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Siverino C, Tirkkonen-Rajasalo L, Freitag L, Günther C, Thompson K, Styger U, Zeiter S, Eglin D, Stadelmann VA. Restoring implant fixation strength in osteoporotic bone with a hydrogel locally delivering zoledronic acid and bone morphogenetic protein 2. A longitudinal in vivo microCT study in rats. Bone 2024; 180:117011. [PMID: 38176642 DOI: 10.1016/j.bone.2023.117011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/06/2024]
Abstract
Osteoporosis poses a major public health challenge, and it is characterized by low bone mass, deterioration of the microarchitecture of bone tissue, causing a consequent increase in bone fragility and susceptibility to fractures and complicating bone fixation, particularly screw implantation. In the present study, our aim was to improve implant stability in osteoporotic bone using a thermoresponsive hyaluronan hydrogel (HA-pNIPAM) to locally deliver the bisphosphonate zoledronic acid (ZOL) to prevent bone resorption and bone morphogenetic protein 2 (BMP2) to induce bone formation. Adult female Wistar rats (n = 36) were divided into 2 treatment groups: one group of SHAM-operated animals and another group that received an ovariectomy (OVX) to induce an osteoporotic state. All animals received a polyetheretherketone (PEEK) screw in the proximal tibia. In addition, subgroups of SHAM or OVX animals received either the HA-pNIPAM hydrogel without or with ZOL/BMP2, placed into the defect site prior to screw implantation. Periprosthetic bone and implant fixation were monitored using longitudinal in vivo microCT scanning post-operatively and at 3, 6, 9, 14, 20 and 28 days. Histological assessment was performed post-mortem. Our data showed that pure hydrogel has no impact of implant fixation The ZOL/BMP2-hydrogel significantly increased bone-implant contact and peri-implant bone fraction, primarily through reduced resorption. STATEMENT OF CLINICAL SIGNIFICANCE: Local delivery of ZOL and BMP2 using a biocompatible hydrogel improved implant stability in osteoporotic bone. This approach could constitute a potent alternative to systemic drug administration and may be useful in avoiding implant loosening in clinical settings.
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Affiliation(s)
| | | | | | | | | | | | | | - David Eglin
- AO Research Institute Davos, Davos, Switzerland; Mines Saint-Étienne, Univ Jean Monnet, INSERM, U1059 Sainbiose, Saint-Étienne, France.
| | - Vincent A Stadelmann
- AO Research Institute Davos, Davos, Switzerland; Schulthess Klinik, Department of Research and Development, Zürich, Switzerland.
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2
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Magré J, Willemsen K, Kolken HMA, Zadpoor AA, Vogely HC, van der Wal BCH, Weinans H. Deformable titanium for acetabular revision surgery: a proof of concept. 3D Print Med 2023; 9:16. [PMID: 37294496 DOI: 10.1186/s41205-023-00177-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/22/2023] [Indexed: 06/10/2023] Open
Abstract
Custom-made triflange acetabular implants are increasingly used in complex revision surgery where supporting bone stock is diminished. In most cases these triflange cups induce stress-shielding. A new concept for the triflange is introduced that uses deformable porous titanium to redirect forces from the acetabular rim to the bone stock behind the implant and thereby reduces further stress-shielding. This concept is tested for deformability and primary stability.Three different designs of highly porous titanium cylinders were tested under compression to determine their mechanical properties. The most promising design was used to design five acetabular implants either by incorporating a deformable layer at the back of the implant or by adding a separate generic deformable mesh behind the implant. All implants were inserted into sawbones with acetabular defects followed by a cyclic compression test of 1800N for 1000 cycles.The design with a cell size of 4 mm and 0.2 mm strut thickness performed the best and was applied for the design of the acetabular implants. An immediate primary fixation was realized in all three implants with an incorporated deformable layer. One of the two implants with a separate deformable mesh needed fixation with screws. Cyclic tests revealed an average additional implant subsidence of 0.25 mm that occurred in the first 1000 cycles with minimal further subsidence thereafter.It is possible to realize primary implant fixation and stability in simulated large acetabular revision surgery using a deformable titanium layer behind the cup. Additional research is needed for further implementation of such implants in the clinic.
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Affiliation(s)
- J Magré
- Department of Orthopedics, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
- 3D Lab, Division of Surgical Specialties, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands.
| | - K Willemsen
- Department of Orthopedics, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- 3D Lab, Division of Surgical Specialties, University Medical Center Utrecht, 3584 CX, Utrecht, The Netherlands
| | - H M A Kolken
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD, Delft, The Netherlands
| | - A A Zadpoor
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD, Delft, The Netherlands
| | - H C Vogely
- Department of Orthopedics, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - B C H van der Wal
- Department of Orthopedics, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - H Weinans
- Department of Orthopedics, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD, Delft, The Netherlands
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Cox ZC, Engstrom SM, Shinar AA, Polkowski GG, Mason JB, Martin JR. Is cement mantle thickness a primary cause of aseptic tibial loosening following primary total knee arthroplasty? Knee 2023; 40:305-312. [PMID: 36592499 DOI: 10.1016/j.knee.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 11/27/2022] [Accepted: 12/13/2022] [Indexed: 01/01/2023]
Abstract
BACKGROUND Aseptic tibial loosening following primary total knee replacement is one of the leading causes of long-term failure. Cement mantle thickness has been implicated as a source of aseptic tibial loosening. Therefore, the following study was designed to determine (1) what is the cement mantle thickness in patients that develop aseptic tibial loosening, and (2) is there a difference in cement mantle thickness based on the interface of failure? METHOD This retrospective cohort included 216 patients revised for aseptic tibial loosening. Patient demographics, operative data, and clinical outcomes were recorded. A preoperative radiographic assessment was performed to determine the interface of failure and the thickness of the cement mantle using the Knee Society Radiographic Evaluation System zones. RESULTS The average patient age was 65 years and body mass index was 33.7 kg/m2. 203 patients demonstrated radiographic failure at the implant-cement interface and 13 patients demonstrated failure at the cement-bone interface. The average cement mantle thickness of each radiographic zone for the entire cohort on the AP and lateral views was 4.4 and 4.5 mm, respectively. The average cement mantle thickness of patients that developed failure at the implant-cement interface was significantly greater than patients that failed at the cement-bone interface in each radiographic zone (p < 0.001). CONCLUSIONS Patients that develop implant loosening at the cement-bone interface were noted to have a significantly decreased cement mantle compared to patients that failed at the implant-cement interface. Methods for decreasing tibial implant loosening should likely focus on improving the fixation at the implant-cement interface.
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Affiliation(s)
- Zach C Cox
- OrthoCarolina Hip and Knee Center, Charlotte, NC, 250 N Caswell Rd Suit 200A, Charlotte, NC 28207, USA
| | - Stephen M Engstrom
- Vanderbilt University Medical Center, 1215 21st Ave S Suite 4200, Nashville, TN 37232, USA
| | - Andrew A Shinar
- Vanderbilt University Medical Center, 1215 21st Ave S Suite 4200, Nashville, TN 37232, USA
| | - Gregory G Polkowski
- Vanderbilt University Medical Center, 1215 21st Ave S Suite 4200, Nashville, TN 37232, USA
| | - J Bohannon Mason
- OrthoCarolina Hip and Knee Center, Charlotte, NC, 250 N Caswell Rd Suit 200A, Charlotte, NC 28207, USA
| | - J Ryan Martin
- Vanderbilt University Medical Center, 1215 21st Ave S Suite 4200, Nashville, TN 37232, USA.
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4
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Abstract
Hip arthroplasty revision management can range from simple procedures using standard implants to complex surgical interventions requiring the combined use of revision cups, metal augments, bone grafts, and antiprotrusio cages. The adequate restoration of biomechanics and function of the hip joint with reconstruction of the original center of rotation can be challenging. We present an overview of various available techniques with the associated implant and anchoring strategies and the respective clinical results depending on the acetabular defect situation.
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Affiliation(s)
- Maik Stiehler
- UniversitätsCentrum für Orthopädie, Unfall- & Plastische Chirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, Haus 29, 01307, Dresden, Deutschland.
| | - Klaus-Peter Günther
- UniversitätsCentrum für Orthopädie, Unfall- & Plastische Chirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, Haus 29, 01307, Dresden, Deutschland
| | - Jens Goronzy
- UniversitätsCentrum für Orthopädie, Unfall- & Plastische Chirurgie, Universitätsklinikum Carl Gustav Carus, TU Dresden, Fetscherstr. 74, Haus 29, 01307, Dresden, Deutschland
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5
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Abstract
Bone cement has been used in spinal surgery for as long as 50 years. In contemporary spinal surgery, cement augmentation of fractured osteoporotic vertebrae in the form of vertebroplasty/kyphoplasty as well as cement augmentation of pedicle screws in instrumented procedures of any etiology are established as standard procedures. Both procedures are very effective, although the benefits of vertebroplasty/kyphoplasty procedures have been controversially discussed in the past. Overall, complications rarely occur. The most relevant complication is cement leakage, which is asymptomatic in the majority of cases but in the worst case might lead to neurological deficits, embolic events and even circulatory collapse. Prevention of cement leakage is therefore crucial. Risk factors for cement leakage and preventive measures are presented in a comprehensive review based on the available literature.
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Affiliation(s)
- Philipp Schleicher
- Zentrum für Wirbelsäulenchirurgie und Neurotraumatologie, BG Unfallklinik Frankfurt am Main gGmbH, Friedberger Landstr. 430, 60389, Frankfurt, Deutschland.
| | - Alexander Wengert
- Zentrum für Wirbelsäulenchirurgie und Neurotraumatologie, BG Unfallklinik Frankfurt am Main gGmbH, Friedberger Landstr. 430, 60389, Frankfurt, Deutschland
| | - Jonathan Neuhoff
- Zentrum für Wirbelsäulenchirurgie und Neurotraumatologie, BG Unfallklinik Frankfurt am Main gGmbH, Friedberger Landstr. 430, 60389, Frankfurt, Deutschland
| | - Frank Kandziora
- Zentrum für Wirbelsäulenchirurgie und Neurotraumatologie, BG Unfallklinik Frankfurt am Main gGmbH, Friedberger Landstr. 430, 60389, Frankfurt, Deutschland
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Laende EK, Mills Flemming J, Astephen Wilson JL, Cantoni E, Dunbar MJ. The associations of implant and patient factors with migration of the tibial component differ by sex : a radiostereometric study on more than 400 total knee arthroplasties. Bone Joint J 2022; 104-B:444-451. [PMID: 35360938 DOI: 10.1302/0301-620x.104b4.bjj-2021-1247.r1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AIMS Thresholds of acceptable early migration of the components in total knee arthroplasty (TKA) have traditionally ignored the effects of patient and implant factors that may influence migration. The aim of this study was to determine which of these factors are associated with overall longitudinal migration of well-fixed tibial components following TKA. METHODS Radiostereometric analysis (RSA) data over a two-year period were available for 419 successful primary TKAs (267 cemented and 152 uncemented in 257 female and 162 male patients). Longitudinal analysis of data using marginal models was performed to examine the associations of patient factors (age, sex, BMI, smoking status) and implant factors (cemented or uncemented, the size of the implant) with maximum total point motion (MTPM) migration. Analyses were also performed on subgroups based on sex and fixation. RESULTS In the overall group, only fixation was significantly associated with migration (p < 0.001). For uncemented tibial components in males, smoking was significantly associated with lower migration (p = 0.030) and BMI approached significance (p = 0.061). For females with uncemented components, smoking (p = 0.081) and age (p = 0.063) approached significance and were both associated with increased migration. The small number of self-reported smokers in this study warrants cautious interpretation and further investigation. For cemented components in females, larger sizes of tibial component were significantly associated with increased migration (p = 0.004). No factors were significant for cemented components in males. CONCLUSION The migration of uncemented tibial components was more sensitive to patient factors than cemented implants. These differences were not consistent by sex, suggesting that it may be of value to evaluate female and male patients separately following TKA. Cite this article: Bone Joint J 2022;104-B(4):444-451.
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Affiliation(s)
- Elise K Laende
- School of Biomedical Engineering, Dalhousie University, Halifax, Canada.,Division of Orthopaedics, Department of Surgery, Dalhousie University, Halifax, Canada.,Queen Elizabeth II Health Sciences Centre, Nova Scotia Health Authority, Halifax, Canada
| | | | - Janie L Astephen Wilson
- School of Biomedical Engineering, Dalhousie University, Halifax, Canada.,Department of Surgery, Dalhousie University, Halifax, Canada
| | - Eva Cantoni
- Research Center for Statistics and Geneva School of Economics and Management, University of Geneva, Geneva, Switzerland
| | - Michael J Dunbar
- School of Biomedical Engineering, Dalhousie University, Halifax, Canada.,Division of Orthopaedics, Department of Surgery, Dalhousie University, Halifax, Canada.,Queen Elizabeth II Health Sciences Centre, Nova Scotia Health Authority, Halifax, Canada
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7
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Grifka J, Baier C, Maderbacher G. Improved femoral component rotation in total knee arthroplasty: an anatomical study with optimized gap balancing. Arch Orthop Trauma Surg 2021; 141:1669-75. [PMID: 32757034 DOI: 10.1007/s00402-020-03557-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 07/20/2020] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Surgically balanced total knee arthroplasties have shown improved functional and clinical outcomes. Two different alignment methods have been proposed, the measured resection technique which uses femoral landmarks on the one hand and the ligament balanced technique which uses spreaders on the other. As anatomical landmarks also vary widely, with regards to the tibial cut irrespective of the collateral ligaments, we hypothesized that anatomical landmarks are not suitable for ideal femoral component rotational alignment. MATERIALS AND METHODS Ten cadaveric bilateral knees underwent TKA using a navigational device and a double tensiometer. By means of the navigational device, flexion gaps were balanced by femoral component size, rotation and flexion until a symmetric flexion and extension gap was obtained. Acquired femoral component rotation was compared to femoral landmarks (Whiteside Line, posterior condylar line and trans-epicondylar line). RESULTS Using the Whiteside line, the posterior condylar line and the surgical trans-epicondylar line to identify femoral component rotation did not balance the flexion gap as well as navigation. Depending on the parameter, deviations in femoral rotation of up to 6° were observed compared to the gap balancing technique. Furthermore, large deviations between these landmarks were observed. CONCLUSION Based on this study flexion gap balancing can be better optimized using ligament balancing technique. As this technique is highly dependent on the proximal tibial cut, we do recommend the use of navigational devices, which additionally assure a neutral leg alignment.
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8
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Abstract
The anti-resorptive properties of bisphosphonates have been explored to manage several conditions that traditionally have required a surgical solution. In osteonecrosis, their use is predicated on the principle that bone collapse occurs during the revascularisation phase of the disease. If the associated resorptive activity were modulated, the resultant preserved joint architecture may improve clinical outcome and reduce the need for joint replacement. Pre-clinical and small-scale clinical studies have given non-conclusive support for this principle. Adequately powered clinical trials with relevant long-term endpoints are still required to firmly clarify the clinical efficacy of this treatment. Several clinical studies have shown that bisphosphonates can reduce periprosthetic bone loss and, in some situations, enhance implant fixation in the early period after joint replacement. This may be advantageous in settings where osseointegration is problematic. However, the ultimate goals of their use in joint replacement has been to reduce the incidence of late periprosthetic inflammatory osteolysis, the main cause of prosthesis failure. Population-based observational studies have associated bisphosphonate use with a lower incidence of revision surgery, supported by pre-clinical data. However, clinical trials have, to date, failed to demonstrate any efficacy for the human disease. The timing of bisphosphonate administration for secondary prevention after acute osteoporotic fracture has been subject to extensive investigation, with pre-clinical studies showing increased callus formation but decreased remodelling and no effect on the restoration of mechanical integrity of bone. Meta-analysis of clinical trial data indicates that early administration of bisphosphonate after acute fracture does not adversely affect fracture union, pain or functional outcomes. Finally, bisphosphonates have also been explored as a treatment for complex regional pain syndrome type-I. A recent meta-analysis has shown a beneficial effect on visual analogue scale pain scores, but an increase in mild adverse events.
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Affiliation(s)
- J Mark Wilkinson
- Department of Oncology and Metabolism, University of Sheffield, United Kingdom.
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9
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Messer-Hannemann P, Weyer H, Campbell GM, Morlock MM. Time-dependent Viscoelastic Response of Acetabular Bone and Implant Seating during Dynamic Implantation of Press-fit Cups. Med Eng Phys 2020; 81:68-76. [PMID: 32507677 DOI: 10.1016/j.medengphy.2020.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 04/04/2020] [Accepted: 05/13/2020] [Indexed: 11/24/2022]
Abstract
Deformation of an acetabular cup implant during cementless implantation is indicative of the radial compressive forces, and such of the initial implant fixation strength. Stress relaxation in the surrounding bone tissue following implantation could reduce the deformation of the cup and thus primary implant fixation. The aim of this study was therefore to determine the early shape change of the implanted cup immediately after implantation with different press-fit levels and whether recording the force during cup impaction can be used to estimate initial cup fixation. Cup implantations into porcine acetabulae (n=10) were performed using a drop tower. The force induced by the drop weight and cup seating after each impact was recorded. Deformation of the implanted cup was determined with strain gauges over a period of 10min. Lever-out torques were measured to assess the initial fixation strength. Stress relaxation in the bone caused a reduction in cup deformation of 13.52±4.06% after 1min and 29.34±5.11% after 10min. The fixation strength increased with a higher force magnitude during impaction (Rs2=0.810, p=0.037). Reduction of the radial compressive forces due to stress relaxation of the surrounding bone should be considered during press-fit cup implantation in order to compensate for the reduced fixation strength over time. In addition, recording the implantation force could help to estimate initial fixation strength.
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10
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Garaycochea O, Manrique-Huarte R, Vigliano M, Ferrán de la Cierva S, Manrique M. Sculpting the temporal bone: an easy reversible cochlear implant electro-array stabilization technique. Eur Arch Otorhinolaryngol 2020; 277:1645-1650. [PMID: 32162058 DOI: 10.1007/s00405-020-05895-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/28/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE Since the beginning of cochlear implant (CI) surgery, several techniques to fixate the electrode array at the cochleostomy and stabilize it have been described; however, most techniques use autologous tissues such as fascia, muscle, fat or fibrin glue. We describe a new surgical technique aimed to stabilize the electrode array of a CI without using autologous tissues or artificial materials. MATERIALS AND METHODS The surgical technique described consists in creating three stabilizing channels in the temporal bone for the electrode array. The first one in a partially opened aditus, the second one in a partially preserved Koerner's septum (KS) and the last one in the sinodural angle. The procedure was performed in five human temporal bones using a straight array; a radiography was made to confirm the correct placement of the electrode array and afterwards all temporal bones were shaken using a Titramax 1000 platform. The correct placement of the array post-shaking was then confirmed using the microscope and another radiography. RESULTS No migration of the electrodes outside the cochlea was observed. The CI cable remained in the same position at the aditus and the KS in all the temporal bones. In three cases (60%), the electrode array moved away from the groove carved in the sinodural angle. CONCLUSIONS The new surgical technique described stabilizes the electrode array using the temporal bone's normal anatomy, preserving the middle ear spaces, facilitating the ulterior explantation and reimplantation if necessary, and may reduce cost and surgery time.
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Affiliation(s)
- Octavio Garaycochea
- Department of Otorhinolaryngology, Clinica Universitaria de Navarra, University of Navarra, Avenida Pío XII 36, 31008, Pamplona, Spain.
| | - Raquel Manrique-Huarte
- Department of Otorhinolaryngology, Clinica Universitaria de Navarra, University of Navarra, Avenida Pío XII 36, 31008, Pamplona, Spain
| | - Melisa Vigliano
- Department of Otorhinolaryngology, Clinica Universitaria de Navarra, University of Navarra, Avenida Pío XII 36, 31008, Pamplona, Spain
| | - Sol Ferrán de la Cierva
- Department of Otorhinolaryngology, Clinica Universitaria de Navarra, University of Navarra, Avenida Pío XII 36, 31008, Pamplona, Spain
| | - Manuel Manrique
- Department of Otorhinolaryngology, Clinica Universitaria de Navarra, University of Navarra, Avenida Pío XII 36, 31008, Pamplona, Spain
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11
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Carpenter RD, Klosterhoff BS, Torstrick FB, Foley KT, Burkus JK, Lee CSD, Gall K, Guldberg RE, Safranski DL. Effect of porous orthopaedic implant material and structure on load sharing with simulated bone ingrowth: A finite element analysis comparing titanium and PEEK. J Mech Behav Biomed Mater 2019; 80:68-76. [PMID: 29414477 DOI: 10.1016/j.jmbbm.2018.01.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 12/29/2022]
Abstract
Osseointegration of load-bearing orthopaedic implants, including interbody fusion devices, is critical to long-term biomechanical functionality. Mechanical loads are a key regulator of bone tissue remodeling and maintenance, and stress-shielding due to metal orthopaedic implants being much stiffer than bone has been implicated in clinical observations of long-term bone loss in tissue adjacent to implants. Porous features that accommodate bone ingrowth have improved implant fixation in the short term, but long-term retrieval studies have sometimes demonstrated limited, superficial ingrowth into the pore layer of metal implants and aseptic loosening remains a problem for a subset of patients. Polyether-ether-ketone (PEEK) is a widely used orthopaedic material with an elastic modulus more similar to bone than metals, and a manufacturing process to form porous PEEK was recently developed to allow bone ingrowth while preserving strength for load-bearing applications. To investigate the biomechanical implications of porous PEEK compared to porous metals, we analyzed finite element (FE) models of the pore structure-bone interface using two clinically available implants with high (> 60%) porosity, one being constructed from PEEK and the other from electron beam 3D-printed titanium (Ti). The objective of this study was to investigate how porous PEEK and porous Ti mechanical properties affect load sharing with bone within the porous architectures over time. Porous PEEK substantially increased the load share transferred to ingrown bone compared to porous Ti under compression (i.e. at 4 weeks: PEEK = 66%; Ti = 13%), tension (PEEK = 71%; Ti = 12%), and shear (PEEK = 68%; Ti = 9%) at all time points of simulated bone ingrowth. Applying PEEK mechanical properties to the Ti implant geometry and vice versa demonstrated that the observed increases in load sharing with PEEK were primarily due to differences in intrinsic elastic modulus and not pore architecture (i.e. 4 weeks, compression: PEEK material/Ti geometry = 53%; Ti material/PEEK geometry = 12%). Additionally, local tissue energy effective strains on bone tissue adjacent to the implant under spinal load magnitudes were over two-fold higher with porous PEEK than porous Ti (i.e. 4 weeks, compression: PEEK = 784 ± 351 microstrain; Ti = 180 ± 300 microstrain; and 12 weeks, compression: PEEK = 298 ± 88 microstrain; Ti = 121 ± 49 microstrain). The higher local strains on bone tissue in the PEEK pore structure were below previously established thresholds for bone damage but in the range necessary for physiological bone maintenance and adaptation. Placing these strain magnitudes in the context of literature on bone adaptation to mechanical loads, this study suggests that porous PEEK structures may provide a more favorable mechanical environment for bone formation and maintenance under spinal load magnitudes than currently available porous 3D-printed Ti, regardless of the level of bone ingrowth.
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Affiliation(s)
- R Dana Carpenter
- Department of Mechanical Engineering, University of Colorado Denver, Denver, CO, USA.
| | - Brett S Klosterhoff
- Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, GA, USA; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - F Brennan Torstrick
- Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, GA, USA; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kevin T Foley
- Departments of Neurosurgery, Orthopaedic Surgery, and Biomedical Engineering, University of Tennessee Health Sciences Center, Memphis, TN, USA; Semmes-Murphey Neurologic & Spine Institute, Memphis, TN, USA
| | | | | | - Ken Gall
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA; Vertera Inc., Atlanta, GA, USA; MedShape Inc., Atlanta, GA, USA
| | - Robert E Guldberg
- Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, GA, USA; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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12
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Bischel OE, Nadorf J, Klein SB, Gantz S, Jakubowitz E, Kretzer JP, Arnholdt J, Seeger JB. Modular tumor prostheses: are current stem designs suitable for distal femoral reconstruction? A biomechanical implant stability analysis in Sawbones. Arch Orthop Trauma Surg 2019; 139:843-849. [PMID: 30887123 DOI: 10.1007/s00402-019-03158-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Indexed: 10/27/2022]
Abstract
INTRODUCTION High loosening rates after distal femoral replacement may be due to implant design not adapted to specific anatomic and biomechanical conditions. MATERIALS AND METHODS A modular tumor system (MUTARS®, Implantcast GmbH) was implanted with either a curved hexagonal or a straight tapered stems in eight Sawbones® in two consecutively generated bone defect (10 cm and 20 cm proximal to knee joint level). Implant-bone-interface micromotions were measured to analyze main fixation areas and to characterize the fixation pattern. RESULTS Although areas of highest relative micromotions were measured distally in all groups, areas and lengths of main fixation differed with respect to stem design and bone defect size. Regardless of these changes, overall micromotions could only be reduced with extending bone defects in case of tapered stems. CONCLUSIONS The tapered design may be favorable in larger defects whereas the hexagonal may be advantageous in defects located more distally.
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Affiliation(s)
- Oliver E Bischel
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany. .,BG Trauma Center, Ludwigshafen am Rhein, Germany.
| | - J Nadorf
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany.,Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen and Marburg (UKGM), Klinikstrasse 33, 35392, Giessen, Germany.,Project Solutions GmbH, Ludwigshafen am Rhein, Germany
| | - S B Klein
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany
| | - S Gantz
- Biometrics Consulting and Project Management, University Heidelberg, Heidelberg, Germany
| | - E Jakubowitz
- Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School, Hannover, Germany
| | - J P Kretzer
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany
| | - J Arnholdt
- Department of Orthopaedic Surgery, König-Ludwig-Haus, Julius-Maximilians-University, Brettreichstr. 11, 97074, Würzburg, Germany
| | - J B Seeger
- Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen and Marburg (UKGM), Klinikstrasse 33, 35392, Giessen, Germany
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Abstract
Background Lycopene prevents bone loss in osteopenic models. However, the role of lycopene in the success rate of dental implants under osteopenic conditions remains unknown. The aim of this study was to evaluate whether lycopene prevents delayed implant osseointegration in an ovariectomized (OVX) rat model. Methods Thirty female Sprague-Dawley rats were randomly divided into the following groups: OVX with vehicle (OVX group), OVX with lycopene (OVX + lycopene group) and sham-operated with vehicle (sham group). Twelve weeks after ovariectomy or sham operation, titanium implants were placed into the distal metaphysis of the bilateral femurs of each rat. These rats were subsequently gavaged with lycopene (50 mg/kg/day) or vehicle. After 12 weeks of gavage, all rats were sacrificed, and specimens were harvested. Sample osseointegration was evaluated by biomechanical testing, 3D micro-computed tomography (micro-CT) analysis and histomorphometric analysis. Results Compared with the OVX group, the OVX + lycopene group showed a 69.3% increase in the maximum push-out force (p < 0.01). Micro-CT data for the femurs in the OVX + lycopene group showed significantly higher bone volume, trabecular thickness and less trabecular space than did those in the OVX group. The bone area (BA) around the implant and bone contact (BC) with the implant were increased by 72.3% (p < 0.01) and 51.4% (p < 0.01) in the OVX + lycopene group, respectively, compared with those in the OVX group. There was no significant difference in the mechanical test, micro-CT scanning and histomorphometric data between the OVX + lycopene and sham groups (p > 0.05). Conclusions Lycopene improved implant osseointegration, fixation and bone formation under osteopenic conditions, suggesting that lycopene is a promising therapeutic agent to prevent delayed implant osseointegration and bone loss under osteopenic conditions.
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Affiliation(s)
- Xiaojie Li
- Department of Prosthodontics, College and Hospital of Stomatology, Guangxi Medical University, 10th Shuangyong Road, Nanning, 530021, China.
| | - Wenli Xue
- Department of Prosthodontics, College and Hospital of Stomatology, Guangxi Medical University, 10th Shuangyong Road, Nanning, 530021, China
| | - Yong Cao
- Department of Prosthodontics, College and Hospital of Stomatology, Guangxi Medical University, 10th Shuangyong Road, Nanning, 530021, China
| | - Yanming Long
- Department of Prosthodontics, College and Hospital of Stomatology, Guangxi Medical University, 10th Shuangyong Road, Nanning, 530021, China
| | - Mengsheng Xie
- Department of Prosthodontics, College and Hospital of Stomatology, Guangxi Medical University, 10th Shuangyong Road, Nanning, 530021, China
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14
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Varga P, Inzana JA, Gueorguiev B, Südkamp NP, Windolf M. Validated computational framework for efficient systematic evaluation of osteoporotic fracture fixation in the proximal humerus. Med Eng Phys 2018; 57:29-39. [PMID: 29728330 DOI: 10.1016/j.medengphy.2018.04.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 02/20/2018] [Accepted: 04/19/2018] [Indexed: 12/24/2022]
Abstract
The high rate of fixation failure in osteoporotic proximal humerus fractures indicate the need for improved solutions. Computer simulations may help to overcome the limitations of the gold standard biomechanical testing in evaluating the performance of new implants and enhance the effectivity and outcome of the design process. This study presents a framework for automated computational analysis that facilitates efficient and systematic evaluation of proximal humerus fracture plating under a variety of conditions including bone quality, fracture pattern, implant configuration and loading regime. The underlying finite element methodology was previously validated. The capabilities of the software tool are demonstrated by virtually reproducing a previously published biomechanical study on the effect of screw augmentation and showing that the models capture the essence of the experimental results. Due to the modular design of the framework, the currently available set of angle-stable plate implants can be readily expanded to include other fixations such as intramedullary nails. Besides the capability to compare already existing solutions, the tool can provide rapid feedback on novel ideas. Therefore, it is expected to efficiently complement and partially replace expensive experimental tests and aid development and optimization of implant designs for improved fixation of osteoporotic proximal humerus fractures.
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Affiliation(s)
- Peter Varga
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland.
| | - Jason A Inzana
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland
| | - Boyko Gueorguiev
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland
| | - Norbert P Südkamp
- Orthopedics and Trauma Department, University Hospital Freiburg, Breisacher Str. 86, 79110 Freiburg im Breisgau, Germany
| | - Markus Windolf
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos, Switzerland
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15
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Takada R, Jinno T, Miyatake K, Yamauchi Y, Koga D, Yagishita K, Okawa A. Longitudinal morphological change of acetabular subchondral bone cyst after total hip arthroplasty in developmental dysplasia of the hip. Eur J Orthop Surg Traumatol 2018; 28:621-5. [PMID: 29299764 DOI: 10.1007/s00590-017-2115-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 12/20/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE The purpose of this study is to clarify morphological changes of acetabular subchondral bone cyst after total hip arthroplasty for osteoarthritis secondary to developmental dysplasia of the hip. METHODS Two hundred and sixty-one primary cementless total hip arthroplasties of 208 patients, 18 males, 190 females, were retrospectively reviewed. Morphological changes of subchondral bone cyst were evaluated by computed tomography (CT). The mean cross-sectional area of the cyst from CT scans at 3 months postoperatively and after 7-10 years (average 8.4 years) were compared. RESULTS Acetabular subchondral bone cysts were found in 49.0% of all cases in preoperative CT scans. There was no cyst which was newly recognized in CT scan performed after postoperative 7-10 years. All the cross-sectional areas of the cysts evaluated in this study were reduced postoperatively. CONCLUSIONS This study revealed that acetabular subchondral bone cysts do not increase or expand after total hip arthroplasty and indicated that the longitudinal morphological change of acetabular bone cysts in patients of developmental dysplasia of the hip do not influence long-term implant fixation in total hip arthroplasty.
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16
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Stempin R, Kaczmarek W, Stempin K, Dutka J. Midterm Results of Cementless and Cemented Unicondylar Knee Arthroplasty with Mobile Meniscal Bearing: A Prospective Cohort Study. Open Orthop J 2017; 11:1173-1178. [PMID: 29290853 PMCID: PMC5721307 DOI: 10.2174/1874325001711011173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/20/2017] [Accepted: 09/12/2017] [Indexed: 11/30/2022] Open
Abstract
Background: Cemented unicompartmental knee arthroplasty (UKA) yields good clinical outcome but common revision reasons are loosening and pain. Cementless UKA may reduce the revision rate. Objective: The current study was designed to assess clinical and radiographic outcome of cemented and cementless UKA, using bone quality as determined by the Bone Hardness Test (BHT) as selection criterion for cementless implantation. Methods: In this prospective comparative cohort study we analyzed 50 cementless and 29 Oxford consecutive UKA cases. Patients with sufficient bone quality were eligible for cementless UKA. Bone quality was assessed with the BHT, which consisted of exercising pressure with the thumb on the bone surface created after resection of the tibia. Results: The average surgical times were 62.5 ± 12.6 and 78 ± 16 minutes in the cementless and the cemented group, respectively (p < 0.01). The average thickness of the polyethylene insert was 4.3 ± 1.2 (range, 3 – 9) and 3.7 ± 0.8 (range, 3 – 6) mm, respectively (p = 0.02). Both types of implants yielded excellent clinical and functional results. At an average follow-up time of seven years, we found non-significant differences between clinical results of cementless versus cemented implants. Conclusion: Shorter surgical time makes cementless implantation more attractive to surgeons when considering UKA options for their patients. The average thickness of the polyethylene insert in cementless group was 0.6 mm thinner than in the cemented group. The BHT is a simple and useful test to assess whether patients are eligible for cementless UKA.
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Affiliation(s)
- Radosław Stempin
- Department of Orthopedic Surgery Promienista Clinic, Poznan, Poland
| | | | - Kacper Stempin
- Department of Orthopedic & Trauma Surgery Westallgäu Clinic, Wangen, Germany
| | - Julian Dutka
- Department of Orthopedic& Trauma Surgery S. Zeromski Memorial Hospital Cracow, Poland
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17
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Nadorf J, Klein SB, Gantz S, Jakubowitz E, Kretzer JP, Bischel OE. Influence of implant length and bone defect situation on primary stability after distal femoral replacement in vitro. Knee 2017; 24:1016-1024. [PMID: 28793976 DOI: 10.1016/j.knee.2017.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 05/17/2017] [Accepted: 07/20/2017] [Indexed: 02/02/2023]
Abstract
BACKGROUND Aseptic loosening is the major reason for failure of distal femoral replacement using current modular megaprostheses. Although the same stems are used for proximal and distal replacement, survival rates in clinical studies with distal reconstruction were lower within the same system compared to proximal reconstruction. We analyzed whether primary stability as presupposition for long-term fixation can be achieved with a current tapered stem design. Additionally, we hypothesized that stem length affects primary stability depending on bone defect situations. METHODS A modular tumor system (Megasystem-C®, Link GmbH, Hamburg, Germany) with two different tapered stems (100 and 160mm) was implanted in eight Sawbones® in two consecutively created defect situations (10 and 20cm proximal to knee joint level). Primary rotational stability was investigated by measuring relative micromotions between implant and bone to identify the main fixation areas and to characterize the fixation pattern. RESULTS The fixation differed between the two stem lengths and with respect to both defect situations; however in each case the main fixation area was located at or close to the femoral isthmus. Highest relative micromotions were measured with the 160-mm stem at the distal end within small bone defects and at the proximal end when defects were increased. CONCLUSIONS The analyzed design seemed to create sufficient primary stability along the main fixation areas of the implant. Based on these results and with respect to oncologic or potential revision situations, we suggest the use of the shorter stem to be more favorable in case of primary implant fixation.
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Affiliation(s)
- Jan Nadorf
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, Heidelberg, Germany
| | - Simon B Klein
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, Heidelberg, Germany
| | - Simone Gantz
- Biometrics Consulting and Project Management, University Heidelberg, Im Neuenheimer Feld 130, Heidelberg, Germany
| | - Eike Jakubowitz
- Laboratory for Biomechanics and Biomaterials, Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 1-7, Hannover, Germany
| | - Jan Philippe Kretzer
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, Heidelberg, Germany
| | - Oliver E Bischel
- Laboratory of Biomechanics and Implant Research, Clinic for Orthopedics and Trauma Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, Heidelberg, Germany; BG Trauma Center, Ludwig-Guttmann-Str. 13, Ludwigshafen, Germany.
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18
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Jin Y, Xu L, Hu X, Liao S, Pathak JL, Liu J. Lithium chloride enhances bone regeneration and implant osseointegration in osteoporotic conditions. J Bone Miner Metab 2017; 35:497-503. [PMID: 27714461 DOI: 10.1007/s00774-016-0783-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 09/07/2016] [Indexed: 01/13/2023]
Abstract
Osteoporotic patients have a high risk of dental and orthopedic implant failure. Lithium chloride (LiCl) has been reported to enhance bone formation. However, the role of LiCl in the success rate of dental and orthopedic implants in osteoporotic conditions is still unknown. We investigated whether LiCl enhances implant osseointegration, implant fixation, and bone formation in osteoporotic conditions. Sprague-Dawley female rats (n = 18) were ovariectomized (OVX) to induce osteoporosis, and another nine rats underwent sham surgery. Three months after surgery, titanium implants were implanted in the tibia of the OVX and sham group rats. After implantation, the OVX rats were gavaged with 150 mg/kg/2 days of LiCl (OVX + LiCl group) or saline (OVX group), and sham group rats were gavaged with saline for 3 months. Implant osseointegration and bone formation were analyzed using histology, biomechanical testing, and micro computed tomography (micro-CT). More bone loss was observed in the OVX group compared to the control, and LiCl treatment enhanced bone formation and implant fixation in osteoporotic rats. In the OVX group, bone-implant contact (BIC) was decreased by 81.2 % compared to the sham group. Interestingly, the OVX + LiCl group showed 4.4-fold higher BIC compared to the OVX group. Micro-CT data of tibia from the OVX + LiCl group showed higher bone volume, trabecular thickness, trabecular number, and osseointegration compared to the OVX group. Maximum push-out force and implant-bone interface shear strength were 2.9-fold stronger in the OVX + LiCl group compared to the OVX group. In conclusion, LiCl enhanced implant osseointegration, implant fixation, and bone formation in osteoporotic conditions, suggesting LiCl as a promising therapeutic agent to prevent implant failure and bone loss in osteoporotic conditions.
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Affiliation(s)
- Yifan Jin
- School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 325027, China
| | - Lihua Xu
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325027, China
| | - Xiaohui Hu
- School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 325027, China
| | - Shixian Liao
- School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 325027, China
| | - Janak L Pathak
- Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Science and Technology (SPST), Tianjin University, Tianjin, 300072, China.
| | - Jinsong Liu
- School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 325027, China.
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19
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Bobbert FSL, Lietaert K, Eftekhari AA, Pouran B, Ahmadi SM, Weinans H, Zadpoor AA. Additively manufactured metallic porous biomaterials based on minimal surfaces: A unique combination of topological, mechanical, and mass transport properties. Acta Biomater 2017; 53:572-84. [PMID: 28213101 DOI: 10.1016/j.actbio.2017.02.024] [Citation(s) in RCA: 192] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 02/08/2017] [Accepted: 02/13/2017] [Indexed: 12/23/2022]
Abstract
Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different types of triply periodic minimal surfaces (TPMS) that mimic the properties of bone to an unprecedented level of multi-physics detail. Sixteen different types of porous biomaterials were rationally designed and fabricated using selective laser melting (SLM) from a titanium alloy (Ti-6Al-4V). The topology, quasi-static mechanical properties, fatigue resistance, and permeability of the developed biomaterials were then characterized. In terms of topology, the biomaterials resembled the morphological properties of trabecular bone including mean surface curvatures close to zero. The biomaterials showed a favorable but rare combination of relatively low elastic properties in the range of those observed for trabecular bone and high yield strengths exceeding those reported for cortical bone. This combination allows for simultaneously avoiding stress shielding, while providing ample mechanical support for bone tissue regeneration and osseointegration. Furthermore, as opposed to other AM porous biomaterials developed to date for which the fatigue endurance limit has been found to be ≈20% of their yield (or plateau) stress, some of the biomaterials developed in the current study show extremely high fatigue resistance with endurance limits up to 60% of their yield stress. It was also found that the permeability values measured for the developed biomaterials were in the range of values reported for trabecular bone. In summary, the developed porous metallic biomaterials based on TPMS mimic the topological, mechanical, and physical properties of trabecular bone to a great degree. These properties make them potential candidates to be applied as parts of orthopedic implants and/or as bone-substituting biomaterials. STATEMENT OF SIGNIFICANCE Bone-substituting biomaterials aim to mimic bone properties. Although mimicking some of bone properties is feasible, biomaterials that could simultaneously mimic all or most of the relevant bone properties are rare. We used rational design and additive manufacturing to develop porous metallic biomaterials that exhibit an interesting combination of topological, mechanical, and mass transport properties. The topology of the developed biomaterials resembles that of trabecular bone including a mean curvature close to zero. Moreover, the developed biomaterials show an unusual combination of low elastic modulus to avoid stress shielding and high strength to provide mechanical support. The fatigue resistance of the developed biomaterials is also exceptionally high, while their permeability is in the range of values reported for bone.
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20
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Baas J, Vestermark M, Jensen T, Bechtold J, Soballe K, Jakobsen T. Topical bisphosphonate augments fixation of bone-grafted hydroxyapatite coated implants, BMP-2 causes resorption-based decrease in bone. Bone 2017; 97:76-82. [PMID: 28082076 PMCID: PMC5367933 DOI: 10.1016/j.bone.2017.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 12/27/2016] [Accepted: 01/06/2017] [Indexed: 11/28/2022]
Abstract
Bone allograft is used in total joint arthroplasties in order to enhance implant fixation. BMPs are known to stimulate new bone formation within allograft, but also known to accelerate graft resorption. Bisphosphonates are strong inhibitor of bone resorption. The aim of this study was to investigate whether the bisphosphonate zoledronate was able to counteract the accelerated graft resorption without interfering with the BMP induced bone formation. In the present study the two drugs alone and in combination were studied in our canine model of impaction bone grafting. We included 10 dogs in this study. Cancellous allograft bone grafts were soaked in either saline or zoledronate solution (0.005mg/mL) and then vehicle or BMP2 (0.15mg rhBMP2) was added. This produced four treatment groups: A) control, B) BMP2, C) zoledronate and D) BMP2+zoledronate. The allograft treated with A, B, C or D was impacted into a circumferential defect of 2.5mm around HA-coated porous Ti implants. Each dog received all four treatment groups with two implants in the distal part of each femur. The group with allograft soaked in zoledronate (C) showed better biomechanical fixation than all other groups (p<0.05). It had less allograft resorption compared to all other groups (p<0.005) without any statistically significant change in new bone formation. The addition of BMP2 to the allograft did not increase new bone formation significantly, but did accelerate allograft resorption. This was also the case where the allograft was treated with BMP2 and zoledronate in combination (D). This caused a decrease in mechanical implant fixation in both these groups compared to the control group, however only statistically significant for the BMP2 group compared to control. The study shows that topical zoledronate can be a valuable tool for augmenting bone grafts when administered optimally. The use of BMP2 in bone grafting procedures seems associated with a high risk of bone resorption and mechanical weakening.
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Affiliation(s)
- Jorgen Baas
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8000 Aarhus C, Denmark
| | - Marianne Vestermark
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8000 Aarhus C, Denmark
| | - Thomas Jensen
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8000 Aarhus C, Denmark
| | - Joan Bechtold
- Minneapolis Medical Research Foundation, University of Minnesota, Minneapolis, MN 55415, USA
| | - Kjeld Soballe
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8000 Aarhus C, Denmark
| | - Thomas Jakobsen
- Orthopaedic Research Laboratory, Aarhus University Hospital, 8000 Aarhus C, Denmark.
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21
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Yang J, Faverjon B, Dureisseix D, Swider P, Marburg S, Peters H, Kessissoglou N. Prediction of the intramembranous tissue formation during perisprosthetic healing with uncertainties. Part 2. Global clinical healing due to combination of random sources. Comput Methods Biomech Biomed Engin 2016; 19:1387-94. [PMID: 26867011 DOI: 10.1080/10255842.2016.1143465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This work proposes to examine the variability of the bone tissue healing process in the early period after the implantation surgery. The first part took into account the effect of variability of individual biochemical factors on the solid phase fraction, which is an indicator of the quality of the primary fixation and condition of its long-term behaviour. The next issue, addressed in this second part, is the effect of cumulative sources of uncertainties on the same problem of a canine implant. This paper is concerned with the ability to increase the number of random parameters to assess the coupled influence of those variabilities on the tissue healing. To avoid an excessive increase in the complexity of the numerical modelling and further, to maintain efficiency in computational cost, a collocation-based polynomial chaos expansion approach is implemented. A progressive set of simulations with an increasing number of sources of uncertainty is performed. This information is helpful for future implant design and decision process for the implantation surgical act.
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Affiliation(s)
- J Yang
- a School of Mechanical and Manufacturing Engineering , UNSW Australia , Sydney , Australia
| | - B Faverjon
- a School of Mechanical and Manufacturing Engineering , UNSW Australia , Sydney , Australia .,b Université de Lyon, CNRS, INSA-Lyon, LaMCoS UMR 5259 , Lyon , France
| | - D Dureisseix
- b Université de Lyon, CNRS, INSA-Lyon, LaMCoS UMR 5259 , Lyon , France
| | - P Swider
- c Université de Toulouse, CNRS, INP-Toulouse, IMFT UMR 5502 , Toulouse , France
| | - S Marburg
- d Faculty of Mechanical Engineering , Institute of Vibroacoustics of Vehicles and Machines, Technische Universität München , Germany
| | - H Peters
- a School of Mechanical and Manufacturing Engineering , UNSW Australia , Sydney , Australia
| | - N Kessissoglou
- a School of Mechanical and Manufacturing Engineering , UNSW Australia , Sydney , Australia
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22
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Bruni D, Bragonzoni L, Gagliardi M, Bontempi M, Akkawi I, Raspugli GF, Iacono F, Patella S, Marcacci M. Roentgen stereophotogrammetric analysis: an effective tool to predict implant survival after an all-poly unicompartmental knee arthroplasty-a 10 year follow-up study. Knee Surg Sports Traumatol Arthrosc 2015; 23:3273-80. [PMID: 25026930 DOI: 10.1007/s00167-014-3106-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 05/27/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE The main purpose of the present study was to determine long-term implant fixation of 15 unicompartmental knee arthroplasty (UKAs) with an all-poly tibial component using Roentgen stereophotogrammetric analysis (RSA) at a mean 10-year follow-up. The secondary purpose was to investigate whether the progressive loss of implant's fixation correlates with a reduction in Knee society score (KSS). METHODS Fifteen non-consecutive patients with primary knee osteoarthritis received a UKA with an all-poly tibial component were assessed using KSS scores pre-operatively and post-operatively and RSA on day 2 after surgery, then at 3, 6, and 12 months and yearly thereafter. The mean last follow-up was 10 years. RESULTS An increase in maximum total point motion (MTPM) values from 6 months to 1 year post-operatively was found respect to post-operative reference. Implants' displacement values were always <2 mm during the first 6 months, and then, two different trends were noticed in revised and non-revised implants. MTPM increase between 1 and 2 years of follow-up in non-revised UKAs was always <0.2 mm, whereas it was >0.2 mm in revised UKAs. A linear and negative correlation with statistical significance was found between MTPM and both clinical and functional KSS scores (p < 0.001). CONCLUSION Also in a long-term follow-up evaluation, RSA is an effective tool to predict functional results after an all-poly UKA providing also a relevant predictive value at 1 year follow-up, and this can be very useful for both patients and surgeons. LEVEL OF EVIDENCE Diagnostic studies, Level III.
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Walsh WR, Bertollo N, Christou C, Schaffner D, Mobbs RJ. Plasma-sprayed titanium coating to polyetheretherketone improves the bone-implant interface. Spine J 2015; 15:1041-9. [PMID: 25543010 DOI: 10.1016/j.spinee.2014.12.018] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 12/02/2014] [Accepted: 12/17/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Rapid and stable fixation at the bone-implant interface would be regarded as one of the primary goals to achieve clinical efficacy, regardless of the surgical site. Although mechanical and physical properties of polyetheretherketone (PEEK) provide advantages for implant devices, the hydrophobic nature and the lack of direct bone contact remains a limitation. PURPOSE To examine the effects of a plasma-sprayed titanium coated PEEK on the mechanical and histologic properties at the bone-implant interface. STUDY SETTING A preclinical laboratory study. METHODS Polyetheretherketone and plasma-sprayed titanium coated PEEK implants (Ti-bond; Spinal Elements, Carlsbad, CA, USA) were placed in a line-to-line manner in cortical bone and in a press-fit manner in cancellous bone of adult sheep using an established ovine model. Shear strength was assessed in the cortical sites at 4 and 12 weeks, whereas histology was performed in cortical and cancellous sites at both time points. RESULTS The titanium coating dramatically improved the shear strength at the bone-implant interface at 4 weeks and continued to improve with time compared with PEEK. Direct bone ongrowth in cancellous and cortical sites can be achieved using a plasma-sprayed titanium coating on PEEK. CONCLUSIONS Direct bone to implant bonding can be achieved on PEEK in spite of its hydrophobic nature using a plasma-sprayed titanium coating. The plasma-sprayed titanium coating improved mechanical properties in the cortical sites and the histology in cortical and cancellous sites.
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Affiliation(s)
- William R Walsh
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, The University of New South Wales, Prince of Wales Hospital, Level 1 Clinical Science Building, Avoca Street, Randwick, Sydney, Australia, 2031.
| | - Nicky Bertollo
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, The University of New South Wales, Prince of Wales Hospital, Level 1 Clinical Science Building, Avoca Street, Randwick, Sydney, Australia, 2031
| | - Chrisopher Christou
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, The University of New South Wales, Prince of Wales Hospital, Level 1 Clinical Science Building, Avoca Street, Randwick, Sydney, Australia, 2031
| | - Dominik Schaffner
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, The University of New South Wales, Prince of Wales Hospital, Level 1 Clinical Science Building, Avoca Street, Randwick, Sydney, Australia, 2031
| | - Ralph J Mobbs
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, The University of New South Wales, Prince of Wales Hospital, Level 1 Clinical Science Building, Avoca Street, Randwick, Sydney, Australia, 2031
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Bernhardsson M, Sandberg O, Aspenberg P. Anti-RANKL treatment improves screw fixation in cancellous bone in rats. Injury 2015; 46:990-5. [PMID: 25744169 DOI: 10.1016/j.injury.2015.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 02/10/2015] [Accepted: 02/10/2015] [Indexed: 02/02/2023]
Abstract
Bisphosphonates improve implant fixation in randomised clinical trials of knee prostheses, hip prostheses and dental implants. However, a limited amount of bone resorption is required for bisphosphonates to exert an effect. Anti-RANKL treatment does not have this limitation, and we therefore tested whether if they might be more effective for improvement of implant fixation. This is of interest, as anti-RANKL treatment with denosumab is now in common clinical use. Male SD rats received a stain-less steel screw in the right proximal tibia and a drill hole in the left (n = 42). They were randomised to subcutaneous injections of either alendronate (20 μg/kg/day), alendronate (200 μg/kg/day), osteoprotegerin with an Fc tag (OPG-Fc; 8 mg/kg, twice weekly), or saline control. After 4 weeks, the fixation of the steel screw was measured by pull-out test. The tibia with the drill hole was evaluated with μCT. OPG-Fc increased the pull-out force compared to saline controls by 153% (p < 0.001). There was no significant difference between OPG-Fc and the alendronate groups. OPG-Fc increased the bone density (BV/TV) in the previous drill hole compared to controls 7-fold (p < 0.001). This increase was higher than with any alendronate dose (p < 0.001). OPG-Fc increased the bone density of the L5 vertebral body, but there was no significant difference between OPG-Fc and alendronate. Our results suggest that screw fixation in cancellous bone can be dramatically improved by an anti-RANKL agent. The effect was comparable to very high bisphosphonate doses. Screw insertion in cancellous bone elicits a metaphyseal fracture healing response, and our findings might be relevant not only for implant fixation, but also for fracture healing in cancellous bone.
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Affiliation(s)
- Magnus Bernhardsson
- Orthopedics, Department of Clinical and Experimental Medicine, Faculty of Health Sciences at Linköping University, SE-581 85 Linköping, Sweden
| | - Olof Sandberg
- Orthopedics, Department of Clinical and Experimental Medicine, Faculty of Health Sciences at Linköping University, SE-581 85 Linköping, Sweden
| | - Per Aspenberg
- Orthopedics, Department of Clinical and Experimental Medicine, Faculty of Health Sciences at Linköping University, SE-581 85 Linköping, Sweden.
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Stenlund P, Murase K, Stålhandske C, Lausmaa J, Palmquist A. Understanding mechanisms and factors related to implant fixation; a model study of removal torque. J Mech Behav Biomed Mater 2014; 34:83-92. [PMID: 24566379 DOI: 10.1016/j.jmbbm.2014.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/28/2014] [Accepted: 02/03/2014] [Indexed: 11/27/2022]
Abstract
Osseointegration is a prerequisite for achieving a stable long-term fixation and load-bearing capacity of bone anchored implants. Removal torque measurements are often used experimentally to evaluate the fixation of osseointegrated screw-shaped implants. However, a detailed understanding of the way different factors influence the result of removal torque measurements is lacking. The present study aims to identify the main factors contributing to anchorage. Individual factors important for implant fixation were identified using a model system with an experimental design in which cylindrical or screw-shaped samples were embedded in thermosetting polymers, in order to eliminate biological variation. Within the limits of the present study, it is concluded that surface topography and the mechanical properties of the medium surrounding the implant affect the maximum removal torque. In addition to displaying effects individually, these factors demonstrate interplay between them. The rotational speed was found not to influence the removal torque measurements within the investigated range.
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Affiliation(s)
- Patrik Stenlund
- Department of Chemistry, Materials and Surfaces, SP Technical Research Institute of Sweden, Box 857, SE-501 15 Borås, Sweden; BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Göteborg, Sweden.
| | - Kohei Murase
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Göteborg, Sweden; Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, 464-8603 Nagoya, Japan
| | | | - Jukka Lausmaa
- Department of Chemistry, Materials and Surfaces, SP Technical Research Institute of Sweden, Box 857, SE-501 15 Borås, Sweden; BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Göteborg, Sweden
| | - Anders Palmquist
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Göteborg, Sweden; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Box 412, SE-405 30 Göteborg, Sweden
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26
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Jakobsen T, Baas J, Bechtold JE, Elmengaard B, Søballe K. The effect on implant fixation of soaking tricalcium phosphate granules in bisphosphonate. Open Orthop J 2012; 6:371-5. [PMID: 22962566 PMCID: PMC3434449 DOI: 10.2174/1874325001206010371] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/30/2012] [Accepted: 06/18/2012] [Indexed: 11/25/2022] Open
Abstract
The use of bone grafting is a well-established way to enhance initial implant fixation in situations with reduced bone stock. Ceramic bone substitutes are inferior alternatives to autogenous or allogeneic bone graft. Improvement of bone graft substitutes is needed. We investigated whether biomechanical implant fixation and osseointegration of experimental implant grafted with β-TCP granules (Conduit) could be improved by soaking the β-TCP granules in bisphosphonate (zoledronate). In 10 dogs, a pair of titanium coated implants surrounded by a 2.5 mm gap was inserted into the proximal part of each tibia. The gap was grafted with β-TCP granules either soaked with zoledronate or saline. At 12 weeks, the implants were evaluated with biomechanical push-out test and histomorphometrical analysis. We found that bisphosphonate increased one of the three biomechanical parameters, but found no difference in the amount of new bone or β-TCP granules between the two treatment groups. This study indicates that local treatment of β-TCP granules with zoledronate not only has the potential to increase implant fixation but also calls for further experimental research in order to optimize the dose of zoledronate.
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Affiliation(s)
- Thomas Jakobsen
- Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark
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