Correlation between Radiologic and Clinical Findings in Charnley Total Hip Replacement

Abstract

The main purpose of this study was to evaluate the relationship between the radiologic findings in clinically successful Charnley total hip replacements (THR) at an average of five years postoperatively (‘5-year follow-up’) and the clinical result 10 to 14 years after operation (‘10-year follow-up’). The study included 150 arthroplasties graded as clinically successful at the 5-year follow-up despite radiologic loosening of the femoral component in 41 per cent and of the acetabular component in 7 per cent. The incidence of clinical failure between the two follow-ups was 7 per cent (10 hips). Only 2 per cent (3/125) of THRs with intact components or a loose stem with migration not exceeding 4 mm became failures. Clinical failures resulted in 28 per cent (7/25) of THRs with more extensive loosening of the stem or with a loose socket. At the 10-year follow-up 47 per cent of the femoral and 13 per cent of the acetabular components were loose. Progression of loosening of the femoral stem occurred in 63 per cent and of the socket in 73 per cent between the two follow-ups. The incidence of loosening of the stem showed a significant correlation both with the extent of cementation distal to the tip and with the orientation of the prosthesis in the sagittal plane.