Periprosthetic Bone Remodeling after 12 Years Differs in Cemented and Uncemented Hip Arthroplasties

BACKGROUND: Different patterns of stress shielding may lead to differences in periprosthetic bone preservation around cemented and uncemented hips in the long term? QUESTIONS/PURPOSES: The purpose of this study is to compare the difference in periprosthetic bone density between cemented Charnley total hip and uncemented hydroxyapatite-coated Furlong THAs at a minimum followup of 12 years (mean, 16 years; range, 12-24 years). METHODS: We studied a cohort of 17 patients who had bilateral THAs with a cemented Charnley THA on one side and an uncemented Furlong hydroxyapatite-coated THA on the other side. At a minimum followup of 12 years, Harris and Oxford hip scores were used to determine the function, and dual-energy x-ray absorptiometry was used to quantify bone mineral density adjacent to the prosthesis. The results of the dual-energy x-ray absorptiometry scan for cemented and uncemented hips were analyzed using paired-sample two-tailed t-tests. To compare the Harris hip scores, a nonparametric Wilcoxon test was used. RESULTS: Bone mineral density was higher on the uncemented Furlong side in Gruen Zones 2, 3, 5, and 6 of the proximal femur and DeLee and Charnley Zone 1 of the acetabulum. In all other zones, there was no difference. Comparison of Harris and Oxford hip scores showed no differences between the two hips. CONCLUSION: Bone density is better preserved around the uncemented hydroxyapatite-coated Furlong stem compared with the Charnley cemented stem. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.