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Shaul JL, Hill RS, Bouxsein ML, Burr DB, Tilton AK, Howe JG. AGN1 implant material to treat bone loss: Resorbable implant forms normal bone with and without alendronate in a canine critical size humeral defect model. Bone 2022; 154:116246. [PMID: 34744020 DOI: 10.1016/j.bone.2021.116246] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/22/2021] [Accepted: 10/25/2021] [Indexed: 11/02/2022]
Abstract
BACKGROUND Fractures secondary to osteoporosis, particularly those of the hip and spine, are a major public health concern with high social and economic costs. The Local Osteo-Enhancement Procedure (LOEP) is an approach intended to strengthen skeletal areas that are at the highest risk for fracture due to osteoporosis. LOEP involves the implantation of AGN1, a triphasic, calcium-based, osteoconductive material which is then resorbed and replaced by bone. Since alendronate is the most prescribed osteoporotic treatment, the purpose of this canine study is to determine if the newly formed bone has the same properties as normal bone and whether alendronate treatment impacts AGN1 resorption and replacement with bone. METHODS Sixty skeletally mature male hounds (24-38 kg) were evenly divided between alendronate (0.2 mg/kg/day) and non-alendronate treatment groups. A critical-size core bone defect created in one proximal humerus was implanted with AGN1 while the contralateral non-operated humerus served as a paired control in each animal. Animals were sacrificed 13, 26, and 52 weeks post-operatively (10 per treatment per timepoint). The control and treatment site bone specimens from each animal were examined using radiographic, histomorphometric, and biomechanical techniques. Results between alendronate-treated and non-alendronate-treated animals were compared as groups. RESULTS AGN1 implant material was consistently resorbed and replaced by bone in all animals. At 52 weeks, only minimal residual implant material could be detected (0.9 ± 2.3% non-alendronate group; 2.2 ± 3.1% alendronate group), and new bone filled the defects in both the non-alendronate and alendronate groups. At 13 and 26 weeks, microCT revealed the newly formed bone in the defects had significantly higher trabecular bone volume and number connectivity than control bone in both groups. Mechanical testing demonstrated that the new bone had ultimate compressive strength and modulus equivalent to control bone as early as 13 weeks post-surgery which was maintained to 52 weeks in both groups. CONCLUSIONS In this canine critical-sized humeral core defect model, AGN1 was progressively replaced by normal bone as evaluated by all outcome measures. Concurrent alendronate therapy did not significantly impact AGN1 resorption or new bone formation. These results demonstrate that AGN1 can be used in conjunction with alendronate in non-osteoporotic animals. CLINICAL RELEVANCE This study suggests that the AGN1 implant material demonstrates potential for local restoration of bone in critical-size core defects, and that the material is compatible with alendronate drug therapy. Further studies will be required to determine if these results apply to other osteoporosis medications.
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Affiliation(s)
| | - Ronald S Hill
- AgNovos Healthcare, Rockville, MD, United States of America
| | - Mary L Bouxsein
- Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - David B Burr
- Indiana University, Indianapolis, IN, United States of America
| | | | - James G Howe
- AgNovos Healthcare, Rockville, MD, United States of America; University of Vermont, Burlington, VT, United States of America
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Hockett SA, Sherrill JT, Self M, Mears SC, Barnes CL, Mannen EM. Augmentation of core decompression with synthetic bone graft does not improve mechanical properties of the proximal femur. J Mech Behav Biomed Mater 2020; 115:104263. [PMID: 33385950 DOI: 10.1016/j.jmbbm.2020.104263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 11/25/2020] [Accepted: 12/08/2020] [Indexed: 11/28/2022]
Abstract
Core decompression is a minimally invasive surgical technique used to treat patients with avascular necrosis of the femoral head. The procedure requires an entry hole in the lateral cortex of the femur which potentially leaves patients susceptible to subtrochanteric fractures. The purpose of this study was to determine if filling the core decompression tract with synthetic bone-graft mechanically strengthens the proximal femur. Twenty composite synthetic femurs underwent a core decompression procedure; ten were augmented with synthetic bone-graft (PRO-DENSE™, Wright Medical) and ten femurs were left unfilled as a control group. Compressive testing to failure was performed using a mechanical testing machine. Stiffness, fracture load, and toughness did not significantly differ between groups. More subtrochanteric fractures were seen in the control group (6 of 10 specimens) compared to the bone-graft augmented group (2 of 10 specimens). In conclusion, augmentation of a core decompression tract does not improve mechanical properties in a synthetic bone model but may be protective of subtrochanteric fracture.
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Affiliation(s)
- Samuel A Hockett
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Department of Engineering and Physics, Harding University, Searcy, AR, USA
| | - John T Sherrill
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Micah Self
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Simon C Mears
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - C Lowry Barnes
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Erin M Mannen
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Mechanical and Biomedical Engineering Department, Boise State University, Boise, ID, USA.
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Horbach AJ, Staat M, Pérez-Viana D, Simmen HP, Neuhaus V, Pape HC, Prescher A, Ciritsis B. Biomechanical in vitro examination of a standardized low-volume tubular femoroplasty. Clin Biomech (Bristol, Avon) 2020; 80:105104. [PMID: 32712527 DOI: 10.1016/j.clinbiomech.2020.105104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/03/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Osteoporosis is associated with the risk of fractures near the hip. Age and comorbidities increase the perioperative risk. Due to the ageing population, fracture of the proximal femur also proves to be a socio-economic problem. Preventive surgical measures have hardly been used so far. METHODS 10 pairs of human femora from fresh cadavers were divided into control and low-volume femoroplasty groups and subjected to a Hayes fall-loading fracture test. The results of the respective localization and classification of the fracture site, the Singh index determined by computed tomography (CT) examination and the parameters in terms of fracture force, work to fracture and stiffness were evaluated statistically and with the finite element method. In addition, a finite element parametric study with different position angles and variants of the tubular geometry of the femoroplasty was performed. FINDINGS Compared to the control group, the work to fracture could be increased by 33.2%. The fracture force increased by 19.9%. The used technique and instrumentation proved to be standardized and reproducible with an average poly(methyl methacrylate) volume of 10.5 ml. The parametric study showed the best results for the selected angle and geometry. INTERPRETATION The cadaver studies demonstrated the biomechanical efficacy of the low-volume tubular femoroplasty. The numerical calculations confirmed the optimal choice of positioning as well as the inner and outer diameter of the tube in this setting. The standardized minimally invasive technique with the instruments developed for it could be used in further comparative studies to confirm the measured biomechanical results.
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Affiliation(s)
- Andreas J Horbach
- FH Aachen University of Applied Sciences, Institute of Bioengineering, Biomechanics Lab., Heinrich-Mußmann-Straße 1, 52428 Jülich, Germany.
| | - Manfred Staat
- FH Aachen University of Applied Sciences, Institute of Bioengineering, Biomechanics Lab., Heinrich-Mußmann-Straße 1, 52428 Jülich, Germany.
| | - Daniel Pérez-Viana
- FH Aachen University of Applied Sciences, Institute of Bioengineering, Biomechanics Lab., Heinrich-Mußmann-Straße 1, 52428 Jülich, Germany.
| | - Hans-Peter Simmen
- Universitätsspital Zürich, Trauma Unit, Rämistrasse 100, 8091 Zürich, Switzerland.
| | - Valentin Neuhaus
- Universitätsspital Zürich, Trauma Unit, Rämistrasse 100, 8091 Zürich, Switzerland.
| | - Hans-Christoph Pape
- Universitätsspital Zürich, Trauma Unit, Rämistrasse 100, 8091 Zürich, Switzerland.
| | - Andreas Prescher
- Institute of Anatomy and Cell Biology, Rheinisch-Westfälische Technische Hochschule Aachen University, Wendlingweg 2, 52074 Aachen, Germany.
| | - Bernhard Ciritsis
- Ente Ospedaliero Cantonale Ospedale di Bellinzona e Valli, Trauma Unit, Via Ospedale 12, 6500 Bellinzona, Switzerland; Centro Ortopedico di Quadrante, Lungolago Buozzi 25, 28887 Omegna (VB), Italy.
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Stroncek JD, Shaul JL, Favell D, Hill RS, Huber BM, Howe JG, Bouxsein ML. In vitro injection of osteoporotic cadaveric femurs with a triphasic calcium-based implant confers immediate biomechanical integrity. J Orthop Res 2019; 37:908-915. [PMID: 30793358 PMCID: PMC6593990 DOI: 10.1002/jor.24239] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 01/21/2019] [Indexed: 02/04/2023]
Abstract
Current pharmaceutical therapies can reduce hip fractures by up to 50%, but compliance to treatment is low and therapies take up to 18 months to reduce risk. Thus, alternative or complementary approaches to reduce the risk of hip fracture are needed. The AGN1 local osteo-enhancement procedure (LOEP) is one such alternative approach, as it is designed to locally replace bone lost due to osteoporosis and provide immediate biomechanical benefit. This in vitro study evaluated the initial biomechanical impact of this treatment on human cadaveric femurs. We obtained 45 pairs of cadaveric femurs from women aged 77.8 ± 8.8 years. One femur of each pair was treated, while the contralateral femur served as an untreated control. Treatment included debridement, irrigation/suction, and injection of a triphasic calcium-based implant (AGN1). Mechanical testing of the femora was performed in a sideways fall configuration 24 h after treatment. Of the 45 pairs, 4 had normal, 16 osteopenic, and 25 osteoporotic BMD T-scores. Altogether, treatment increased failure load on average by 20.5% (p < 0.0001). In the subset of osteoporotic femurs, treatment increased failure load by 26% and work to failure by 45% (p < 0.01 for both). Treatment did not significantly affect stiffness in any group. These findings provide evidence that local delivery of the triphasic calcium-based implant in the proximal femur is technically feasible and provides immediate biomechanical benefit. Our results provide strong rationale for additional studies investigating the utility of this approach for reducing the risk of hip fracture. © 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society.
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Affiliation(s)
- John D. Stroncek
- AgNovos Healthcare7301 Calhoun Place Suite 100RockvilleMaryland 20855
| | - Jonathan L. Shaul
- AgNovos Healthcare7301 Calhoun Place Suite 100RockvilleMaryland 20855
| | - Dominique Favell
- AgNovos Healthcare7301 Calhoun Place Suite 100RockvilleMaryland 20855
| | - Ronald S. Hill
- AgNovos Healthcare7301 Calhoun Place Suite 100RockvilleMaryland 20855
| | - Bryan M. Huber
- Copley Hospital528 Washington HwyMorrisvilleVermont 05661
| | - James G. Howe
- AgNovos Healthcare7301 Calhoun Place Suite 100RockvilleMaryland 20855
| | - Mary L. Bouxsein
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center and Dept. of Orthopedic SurgeryHarvard Medical School330 Brookline AveBostonMassachusetts 02215
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Freitas A, Silva LCDA, Godinho NDV, Farvardin A, Armand M, Paula APDE. EVALUATION OF A BONE REINFORCEMENT TECHNIQUE USING FINITE ELEMENT ANALYSIS. ACTA ORTOPEDICA BRASILEIRA 2018; 26:59-62. [PMID: 29977147 PMCID: PMC6025497 DOI: 10.1590/1413-785220182601181560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Objectives: To compare the results of a simulated fall on the greater trochanter in the proximal portion of a synthetic femur before and after femoral reinforcement with tricalcium phosphate bone cement (TP) and polymethyl methacrylate (PMMA), using finite element analysis (FEA). Methods: Using two synthetic proximal femurs, a FEA simulating a fall on the greater trochanter was performed, using the Bi-directional Evolutionary Structural Optimization (BESO) program. For this analysis, the femurs were filled with TP and PMMA after perforations were created in the trochanteric region and neck. The results were compared with the strength values obtained from testing the control specimen, a synthetic bone without reinforcement. Results: FEA showed a value of 600 N prior to reinforcement. After cementing with PMMA, the load increased by 57.5% (945 N), and by 53% (920 N) after cementing with TP. Conclusion: Synthetic femurs gained resistance to fracture-causing forces in a simulated fall on the trochanter after bone reinforcement with PMMA and TP. Level of Evidence III; Experimental study.
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Affiliation(s)
- Anderson Freitas
- . Hospital Ortopédico e Medicina Especializada, Brasília, DF, Brazil.,. Hospital Regional do Gama, Brasília, DF, Brazil
| | | | | | - Amirhossein Farvardin
- . Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mehran Armand
- . Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ana Patrícia DE Paula
- . Postgraduate program, Fundação de Ensino e Pesquisa em Ciências da Saúde (FEPECS), Brasília, DF, Brazil
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Varga P, Inzana JA, Schwiedrzik J, Zysset PK, Gueorguiev B, Blauth M, Windolf M. New approaches for cement-based prophylactic augmentation of the osteoporotic proximal femur provide enhanced reinforcement as predicted by non-linear finite element simulations. Clin Biomech (Bristol, Avon) 2017; 44:7-13. [PMID: 28282569 DOI: 10.1016/j.clinbiomech.2017.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 02/27/2017] [Accepted: 03/01/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND High incidence and increased mortality related to secondary, contralateral proximal femoral fractures may justify invasive prophylactic augmentation that reinforces the osteoporotic proximal femur to reduce fracture risk. Bone cement-based approaches (femoroplasty) may deliver the required strengthening effect; however, the significant variation in the results of previous studies calls for a systematic analysis and optimization of this method. Our hypothesis was that efficient generalized augmentation strategies can be identified via computational optimization. METHODS This study investigated, by means of finite element analysis, the effect of cement location and volume on the biomechanical properties of fifteen proximal femora in sideways fall. Novel cement cloud locations were developed using the principles of bone remodeling and compared to the "single central" location that was previously reported to be optimal. FINDINGS The new augmentation strategies provided significantly greater biomechanical benefits compared to the "single central" cement location. Augmenting with approximately 12ml of cement in the newly identified location achieved increases of 11% in stiffness, 64% in yield force, 156% in yield energy and 59% in maximum force, on average, compared to the non-augmented state. The weaker bones experienced a greater biomechanical benefit from augmentation than stronger bones. The effect of cement volume on the biomechanical properties was approximately linear. Results of the "single central" model showed good agreement with previous experimental studies. INTERPRETATION These findings indicate enhanced potential of cement-based prophylactic augmentation using the newly developed cementing strategy. Future studies should determine the required level of strengthening and confirm these numerical results experimentally.
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Affiliation(s)
| | | | - Jakob Schwiedrzik
- Institute of Surgical Technology and Biomechanics, University of Bern, Switzerland
| | - Philippe K Zysset
- Institute of Surgical Technology and Biomechanics, University of Bern, Switzerland
| | | | - Michael Blauth
- Department for Trauma Surgery, Medical University Innsbruck, Austria
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Hananouchi T. Prophylactic bioactive screw fixation as an alternative augmentation for femoroplasty. ACTA ACUST UNITED AC 2016; 60:165-9. [PMID: 25581740 DOI: 10.1515/bmt-2014-0169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 12/03/2014] [Indexed: 11/15/2022]
Abstract
Femoroplasty is theoretically a prophylactic surgical procedure for femoral neck fracture. Although bone cement is generally used for augmentation, its distribution cannot be easily controlled. This study investigated whether a bioactive screw is feasible for femoroplasty as an alternative augmentation material. A mechanical test was done to compare the strength of four types of augmentation bioactive screw (Superfixsorb), two bioinert cements, or no intervention in a composite femoral bone. The peak load to fracture under simulated falling was compared among the four groups. The mean peak load to failure in the bioactive screw group (2667 N) was significantly higher than that in the intact group (2391 N) (p=0.028), comparable to that in the Simplex P cement group (2864 N) (p=0.11), and significantly lower than that of the cranioplastic cement group (3022 N) (p=0.006). The strength of a composite femur with the bioactive screw was higher than that of an intact bone and comparable to one cement augmentation. Thus, this bioactive screw can be potentially used as augmentation material for femoroplasty.
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Varga P, Hofmann-Fliri L, Blauth M, Windolf M. Prophylactic augmentation of the osteoporotic proximal femur-mission impossible? BONEKEY REPORTS 2016; 5:854. [PMID: 28018586 DOI: 10.1038/bonekey.2016.86] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/01/2016] [Indexed: 11/09/2022]
Abstract
The high incidence of secondary hip fractures and the associated markedly increased mortality call for preventive actions that could help to avoid these injuries. By providing immediate strengthening and not relying on patient compliance, internal prophylactic augmentation of the osteoporotic proximal femur may overcome the main limitations of systemic bone drugs and wearable protective pads. However, such a method would have to provide sufficient and reliable strengthening effect with minimal risks and side effects to justify the need of an invasive treatment. The requirements for an internal reinforcement approach are thus strict and include mechanical, biological, clinical, ethical and financial criteria. Here we first attempt to describe the properties of an ideal augmentation method. Previously published methodologies and techniques developed at our research institute, including approaches using cements, metals, other materials or combined approaches, are then reviewed and evaluated according to these aspects. We conclude that none of the discussed methodologies appears to be able to deliver a sufficiently high gain-versus-risk ratio that could justify the clinical application and thus augmentation of the osteoporotic proximal femur remains a challenge. Finally, we provide suggestions for the development and evaluation of future strategies.
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Affiliation(s)
- Peter Varga
- AO Research Institute Davos , Davos Platz, Switzerland
| | | | - Michael Blauth
- Department for Trauma Surgery, Medical University Innsbruck , Innsbruck, Austria
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Prophylactic augmentation of the proximal femur: an investigation of two techniques. Arch Orthop Trauma Surg 2016; 136:345-51. [PMID: 26749332 DOI: 10.1007/s00402-015-2400-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Osteoporotic hip fractures are an increasing problem in an ageing population. They result in high morbidity, mortality and high socioeconomic costs. For patients with poor bone quality, prophylactic augmentation of the proximal femur might be an option for fracture prevention. METHODS In two groups of paired human femora the potential of limited polymethyl-methacrylate (PMMA) augmentation (11-15 ml) in a V-shape pattern and the insertion of a proximal femur nail antirotation (PFNA) blade were investigated. The testing was carried out pair wise simulating the single leg stand. The untreated femur in each pair served as control. An axial load was applied until failure. Load displacement parameters and temperature increase during the augmentation process were recorded. RESULTS In the PMMA group no significant difference was found between the augmented and non-augmented specimen concerning load to failure (p = 0.35) and energy to failure (p = 0.9). A median temperature increase of 9.5 °C was observed in the augmented specimen. A significant correlation was found between the amount of applied PMMA and the temperature increase (Cor. Coef. = 0.82, p = 0.042). In the PFNA group, a significant decrease of load to failure and a non-significant decrease of energy to failure were observed (p = 0.037 and p = 0.075). CONCLUSION Limited V-shaped PMMA augmentation and PFNA blade insertion did not show any improvement in failure load or energy to failure. Volumes of up to 15 ml PMMA did not cause a critical surface temperature increase.
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Bettamer A, Hambli R, Allaoui S, Almhdie-Imjabber A. Using visual image measurements to validate a novel finite element model of crack propagation and fracture patterns of proximal femur. COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING-IMAGING AND VISUALIZATION 2015. [DOI: 10.1080/21681163.2015.1079505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Szpalski M, Gunzburg R, Aebi M, Delimoge C, Graf N, Eberle S, Vienney C. A new approach to prevent contralateral hip fracture: Evaluation of the effectiveness of a fracture preventing implant. Clin Biomech (Bristol, Avon) 2015; 30:713-9. [PMID: 26043935 DOI: 10.1016/j.clinbiomech.2015.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Among the millions of people suffering from a hip fracture each year, 20% may sustain a contralateral hip fracture within 5 years with an associated mortality risk increase reaching 64% in the 5 following years. In this context, we performed a biomechanical study to assess the performance of a hip fracture preventing implant. METHODS The implant consists of two interlocking peek rods unified with surgical cement. Numerical and biomechanical tests were performed to simulate single stance load or lateral fall. Seven pairs of femurs were selected from elderly subjects suffering from osteoporosis or osteopenia, and tested ex-vivo after implantation of the device on one side. FINDINGS The best position for the implant was identified by numerical simulations. The loadings until failure showed that the insertion of the implant increased significantly (P<0.05) both fracture load (+18%) and energy to fracture (+32%) of the implanted femurs in comparison with the intraindividual controls. The instrumented femur resisted the implementation of the non-instrumented femur fracture load for 30 cycles and kept its performance at the end of the cyclic loading. INTERPRETATION Implantation of the fracture preventing device improved both fracture load and energy to fracture when compared with intraindividual controls. This is consistent with previous biomechanical side-impact testing on pairs of femur using the same methodology. Implant insertion seems to be relevant to support multiple falls and thus, to prevent a second hip fracture in elderly patients.
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Affiliation(s)
- Marek Szpalski
- Hôpitaux Iris Sud, Department of Orthopedic and Trauma Surgery, Brussels, Belgium
| | - Robert Gunzburg
- Edith Cavell Clinic, Orthopedic Department, Brussels, Belgium
| | - Max Aebi
- Salem Spital, Orthopedic Department, Bern, Switzerland
| | | | | | - Sebastian Eberle
- Institute of Biomechanics, Trauma Center Murnau, Murnau, Germany
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Schaasberg W, van der Steenhoven TJ, van de Velde SK, Nelissen RGHH, Valstar ER. Feasibility of osteosynthesis of fractured cadaveric hips following preventive elastomer femoroplasty. Clin Biomech (Bristol, Avon) 2014; 29:742-6. [PMID: 25001328 DOI: 10.1016/j.clinbiomech.2014.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 06/10/2014] [Accepted: 06/10/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND In vitro cadaveric studies showed that elastomer femoroplasty prevents displacement of fracture parts after proximal hip fracture allowing for conservative treatment. In the event that secondary displacement does occur, the purpose of this present study was to determine the feasibility of performing osteosynthesis of a fractured hip after preventive treatment with elastomer femoroplasty. METHODS Ten pairs of human cadaveric femurs were fractured in a simulated fall configuration. From each pair, one femur was randomly selected for elastomer femoroplasty prior to fracture generation and the contralateral femur was used as control. Following hip fracture generation, osteosynthesis was performed in all femurs. The operative time per case, technical difficulties during the procedure, and postoperative energy-to-failure load were recorded. RESULTS The mean (SD) time to perform osteosynthesis was 20 (6) minutes in the control-group and 19 (5) minutes in the elastomer femoroplasty-group (P=0.69). During osteosynthesis of the fractured hip in the elastomer femoroplasty-group, no difficulties including the need for additional instruments to remove elastomer from the proximal femur were recorded. Postoperative energy-to-failure load was similar in the control-group and the elastomer femoroplasty-group. CONCLUSION Fixation with routine osteosynthesis of displaced cadaveric hip fractures is not hindered by the presence of previously injected elastomer.
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Affiliation(s)
- W Schaasberg
- Leiden University Medical Center, Department of Orthopaedics, Leiden, The Netherlands.
| | | | - S K van de Velde
- Leiden University Medical Center, Department of Orthopaedics, Leiden, The Netherlands
| | - R G H H Nelissen
- Leiden University Medical Center, Department of Orthopaedics, Leiden, The Netherlands
| | - E R Valstar
- Leiden University Medical Center, Biomechanics and Imaging Group, Department of Orthopaedics, Leiden, The Netherlands; Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, TU Delft, The Netherlands
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van der Steenhoven TJ, Schaasberg W, de Vries AC, Valstar ER, Nelissen RGHH. Cyclic loading of fractured cadaveric femurs after elastomer femoroplasty: an in vitro biomechanical study. Clin Biomech (Bristol, Avon) 2012; 27:819-23. [PMID: 22682558 DOI: 10.1016/j.clinbiomech.2012.05.007] [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] [Received: 08/31/2011] [Revised: 05/14/2012] [Accepted: 05/15/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND Elastomer femoroplasty is a novel and experimental approach in the prevention of hip fracture surgery. Previously, we published the results of an in vitro cadaveric experiment in which we showed a significant reduction of fracture displacement in treated femurs. The aim of the present study was to establish the failure loads and inter-fragmentary movement of fractured, elastomer femoroplasty treated femurs during cyclic loading. METHODS 16 cadaveric femurs were treated with elastomer femoroplasty and fractured in a simulated fall configuration. Each specimen underwent 10 cycles with a preload of 50 N, starting with a peak load of 250 N followed by 10 cycles of 500 N and continued with 500 N increments. The crosshead speed was 2 mm/s. The failure load, the number of completed cycles, and crosshead extensions were recorded. FINDINGS The mean failure load was 2709 N (SD 1094). The number of completed cycles until failure was 60 (SD 22). The mean translation during maximum loading was 5.25 mm (SD 0.9). At 1500 N (two times the bodyweight of a 75 kg individual) the extension was 3.16 mm. INTERPRETATION Preventive elastomer femoroplasty leads to the stabilization of the proximal femur after fracture. In a single leg stance configuration, cyclic loading with mean failure loads that well exceed the peak loads during normal gait is feasible.
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Kolta S, Paratte S, Amphoux T, Persohn S, Campana S, Skalli W, Paternotte S, Argenson JN, Bouler JM, Gagey O, Roux C. Bone texture analysis of human femurs using a new device (BMA™) improves failure load prediction. Osteoporos Int 2012; 23:1311-6. [PMID: 21656265 DOI: 10.1007/s00198-011-1674-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
Abstract
UNLABELLED We measured bone texture parameters of excised human femurs with a new device (BMA™). We also measured bone mineral density by DXA and investigated the performance of these parameters in the prediction of failure load. Our results suggest that bone texture parameters improve failure load prediction when added to bone mineral density. INTRODUCTION Bone mineral density (BMD) is a strong determinant of bone strength. However, nearly half of the fractures occur in patients with BMD which does not reach the osteoporotic threshold. In order to assess fracture risk properly, other factors are important to be taken into account such as clinical risk factors as well as macro- and microarchitecture of bone. Bone microarchitecture is usually assessed by high-resolution QCT, but this cannot be applied in routine clinical settings due to irradiation, cost and availability concerns. Texture analysis of bone has shown to be correlated to bone strength. METHODS We used a new device to get digitized X-rays of 12 excised human femurs in order to measure bone texture parameters in three different regions of interest (ROIs). We investigated the performance of these parameters in the prediction of the failure load using biomechanical tests. Texture parameters measured were the fractal dimension (Hmean), the co-occurrence matrix, and the run length matrix. We also measured bone mineral density by DXA in the same ROIs as well as in standard DXA hip regions. RESULTS The Spearman correlation coefficient between BMD and texture parameters measured in the same ROIs ranged from -0.05 (nonsignificant (NS)) to 0.57 (p = 0.003). There was no correlation between Hmean and co-occurrence matrix nor Hmean and run length matrix in the same ROI (r = -0.04 to 0.52, NS). Co-occurrence matrix and run length matrix in the same ROI were highly correlated (r = 0.90 to 0.99, p < 0.0001). Univariate analysis with the failure load revealed significant correlation only with BMD results, not texture parameters. Multiple regression analysis showed that the best predictors of failure load were BMD, Hmean, and run length matrix at the femoral neck, as well as age and sex, with an adjusted r (2) = 0.88. Added to femoral neck BMD, Hmean and run length matrix at the femoral neck (without the effect of age and sex) improved failure load prediction (compared to femoral neck BMD alone) from adjusted r (2) = 0.67 to adjusted r (2) = 0.84. CONCLUSION Our results suggest that bone texture measurement improves failure load prediction when added to BMD.
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Affiliation(s)
- S Kolta
- Rheumatology Department, Cochin Hospital, Paris Descartes University, Paris, France.
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Beckmann J, Springorum R, Vettorazzi E, Bachmeier S, Lüring C, Tingart M, Püschel K, Stark O, Grifka J, Gehrke T, Amling M, Gebauer M. Fracture prevention by femoroplasty--cement augmentation of the proximal femur. J Orthop Res 2011; 29:1753-8. [PMID: 21500251 DOI: 10.1002/jor.21410] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 02/24/2011] [Indexed: 02/04/2023]
Abstract
The prevention of hip fractures is a desirable goal to reduce morbidity, mortality, and socio-economic burden. We evaluated the influence on femoral strength of different clinically applicable cementing techniques as "femoroplasty." Twenty-eight human cadaveric femora were augmented by means of four clinically applicable percutaneous cementing techniques and then tested biomechanically against their native contralateral control to determine fracture strength in an established biomechanical model mimicking a fall on the greater trochanter. The energy applied until fracture could be significantly increased by two of the methods by 160% (53.1 Nm vs. 20.4 Nm, p < 0.001) and 164% (47.1 Nm vs. 17.8 Nm, p = 0.008), respectively. The peak load to failure was significantly increased by three of the methods by 23% (3818.3 N vs. 3095.7 N, p = 0.003), 35% (3698.4 N vs. 2737.5 N, p = 0.007), and 12% (3056.8 N vs. 2742.8 N, p = 0.005), respectively. The femora augmented with cemented double drill holes had a lower fracture strength than the single drilled ones. Experimental femoroplasty is a technically feasible procedure for the prophylactic reinforcement of the osteoporotic proximal femur and, hence, could be an auxiliary treatment option to protect the proximal femur against osteoporotic fractures.
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Affiliation(s)
- J Beckmann
- Department of Orthopaedics, University of Regensburg, Asklepios Klinik Bad Abbach, Regensburg, Germany.
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van der Steenhoven TJ, Schaasberg W, de Vries AC, Valstar ER, Nelissen RGHH. Elastomer femoroplasty prevents hip fracture displacement In vitro biomechanical study comparing two minimal invasive femoroplasty techniques. Clin Biomech (Bristol, Avon) 2011; 26:464-9. [PMID: 21255888 DOI: 10.1016/j.clinbiomech.2010.12.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 12/13/2010] [Accepted: 12/13/2010] [Indexed: 02/07/2023]
Abstract
UNLABELLED The purpose of this study was to test femur strength and the ability to prevent fracture displacement of two minimal invasive Elastomer femoroplasty techniques. METHODS A total of sixteen fixed human cadaveric femur pairs were used. From each pair one femur was randomly assigned for Elastomer femoroplasty. In these femora we drilled a 3.5mm entrance in the lateral cortex. Cavities for the Elastomer were created by: group A, balloon and group B an excentric drill. All femora were fractured by simulating a fall on the greater trochanter. Neck-shaft-angles on plain anterior posterior radiographs were measured to determine fracture displacement. FINDINGS There was no significant difference in fracture load between controls and treated femora for group A, 2904N (SD 1091) versus 2803N (SD 627) and group B, 2773N (SD 747) versus 2597N (SD 834). In group A the mean displacement was 35° (SD 14) for the control femora and 3° (SD 2) for the treated femora (P<0.001). In group B the mean displacement was 38° (SD 10) for the controls and 8° (SD 13) for the treated femora (P<0.001). INTERPRETATION The results of this study show that minimal invasive Elastomer femoroplasty prevents fracture displacement of the proximal femur. We found no significant compromise in load-to-fracture after minimal invasive balloon or excentric drill femoroplasty.
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Verron E, Gauthier O, Janvier P, Pilet P, Lesoeur J, Bujoli B, Guicheux J, Bouler JM. In vivo bone augmentation in an osteoporotic environment using bisphosphonate-loaded calcium deficient apatite. Biomaterials 2011; 31:7776-84. [PMID: 20643480 DOI: 10.1016/j.biomaterials.2010.06.047] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 06/28/2010] [Indexed: 01/22/2023]
Abstract
Resorbable calcium phosphate (CaP) biomaterials have demonstrated considerable efficacy in bone reconstructive surgery. Furthermore, bisphosphonates (BPs) are well known anti-resorptive agents largely used in clinical treatments for osteoporosis. An injectable BP-combined CaP matrix has been developed in order to biologically reinforce osteoporotic bone by increasing the bone fraction and improving bone micro-architecture. Our previous in vitro studies have shown that CaP is effective for loading and releasing BPs at doses that can inhibit excessive bone resorption without affecting osteoblasts. In vivo studies in relevant animal models are necessary to explore the effect of our injectable BP-combined biomaterial on femur bone structure by performing three-dimensional microtomography analysis, histological studies and SEM observations. Firstly, in rat model, our BP-combined CaP matrix significantly improved the bone micro-architecture as compared to CaP alone. The implantation of the BP-loaded biomaterial within proximal femurs of osteoporotic ewes led to a significant increase in relative bone content and an improvement of its micro-architecture. These modifications were confirmed by histological and SEM observations, which revealed CaP granule resorption and new bone trabeculae formation. This approach could be considered in the future for preventing osteoporotic fractures that are preferentially localized in the proximal femur, vertebral bodies or wrist.
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Affiliation(s)
- Elise Verron
- PRES UNAM, INSERM UMR 791, LIOAD, BP 84215, Nantes, France
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Kok LM, van der Steenhoven TJ, Nelissen RGHH. A retrospective analysis of bilateral fractures over sixteen years: localisation and variation in treatment of second hip fractures. INTERNATIONAL ORTHOPAEDICS 2010; 35:1545-51. [PMID: 21165617 PMCID: PMC3174297 DOI: 10.1007/s00264-010-1176-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 11/17/2010] [Accepted: 11/17/2010] [Indexed: 11/24/2022]
Abstract
The aim of this study was the evaluation of contralateral hip fractures after a previous hip fracture. For this retrospective analysis patients were selected from the database of the LUMC, a teaching hospital in the south-west of the Netherlands. We analyzed all patients with a second fracture of a hip between 1992 and 2007. The exclusion criteria were high impact trauma and patients with diseases or medication known to have a negative effect on bone metabolism. A total of 1,604 hip fractures were identified. The possible predictive factors for the second fracture and descriptive statistics related to surgery (Hb and HT before and after the operation, total amount of intra- and postoperative blood loss, type of osteosynthesis, complications, time of death after the last fracture, time between arrival in the hospital and operation and hospital stay for both fractures) were recorded. A total of 32 second hip fractures were identified (2%) at a mean of 27.5 (SD 28.9) months after the initial hip fracture. The mean age at the first fracture was 77.2 years (SD 11.7), and 27 of 32 patients were female. Of these 32 patients (64 bilateral hip fractures), 32 fractures were intracapsular (1 femoral neck, 31 subcapital) and 32 were extracapsular fractures (6 subtrochanteric, 26 transtrochanteric). Although 24 of the 32 patients had identical first and second hip fractures, only eight out of 32 hips were treated with the same implants. There was a significant difference in Singh index between both hips at the time of the first fracture. There was also a significant difference in Singh index between the hip which was not fractured compared with its subsequent index when it was broken. All other studied patient and fracture characteristics were not significantly different. In this population the percentage of second hip fractures was relatively low compared to other studies. The choice of implants in this study shows that implants were chosen randomly. Because there is a significant difference in the Singh index during first and second hip fracture, osteoporosis medication might help reduce the incidence of second hip fractures.
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Affiliation(s)
- Laura M Kok
- Leiden University Medical Center, Leiden, The Netherlands.
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The effect of injectable biocompatible elastomer (PDMS) on the strength of the proximal fixation of endovascular aneurysm repair grafts: An in vitro study. J Vasc Surg 2010; 52:152-8. [DOI: 10.1016/j.jvs.2010.01.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 12/28/2009] [Accepted: 01/03/2010] [Indexed: 11/17/2022]
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Aortic Customize: A new alternative endovascular approach to aortic aneurysm repair using injectable biocompatible elastomer. An in vitro study. J Vasc Surg 2010; 51:1230-7. [DOI: 10.1016/j.jvs.2009.08.093] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Revised: 08/28/2009] [Accepted: 08/30/2009] [Indexed: 11/24/2022]
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