The temporal progression of pelvic osteolysis after uncemented total hip arthroplasty.

This study examined the natural progression of pelvic osteolysis post uncemented total hip arthroplasty. Serial radiographs from 145 total hip arthroplasties with minimum 10-year follow-up were examined. Thirty-two lesions were identified in 25 hips and their 2-dimensional radiographic size over time was measured via computer. Lesion growth rate averaged 42.7 +/- 49.0 mm2/y. Linear models were generally a good fit for lesion growth as evidenced by a high mean r2 value (0.77 +/- 0.18); lesions progressed steadily during the first 10 postoperative years. Although lesions were first radiographically evident 5.7 years postarthroplasty, the x-intercept of the linear model, approximating the mean time when the lesions first began to develop, averaged 1.3 years. Because this study expands our understanding of when and how peri-acetabular lesions develop, it can be useful to clinicians in determining how often to see patients postoperatively.