[Acetabular centralization in total hip arthroplasty for acetabular dysplasia].

OBJECTIVE: To explore the correct localization of the acetabular component, surgical technique and the outcome in total hip arthroplasty (THA) for acetabular dysplasia with secondary osteoarthritis.

METHODS: A retrospective review was undertaken of 39 hips (33 patients) that had been performed a total hip arthroplasty for acetabular dysplasia with secondary osteoanthritis from September 1989 to January 2003. These patients were divided into two groups, 16 patients (20 hips) who were performed by regular THA of Harris method were defined as group A and the other 17 patients (19 hips) by acetabular centralization technique as group B. The hip function was evaluated using Harris hip score before and after operation. The horizontal location of the center of the hip (the distance along the intertear drop line extending lateral or medial from the inferior point of the teardrop to the perpendicular line dropped from the center of the femoral head), abduction angle of the cup, and femoral offset was measured.

RESULTS: At the most recent follow-up, the mean Harris hip score was 88.9 +/- 5.8, and 82.3 +/- 8.4 for the anatomical position reconstruction and the lateral displacement hips, respectively (P < 0.05). The horizontal distance between the teardrop and the hip center was significantly shorter in B group [(37.3 +/- 3.4) mm] than in A group [(46.1 +/- 5.3) mm] (P < 0.05). Two patients had bone resorption of autograft and malposition of the acetabular component during follow-up, while others had no revision, loosening, or migration of the acetabular component.

CONCLUSION: Accurately confirmed acetabular position, stable acetabular component, and appropriate techniques are important to guarantee the clinical efficacy of THA.