures found in the femur, hinting at intrinsic congruency between nature's design process and topology optimisation. The developed topology optimisation process enables compliant hip implant design for more natural load transfer, reduced strain shielding and improved implant survivorship.
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Affiliation(s)
| | - Richard J. van Arkel
- Department of Mechanical Engineering, Imperial College London, London SW7 2AZ, UK;
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Cardile C, Arrigoni P, Cazzaniga C, Zaolino C, Ragni P, Randelli PS. Traumatic acute stem rupture in stress shielding bone resorption of a bipolar radial head arthroplasty: case report and literature review. Acta Biomed 2021; 92:e2021252. [PMID: 34747389 PMCID: PMC10523031 DOI: 10.23750/abm.v92is1.11790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/23/2022]
Abstract
Bone resorption around the proximal portion of the stem of a radial head prosthesis is a frequent phenomenon. In the vast majority of cases it is not correlated with to be without clinical manifestations. This radiographic sign, refers to the stress shielding effect has been more described in total hip replacement surgery. Few authors have noticed this phenomenon in radial head replacement. however, given the increasing number of these procedures, a careful surveillance is required in patients presenting this sign. We report a literature review and a case presentation of proximal stem rupture following a trauma in association to radiological periprosthetic bone resorption due to stress shielding and treated with revision surgery.
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Affiliation(s)
- Carlo Cardile
- U.O. Ortopedia e Traumatologia Ospedale Salvini , Asst Rhodense, viale Forlanini 95, 20024 Garbagnate M.se, Milano, Italy.
| | - Paolo Arrigoni
- U.O. Clinica Ortopedica e Traumatologica Universitaria CTO, Asst Pini-CTO, Piazza Cardinal Ferrari 1, 20122 Milano, Italy.
| | - Carlo Cazzaniga
- U.O. Ortopedia e Traumatologia Ospedale Salvini , Asst Rhodense, viale Forlanini 95, 20024 Garbagnate M.se, Milano, Italy.
| | - Carlo Zaolino
- U.O. Clinica Ortopedica e Traumatologica Universitaria CTO, Asst Pini-CTO, Piazza Cardinal Ferrari 1, 20122 Milano, Italy.
| | - Paolo Ragni
- U.O. Ortopedia e Traumatologia Ospedale Salvini , Asst Rhodense, viale Forlanini 95, 20024 Garbagnate M.se, Milano, Italy.
| | - Pietro Simone Randelli
- U.O. Clinica Ortopedica e Traumatologica Universitaria CTO, Asst Pini-CTO, Piazza Cardinal Ferrari 1, 20122 Milano, Italy, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, 20133 Milano, Italy.
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45
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Synnott S, Langohr GDG, Reeves JM, Johnson JA, Athwal GS. The effect of humeral implant thickness and canal fill on interface contact and bone stresses in the proximal humerus. JSES Int 2021; 5:881-888. [PMID: 34505100 PMCID: PMC8411059 DOI: 10.1016/j.jseint.2021.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background Stem size is an important element for successful time zero primary fixation of a press-fit humeral stem in shoulder arthroplasty. Little basic science research, however, has been conducted on the effects of implant thickness and canal fill on load transfer, contact, and stress shielding. The purpose of this finite element study was to determine the effects of varying stem thickness on bone contact, bone stresses, and bone resorption owing to stress shielding. Methods Three generic short-stem implant models were developed and varied based on cross-sectional thickness (thinner - 8 mm, medium - 12 mm, thicker - 16 mm). Using a finite element model, three outcome measures were determined (1) the amount of bone-to-implant contact, (2) changes in cortical and trabecular bone stresses from the intact state, and (3) changes in cortical and trabecular strain energy densities which can predict bone remodeling or stress shielding. Results Increasing the size of the humeral stem had no significant effects on bone-to-implant contact during loading (P > .07). The thinner implant with the lowest canal fill ratio produced significantly lower changes in stress from the intact state in both cortical and trabecular bone (P < .002). In addition, the thinner implant resulted in a substantially lower volume of bone predicted to stress shield and resorb when compared with the medium and thicker stems. Discussion The results demonstrate that thinner implants and lower canal fill may be beneficial over thicker sizes, provided equal initial fixation can be achieved. The thinner implant has a greater degree of load sharing and increases the mechanical load placed on surrounding bone, reducing the risk of stress shielding and bone resorption.
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Affiliation(s)
- Stephanie Synnott
- Roth
- McFarlane Hand and Upper Limb Center Biomechanics Laboratory, London, ON, Canada
| | - G Daniel G Langohr
- Roth
- McFarlane Hand and Upper Limb Center Biomechanics Laboratory, London, ON, Canada
| | - Jacob M Reeves
- Roth
- McFarlane Hand and Upper Limb Center Biomechanics Laboratory, London, ON, Canada
| | - James A Johnson
- Roth
- McFarlane Hand and Upper Limb Center Biomechanics Laboratory, London, ON, Canada
| | - George S Athwal
- Roth
- McFarlane Hand and Upper Limb Center Biomechanics Laboratory, London, ON, Canada
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Hirao M, Miyatake K, Takada R, Tachibana T, Okawa A, Jinno T. Periprosthetic fragility fracture of the femur after primary cementless total hip arthroplasty. Mod Rheumatol 2021; 32:626-633. [PMID: 34897489 DOI: 10.1093/mr/roab025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/15/2021] [Accepted: 06/21/2021] [Indexed: 11/14/2022]
Abstract
OBJECTIVES Periprosthetic bone fragility due to stress shielding (SS) can be a risk factor of periprosthetic fracture after cementless total hip arthroplasty (THA). We aimed to obtain epidemiological information on periprosthetic fragility fracture of the femur (PPFF) after THA. METHODS We retrospectively reviewed the medical records of 1062 hips that had undergone cementless THA. We evaluated the epidemiological data as well as the features of PPFFs. RESULTS Of the 1062 hips, 8 (0.8%) were diagnosed with PPFFs. The survival rates, with the occurrence of PPFF as the end point, were 99.2% and 97.6% at 10 and 16 years postoperatively, respectively. When patients were classified as having either mild or severe SS on radiographs 5 years postoperatively, there was no significant difference in the survival rate, with PPFF as the end point. CONCLUSIONS In our cases, the incidence of PPFF after cementless THA was 0.8%.
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Affiliation(s)
- Masanobu Hirao
- Department of Orthopaedic Surgery, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
| | - Kazumasa Miyatake
- Department of Orthopaedic Surgery, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
| | - Ryohei Takada
- Department of Orthopaedic Surgery, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
| | - Tetsuya Tachibana
- Department of Orthopaedic Surgery, Dokkyo Medical University Saitama Medical Center, Saitama, Japan
| | - Atsushi Okawa
- Department of Orthopaedic Surgery, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
| | - Tetsuya Jinno
- Department of Orthopaedic Surgery, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan.,Department of Orthopaedic Surgery, Dokkyo Medical University Saitama Medical Center, Saitama, Japan
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Zhao H, Han Y, Pan C, Yang D, Wang H, Wang T, Zeng X, Su P. Design and Mechanical Properties Verification of Gradient Voronoi Scaffold for Bone Tissue Engineering. Micromachines (Basel) 2021; 12:mi12060664. [PMID: 34198927 PMCID: PMC8226550 DOI: 10.3390/mi12060664] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 12/03/2022]
Abstract
In order to obtain scaffold that can meet the therapeutic effect, researchers have carried out research on irregular porous structures. However, there are deficiencies in the design method of accurately controlling the apparent elastic modulus of the structure at present. Natural bone has a gradient porous structure. However, there are few studies on the mechanical property advantages of gradient bionic bone scaffold. In this paper, an improved method based on Voronoi-tessellation is proposed. The method can get controllable gradient scaffolds to fit the modulus of natural bone, and accurately control the apparent elastic modulus of porous structure, which is conducive to improving the stress shielding. To verify the designed structure can be fabricated by additive manufacturing, several designed models are obtained by SLM and EBM. Through finite element analysis (FEA), it is verified that the irregular porous structure based on Voronoi-tessellation is more stable than the traditional regular porous structure of the same structure volume, the same pore number and the same material. Furthermore, it is verified that the gradient irregular structure has a better stability than the non-gradient structure. An experiment is conducted successfully to verify the stability performance got by FEA. In addition, a dynamic impact FEA is also performed to simulate impact resistance. The result shows that the impact resistance of the regular porous structure, the irregular porous structure and the gradient irregular porous structure becomes better in turn. The mechanical property verification provides a theoretical basis for the structural design of gradient irregular porous bone tissue engineering scaffolds.
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Affiliation(s)
- Haiyuan Zhao
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
| | - Yafeng Han
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
- Correspondence:
| | - Chen Pan
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
- Institute of Engineering Medicine, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China;
| | - Ding Yang
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
| | - Haotian Wang
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
| | - Tingyu Wang
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
- Institute of Engineering Medicine, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China;
| | - Xinyun Zeng
- Institute of Engineering Medicine, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China;
| | - Penglei Su
- School of Mechanical Engineering, Beijing Institute of Technology, Zhongguancun South Street No.5, Haidian District, Beijing 100081, China; (H.Z.); (C.P.); (D.Y.); (H.W.); (T.W.); (P.S.)
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Hashimoto Y, Ando W, Sakai T, Takao M, Hamada H, Sugano N. The Effects of Rasp Oversize on the Clinical and Radiographic Outcomes of Total Hip Arthroplasty With a Collared Satin-Finished Composite Beam Cemented Stem. J Arthroplasty 2021; 36:2055-2061. [PMID: 33637384 DOI: 10.1016/j.arth.2021.01.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/07/2021] [Accepted: 01/18/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND This study aimed to compare the clinical and radiographic outcomes of using two different oversized rasps in total hip arthroplasty (THA) with a composite beam cemented stem (DCM-J). METHODS A consecutive series of 105 hips underwent hybrid THA using the DCM-J stem between 2006 and 2010. Among the patients with a minimum 10-year follow-up, a 1.5-mm oversized rasp was used in 38 hips (group S), whereas a 0.5-mm oversized rasp was used in 36 hips (group M). The Japanese Orthopedic Association hip score and radiographic findings were evaluated, including cement mantle thickness, stress shielding, and cortical hypertrophy. RESULTS The Japanese Orthopedic Association hip score was significantly improved postoperatively with 100% of the implant survival rate in both groups when septic loosening was excluded. Radiographic assessment performed immediately postoperatively revealed that the cement mantle thickness was significantly larger in group M than group S in Gruen zone 1 but did not differ between groups in zones 2-7. Stress shielding was significantly more frequent in group M than group S at 2 years (P = .011), 5 years (P = .012), and ≥10 years postoperatively (P = .038). Cortical hypertrophy appeared in a time-dependent manner; however, the prevalence did not significantly differ between groups at final follow-up at a mean of 11.7 years (range 10-14 years) postoperatively. CONCLUSIONS The DCM-J stem achieved good clinical results in both groups. Stress shielding was significantly more frequent in THA using the 0.5-mm rasp than the 1.5-mm rasp, indicating that sufficient cement mantle room should be prepared for the cemented stem.
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Affiliation(s)
- Yoshichika Hashimoto
- Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Wataru Ando
- Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takashi Sakai
- Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Masaki Takao
- Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hidetoshi Hamada
- Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Nobuhiko Sugano
- Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Osaka, Japan
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Songy CE, Kennon JC, Barlow JD, Sanchez-Sotelo J, O'Driscoll SW, Morrey ME. Radial Head Replacement for Acute Radial Head Fractures: Outcome and Survival of Three Implant Designs With and Without Cement Fixation. J Orthop Trauma 2021; 35:e202-e208. [PMID: 34006797 PMCID: PMC8115875 DOI: 10.1097/bot.0000000000001983] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/13/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To determine outcomes of radial head replacement (RHR) for acute fractures using 3 different implant designs with or without cement fixation. DESIGN Retrospective. SETTING Tertiary referral hospital. PATIENTS/PARTICIPANTS One hundred fourteen elbows underwent RHR for an acute radial head fracture using either (1) a nonanatomic design and smooth stem (n = 60), (2) a nonanatomic design with a grit-blasted, ingrowth, curved stem (n = 21), or (3) an anatomic design with a grit-blasted ingrowth straight stem (n = 33). Cemented (25%) or uncemented (75%) fixation was used at the discretion of the treating surgeon. INTERVENTION RHR. MAIN OUTCOME MEASUREMENTS The primary outcome was implant survivorship free of revision or removal for any reason. All elbows were evaluated clinically (the Mayo Elbow Performance Score and reoperations/complications) and radiographically. RESULTS Fourteen implants (12%) were revised. Of elbows with a minimum 2-year clinical follow-up, the average Mayo Elbow Performance Score was 88. The rate of survivorship free from revision was 92% [95% confidence interval (CI) = 87%-98%] at 2 years, 90% (CI = 84%-96%) at 5 years and 84% (CI = 75%-94%) at 10 years. The differences in survivorship between the 3 implants did not reach statistical significance, but the nonanatomic design with a grit-blasted ingrowth curved stem had a hazard ratio of 4.6 (95% CI = 0.9%-23%) for failure. There were no differences in survivorship between cemented versus uncemented stems. For those elbows with a minimum of 2 years of radiographic follow-up, implant tilt was observed in 10 (16%) elbows and loosening in 16 (26%) elbows. Stress shielding was present in 19 (42%) of well-fixed implants. CONCLUSIONS RHR for acute trauma leads to survivorship greater than 80% at 10 years. Radiographic changes (loosening, stress shielding, and implant tilting) can be expected in a substantial portion of elbows at long-term follow-up. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Chad E Songy
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
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Pan CT, Lin CH, Huang YK, Jang JSC, Lin HK, Kuo CN, Lin DY, Huang JC. Design of Customize Interbody Fusion Cages of Ti64ELI with Gradient Porosity by Selective Laser Melting Process. Micromachines (Basel) 2021; 12:307. [PMID: 33804190 DOI: 10.3390/mi12030307] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 11/17/2022]
Abstract
Intervertebral fusion surgery for spinal trauma, degeneration, and deformity correction is a major vertebral reconstruction operation. For most cages, the stiffness of the cage is high enough to cause stress concentration, leading to a stress shielding effect between the vertebral bones and the cages. The stress shielding effect affects the outcome after the reconstruction surgery, easily causing damage and leading to a higher risk of reoperation. A porous structure for the spinal fusion cage can effectively reduce the stiffness to obtain more comparative strength for the surrounding tissue. In this study, an intervertebral cage with a porous gradation structure was designed for Ti64ELI alloy powders bonded by the selective laser melting (SLM) process. The medical imaging software InVesalius and 3D surface reconstruction software Geomagic Studio 12 (Raindrop Geomagic Inc., Morrisville, NC, USA) were utilized to establish the vertebra model, and ANSYS Workbench 16 (Ansys Inc., Canonsburg, PA, USA) simulation software was used to simulate the stress and strain of the motions including vertical body-weighted compression, flexion, extension, lateral bending, and rotation. The intervertebral cage with a hollow cylinder had porosity values of 80–70–60–70–80% (from center to both top side and bottom side) and had porosity values of 60–70–80 (from outside to inside). In addition, according to the contact areas between the vertebras and cages, the shape of the cages can be custom-designed. The cages underwent fatigue tests by following ASTM F2077-17. Then, mechanical property simulations of the cages were conducted for a comparison with the commercially available cages from three companies: Zimmer (Zimmer Biomet Holdings, Inc., Warsaw, IN, USA), Ulrich (Germany), and B. Braun (Germany). The results show that the stress and strain distribution of the cages are consistent with the ones of human bone, and show a uniform stress distribution, which can reduce stress concentration.
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