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McCabe MV, Van Citters DW, Chapman RM. Hip Joint Angles and Moments during Stair Ascent Using Neural Networks and Wearable Sensors. Bioengineering (Basel) 2023; 10:784. [PMID: 37508811 PMCID: PMC10376156 DOI: 10.3390/bioengineering10070784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/22/2023] [Accepted: 06/25/2023] [Indexed: 07/30/2023] Open
Abstract
End-stage hip joint osteoarthritis treatment, known as total hip arthroplasty (THA), improves satisfaction, life quality, and activities of daily living (ADL) function. Postoperatively, evaluating how patients move (i.e., their kinematics/kinetics) during ADL often requires visits to clinics or specialized biomechanics laboratories. Prior work in our lab and others have leveraged wearables and machine learning approaches such as artificial neural networks (ANNs) to quantify hip angles/moments during simple ADL such as walking. Although level-ground ambulation is necessary for patient satisfaction and post-THA function, other tasks such as stair ascent may be more critical for improvement. This study utilized wearable sensors/ANNs to quantify sagittal/frontal plane angles and moments of the hip joint during stair ascent from 17 healthy subjects. Shin/thigh-mounted inertial measurement units and force insole data were inputted to an ANN (2 hidden layers, 10 total nodes). These results were compared to gold-standard optical motion capture and force-measuring insoles. The wearable-ANN approach performed well, achieving rRMSE = 17.7% and R2 = 0.77 (sagittal angle/moment: rRMSE = 17.7 ± 1.2%/14.1 ± 0.80%, R2 = 0.80 ± 0.02/0.77 ± 0.02; frontal angle/moment: rRMSE = 26.4 ± 1.4%/12.7 ± 1.1%, R2 = 0.59 ± 0.02/0.93 ± 0.01). While we only evaluated healthy subjects herein, this approach is simple and human-centered and could provide portable technology for quantifying patient hip biomechanics in future investigations.
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Affiliation(s)
- Megan V McCabe
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
| | | | - Ryan M Chapman
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
- Department of Kinesiology, University of Rhode Island, Kingston, RI 02881, USA
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Huang CC, Cheng CK, Wei HW. A Time-Dependent Design Concept of a Cementless Hip Stem Prosthesis for Improving Physiological Load Transfer in Proximal Femur: A Finite Element Analysis. J Med Biol Eng 2022. [DOI: 10.1007/s40846-022-00728-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nandi S, Shah A, Joukar A, Becker K, Crutchfield C, Goel V. Short single-wedge stems have higher risk of periprosthetic fracture than other cementless stem designs in Dorr type A femurs: a finite element analysis. Hip Int 2022; 32:298-303. [PMID: 32865039 DOI: 10.1177/1120700020949185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The use of total hip arthroplasty (THA) femoral stems that transmit force in a favourable manner to the femur may minimise periprosthetic fractures. Finite element analysis (FEA) is a computerised method that analyses the effect of forces applied to a structure with complex shape. Our aim was to apply FEA to compare primary THA cementless stem designs and their association with periprosthetic fracture risk. METHODS 3-dimensional (3D) models of a Dorr Type A femur and 5 commonly used primary THA cementless stem designs (short single wedge, standard-length single wedge, modular, double-wedge metaphyseal filling, and cylindrical fully coated) were developed using computed tomography (CT) imaging. Implant insertion, single-leg stance, and twisting with a planted foot were simulated. FEA was performed, and maximum femoral strain along the implant-bone interface recorded. RESULTS Femoral strain was highest with short single-wedge stem design (0.3850) and lowest with standard-length single-wedge design (0.0520). Location of maximum femoral strain varied by stem design, but not with implant insertion, single-leg stance, or twisting with a planted foot. Strain was as high during implant insertion as with single-leg stance or twisting with a planted foot. CONCLUSIONS Our results suggest the risk of intraoperative and postoperative periprosthetic fracture with THA in a Dorr A femur is highest with short single-wedge stems and lowest with standard-length single-wedge stems. Consideration may be given to minimising the use of short single-wedge stems in THA. Implant-specific sites of highest strain should be carefully inspected for fracture.
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Affiliation(s)
- Sumon Nandi
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Anoli Shah
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH, USA
| | - Amin Joukar
- Purdue University School of Mechanical Engineering, West Lafayette, IN, USA
| | - Kevin Becker
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH, USA
| | - Cody Crutchfield
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH, USA
| | - Vijay Goel
- Department of Bioengineering, University of Toledo College of Engineering, Toledo, OH, USA
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Peng MJQ, Xu H, Chen HY, Lin Z, Li X, Shen C, Lau Y, He E, Guo Y. Biomechanical analysis for five fixation techniques of Pauwels-III fracture by finite element modeling. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 193:105491. [PMID: 32388067 DOI: 10.1016/j.cmpb.2020.105491] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/17/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND OBJECTIVES There are many fixation methods for Pauwels- III fracture, the most common implants are Locking Plate (LP), Dynamic Hip Screw (DHS), Multiple Lag Screw (MLS), and mixed fixture (DHS+MLS) implants, the common procedure is HemiArthroplasty (HA). However, how these fixtures biomechanically function is not clear. The aims of this study are to compare the mechanical behaviors of these five implants by finite element modeling and determinate the most suitable procedure for individuals with Pauwels- III fractures. METHODS We gathered 20 sets of femur images from CT scans in the *.dicom format first, and then processed them by using reverse engineering software programs, such as Mimics, Geomagic Studio, UG-8, Pro-Engineer and HyperMesh. Finally, we assembled and analyzed the five types of fixture models, the LP, DHS, MLS, DHS+LS and HA models, by AnSys. RESULTS These numerical models of Pauwels III fractures, including fixators and a simulative HA, were validated by a previous study and a cadaver test. Our analytical findings include the following: the displacements of all fixtures were between 0.3801 and 1.0834 mm, and the differences were not statistically significantly different; the resulting average peaks in stress were e(Ha) = 43.859 ≤ d(LP) = 60.435 ≤ b(MLS) = 68.678 < c(LS+DHS) = 98.478 < a(DHS) = 248.595 in Mpa, indicating that the stress of DHS and DHS+LS are greater than those of LP, HA and MLS, while the last 3 models were not significantly different. CONCLUSIONS To optimize the treatment for Pauwels III factures clinically, HA and LP should be proposed.
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Affiliation(s)
| | - HongWen Xu
- Pediatric Orthopedics Dept. of GuangZhou Women & Children's Medical Center, China
| | - Hai-Yan Chen
- Orthopedics Department of HuiDong People's Hospital, HuiDong, GuangDong, China
| | - Ze Lin
- Orthopedics Dept. of 1st Affiliated Hospital, GuangZhou Medical University, China
| | - XinXu Li
- Traumatic Orthopedics Dept. SanShui People's Hospital, FoShan, China
| | - ChuLong Shen
- Dept. of Orthopedics, FoShan Hospital of Traditional Chinese Medicine, China
| | - YongQiang Lau
- Dept. of Orthopedics, FoShan Hospital of Traditional Chinese Medicine, China
| | - ErXing He
- Orthopedics Dept. of 1st Affiliated Hospital, GuangZhou Medical University, China.
| | - YueMing Guo
- Dept. of Orthopedics, FoShan Hospital of Traditional Chinese Medicine, China.
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PENG MATTHEWJIANQIAO, XU HONGWEN, CHEN HAIYAN, JU XIANGYANG, HU YONG, AYOUB ASHRAF, KHAMBAY BALVINDER, GUO YUEMING, BAI BO. COMPARATIVE ANALYSIS FOR THREE FIXTURES OF PAUWELLS-II BY THE BIOMECHANICAL FINITE ELEMENT METHOD. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419500799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Little is known about why and how biomechanics govern the hypothesis that three-Lag-Screw (3LS) fixation is a preferred therapeutic technique. A series models of surgical internal-fixation for femoral neck fractures of Pauwells-II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Seventeen sets of CT scanned femora were imported onto Mimics extracting 3D models; these specimens were transferred to Geomagic Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; three sorts of internal fixators were expressed virtually by Pro-Engineer. Processed by Hypermesh, all compartments were assembled onto three systems actually as “Dynamic hip screw (DHS), 3LS and DHS+LS”. Eventually, numerical models of Finite Elemental Analysis (FEA) were exported to AnSys for solution. Three models for fixtures of Pauwells-II were established, validated and analyzed with the following findings: Femoral-shaft stress for [Formula: see text](3LS) is the least; Internal-fixator stress (MPa) for [Formula: see text]; Integral stress (MPa) for [Formula: see text]; displacement of femoral head (mm) for a[Formula: see text](DHS+LS) = 0.735; displacement of femoral shaft (mm) for [Formula: see text]; and displacement of fixators for [Formula: see text]. Mechanical comparisons for other femoral parks are insignificantly different, and these data can be abstracted as follows: the stress of 3LS-system was checked to be the least, and an interfragmentary displacement of DHS+LS assemblages was assessed to be the least”. A 3LS-system should be recommended to clinically optimize a Pauwells-II facture; if treated by this therapeutic fixation, breakage of fixators or secondary fracture is supposed to occur rarely. The strength of this study is that it was performed by a computer-aided simulation, allowing for design of a preoperative strategy that could provide acute correction and decrease procedure time, without harming to humans or animals.
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Affiliation(s)
- MATTHEW JIAN-QIAO PENG
- Department of Orthopedics, First Affiliated Hospital, GuangZhou Medical University, P. R. China
| | - HONGWEN XU
- Department of Pediatric Orthopaedics, GuangZhou Women and Children’s Medical Center, P. R. China
| | - HAI-YAN CHEN
- Department of Orthopedics, HuiDong People’s Hospital, HuiDong, P. R. China
| | - XIANGYANG JU
- Department of Clinical Physics and Bioengineering, University of Glasgow, U.K
| | - YONG HU
- Neural Electrophysiology Lab, University of Hong Kong, Hong Kong
| | - ASHRAF AYOUB
- Department of Clinical Physics and Bioengineering, University of Glasgow, U.K
| | - BALVINDER KHAMBAY
- Department of Clinical Physics and Bioengineering, University of Glasgow, U.K
| | - YUEMING GUO
- Department of Pediatric Orthopaedics, FoShan Hospital of Traditional Chinese Medicine, FoShan, P. R. China
| | - BO BAI
- Department of Orthopedics, First Affiliated Hospital, GuangZhou Medical University, P. R. China
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Akrami M, Craig K, Dibaj M, Javadi AA, Benattayallah A. A three-dimensional finite element analysis of the human hip. J Med Eng Technol 2019; 42:546-552. [PMID: 30875263 DOI: 10.1080/03091902.2019.1576795] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A three-dimensional hip model was created from the MRI scans of one human subject based on constructing the entire pelvis and femur. The ball and socket joint was modelled between the hip's acetabulum and the femoral head to analyse the multiaxial loads applied in the hip joint. The three key ligaments that reinforce the external surface of the hip to help to stabilise the joint were also modelled which are the iliofemoral, the pubofemoral and ischiofemoral ligaments. Each of these ligaments wraps around the joint connection to form a seal over the synovial membrane, a line of attachment around the head of the femur. This model was tested for different loading and boundary conditions to analyse their sensitivities on the cortical and cancellous tissues of the human hip bones. The outcomes of a one-legged stance finite element analysis revealed that the maximum of 0.056 mm displacement occurred. The stress distribution varied across the model which the majority occurring in the cortical femur and dissipating through the cartilage. The maximum stress value occurring in the joint was 110.1 MPa, which appeared at the free end of the proximal femur. This developed finite element model was validated against the literature data to be used as an asset for further research in investigating new methods of total hip arthroplasty, to minimise the recurrence of dislocations and discomfort in the hip joint, as well as increasing the range of movement available to a patient after surgery.
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Affiliation(s)
- Mohammad Akrami
- a Department of Engineering, College of Engineering , Mathematics, and Physical Sciences, University of Exeter , Exeter , UK
| | - Kim Craig
- a Department of Engineering, College of Engineering , Mathematics, and Physical Sciences, University of Exeter , Exeter , UK
| | - Mahdieh Dibaj
- a Department of Engineering, College of Engineering , Mathematics, and Physical Sciences, University of Exeter , Exeter , UK
| | - Akbar A Javadi
- a Department of Engineering, College of Engineering , Mathematics, and Physical Sciences, University of Exeter , Exeter , UK
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Jian-Qiao Peng M, Chen HY, Ju X, Hu Y, Ayoub A, Khambay B, Liu Z, Bai B. Comparative analysis for five fixations of Pauwels-I by the biomechanical finite-element method. J INVEST SURG 2018; 33:428-437. [PMID: 30516078 DOI: 10.1080/08941939.2018.1533054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Background: Little is known about how biomechanics govern the five fixtures such as DHS, MLS, DHS + LS, LP, and HA are accepted as common therapeutic techniques. Aims and objectives: A series of numerical models for a femoral neck fracture of Pauwels-I will be constructed by innovative approach of finite element in order to determine the most optimized option in comparison with biomechanical performance. Method: Twenty sets of computer tomography scanned femora were imported onto Mimics to extract 3 D models; these specimens were transferred to Geomagic-Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; 5 sorts of fixture were then expressed by Pro-Engineer virtually. After processing with HyperMesh, all compartments (fracture model + internal implant) were assembled onto 5 systems: "Dynamic Hip Screw (DHS), Multiple Lag screw (MLS), DHS + LS, femoral Locking Plate (LP) and HemiArthroplasty (HA)." Eventually, numerical models of the finite-elemental analysis were exported to AnSys to determine the solution. Result: Four models of fixation and a simulation of HA for Pauwels-I were established, validated, and analyzed with the following findings: In term of displacement, these 5 fixtures ranged between 0.3801 and 0.7536 mm have no significant difference; in term of stress, the averages of peaks for integral assemblage are b(MLS) = 43.5766 ≈< d(LP) = 43.6657 ≈< e(Ha) = 43.6657 < c(DHS + LS) = 66.5494 < a(DHS) = 105.617 in MPa indicate that MLS, LP and HA are not significantly different, but less than DHS + LS or DHS in each. Conclusion: A fixture of MLS or LP with optional HA should be recommended to clinically optimize a Pauwels-I facture.
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Affiliation(s)
- Matthew Jian-Qiao Peng
- Orthopedics Dept. of 1st Affiliated Hospital, GuangZhou Medical University, GuangDong, China
| | - Hai-Yan Chen
- Orthopedics Dept. of HuiDong People's Hospital, HuiZhou, GuangDong, China
| | - XiangYang Ju
- Dept. of Clinical Physics and Bioengineering, University of Glasgow, Glasgow, U.K
| | - Yong Hu
- Neural Electrophysiology Lab, University of Hongkong, Hongkong
| | - Ashraf Ayoub
- Dept. of Clinical Physics and Bioengineering, University of Glasgow, Glasgow, U.K
| | - Balvinder Khambay
- Dept. of Clinical Physics and Bioengineering, University of Glasgow, Glasgow, U.K
| | - ZiQing Liu
- Traumatic Orthopedics Dept. of SanShui People's Hospital, FoShan, GuangDong, China
| | - Bo Bai
- Orthopedics Dept. of 1st Affiliated Hospital, GuangZhou Medical University, GuangDong, China
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Cetin ME, Sofuoglu H. A statistical approach to explore cemented total hip reconstruction performance. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2018; 41:177-188. [PMID: 29460208 DOI: 10.1007/s13246-018-0627-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 02/10/2018] [Indexed: 11/27/2022]
Abstract
This study was carried out to determine mechanical behavior and bone adaptation of total hip arthroplasty (THA) subject to concentrated and distributed muscle loads and hip contact forces during activities of walking and stair climbing. Finite element modeling of THA with different prostheses, activity and loading types was developed by adopting a statistical method. Two levels of prostheses, activity, and loading types were selected for the study. 23 factorial method was then pursued to design input and output data of finite element analysis. Maximum von Mises stresses were chosen to be output data on which statistical investigation was performed to investigate contribution and interaction of main factors on mechanical failure of cemented THA reconstructions by utilizing analysis of variance method (ANOVA). This study illustrated that the maximum von Mises stresses of THA showed considerable variation for main factors and their two-factor interactions.
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Affiliation(s)
- Mehmet Emin Cetin
- Department of Aeronautical Engineering, Necmettin Erbakan University, Konya, Turkey.
| | - Hasan Sofuoglu
- Department of Mechanical Engineering, Karadeniz Technical University, Trabzon, Turkey
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Sylvester AD, Kramer PA. Young's Modulus and Load Complexity: Modeling Their Effects on Proximal Femur Strain. Anat Rec (Hoboken) 2018; 301:1189-1202. [PMID: 29451371 DOI: 10.1002/ar.23796] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/23/2017] [Accepted: 11/27/2017] [Indexed: 01/22/2023]
Abstract
Finite element analysis (FEA) is a powerful tool for evaluating questions of functional morphology, but the application of FEA to extant or extinct creatures is a non-trivial task. Three categories of input data are needed to appropriately implement FEA: geometry, material properties, and boundary conditions. Geometric data are relatively easily obtained from imaging techniques, but often material properties and boundary conditions must be estimated. Here we conduct sensitivity analyses of the effect of the choice of Young's Modulus for elements representing trabecular bone and muscle loading complexity on the proximal femur using a finite element mesh of a modern human femur. We found that finite element meshes that used a Young's Modulus between 500 and 1,500 MPa best matched experimental strains. Loading scenarios that approximated the insertion sites of hip musculature produced strain patterns in the region of the greater trochanter that were different from scenarios that grouped muscle forces to the superior greater trochanter, with changes in strain values of 40% or more for 20% of elements. The femoral head, neck, and proximal shaft were less affected (e.g. approximately 50% of elements changed by 10% or less) by changes in the location of application of muscle forces. From our sensitivity analysis, we recommend the use of a Young's Modulus for the trabecular elements of 1,000 MPa for the proximal femur (range 500-1,500 MPa) and that the muscular loading complexity be dependent on whether or not strains in the greater trochanter are the focus of the analytical question. Anat Rec, 301:1189-1202, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Adam D Sylvester
- The John Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, 1830 E. Monument Street, Baltimore, Maryland
| | - Patricia A Kramer
- Department of Anthropology, University of Washington, 314 Denny Hall, Seattle, Washington
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Farzi M, Morris RM, Penny J, Yang L, Pozo JM, Overgaard S, Frangi AF, Wilkinson JM. Quantitating the effect of prosthesis design on femoral remodeling using high-resolution region-free densitometric analysis (DXA-RFA). J Orthop Res 2017; 35:2203-2210. [PMID: 28169450 PMCID: PMC5655934 DOI: 10.1002/jor.23536] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/02/2017] [Indexed: 02/04/2023]
Abstract
Dual energy X-ray absorptiometry (DXA) is the reference standard method used to study bone mineral density (BMD) after total hip arthroplasty (THA). However, the subtle, spatially complex changes in bone mass due to strain-adaptive bone remodeling relevant to different prosthesis designs are not readily resolved using conventional DXA analysis. DXA region free analysis (DXA RFA) is a novel computational image analysis technique that provides a high-resolution quantitation of periprosthetic BMD. Here, we applied the technique to quantitate the magnitude and areal size of periprosthetic BMD changes using scans acquired during two previous randomized clinical trials (2004 to 2009); one comparing three cemented prosthesis design geometries, and the other comparing a hip resurfacing versus a conventional cementless prosthesis. DXA RFA resolved subtle differences in magnitude and area of bone remodeling between prosthesis designs not previously identified in conventional DXA analyses. A mean bone loss of 10.3%, 12.1%, and 11.1% occurred for the three cemented prostheses within a bone area fraction of 14.8%, 14.4%, and 6.2%, mostly within the lesser trochanter (p < 0.001). For the cementless prosthesis, a diffuse pattern of bone loss (-14.3%) was observed at the shaft of femur in a small area fraction of 0.6% versus no significant bone loss for the hip resurfacing prosthesis (p < 0.001). BMD increases were observed consistently at the greater trochanter for all prostheses except the hip-resurfacing prosthesis, where BMD increase was widespread across the metaphysis (p < 0.001). DXA RFA provides high-resolution insights into the effect of prosthesis design on the local strain environment in bone. © 2017 The Authors Journal of Orthopaedic Research published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:2203-2210, 2017.
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Affiliation(s)
- Mohsen Farzi
- University of Sheffield, Academic Unit of Bone MetabolismNorthern General HospitalSheffieldUnited Kingdom,Department of Electronic and Electrical EngineeringCentre for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)University of SheffieldSheffieldUnited Kingdom
| | - Richard M. Morris
- University of Sheffield, Academic Unit of Bone MetabolismNorthern General HospitalSheffieldUnited Kingdom
| | - Jeannette Penny
- Department of Orthopaedic Surgery and TraumatologyOdense University HospitalUniversity of Southern DenmarkInstitute of Clinical ResearchOdenseDenmark
| | - Lang Yang
- University of Sheffield, Academic Unit of Bone MetabolismNorthern General HospitalSheffieldUnited Kingdom
| | - Jose M. Pozo
- Department of Electronic and Electrical EngineeringCentre for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)University of SheffieldSheffieldUnited Kingdom
| | - Søren Overgaard
- Department of Orthopaedic Surgery and TraumatologyOdense University HospitalUniversity of Southern DenmarkInstitute of Clinical ResearchOdenseDenmark
| | - Alejandro F. Frangi
- Department of Electronic and Electrical EngineeringCentre for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)University of SheffieldSheffieldUnited Kingdom
| | - Jeremy Mark Wilkinson
- University of Sheffield, Academic Unit of Bone MetabolismNorthern General HospitalSheffieldUnited Kingdom
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Prediction of damage formation in hip arthroplasties by finite element analysis using computed tomography images. Med Eng Phys 2017; 44:8-15. [DOI: 10.1016/j.medengphy.2017.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 08/29/2016] [Accepted: 03/13/2017] [Indexed: 11/22/2022]
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WANG MONAN. OPTIMIZATION OF FEMORAL PROSTHESIS BASED ON COMPREHENSIVE EVALUATION OF STRUCTURE AND MATERIAL PROPERTIES. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416400133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this study, the optimized structure of a femoral prosthesis for a patient was determined by biomechanical analysis, and the materials that match the model of the prosthesis were determined by multi-objective comprehensive evaluation using a fuzzy matter-element method. The suitable material for the ellipsoidal femoral head of the prosthesis was determined to be a carbon-fiber-enhanced polyether-ketone (CF/PEK) composite, and that for the stem was determined to be a zirconium–niobium alloy (Zr–Nb alloy). The study successfully demonstrated the potential of the developed method for use in selecting the best structure and materials for fabricating a customized prosthesis.
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Affiliation(s)
- MONAN WANG
- Robotics Institute, Harbin University of Science and Technology, Harbin 150080, P. R. China
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Matsuyama K, Ishidou Y, Guo YM, Kakoi H, Setoguchi T, Nagano S, Kawamura I, Maeda S, Komiya S. Finite element analysis of cementless femoral stems based on mid- and long-term radiological evaluation. BMC Musculoskelet Disord 2016; 17:397. [PMID: 27642748 PMCID: PMC5028915 DOI: 10.1186/s12891-016-1260-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 09/15/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Femoral bone remodeling in response to stress shielding induces periprosthetic bone loss. Computerized finite element analysis (FEA) is employed to demonstrate differences in initial stress distribution. However, FEA is often performed without considering the precise sites at which the stem was fixed. We determined whether FEA reflects mid-term radiological examination exactly as predicted following long-term stress shielding. METHODS Femur-stem fixation sites were evaluated radiologically according to the location of spot welds in two anatomical cementless stem designs. Based on mid-term radiological results, four femur-stem bonding site conditions were defined as: (Condition A) no bonding; (Condition B) bonding within the 10 mm area proximal to the distal border of the porous area; (Condition C) bonding of the entire porous area; and (Condition D) bonding of the entire femoral stem, prior to conducting FEA analysis. Furthermore, we radiographically evaluated mid- and long-term stress shielding, and measured bone mineral density of the femur 10 years after total hip arthroplasty. RESULTS Spot welds appeared frequently around the border between the porous and smooth areas. FEA showed that, based on mid-term radiological evaluation, von Mises stress was reduced in condition B in the area proximal to the femur-stem bonding sites for both stem designs compared with condition A (no bonding). Conversely, von Mises stress at all areas of the femur-stem bonding sites in conditions C and D was higher than that in condition A. With respect to stress shielding progression, there was no significant difference between the two types of stem designs. However, stress shielding progressed and was significantly higher in the presence of spot welds (p = 0.001). In both stem designs, bone mineral density in zone VII was significantly lower than that in the contralateral hips. CONCLUSIONS These results indicate that FEA based on mid-term radiological evaluation may be helpful to predict the influence of long-term stress shielding more precisely.
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Affiliation(s)
- Kanehiro Matsuyama
- Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
| | - Yasuhiro Ishidou
- Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan.
| | - Yong-Ming Guo
- Department of Mechanical Engineering, Graduate School of Science and Engineering, Kagoshima University, Kagoshima, Japan
| | - Hironori Kakoi
- Department of Orthopaedic Surgery, Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan
| | - Takao Setoguchi
- The Near-Future Locomotor Organ Medicine Creation Course (Kusunoki Kai), Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan
| | - Satoshi Nagano
- Department of Orthopaedic Surgery, Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan
| | - Ichiro Kawamura
- Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
| | - Shingo Maeda
- Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan
| | - Setsuro Komiya
- Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8520, Japan.,Department of Orthopaedic Surgery, Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan.,The Near-Future Locomotor Organ Medicine Creation Course (Kusunoki Kai), Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan
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14
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Abstract
There is no published literature to support mid to long term results of hip resurfacing (HR) arthroplasty in patients over the age of 70 years. The purpose of our study was to evaluate the function HR in this age group (70 or older at the time of surgery) at medium to long term follow-up. Between July 1997 and November 2002, the Oswestry Outcome Centre independently and prospectively collected data on 5000 Birmingham Hip Resurfacings (BHRs). 106 had been implanted in elderly patients who were 70 years of age or older. The post-operative Harris and Merle D'Aubigné and Postel (MDP) hip scores and causes for revision were used to ascertain function and implant survival. Hip scores for the older BHR patients were compared with those from younger patients. The average age at surgery of the elderly BHR cohort was 73.2 years (range, 70.0 to 87.9 years) with a mean follow-up of 7.1 years (range, 0.5 to 10.9 years). Four patients had a femoral neck fracture and required conversion to a conventional total hip replacement. There were no patients lost to follow-up and no dislocations in this series. The median Harris hip score (HHS) was significantly better in the younger BHR group compared with the elderly BHR group, (96 vs. 94 p=0.008). There was no significant difference in recovery rates after surgery. There was a significantly higher rate of revision in women than men among the elderly patients (male= 1 of 65 (1.5%); women = 3 of 19 (15.8%), p=0.03). At latest follow-up the elderly patients continued to function well when compared with the younger BHR patients. There was a high mid to long term success rate after HR in patients who were 70 years of age or older, without the failure burden possibly anticipated. Elderly patients had a poorer functional outcome, but a difference in HHS of two points may be of only minor clinical significance.
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15
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Ajami S, Blunn GW, Lambert S, Alexander S, Foxall Smith M, Coathup MJ. Histological evaluation of two designs of shoulder surface replacement implants. Bone Joint J 2016; 98-B:504-11. [PMID: 27037433 DOI: 10.1302/0301-620x.98b4.36600] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 11/20/2015] [Indexed: 11/05/2022]
Abstract
AIMS To assess the extent of osteointegration in two designs of shoulder resurfacing implants. Bony integration to the Copeland cylindrical central stem design and the Epoca RH conical-crown design were compared. PATIENTS AND METHODS Implants retrieved from six patients in each group were pair-matched. Mean time to revision surgery of Copeland implants was 37 months (standard deviation (sd) 23; 14 to 72) and Epoca RH 38 months (sd 28; 12 to 84). The mean age of patients investigated was 66 years (sd 4; 59 to 71) and 58 years (sd 17; 31 to 73) in the Copeland and Epoca RH groups respectively. None of these implants were revised for loosening. RESULTS Increased osteointegration was measured under the cup in the Copeland implant group with limited bone seen in direct contact with the central stem. Bone adjacent to the Epoca RH implants was more uniform. CONCLUSION This difference in the distribution of bone-implant contact and bone formation was attributed to the Epoca implant's conical crown, which is positioned in more dense peripheral bone. The use of a central stem may not be necessary provided there is adequate peripheral fixation within good quality humeral bone. TAKE HOME MESSAGE Poor osteointegration of cementless surface replacement shoulder prosthesis may be improved by implant design.
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Affiliation(s)
- S Ajami
- University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK
| | - G W Blunn
- University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK
| | - S Lambert
- University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK
| | - S Alexander
- University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK
| | - M Foxall Smith
- University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK
| | - M J Coathup
- University College London, John Scales Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex HA7 4LP, UK
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16
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Arnould A, Boureau F, Benad K, Pasquier G, Migaud H, Girard J. Computed tomography evaluation of hip geometry restoration after total hip resurfacing. Orthop Traumatol Surg Res 2015; 101:571-5. [PMID: 26148967 DOI: 10.1016/j.otsr.2015.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 04/08/2015] [Accepted: 04/16/2015] [Indexed: 02/02/2023]
Abstract
BACKGROUND Anatomic reconstruction of the hip is among the main requirements for hip arthroplasty to be successful. Resurfacing arthroplasty may improve replication of the native joint geometry but has been evaluated only using standard radiographs. We therefore performed a computed tomography (CT) study to assess restoration of hip geometry after total hip resurfacing (HR), comparatively with the non-operated side. HYPOTHESIS HR does not change native extra-medullary hip geometry by more than 5mm and/or 5°. PATIENTS AND METHODS CT was used to evaluate unilateral HR in 75 patients with a mean age of 52.2years (range, 22-67years). The normal non-operated side served as the control in each patient. Mean follow-up was 2.5years (range, 1.9-3.1years). The primary evaluation criteria were femoral offset (FO) and femoral neck anteversion (FNA) and the secondary criteria were cup inclination angle, cup anteversion angle, and lower-limb length. RESULTS FO showed a non-significant decrease (mean, -2.2mm; range, -4.5 to +3.7mm). FNA was preserved, with a difference of less than 2° at last follow-up versus the preoperative value. Cup measurements showed a mean anteversion angle of 24.8° (0.9-48.6) and mean inclination angle of 44.1° (32.1-56.3); corresponding values for the native acetabulum were 38.9° (20.5-54.8) and 24.8° (4.8-33.6). The residual lower-limb length discrepancy was less than 1mm (mean, -0.04mm [-1.2 to +1.6mm]). The mean angle between the femoral implant and the femoral neck axis was 5.4° of valgus. DISCUSSION Our results show that HR accurately restored the native extra-medullary hip geometry. LEVEL OF EVIDENCE III, prospective diagnostic case-control study.
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Affiliation(s)
- A Arnould
- Service orthopédie D, centre hospitalier régional universitaire de Lille, 2, avenue Oscar-Lambret, 59037 Lille cedex, France; Université Lille-Nord de France, 59000 Lille, France.
| | - F Boureau
- Service orthopédie D, centre hospitalier régional universitaire de Lille, 2, avenue Oscar-Lambret, 59037 Lille cedex, France; Université Lille-Nord de France, 59000 Lille, France
| | - K Benad
- Service orthopédie D, centre hospitalier régional universitaire de Lille, 2, avenue Oscar-Lambret, 59037 Lille cedex, France; Université Lille-Nord de France, 59000 Lille, France
| | - G Pasquier
- Service orthopédie D, centre hospitalier régional universitaire de Lille, 2, avenue Oscar-Lambret, 59037 Lille cedex, France; Université Lille-Nord de France, 59000 Lille, France
| | - H Migaud
- Université Lille-Nord de France, 59000 Lille, France; Service orthopédie C, centre hospitalier régional universitaire de Lille, 2, avenue Oscar-Lambret, 59037 Lille cedex, France
| | - J Girard
- Université Lille-Nord de France, 59000 Lille, France; Service orthopédie C, centre hospitalier régional universitaire de Lille, 2, avenue Oscar-Lambret, 59037 Lille cedex, France; Domaine médecine et sport, faculté de médecine de Lille 2, 59037 Lille cedex, France
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17
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Schmidutz F, Sprecher CM, Milz S, Gohlke F, Hertel R, Braunstein V. Resurfacing of the humeral head: An analysis of the bone stock and osseous integration under the implant. J Orthop Res 2015; 33:1382-90. [PMID: 25808101 DOI: 10.1002/jor.22902] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 03/10/2015] [Indexed: 02/04/2023]
Abstract
Cementless-surface-replacement-arthroplasty (CSRA) of the shoulder aims for functional joint restoration with minimal bone loss. Good clinical results have been reported, but due to the radiopaque metal shell no data is available on the structure, osseous integration, and bone stock under the implant. 14 hemi-CSRAs (4 manufacturers) with two geometries (crown [n = 7]/ stem [n = 7] fixation) were retrieved from patients undergoing revision due to glenoidal erosion. Histological sections cutting through the implant centre and bone were analysed. Quantitative histomorphometry evaluated the bone-implant-contact and compared the bone-area to native humeral retrievals (n = 7). The bone-implant-interface was further assessed by scanning-electron-microscopy (SEM) and energy-dispersive-x-ray (EDX). Qualitative histology revealed a reduced and inhomogeneous bone stock. Obvious signs of stress shielding were observed with bone predominantly visible at the stem and implant rim. Quantitative histomorphometry confirmed the significantly reduced bone-area (9.2 ± 3.9% [crown 9.9 ± 4.3%, stem 8.6 ± 3.6%]) compared to native humeri (21.2 ± 9.1%; p < 0.05). Bone-implant-contact was 20.5 ± 5.8% (crown 21.8 ± 6.2%, stem 19.2 ± 5.6%) which was confirmed by SEM and EDX. Altogether, CRSA shows satisfactory bone ingrowth at the interface suggesting sufficient primary stability to allow osseous integration. However, clear signs of stress shielding with an inhomogeneous and reduced bone stock were observed. The impact on the long-term-results is unclear requiring further investigation.
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Affiliation(s)
- Florian Schmidutz
- AO Research Institute Davos, Switzerland.,Department of Orthopaedic Surgery, University of Munich (LMU), Germany
| | | | - Stefan Milz
- AO Research Institute Davos, Switzerland.,University of Munich (LMU), Anatomische Anstalt, Germany
| | | | | | - Volker Braunstein
- AO Research Institute Davos, Switzerland.,Ortho-Plus Munich, Germany.,Department of General-, Trauma-, Hand and Plastic Surgery, University of Munich (LMU), Germany
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18
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Sofuoglu H, Cetin ME. An investigation on mechanical failure of hip joint using finite element method. BIOMED ENG-BIOMED TE 2015; 60:603-16. [PMID: 25996481 DOI: 10.1515/bmt-2014-0173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/30/2015] [Indexed: 11/15/2022]
Abstract
The aim of this work was to study how the stress distributions of the hip joint's components were changed if the activity was switched from walking to stair climbing for three different prostheses types subjected to either concentrated or distributed load. In the scope of the study, three different cemented prostheses, namely, Charnley, Muller, and Hipokrat were used for cemented total hip arthroplasty (THA) reconstruction. The finite element modeling of the hip joint with prosthesis was developed for both hip contact and muscle forces during walking and stair climbing activities. The finite element analyses were then pursued for both concentrated and distributed loading conditions applied statically on these models. Maximum von Mises stresses and strains occurred on the cortical and trabecular layers of bones; prosthesis and cement mantle were determined in order to investigate the mechanical failure of cemented THA reconstruction subjected to the different femoral loading and the activity conditions. This study showed that prosthesis, loading, and activity types had a significant effect on the stresses of components of the hip joint utilized for predicting mechanical failure of the cemented THA reconstruction.
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19
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Schmidutz F, Agarwal Y, Müller PE, Gueorguiev B, Richards RG, Sprecher CM. Stress-shielding induced bone remodeling in cementless shoulder resurfacing arthroplasty: a finite element analysis and in vivo results. J Biomech 2014; 47:3509-16. [PMID: 25278045 DOI: 10.1016/j.jbiomech.2014.08.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 08/24/2014] [Accepted: 08/30/2014] [Indexed: 12/01/2022]
Abstract
Cementless surface replacement arthroplasty (CSRA) of the shoulder was designed to preserve the individual anatomy and humeral bone stock. A matter of concern in resurfacing implants remains the stress shielding and bone remodeling processes. The bone remodeling processes of two different CSRA fixation designs, conical-crown (Epoca RH) and central-stem (Copeland), were studied by three-dimensional (3-D) finite element analysis (FEA) as well as evaluation of contact radiographs from human CSRA retrievals. FEA included one native humerus model with a normal and one with a reduced bone stock quality. Compressive strains were evaluated before and after virtual CSRA implantation and the results were then compared to the bone remodeling and stress-shielding pattern of eight human CSRA retrievals (Epoca RH n=4 and Copeland n=4). FEA revealed for both bone stock models increased compressive strains at the stem and outer implant rim for both CSRA designs indicating an increased bone formation at those locations. Unloading of the bone was seen for both designs under the central implant shell (conical-crown 50-85%, central-stem 31-93%) indicating high bone resorption. Those effects appeared more pronounced for the reduced than for the normal bone stock model. The assumptions of the FEA were confirmed in the CSRA retrieval analysis which showed bone apposition at the outer implant rim and stems with highly reduced bone stock below the central implant shell. Overall, clear signs of stress shielding were observed for both CSRAs designs in the in vitro FEA and human retrieval analysis. Especially in the central part of both implant designs the bone stock was highly resorbed. The impact of these bone remodeling processes on the clinical outcome as well as long-term stability requires further evaluation.
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Affiliation(s)
- F Schmidutz
- AO Research Institute Davos, Switzerland; Department of Orthopaedic Surgery, University of Munich (LMU), Germany.
| | - Y Agarwal
- AO Research Institute Davos, Switzerland
| | - P E Müller
- Department of Orthopaedic Surgery, University of Munich (LMU), Germany
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20
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Tai CL, Chen YC, Hsieh PH. The effects of necrotic lesion size and orientation of the femoral component on stress alterations in the proximal femur in hip resurfacing - a finite element simulation. BMC Musculoskelet Disord 2014; 15:262. [PMID: 25095740 PMCID: PMC4124961 DOI: 10.1186/1471-2474-15-262] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 07/30/2014] [Indexed: 01/19/2023] Open
Abstract
Background Due to the advantages of its bone-conserving nature, hip resurface arthroplasty (HRA) has recently gained the interest of orthopedic surgeons for the treatment of young and active patients who have osteonerosis of the femoral head. However, in long-term follow-up studies after HRA, narrowing of the femoral neck has often been found, which may lead to fracture. This phenomenon has been attributed to the stress alteration (stress shielding). Studies addressing the effects of necrotic size and the orientation of the implant on stress alterations are lacking. Methods Computed tomography images of a standard composite femur were used to create a three-dimensional finite-element (FE) intact femur model. Based on the intact model, FE models simulating four different levels of necrotic regions (0°, 60°, 100°, 115°) and three different implant insertion angles (varus 10°, neutral, valgus 10°) were created. The von Mises stress distributions and the displacement of the stem tip of each model were analyzed and compared for loading conditions that simulated a single-legged stance. Results Stress shielding occurred at the femoral neck after HRA. More severe stress shielding and an increased displacement of the stem tip were found for femoral heads that had a wider necrotic lesion. From a biomechanics perspective, the results were consistent with clinical evidence of femoral neck narrowing after HRA. In addition, a varus orientation of the implant resulted in a larger displacement of the stem tip, which could lead to an increased risk of implant loosening. Conclusions A femoral head with a wide necrotic lesion combined with a varus orientation of the prosthesis increases the risk of femoral neck narrowing and implant loosening following HRA.
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Affiliation(s)
| | | | - Pang-Hsin Hsieh
- Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
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21
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Tan TL, Ebramzadeh E, Campbell PA, Al-Hamad M, Amstutz HC. Long-term outcome of a metal-on-polyethylene cementless hip resurfacing. J Arthroplasty 2014; 29:802-7. [PMID: 24090660 DOI: 10.1016/j.arth.2013.08.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 07/30/2013] [Accepted: 08/16/2013] [Indexed: 02/01/2023] Open
Abstract
Due to the well-documented problems surrounding metal-on-metal bearings, the use of hip resurfacing has declined. Since the potential benefits of hip resurfacing remain desirable, it may be beneficial to investigate the long-term outcome of hip resurfacings using metal-on-polyethylene in the 1980's. We report the long-term survivorship and modes of failure of a cementless metal-on-polyethylene resurfacing (n = 178) with different porous ingrowth surfaces. While acetabular loosening was absent, a high incidence of femoral failures (femoral loosening = 18.1%, osteolytic neck fracture = 21%) occurred despite using the same ingrowth surface for both components. Ongoing developments using the lessons learned from these previous generation components and utilizing modern low wear materials, e.g., cross-linked polyethylene, may lead to improved implants for future hip resurfacings.
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Affiliation(s)
- Timothy L Tan
- David Geffen School of Medicine, University of California, Los Angeles; J. Vernon Luck, Sr., MD Orthopaedic Research Center at Los Angeles Orthopaedic Hospital, in Alliance with UCLA Department of Orthopaedic Surgery
| | - Edward Ebramzadeh
- J. Vernon Luck, Sr., MD Orthopaedic Research Center at Los Angeles Orthopaedic Hospital, in Alliance with UCLA Department of Orthopaedic Surgery
| | - Patricia A Campbell
- J. Vernon Luck, Sr., MD Orthopaedic Research Center at Los Angeles Orthopaedic Hospital, in Alliance with UCLA Department of Orthopaedic Surgery
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22
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Pérez M, Vendittoli PA, Lavigne M, Nuño N. Bone remodeling in the resurfaced femoral head: Effect of cement mantle thickness and interface characteristics. Med Eng Phys 2014; 36:185-95. [DOI: 10.1016/j.medengphy.2013.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 09/25/2013] [Accepted: 10/15/2013] [Indexed: 11/29/2022]
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23
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Early failure of the Durom prosthesis in metal-on-metal hip resurfacing in Chinese patients. J Arthroplasty 2013; 28:1816-21. [PMID: 23831082 DOI: 10.1016/j.arth.2013.05.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 05/14/2013] [Accepted: 05/30/2013] [Indexed: 02/01/2023] Open
Abstract
Hip resurfacing (HR) is being used increasingly as an alterative to total hip arthroplasty in osteonecrosis (ON) and ankylosing spondylitis (AS) of the hip. We performed 141 consecutive HR arthroplasties in 111 patients comprising 3 etiology groups: ON, AS, and osteoarthritis (OA). After retrospective study of retrieved components, we hypothesized that the main reason for revision was femoral loosening in the ON group (4 of 46 hips; 8.7%) and femoral-neck fracture in the AS group (3 of 58 hips; 5.2%). Necrotic areas were seen on femoral heads retrieved from patients with femoral loosening, whereas femoral heads were fixed tightly to components in patients with femoral-neck fractures. Etiology may be an important risk factor for postoperative complications.
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24
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Wang W, Geller JA, Hasija R, Choi JK, Jr. DAP, Macaulay W. Longitudinal evaluation of time related femoral neck narrowing after metal-on-metal hip resurfacing. World J Orthop 2013; 4:75-79. [PMID: 23610755 PMCID: PMC3631955 DOI: 10.5312/wjo.v4.i2.75] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/23/2013] [Accepted: 02/06/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To track the short-term neck narrowing changes in Birmingham metal-on-metal hip resurfacing (MOMHR) patients.
METHODS: Since 2001, the Center for Hip and Knee Replacement started a registry to prospectively collect data on hip and knee replacement patients. From June 2006 to October 2008, 139 MOMHR were performed at our center by two participate surgeons using Birmingham MOMHR prosthesis (Smith Nephew, United States). It is standard of care for patients to obtain low, anteriorposterior (LAP) pelvis radiographs immediately after MOMHR procedure and then at 3 mo, 1 year and 2 year follow up office visits. Inclusion criteria for the present study included patients who came back for follow up office visit at above mentioned time points and got LAP radiographs. Exclusion criteria include patients who missed more than two follow up time points and those with poor-quality X-rays. Two orthopaedic residency trained research fellows reviewed the X-rays independently at 4 time points, i.e., immediate after surgery, 3 mo, 1 year and 2 year. Neck-to-prosthesis ratio (NPR) was used as main outcome measure. Twenty cases were used as subjects to identify the reliability between two observers. An intraclass correlation coefficient at 0.8 was considered as satisfied. A paired t-test was used to evaluate the significant difference between different time points with P < 0.05 considered to be statistically significant.
RESULTS: The mean NPRs were 0.852 ± 0.056, 0.839 ± 0.052, 0.835 ± 0.051, 0.83 ± 0.04 immediately, 3 mo, 1 year and 2 years post-operatively respectively. At 3 mo, NPR was significantly different from immediate postoperative X-ray (P < 0.001). There was no difference between 3 mo and 1 year (P = 0.14) and 2 years (P = 0.53). Femoral neck narrowing (FNN) exceeding 10% of the diameter of the neck was observed in only 4 patients (5.6%) at two years follow up. None of these patients developed a femoral neck fracture (FNF).
CONCLUSION: Femoral neck narrowing after MOMHR occurred as early as 3 mo postoperatively, and stabilized thereafter. Excessive FNN was not common in patients within the first two years of surgery and was not correlated with risk of FNF.
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25
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Abstract
BACKGROUND Metal-on-metal bearing with cemented femoral component and cementless acetabular fixation is the current standard in surface replacement arthroplasty (RSA) of the hip. Because of concerns about the long-term survivorship of cemented stems in conventional hip arthroplasty, it seems logical to achieve cementless fixation on the femoral side with RSA. QUESTIONS/PURPOSES The goals of this review were to evaluate clinical and radiological data reported from previously published cementless RSA series. In addition, we intend to review author's preliminary experience with Conserve Plus cementless devices specifically assessing the clinical outcomes, the complications rate, the survivorship, and the metallic ions levels measured in follow-up. METHODS A references search was done with PubMed using the key words "cementless hip resurfacing", "cementless hip resurfacing prosthesis", and "femoral cementless hip resurfacing". Additionally, the clinical outcomes, the complications rate, the survivorship, and the metallic ions levels were measured in 94 cementless Conserve Plus(©) devices in 90 patients (68 males and 22 females) with a mean age of 41.1 years (18-59). Mean follow-up was 13.1 months (8-16). RESULTS No revision was performed during the observed follow-up. Neither radiological signs of loosening nor neck narrowing >10% were evident. Chromium and cobalt levels in whole blood samples rose respectively from 0.53 μg/l (0.1-1.7) to 1.7 μg/l (0.6-2.9) and from 0.54 μg/l (0.1-1.4) to 1.98 μg/l (0.1-2.8). CONCLUSIONS Cementless "fit and fill" femoral-side fixation, which seems to be potentially evolved and design-related, should be considered for future hip-resurfacing device generations.
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Affiliation(s)
- Julien Girard
- Department of Orthopaedic Surgery, Roger Salengro Hospital, University of Lille, 2 avenue Oscar Lambret, Lille, France
- Department of Sports Medicine, University of Lille 2, Lille cedex, 59037 France
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26
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Dickinson A, Taylor A, Browne M. Implant–bone interface healing and adaptation in resurfacing hip replacement. Comput Methods Biomech Biomed Engin 2012; 15:935-47. [DOI: 10.1080/10255842.2011.567269] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Tapaninen T, Kröger H, Jurvelin J, Venesmaa P. Femoral Neck Bone Mineral Density after Resurfacing Hip Arthroplasty. Scand J Surg 2012; 101:211-5. [DOI: 10.1177/145749691210100312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Introduction: Resurfacing hip arthroplasty (RHA) has been suggested to provide an alternative to conventional total hip arthroplasty in younger, active patients. It seems to have an ability to conserve the bone mass on the femoral side. Some controversy exists regarding to the possible disadvantages of RHA and some of them are connected to poor femoral bone quality after surgery. Hence we wanted to study the bone mineral density changes 3 and 12 months after RHA. Materials and Methods: A total of 26 patients (22 men and 4 women, 28 hips) underwent a hip resurfacing arthroplasty. The mean age of the patients was 55,2 (range 38–69) years. Bone mineral density (BMD) of the proximal femur was measured by using the dual-energy X-ray absorptiometry (DXA) postoperatively and within 3 and 12 months from surgery. For analysis, we divided the femoral neck area into four equal-sized regions of interest ranging from the prosthesis to the trochanter level. Results: At three months follow-up the BMD changes varied between −5.1% (ROIC) and + 1.9% (ROIA), as compared with the immediate postoperative values. After one year follow-up the BMD changes were + 1.1% in the ROIA, + 5.4% in the ROIB, −3.9% in the ROIC and + 1.3% in the ROID. The changes in BMD were not statistically significant. Discussion: While there is still much debate and room for additional research in this topic, the results suggest that BMD is conserved in the femoral neck one year after hip resurfacing arthroplasty.
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Affiliation(s)
- T. Tapaninen
- Department of Surgery, North-Carelia Central Hospital, Joensuu, Finland
- Department of Orthopedic and Traumatology, Kuopio University Hospital, Kuopio, Finland
| | - H. Kröger
- Department of Orthopedic and Traumatology, Kuopio University Hospital, Kuopio, Finland
| | - J. Jurvelin
- Deparment of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - P. Venesmaa
- Department of Orthopedic and Traumatology, Kuopio University Hospital, Kuopio, Finland
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Bryan R, Nair PB, Taylor M. Influence of femur size and morphology on load transfer in the resurfaced femoral head: A large scale, multi-subject finite element study. J Biomech 2012; 45:1952-8. [PMID: 22704609 DOI: 10.1016/j.jbiomech.2012.05.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 05/11/2012] [Accepted: 05/13/2012] [Indexed: 11/29/2022]
Abstract
Femoral resurfacing has become an increasingly popular procedure, especially for young, active patients. The procedure is known to alter load transfer through the proximal femur and this has been linked with the most commonly observed complication, neck fracture. An intriguing observation noted by registry data and clinical studies is an inverse relationship between implant size and revision rate. While computational analysis has become an established part of biomedical engineering, the majority of work uses a single or small set of bone models, with a single implant size, due to the constraints of time and data availability. Therefore, it has been infeasible to run a study incorporating natural inter-patient variability or the performance of smaller implants could not be meaningfully studied. In previous work a statistical model of the whole femur was used to generate large numbers of unique, realistic, FE-ready femur models describing both geometry and material properties. The current study demonstrates a methodology for virtually implanting and performing stress analysis of cemented femoral resurfacing components, with model specific sizing and orientation. Automated analysis of 400 generated femurs, in both implanted and intact configurations showed the strain changes induced by resurfacing. This produced a statistically meaningful number of results and allowed the examination of outliers. Results showed increased femoral neck strain changes potentially increasing the risk of neck fracture, associated with smaller, less dense femurs and smaller implant sizes; agreeing with clinical observations. The study demonstrates a methodology for more comprehensive analyses, based on populations rather than individuals.
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Affiliation(s)
- Rebecca Bryan
- Bioengineering Sciences Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
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Jacobs MA, Kennedy WR, Bhargava T, Chodos MD. Postresurfacing periprosthetic femoral neck fractures: nonoperative treatment. Orthopedics 2012; 35:e732-6. [PMID: 22588417 DOI: 10.3928/01477447-20120426-29] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Femoral neck fractures after total hip resurfacing procedures occur infrequently but require immediate orthopedic intervention. Historically, they have been treated by conversion to traditional total hip arthroplasty. However, to the authors' knowledge, no treatment algorithm has ever been described. The authors have directly treated or consulted on 13 cases of periprosthetic femoral neck fractures after metal-on-metal hip resurfacing arthroplasties that were successfully treated nonoperatively: all fractures healed with protected weight bearing, producing excellent clinical results. Two cases are described in detail, and the authors propose a classification system that can assist the orthopedist in choosing the treatment regimen. Type I fractures are nondisplaced and should be initially treated nonoperatively with a course of protected weight bearing. If successful, the overall success of the resurfacing should not be compromised. Partially displaced, or type II, fractures may heal with nonoperative management. However, if the components have shifted, it may affect the long-term durability of the arthroplasty and eventually result in premature conversion to a traditional total hip replacement. Depending on the position of the components, it may also have an effect on the ion generation potential of the metal-on-metal articulation. This treatment pathway can be undertaken only with a full and detailed explanation of all of the possible complications and outcomes with the patient. Completely displaced, or type III, fractures require immediate conversion to total hip arthroplasty.
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Affiliation(s)
- Michael A Jacobs
- Department of Orthopaedic Surgery, The Johns Hopkins University, Johns Hopkins Bayview Medical Center, Baltimore, MD 21224-2780, USA.
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Kwon YM, Mellon SJ, Monk P, Murray DW, Gill HS. In vivo evaluation of edge-loading in metal-on-metal hip resurfacing patients with pseudotumours. Bone Joint Res 2012; 1:42-9. [PMID: 23610670 PMCID: PMC3626206 DOI: 10.1302/2046-3758.14.2000019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 03/20/2012] [Indexed: 12/12/2022] Open
Abstract
Objectives Pseudotumours (abnormal peri-prosthetic soft-tissue reactions)
following metal-on-metal hip resurfacing arthroplasty (MoMHRA) have
been associated with elevated metal ion levels, suggesting that
excessive wear may occur due to edge-loading of these MoM implants.
This study aimed to quantify in vivo edge-loading
in MoMHRA patients with and without pseudotumours during functional
activities. Methods The duration and magnitude of edge-loading in vivo was
quantified during functional activities by combining the dynamic
hip joint segment contact force calculated from the three-dimensional
(3D) motion analysis system with the 3D reconstruction of orientation
of the acetabular component and each patient’s specific hip joint
centre, based on CT scans. Results Edge-loading in the hips with pseudotumours occurred with a four-fold
increase in duration and magnitude of force compared with the hips
without pseudotumours (p = 0.02). Conclusions The study provides the first in vivo evidence to support that
edge-loading is an important mechanism that leads to localised excessive
wear (edge-wear), with subsequent elevation of metal ion levels
in MoMHRA patients with pseudotumours.
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Affiliation(s)
- Y-M Kwon
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Suite 3B, Boston, Massachusetts 02114, USA
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Bedigrew KM, Ruh EL, Zhang Q, Clohisy JC, Barrack RL, Nunley RM. 2011 Marshall Urist Young Investigator Award: when to release patients to high-impact activities after hip resurfacing. Clin Orthop Relat Res 2012; 470:299-306. [PMID: 22006198 PMCID: PMC3237978 DOI: 10.1007/s11999-011-2131-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 10/03/2011] [Indexed: 01/31/2023]
Abstract
BACKGROUND Surface replacement arthroplasties are commonly performed in young, active patients who desire return to high-impact activities including heavy manual labor and recreational sports. Femoral neck fracture is an arthroplasty-related complication unique to surface replacement arthroplasty. However, it is unclear regarding whether patients are at lower risk for fracture after a certain postoperative time. QUESTIONS/PURPOSES We therefore raised the following questions: (1) does stress shielding occur after surface replacement arthroplasty, and (2) when does bone mineral density return to normal so patients can return to high-impact activities without excessive risk of fracture? PATIENTS AND METHODS We prospectively enrolled 90 patients (96 hips) with either surface replacement arthroplasty or THA, and performed dual energy x-ray absorptiometry scans at 6 weeks, 6 months, 1 year, and 2 years. We analyzed bone density by Gruen zone in both groups, and six femoral neck zones in the patients who had surface replacement arthroplasties. We calculated 6-month, 1-year, and 2-year ratios for the change in bone density compared with baseline. RESULTS Bone density was greater in patients who had surface replacement arthroplasties than for patients who had THAs at 6 months and 1 year in Gruen Zones 1, 2, 6, and 7, with the largest increase in femoral neck bone density on the tension side at 6 months in Zone L1. We saw no decrease in bone density in patients who had surface replacement arthroplasties in any Gruen zone at any time, and observed no decrease in bone density in female patients. CONCLUSIONS Increased bone density at 6 months postoperatively in patients who had surface replacement arthroplasties provides evidence that clinically relevant stress shielding does not occur after surface replacement arthroplasty. Owing to the increased bone mineral density at 6 months, we believe patients who underwent surface replacement arthroplasties may to return to high-impact activities at that time without increased risk of fracture.
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Affiliation(s)
| | - Erin L. Ruh
- Department of Orthopaedics, Washington University/Barnes Jewish Hospital, St Louis, MO USA
| | - Qin Zhang
- Department of Biostatistics, Washington University School of Medicine, St Louis, MO USA
| | - John C. Clohisy
- Department of Orthopaedics, Washington University/Barnes Jewish Hospital, St Louis, MO USA
| | - Robert L. Barrack
- Department of Orthopaedics, Washington University/Barnes Jewish Hospital, St Louis, MO USA
| | - Ryan M. Nunley
- Department of Orthopaedics, Washington University/Barnes Jewish Hospital, St Louis, MO USA ,John Cochran Division, VA Medical Center, St Louis, MO USA ,Department of Orthopaedic Surgery, Washington University School of Medicine, One Barnes-Jewish Hospital Plaza, 11300 West Pavilion, St Louis, MO 63110 USA
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A seven-zone rating system for assessing bone mineral density after hip resurfacing using implants with metaphyseal femoral stems. Hip Int 2011; 21:463-7. [PMID: 22167855 DOI: 10.5301/hip.2011.8518] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The seven Gruen zones are widely accepted for the assessment of periprosthestic bone mineral density (BMD) following traditional total hip arthroplasty, but no comparable rating system exists for hip resurfacing arthroplasty (HRA).We describe a seven-zone rating system around the femoral component of a typical HRA implant with a short metaphyseal stem and its intra- and inter-observer reliability.A cohort of 23 selected male patients underwent bone mineral density (BMD) measurements by dual energy X-ray absorptiometry (DEXA) two years after HRA. After development of the new seven-zone rating system, reliability was assessed using intraclass correlation coefficients (ICC). The coefficient of variation was also determined. The new rating-system proved high reliability with ICCs for the intra and inter-observer reliability ranging from 0.92 to 1.0. The coefficient of variation ranged from 1.4% to 3.3%. Mean BMD values were highest in the medial zones 5 to 7 and lowest in the lateral zones 1 to 3 and below the stem tip, corresponding to zone 4. We observed that BMD after HRA can be measured reliably in seven zones around the femoral component. The use of this easily applicable method in future investigations might enhance the comparability of study results. However, the rating system described may have limitations in HRA implants with very short metaphyseal femoral stems.
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Is the increase in bone mineral density after hip resurfacing uniform across the femoral neck? INTERNATIONAL ORTHOPAEDICS 2011; 36:901. [PMID: 22086190 DOI: 10.1007/s00264-011-1406-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 10/23/2011] [Indexed: 10/15/2022]
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Rothstock S, Uhlenbrock A, Bishop N, Laird L, Nassutt R, Morlock M. Influence of interface condition and implant design on bone remodelling and failure risk for the resurfaced femoral head. J Biomech 2011; 44:1646-53. [DOI: 10.1016/j.jbiomech.2011.02.076] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Revised: 01/16/2011] [Accepted: 02/20/2011] [Indexed: 10/18/2022]
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Ho KKW, Beazley J, Parsons N, Costa ML, Foguet P. Narrowing of the femoral neck after resurfacing arthroplasty of the hip: a comparison of cemented and uncemented femoral components. Hip Int 2011; 20:542-6. [PMID: 21157762 DOI: 10.1177/112070001002000420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/04/2010] [Indexed: 02/04/2023]
Abstract
We performed a radiographic review of a consecutive series of 87 resurfacing arthroplasties of the hip, performed between 2004 and 2006. There were 54 cemented femoral components and 33 uncemented femoral components. All of the procedures were performed by the same surgeon using the same approach. There was no difference between the groups with regards to gender, age, pre-operative diagnosis and the average diameter of the components. The primary outcome measured was the neck-prosthesis ratio on standard anterior-posterior pelvis radiographs taken post-operatively and at a minimum follow up of two years. The difference between the immediate post-operative ratio and the most recent radiograph was statistically significant in patients with cemented femoral components (p=0.006), but not in the group with uncemented components (p=0.173). We have demonstrated a difference in narrowing of the femoral neck between cemented and uncemented femoral components in the first two years following surgery.
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Affiliation(s)
- Kevin K W Ho
- Department of Orthopaedic Surgery, University Hospital Coventry and Warwickshire NHS Trust, Coventry, UK.
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36
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Amstutz HC, Le Duff MJ, Campbell PA, Wisk LE, Takamura KM. Complications after metal-on-metal hip resurfacing arthroplasty. Orthop Clin North Am 2011; 42:207-30, viii. [PMID: 21435496 DOI: 10.1016/j.ocl.2010.12.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This article determines the incidence and cause of the complications commonly associated with metal-on-metal hip resurfacing implants and the proposed methods to prevent these complications. The literature available in PubMed was reviewed. Complication rates after hip resurfacing are low, and the procedure has shown both safety and efficacy in the hands of surgeons trained in specialized centers. Proper surgical technique can further reduce the incidence of femoral neck fracture, component loosening, and abnormal wear of the prosthesis. A more systematic detection of adverse local tissue reactions is needed to provide accurate assessments of their prevalence.
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Affiliation(s)
- Harlan C Amstutz
- Joint Replacement Institute at Saint Vincent Medical Center, Los Angeles, CA 90057, USA.
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Olsen M, Davis ET, Whyne CM, Zdero R, Schemitsch EH. The biomechanical consequence of insufficient femoral component lateralization and exposed cancellous bone in hip resurfacing arthroplasty. J Biomech Eng 2010; 132:081011. [PMID: 20670060 DOI: 10.1115/1.4001159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Insufficient lateralization of the femoral component coupled with exposed reamed cancellous bone has been speculated to predispose to femoral neck fracture. The current study examined the effect of mediolateral implant position and exposed cancellous bone on the strength of the resurfaced proximal femur. Composite femurs were prepared in three configurations: (1) partial, with the implant placed at the native femoral head offset of the femur, partially exposing reamed cancellous bone; (2) proud, with a medialized implant exposing a circumferential ring of cancellous bone; and (3) complete, with a lateralized implant covering all reamed cancellous bone. Specimens were loaded to failure in axial compression. A finite element model was used to further explore the effect of exposed cancellous bone, cement mantle thickness, and relative valgus orientation on the strain distributions in the resurfaced femur. The proud group (2063 N) was significantly weaker than both the partial (2974 N, p=0.004) and complete groups (5899 N, p=0.001) when tested to failure. The partial group was also significantly weaker than the complete group when tested to failure (p=0.001). The finite element model demonstrated increasing levels of strain in the superior reamed cortical-cancellous bone interface with increasing degree of exposed cancellous bone. The condition of the femoral component medialized as the result of a thick cement mantle had the greatest detrimental impact on strain level in the superior reamed cancellous bone while a valgus oriented implant provided a protective effect. This study provides biomechanical evidence that exposed reamed cancellous bone significantly reduces the load-to-failure and increases maximum strains in the resurfaced proximal femur. The perceived benefit of reconstructing the femur to its native geometry may inherently weaken the proximal femur and increase femoral neck fracture risk if the femoral component is not sufficiently lateralized to cover all unsupported reamed cancellous bone. Relative valgus orientation of the implant may help to minimize the risk of neck fracture if reamed cancellous bone remains exposed following implant impaction.
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Affiliation(s)
- Michael Olsen
- Martin Orthopaedic Biomechanics Laboratory, St. Michael's Hospital, 5-066 Shuter Wing, 30 Bond Street, Toronto, ON, M5B1W8, Canada.
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38
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Sakagoshi D, Kabata T, Umemoto Y, Sakamoto J, Tomita K. A mechanical analysis of femoral resurfacing implantation for osteonecrosis of the femoral head. J Arthroplasty 2010; 25:1282-9. [PMID: 19879726 DOI: 10.1016/j.arth.2009.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 09/12/2009] [Indexed: 02/01/2023] Open
Abstract
Hip resurfacing is becoming a popular procedure for treating osteonecrosis of the femoral head. However, the biomechanical changes that occur after femoral resurfacing have not been fully investigated with respect to the individual extent of the necrosis. In this study, we evaluated biomechanical changes at various extents of necrosis and implant alignments using the finite element analysis method. We established 3 patterns of necrosis by depth from the surface of femoral head and 5 stem angles. For these models, we evaluated biomechanical changes associated with the extent of necrosis and the stem alignment. Our results indicate that stress distribution near the bone-cement interface increased with expansion of the necrosis. The maximum stress on the prosthesis was decreased with stem angles ranging from 130° to 140°. The peak stress of cement increased as the stem angle became varus. This study indicates that resurfacing arthroplasty will have adverse biomechanical effects when there is a large extent of osteonecrosis and excessive varus or valgus implantation of the prosthesis.
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Affiliation(s)
- Daigo Sakagoshi
- Department of Orthopaedics Surgery, School of Medichine, Kanazawa University, Kanazawa, Japan
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39
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Smith TO, Nichols R, Donell ST, Hing CB. The clinical and radiological outcomes of hip resurfacing versus total hip arthroplasty: a meta-analysis and systematic review. Acta Orthop 2010; 81:684-95. [PMID: 21067432 PMCID: PMC3216078 DOI: 10.3109/17453674.2010.533933] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND AND PURPOSE Hip resurfacing (HRS) procedures have gained increasing popularity for younger, higher-demand patients with degenerative hip pathologies. However, with concerns regarding revision rates and possible adverse metal hypersensitivity reactions with metal-on-metal articulations, some authors have questioned the hypothesized superiority of hip resurfacing over total hip arthroplasty (THA). In this meta-analysis, we compared the clinical and radiological outcomes and complication rates of these 2 procedures. METHODS A systematic review was undertaken of all published (Medline, CINAHL, AMED, EMBASE) and unpublished or gray literature research databases up to January 2010. Clinical and radiological outcomes as well as complications of HRS were compared to those of THA using risk ratio, mean difference, and standardized mean difference statistics. Studies were critically appraised using the CASP appraisal tool. RESULTS 46 studies were identified from 1,124 citations. These included 3,799 HRSs and 3,282 THAs. On meta-analysis, functional outcomes for subjects following HRS were better than or the same as for subjects with a THA, but there were statistically significantly greater incidences of heterotopic ossification, aseptic loosening, and revision surgery with HRS compared to THA. The evidence base showed a number of methodological inadequacies such as the limited use of power calculations and poor or absent blinding of both patients and assessors, possibly giving rise to assessor bias. INTERPRETATION On the basis of the current evidence base, HRS may have better functional outcomes than THA, but the increased risks of heterotopic ossification, aseptic loosening, and revision surgery following HRS indicate that THA is superior in terms of implant survival.
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Affiliation(s)
- Toby O Smith
- Faculty of Health, University of East Anglia, Norwich
| | - Rachel Nichols
- Physiotherapy Department, Dereham Hospital, Norfolk PCT, Norwich
| | - Simon T Donell
- Institute of Orthopaedics, Norfolk and Norwich University Hospital, Norwich
| | - Caroline B Hing
- Department of Trauma and Orthopaedics, St. George's Hospital, London, UK
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40
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Smolders JMH, Hol A, Rijnders T, van Susante JLC. Changes in bone mineral density in the proximal femur after hip resurfacing and uncemented total hip replacement. ACTA ACUST UNITED AC 2010; 92:1509-14. [DOI: 10.1302/0301-620x.92b11.24785] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p < 0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery.
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Affiliation(s)
| | - A. Hol
- Department of Orthopaedics
| | - T. Rijnders
- Department of Nuclear Medicine, Rijnstate Hospital, Postbox 9555, 6800 TA Arnhem, Netherlands
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41
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Zhang W, Titze M, Cappi B, Wirtz DC, Telle R, Fischer H. Improved mechanical long-term reliability of hip resurfacing prostheses by using silicon nitride. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:3049-3057. [PMID: 20725769 DOI: 10.1007/s10856-010-4144-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 08/03/2010] [Indexed: 05/29/2023]
Abstract
Although ceramic prostheses have been successfully used in conventional total hip arthroplasty (THA) for many decades, ceramic materials have not yet been applied for hip resurfacing (HR) surgeries. The objective of this study is to investigate the mechanical reliability of silicon nitride as a new ceramic material in HR prostheses. A finite element analysis (FEA) was performed to study the effects of two different designs of prostheses on the stress distribution in the femur-neck area. A metallic (cobalt-chromium-alloy) Birmingham hip resurfacing (BHR) prosthesis and our newly designed ceramic (silicon nitride) HR prosthesis were hereby compared. The stresses induced by physiologically loading the femur bone with an implant were calculated and compared with the corresponding stresses for the healthy, intact femur bone. Here, we found stress distributions in the femur bone with the implanted silicon nitride HR prosthesis which were similar to those of healthy, intact femur bone. The lifetime predictions showed that silicon nitride is indeed mechanically reliable and, thus, is ideal for HR prostheses. Moreover, we conclude that the FEA and corresponded post-processing can help us to evaluate a new ceramic material and a specific new implant design with respect to the mechanical reliability before clinical application.
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Affiliation(s)
- Wen Zhang
- Department of Ceramics and Refractory Materials, RWTH Aachen University, Mauerstrasse 5, 52064 Aachen, Germany.
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42
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Pal B, Gupta S, New AMR. Influence of the change in stem length on the load transfer and bone remodelling for a cemented resurfaced femur. J Biomech 2010; 43:2908-14. [PMID: 20728891 DOI: 10.1016/j.jbiomech.2010.07.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 07/15/2010] [Accepted: 07/16/2010] [Indexed: 11/28/2022]
Affiliation(s)
- Bidyut Pal
- Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur, Kharagpur 721 302, West Bengal, India
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43
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Martelli S, Taddei F, Cristofolini L, Gill HS, Viceconti M. Extensive Risk Analysis of Mechanical Failure for an Epiphyseal Hip Prothesis: A Combined Numerical—Experimental Approach. Proc Inst Mech Eng H 2010; 225:126-40. [DOI: 10.1243/09544119jeim728] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
There has been recent renewed interest in proximal femur epiphyseal replacement as an alternative to conventional total hip replacement. In many branches of engineering, risk analysis has proved to be an efficient tool for avoiding premature failures of innovative devices. An extensive risk analysis procedure has been developed for epiphyseal hip prostheses and the predictions of this method have been compared to the known clinical outcomes of a well-established contemporary design, namely hip resurfacing devices. Clinical scenarios leading to revision (i.e. loosening, neck fracture and failure of the prosthetic component) were associated with potential failure modes (i.e. overload, fatigue, wear, fibrotic tissue differentiation and bone remodelling). Driving parameters of the corresponding failure mode were identified together with their safe thresholds. For each failure mode, a failure criterion was identified and studied under the most relevant physiological loading conditions. All failure modes were investigated with the most suitable investigation tool, either numerical or experimental. Results showed a low risk for each failure scenario either in the immediate postoperative period or in the long term. These findings are in agreement with those reported by the majority of clinical studies for correctly implanted devices. Although further work is needed to confirm the predictions of this method, it was concluded that the proposed risk analysis procedure has the potential to increase the efficacy of preclinical validation protocols for new epiphyseal replacement devices.
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Affiliation(s)
- S Martelli
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - F Taddei
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - L Cristofolini
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Bologna, Italy
- Engineering Faculty, University of Bologna, Italy
| | - H S Gill
- Nuffield Department Of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, UK
| | - M Viceconti
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Bologna, Italy
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44
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Dabirrahmani D, Hogg M, Kohan L, Gillies M. Primary and long-term stability of a short-stem hip implant. Proc Inst Mech Eng H 2010; 224:1109-19. [DOI: 10.1243/09544119jeim704] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The new generation short-stem hip implants are designed to encourage physiological-like loading, to minimize stress—strain shielding and therefore implant loosening in the long term. As yet there are no long-term clinical studies available to prove the benefits of these short-stem implants. Owing to this lack of clinical data, numerical simulation may be used as a predictor of longer term behaviour. This finite element study predicted both the primary stability and long-term stability of a short-stem implant. The primary implant stability was evaluated in terms of interface micromotion. This study found primary stability to fall within the critical threshold for osseointegration to occur. Longer term stability was evaluated using a strain-adaptive bone remodelling algorithm to predict the long-term behaviour of the bone in terms of bone mineral density (BMD) changes. No BMD loss was observed in the classical Gruen zones 1 and 7 and bone remodelling patterns were comparable with hip resurfacing results in the literature.
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Affiliation(s)
| | - M Hogg
- Medical Device Research Australia, Sydney, Australia
| | - L Kohan
- Joint Orthopaedics Centre, Sydney, Australia
| | - M Gillies
- Medical Device Research Australia, Sydney, Australia
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45
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Pal B, Gupta S, New AM. Design considerations for ceramic resurfaced femoral head: effect of interface characteristics on failure mechanisms. Comput Methods Biomech Biomed Engin 2010; 13:143-55. [DOI: 10.1080/10255840903067064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Taddei F, Martelli S, Gill HS, Cristofolini L, Viceconti M. Finite Element Modeling of Resurfacing Hip Prosthesis: Estimation of Accuracy Through Experimental Validation. J Biomech Eng 2010; 132:021002. [DOI: 10.1115/1.4000065] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Metal-on-metal hip resurfacing is becoming increasingly popular, and a number of new devices have been recently introduced that, in the short term, appear to have satisfactory outcome but many questions are still open on the biomechanics of the resurfaced femur. This could be investigated by means of finite element analysis, but, in order to be effective in discerning potential critical conditions, the accuracy of the models’ predictions should be assessed. The major goal of this study was to validate, through a combined experimental-numerical study, a finite element modeling procedure for the simulation of resurfaced femurs. In addition, a preliminary biomechanical analysis of the changes induced in the femoral neck biomechanics by the presence of the device was performed, under a physiologic range of hip joint reaction directions. For this purpose, in vitro tests and a finite element model based on the same specimen were developed using a cadaver femur. The study focused on the Conserve Plus, one of the most common contemporary resurfacing designs. Five loading configurations were identified to correspond to the extremes of physiological directions for the hip joint. The agreement between experimental measurements and numerical predictions was good both in the prediction of the femoral strains (R2>0.9), and in the prosthesis micromotions (error<20 μm), giving confidence in the model predictions. The preliminary biomechanical analysis indicated that the strains in the femoral neck are moderately affected by the presence of the prosthesis, apart from localized strain increments that can be considerable, always predicted near the stem. Low micromotions and contact pressure were predicted, suggesting a good stability of the prosthesis. The model accuracy was good in the prediction of the femoral strains and moderately good in the prediction of the bone-prosthesis micromovements. Although the investigated loading conditions were not completely physiological, the preliminary biomechanical analysis showed relatively small changes for the proximal femur after implantation. This validated model can support realistic simulations to examine physiological load configurations and the effects of variations in prosthesis design and implantation technique.
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Affiliation(s)
- Fulvia Taddei
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
| | - Saulo Martelli
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy; Facoltà di Ingegneria, Università degli Studi di Bologna, Viale Risorgimento 2, 40136 Bologna, Italy
| | - Harinderjit Singh Gill
- Nuffield Department of Orthopaedic Surgery, University of Oxford, Nuffield Orthopaedic Centre, Oxford, UK
| | - Luca Cristofolini
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy; Facoltà di Ingegneria, Università degli Studi di Bologna, Viale Risorgimento 2, 40136 Bologna, Italy
| | - Marco Viceconti
- Laboratorio di Tecnologia Medica, Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy
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Dickinson AS, Taylor AC, Jeffers JRT, Browne M. Performance of the resurfaced hip. Part 2: The influence of prosthesis stem design on remodelling and fracture of the femoral neck. Proc Inst Mech Eng H 2009; 224:841-51. [DOI: 10.1243/09544119jeim680] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hip resurfacing is a popular treatment for osteoarthritis in young, active patients. Previous studies have shown that occasional failures — femoral neck fracture and implant loosening, possibly associated with bone adaptation — are affected by prosthesis sizing and positioning, in addition to patient and surgical factors. With the aim of improving tolerance to surgical variation, finite element modelling was used to indicate the effects of prosthesis metaphyseal stem design on bone remodelling and femoral neck fracture, with a range of implant orientations. The analysis suggested that the intact femoral neck strength in trauma could be maintained across a wider range of varus—valgus orientations for short-stemmed and stemless prostheses. Furthermore, the extent of periprosthetic bone remodelling was lower for the short-stemmed implant, with slightly reduced stress shielding and considerably reduced densification around the stem, potentially preventing further progressive proximal stress shielding. The study suggests that a short-stemmed resurfacing head offers improved tolerance to misalignment and remodelling stimulus over traditional designs. While femoral neck fracture and implant loosening are multifactorial, biomechanical factors are of clear importance to the clinical outcome, so this may reduce the risk for patients at the edge of the indications for hip resurfacing, or shorten the surgical learning curve.
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Affiliation(s)
- A S Dickinson
- Bioengineering Science Research Group, University of Southampton, Southampton, UK
| | - A C Taylor
- Finsbury Development Ltd, Leatherhead, Surrey, UK
| | | | - M Browne
- Bioengineering Science Research Group, University of Southampton, Southampton, UK
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Dickinson AS, Taylor AC, Browne M. Performance of the resurfaced hip. Part 1: The influence of the prosthesis size and positioning on the remodelling and fracture of the femoral neck. Proc Inst Mech Eng H 2009; 224:427-39. [DOI: 10.1243/09544119jeim679] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hip resurfacing is an established treatment for osteoarthritis in young active patients. Failure modes include femoral neck fracture and prosthesis loosening, which may be associated with medium-term bone adaptation, including femoral neck narrowing and densification around the prosthesis stem. Finite element modelling was used to indicate the effects of prosthesis sizing and positioning on the bone remodelling and fracture strength under a range of normal and traumatic loads, with the aim of understanding these failure modes better. The simulations predicted increased superior femoral neck stress shielding in young patients with small prostheses, which required shortening of the femoral neck to give an acceptable implant—bone interface. However, with a larger prosthesis, natural femoral head centre recreation in the implanted state was possible; therefore stress shielding was restricted to the prosthesis interior, and its extent was less sensitive to prosthesis orientation. With valgus orientation, the implanted neck strength was, at worst, within 3 per cent of its intact strength. The study suggests that femoral neck narrowing may be linked to a reduction in the horizontal femoral offset, occurring if the prosthesis is excessively undersized. As such, hip resurfacing should aim to reproduce the natural femoral head centre, and, for valgus prosthesis orientation, to avoid femoral neck fracture.
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Affiliation(s)
- A S Dickinson
- Bioengineering Science Research Group, University of Southampton, Highfield, Southampton, UK
| | - A C Taylor
- Finsbury Development Ltd, Leatherhead, Surrey, UK
| | - M Browne
- Bioengineering Science Research Group, University of Southampton, Highfield, Southampton, UK
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Pal B, Gupta S, New AM. A numerical study of failure mechanisms in the cemented resurfaced femur: effects of interface characteristics and bone remodelling. Proc Inst Mech Eng H 2009; 223:471-84. [PMID: 19499837 DOI: 10.1243/09544119jeim488] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Failure mechanisms of the resurfaced femoral head include femoral neck fracture in the short-term and stress shielding and implant loosening in the long-term. In this study, finite element simulations of the resurfaced femur considering a debonded implant-cement interface, variable stem-bone interface conditions, and bone remodelling were used to study load transfer within the resurfaced femur and to investigate its relationship with known failure mechanisms. Realistic three-dimensional finite element models of an intact and resurfaced femur were used. Various conditions at the interface between the stem of the prosthesis and the bone were considered. Loading conditions included normal walking and stair climbing. For all stem-bone contact conditions, the tensile stresses in the cement mantle varied between 1 MPa and 5.4 MPa, except near the distal rim of the resurfacing component where they reached 5.4-7MPa. In the case of full stem-bone contact, high von Mises stresses (114-121MPa) were generated in the implant at the stem-cup junction. These stresses were considerably reduced (maximum von Mises stress, 76 MPa) where a gap was present at the stem-bone interface. Resurfacing led to strain shielding of the bone of the femoral head (20-75 per cent strain reductions) and periprosthetic bone resorption (50-80 per cent bone density reductions) for all interface stem-bone contact conditions. In the lateral femoral head and the proximal femoral shaft around the trochantric region, bone density reductions varied between 10 per cent and 50 per cent. Bone apposition was observed in the inferior-medial part of the femoral head and proximal femoral neck region. For full stem-bone contact, more load was transferred through the stem to the surrounding bone, exacerbating strain shielding. Although femoral hip resurfacing conserves bone stock at the primary operation, strain shielding and periprosthetic bone resorption might lead to eventual loosening over time. Post-operatively, the resurfacing procedure generated elevated strains (0.50-0.75 per cent strain) in the proximal femoral neck-component junction irrespective of the variation in interface conditions, indicating an initial risk of femoral neck fracture. Subsequent to bone remodelling, this strain concentration was considerably reduced (0.35-0.50 per cent strain), lowering the risk of neck fracture. In order to reduce the potential risk of neck fracture, patients should avoid activities which might induce high loading of the hip during the early post-operative period to allow the bone around the proximal femoral neck to remodel and heal.
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Affiliation(s)
- B Pal
- Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur, Kharagpur, West Bengal 721302, India
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Deuel CR, Jamali AA, Stover SM, Hazelwood SJ. Alterations in femoral strain following hip resurfacing and total hip replacement. ACTA ACUST UNITED AC 2009; 91:124-30. [PMID: 19092017 DOI: 10.1302/0301-620x.91b1.20789] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Bone surface strains were measured in cadaver femora during loading prior to and after resurfacing of the hip and total hip replacement using an uncemented, tapered femoral component. In vitro loading simulated the single-leg stance phase during walking. Strains were measured on the medial and the lateral sides of the proximal aspect and the mid-diaphysis of the femur. Bone surface strains following femoral resurfacing were similar to those in the native femur, except for proximal shear strains, which were significantly less than those in the native femur. Proximomedial strains following total hip replacement were significantly less than those in the native and the resurfaced femur. These results are consistent with previous clinical evidence of bone loss after total hip replacement, and provide support for claims of bone preservation after resurfacing arthroplasty of the hip.
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Affiliation(s)
- C R Deuel
- Department of Orthopaedic Surgery, Univesity of California Davis Medical Center, Sacramento, California 95817, USA
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