Biomechanical rationale of acetabular wall augmentation method for joint replacement in condition of osteoporosis

Abstract

Osteoporosis worsens the qualitative and quantitative characteristics of bone, which is a hostile environment for the stable long-fixation of acetabular component in hip joint endoprosthesis. Despite the large number of biomechanical studies of the stress-strain distribution in the acetabular component after hip arthroplasty, fixation of cup under osteoporotic conditions remains controversial and not studied well. Object: biomechanical reasoning for methods of acetabular wall augmentation during hip joint arthroplasty under the conditions of osteoporosis.Methods: in thisstudyfinite element method has been used. Pelvis and hip joint simulation in the different walking phases after total hip arthroplasty has been performed. We consider three phases for two cases of arthroplasty. The work is a continuation of earlier research conducted on a mathematical model of the pelvis, which made some changes. Simulation of left hip joint arthroplasty with endoprosthesis «Zimmer» with polyethylene liner. Bone density characteristic of the acetabular part has been changed as for osteoporosis. Also for the second option in osteoporotic acetabular zone cylindrical shape autotransplantats with a diameter of 6 mm and a length of 6 to 13 mm modeled. Results revealed that level of stress-strain state of the acetabulum in all phases of walking increases after arthroplasty in terms of osteoporosis as compared to normal model and in the case of walls augmentation using autotransplantat it is reduced. Conclusion:it has been proved the feasibility of bone autotransplantat using for acetabular walls augmentation during hip joint arthroplasty.