The Results of Hip Arthroplasty with Hydroxyapatite Coated Anatomical Profile(R) Femoral Stem: Result After 5-Years to 10-years Follow up

Han, Chang Dong; Kim, Ho Joong; Yang, Ick Hwan

Abstract

PURPOSE
To report the results of hip arthroplasty using an uncemented hydroxyapatite (HA) coated anatomical Profile(R) femoral stem during a follow-up period of five to ten years. MATERIALS AND METHODS: Eighty-eight patients, ninety-nine cases of hip arthroplasty, who underwent surgery from May 1993 to February 1998, were reviewed clinically and radiographically. RESULTS: The mean Harris hip rating score was 54.4 preoperatively, which improved to 88.2 at the last follow up postoperatively. The radiographic evaluations revealed that endosteal new bone formation developed at Gruen zone 1 and 7 in all cases (100%) between 6 month and one year after surgery. Approximately 20 cases (20%) showed proximal osteoporosis due to profound stress shielding, and 83 cases (83.8%) showed distal cortical hypertrophy (zone 2, 6). These femoral remodelings correlated with the clinical results statistically. There was no aseptic loosening, but the polyethylene liner was changed only in one hip due to severe liner wear. CONCLUSION: This study indicate that the anatomical Profile(R) femoral stem can provide excellent initial stability and osseointegration. However, profound proximal bone loss was noted secondary to distal cortical hypertrophy in the long-term follow up. Therefore, other design concepts are needed, in which the femoral strain transfers more proximally rather than distally.