Finite element analysis of the ovine hip: Development, results and comparison with the human hip

Summary

Objectives: The ovine hip is often used as an experimental research model to simulate the human hip. However, little is known about the contact pressures on the femoral and acetabular cartilage in the ovine hip, and if those are representative for the human hip.

Methods: A model of the ovine hip, including the pelvis, femur, acetabular cartilage, femoral cartilage and ligamentum transversum, was built using computed tomography and microcomputed tomography. Using the finite element method, the peak forces were analysed during simulated walking.

Results: The evaluation revealed that the contact pressure distribution on the femoral cartilage is horseshoe-shaped and reaches a maximum value of approximately 6 MPa. The maximum contact pressure is located on the dorsal acetabular side and is predominantly aligned in the cranial-to-caudal direction. The surface stresses acting on the pelvic bone reach an average value of approximately 2 MPa.

Conclusions: The contact pressure distribution, magnitude, and the mean surface stress in the ovine hip are similar to those described in the current literature for the human hip. This suggests that in terms of load distribution, the ovine hip is well suited for the preclinical testing of medical devices designed for the human hip.

Keywords

Hip joint - sheep - contact pressure - bone stress - finite element method

• References

• 1 Mann KA, Miller MA, Khorasani M. et al. The dog as a preclinical model to evaluate interface morphology and micro-motion in cemented total knee replacement. Vet Comp Orthop Traumatol 2012; 25: 1-10.
• 2 Schramme M, Hunter S, Campbell N. et al. A surgical tendonitis model in horses: technique, clinical, ultrasonographic and histological characterisation. Vet Comp Orthop Traumatol 2010; 23: 231-239.
• 3 Langhoff JD, Mayer J, Faber L. et al. Does surface anodisation of titanium implants change osseointegration and make their extraction from bone any easier?. Vet Comp Orthop Traumatol 2008; 21: 202-210.
• 4 Field JR, McGee M, Stanley R. et al. The efficacy of allogeneic mesenchymal precursor cells for the repair of an ovine tibial segmental defect. Vet Comp Orthop Traumatol 2011; 24: 113-121.
• 5 Bertollo N, Bell DJ, Walsh WR. Intraoperative patellar kinematics following resection of the central one-third of the patellar tendon in the ovine stifle joint. Vet Comp Orthop Traumatol 2011; 24: 197-204.
• 6 Field JR, Stanley R, Appleyard R. et al. An evaluation of prosthetic femoral head impact on acetabular articular cartilage in a hemiarthroplasty model. Vet Comp Orthop Traumatol 2009; 22: 142-147.
• 7 Dozza B, Di BC, Lucarelli E, Giavaresi G. et al. Mesenchymal stem cells and platelet lysate in fibrin or collagen scaffold promote non-cemented hip prosthesis integration. J Orthop Res 2011; 29: 961-968.
• 8 Bergmann G, Siraky J, Rohlmann A. et al. A comparison of hip-joint forces in sheep, dog and man. J Biomech 1984; 17: 907-921.
• 9 Bergmann G, Graichen F, Rohlmann A. Hip joint forces in sheep. J Biomech 1999; 32: 769-777.
• 10 Taylor WR, Ehrig RM, Heller MO. et al. Tibio-femoral joint contact forces in sheep. J Biomech 2006; 39: 791-798.
• 11 Bergmann G, Deuretzbacher G, Heller M. et al. Hip contact forces and gait patterns from routine activities. J Biomech 2001; 34: 859-871.
• 12 Frisbie DD, Cross MW, McIlwraith CW. A comparative study of articular cartilage thickness in the stifle of animal species used in human pre-clinical studies compared to articular cartilage thickness in the human knee. Vet Comp Orthop Traumatol 2006; 19: 142-146.
• 13 Mizrahi J, Solomon L, Kaufman B. et al. An experimental method for investigating load distribution in the cadaveric human hip. J Bone Joint Surg Br 1981; 63B: 610-613.
• 14 Brown TD, Shaw DT. In vitro contact stress distributions in the natural human hip. J Biomech 1983; 16: 373-384.
• 15 Adams D, Swanson SAV. Direct measurement of local pressures in the cadaveric human hip joint during simulated level walking. Ann Rheum Dis 1985; 44: 658-666.
• 16 Afoke NYP, Byers PD, Hutton WC. Contact pressures in the human hip joint. J Bone Joint Surg Br 1987; 69: 536-541.
• 17 von Eisenhart R, Adam C, Steinlechner M. et al. Quantitative determination of joint incongruity and pressure distribution during simulated gait and cartilage thickness in the human hip joint. J Orthop Res 1999; 17: 532-539.
• 18 Anderson AE, Ellis BJ, Maas SA. et al. Validation of finite element predictions of cartilage contact pressure in the human hip joint. J Biomech Eng. 2008 130. 051008.
• 19 Rushfeldt PD, Mann RW, Harris WH. Improved techniques for measuring in vitro the geometry and pressure distribution in the human acetabulum .II. Instrumented endoprosthesis measurement of articular surface pressure distribution. J Biomech 1981; 14: 315-323.
• 20 Hodge WA, Carlson KL, Fijan RS. et al. Contact pressures from an instrumented hip endoprosthesis. J Bone Joint Surg Am 1989; 71: 1378-1386.
• 21 Park S, Krebs DE, Mann RW. Hip muscle co-contraction: evidence from concurrent in vivo pressure measurement and force estimation. Gait Posture 1999; 10: 211-222.
• 22 McCartney WT, Comiskey D, MacDonald B. Use of transilial pinning for the treatment of sacroiliac separation in 25 dogs and finite element analysis of repair methods. Vet Comp Orthop Traumatol 2007; 20: 38-42.
• 23 McCartney WT, Comiskey DP, Mac DB. et al. Fixation of humeral intercondylar fractures using a lateral plate in 14 dogs supported by finite element analysis of repair. Vet Comp Orthop Traumatol 2007; 20: 285-290.
• 24 Anderson AE, Ellis BJ, Maas SA. et al. Effects of idealized joint geometry on finite element predictions of cartilage contact stresses in the hip. J Biomech 2010; 43: 1351-1357.
• 25 Anderson AE, Peters CL, Tuttle BD. et al. Subject-specific finite element model of the pelvis: development, validation and sensitivity studies. J Biomech Eng 2005; 127: 364-373.
• 26 Bachtar F, Chen X, Hisada T. Finite element contact analysis of the hip joint. Med Biol Eng Comput 2006; 44: 643-651.
• 27 Phillips ATM, Pankaj P, Howie CR. et al. Finite element modelling of the pelvis: Inclusion of muscular and ligamentous boundary conditions. Med Eng Phys 2007; 29: 739-748.
• 28 Shim VB, Pitto RP, Streicher RM. et al. Development and validation of patient-specific finite element models of the hemipelvis generated from a sparse CT data set. J Biomech Eng. 2008 130. 051010.
• 29 Zhang QH, Wang JY, Lupton C. et al. A subject-specific pelvic bone model and its application to cemented acetabular replacements. J Biomech 2010; 43: 2722-2727.
• 30 Dalstra M, Huiskes R, Vanerning L. Development and validation of a 3-dimensional finite-element model of the pelvic bone. J Biomech Eng 1995; 117: 272-278.
• 31 Murakami T, Higaki H, Sawae Y. et al. Adaptive multimode lubrication in natural synovial joints and artificial joints. Proc Instit Mech Eng H 1998; 212: 23-35.
• 32 ANSYS. Mechanical (formerly Simulation). ANSYS® Academic Research; Release 12.0 2009. [cited 2011 September 10]. Available from: http://www1.ansys.com/customer/content/documentation/120/wb_sim.pdf.
• 33 Greenwald AS, Haynes DW. Weight-bearing areas in the human hip joint. J Bone Joint Surg Br 1972; 54: 157-163.