RESUMO
BACKGROUND:Failure rate is higher in patients with osteonecrosis of femoral head than in osteoarthritis patients after primary total hip arthroplasty, especial y acetabular prosthesis. Bone mineral density around the prosthesis is a key factor for quality of life of the prosthesis. OBJECTIVE:To observe the difference in periprosthetic bone mineral density between patients with osteonecrosis of the femoral head and osteoarthritis patients and the exact location of differences after primary total hip arthroplasty. METHODS:Fifty patients with osteonecrosis of femoral head and fifty osteoarthritis patients were enrol ed in this study. Dual energy X-ray absorptiometry examination was used to compare bone mineral density 5 years after total hip arthroplasty. In accordance with De Lee’s and Charnley’s methods, images of acetabulum were divided. The bone mineral density of different areas of the acetabulum was compared between the two groups. RESULTS AND CONCLUSION:(1) Periprosthetic bone mineral density:Bone mineral density in the lower part and upper part of the acetabulum was significantly lower in the osteonecrosis group than in the osteoarthritis group (P<0.05). No significant difference in bone mineral density in the middle of the acetabulum was detected between the two groups. (2) Results confirmed that the bone mineral density in the lower and the upper parts of the acetabular component was significantly lower in patients with osteonecrosis of femoral head than in patients with osteoarthritis.