고관절 이형성증에 시행한 무시멘트 고관절 전치환술

Abstract

A study was undertaken to evaluate the result of cementless total hip replacement for dysplastic hips with secondary osteoarthritis when the host bone covers over 70% of the cup. Thirty-three cementless total hip arthroplasties were performed without using bone graft. Preoperatively the patients had Crowe type-I, II or III subluxation. The average C-E angle was 4.4 degrees and it acetabular angle was 51 degree. The clinical and radiological results were reviewed retrospectively at a mean of 4.4 years(range, three to nine years). We also determined the vertical coordinate of the locus of the hip center and the horizontal coordinate to evaluate the correlation between the vertical and horizontal loci of the hip center and the loosening rate. The average Harris hip score improved from a preoperative value of 50 points to a postoperative value of 89 points. After acetabular reconstruction, the mean vertical locus of the hip center above the intertear drop line was 24.7 mm compared to a mean of 20.7 mm for contralateral hips. The mean horizontal locus of the hip center was only 32.5 mm compared to a mean of 34.2mm for contralateral hips. One socket(3 percent) was revised because of symptomatic loosening of the cup. The rate of radiographic loosening of the femoral component was 9 percent(3 cases). We did not find a relationship between the amount of horizontal or vertical displacement of the center of the femoral head and the rate of loosening. and concluded that, for patients who have Crowe type-I, II or III dysplasia of the hip, good results can be obtained by the insertion of a cementless cup without bone graft when the host bone covers over 70% of the cup.