Mechanics of the canine femur with two types of hip replacement stems

R. Shahar; L. Banks-Sills; R. Eliasy

doi:10.1055/s-0038-1632770

Veterinary and Comparative Orthopaedics and Traumatology, Inhaltsverzeichnis

Vet Comp Orthop Traumatol 2003; 16(03): 145-52
DOI: 10.1055/s-0038-1632770

Original Research

Schattauer GmbH

Mechanics of the canine femur with two types of hip replacement stems

Finite element analysis

Authors

R. Shahar

¹Section of Surgery, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Israel
L. Banks-Sills

²The Dreszer Fracture Mechanics Laboratory, Department of Solid Mechanics, Materials and Systems, The Fleischman Faculty of Engineering, Tel Aviv University, Israel
R. Eliasy

²The Dreszer Fracture Mechanics Laboratory, Department of Solid Mechanics, Materials and Systems, The Fleischman Faculty of Engineering, Tel Aviv University, Israel

Abstract

Summary

The long-term performance of total hip replacement is of concern to veterinary surgeons. Two of the main complications associated with this procedure are implant loosening and stress shielding. Designs of the femoral stem which will avoid loosening and achieve maximum endurance while reducing stress shielding and periprosthetic bone loss are sought.

In the intact femur the stress is distributed over the entire cross section of the bone. After hip replacement this pattern of stress distribution is altered because of the manner in which the load is transferred from the prosthesis to the bone.

The objective of this study was to examine the stresses that develop in the femur and implant components of two different methods of hip replacement used clinically in dogs. Anatomic, three-dimensional finite element models of the canine femur with a cemented femoral stem and a Zurich cementless stem were constructed. The stresses and displacements were calculated by the finite element analysis method, under physiologic loads that included muscle forces and joint reaction forces. The results were compared to results obtained by a similar analysis of an intact femur.

This study demonstrates that the Zurich cementless method causes less stress shielding in the proximal femoral cortex than does the cemented method. Implant stresses are higher in the Zurich cementless stem, but still within an acceptable range.

Keywords

Finite element - femur - hip replacement

Volltext

Referenzen

References
1 Chang PB, Mann KA, Bartel DL. Cemented femoral stem performance. Clin Orth Rel Res 1998; 355: 57-69.
2 Cheal EJ, Spector M, Hayes WC. Role of loads and prosthesis material properties on the mechanics of the proximal femur after total hip arthroplasty. J Orth Res 1992; 10: 405-22.
3 Cook Sd, Skinner HB, Weinstein AM, Lavernia CJ, Midgett RJ. The mechanical behavior of normal and osteoporotic canine femora before and after hemiarthroplasty. Clin Orth Clin Res 1982; 170: 303-12.
4 Cross AR, Aron DN, Budsberg SC, Foutz TL, Pearman BT, Evans MD. Validation of a finite element model of the Kirschner-Ehmer external skeletal fixation system. Am J Vet Res 1999; 60: 615-20.
5 Edidin AA, Merritt PO, Hack BH, Manley MT. A ported, proximally-cemented femoral stem for total hip arthroplasty. J Bone Joint Surg 1998; 80: 869-75.
6 Edwards MR, Egger EL, Schwartz PD. Aseptic loosening of the femoral implant after cemented total hip arthroplasty in dogs: 11 cases in 10 dogs (1991-1995). J Am Vet Med Assoc 1997; 211: 580-6.
7 Estok DM, Orr TE, Harris WH. Factors affecting cement strains near the tip of a cemented femoral component. The Journal of Arthroplasty 1997; 12: 40-8.
8 Hertzberg RW. (ed). Deformation and fracture mechanics of engineering materials. Ed 3. New York: John Wiley & Sons; 1989: 477.
9 Huiskes R. The various stress patterns of pressfit, ingrown, and cemented femoral stems. Clin Orth Rel Res 1990; 261: 27-38.
10 Huiskes R, Van Rietbergen B. Preclinical testing of total hip stems. Clin Orth Rel Res 1995; 319: 64-76.
11 Joshi MG, Advani SG, Miller F, Santare MH. Analysis of a femoral hip prosthesis designed to reduce stress shielding. J Biomech 2000; 33: 1655-62.
12 Joshi MG, Santare MH, Advani SG. Survey of stress analyses of the femoral hip prosthesis. Appl Mech Rev 2000; 53: 1-18.
13 Kerner J, Huiskes R, Van Lenthe GH, Weinamns H, Van Rietbergen B, Engh CA, Amis AA. Correlation between pre-operative periprosthetic bone density and post-operative bone loss in THA can be explained by strainadaptive remodeling. J Biomech 1999; 32: 695-703.
14 Lee IY, Skinner HB, Keyak JH. Effects of variation of cement thickness on bone and cement stress at the tip of a femoral implant. The Iowa Orthopedic Journal 1993; 13: 155-9.
15 Mann KA, Bartel DL, Ayers DC. Influence of stem geometry on mechanics of cemented femoral hip components with a proximal bond. J Orth Res 1997; 15: 700-6.
16 McNamara BP, Cristofolini L, Toni A, Taylor D. Relationship between bone-prosthesis bonding and load transfer in total hip reconstruction. J Biomeh 1997; 30: 621-30.
17 Muntig E, Verhelpen M. Fixation and effect on bone strain pattern of a stemless hip prosthesis. J Biomech 1995; 28: 949-61.
18 Peck JN, DeHaan JJ. The Zurich cementless total hip replacement. ACVS Proceedings 2001; 145-7.
19 Prendergast PJ, Taylor D. Stress analysis of the proximo-medial femur after total hip replacement. J Biomed Eng 1990; 12: 379-82.
20 Rohlmann A, Mossner U, Bergmann G, Hees G, Kolbelt R. Effects of stem design and material properties on stresses in hip endoprostheses. J Biomed Eng 1987; 09: 77-83.
21 Saha S, Pal S. Mechanical properties of bone cement: a review. J Biomed Maters Res 1984; 18: 435-462.
22 Schulz KS. Application of arthroplasty principles to canine cemented total hip replacement. Vet Surg 2000; 29: 578-93.
23 Shahar R, Milgram J. Morphometric and anatomic study of the canine hind limb. Am J Vet Res 2001; 62: 928-33.
24 Shahar R, Banks-Sills L. Biomechanical analysis of the canine hind limb: calculation of forces during three-legged stance. The Vet J 2002; 163: 240-50.
25 Shahar R, Banks-Sills L, Eliasy R. Stress and strain in the intact canine femur: finite element analysis. Medical Engineering and Physics 2003; 25: 387-95.
26 Taylor ME, Tanner KE, Freeman MAR, Yettram AL. Stress and strain distribution within the intact femur: Compression or bending?. Med Eng Phys 1996; 18: 122-31.
27 Wang X, Shanbhag AS, Rubash HE, Agrawal CM. Short term effects of bisphosphonates on the biomechanical properties of canine bone. J Biomed Mater Res 1999; 44: 456-66.
28 Weinans H, Huiskes R, Grootenboer HJ. Effects of material properties of femoral hip components on bone remodeling. J Orth Res 1992; 10: 845-53.
29 Weinans H, Huiskes R, Grootenboer HJ. Effects of fit and bonding characteristics of femoral stems on adaptive bone remodeling. J Biomech Eng 1994; 116: 393-400.
30 Wylie KB, DeYoung DJ, Drost WT, DeYoung BA. The effect of surgical approach on femoral stem position in canine cemented total hip replacement. Vet Surg 1997; 26: 62-6.
31 Yoon YS, Jang GH, Kim YY. Shape optimal design of the stem of a cemented hip prosthesis to minimize stress concentration in the cement layer. J Biomech 1989; 22: 1279-84.