Total hip arthroplasty for Crowe type Ⅳ developmental dysplasia.

The purposes of this study were to evaluate the midterm clinical and radiographic results of total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia and to evaluate whether low back pain would improve after THA. Eighteen consecutive patients (20 hips) were included in this study. The average age at the time of surgery was 58.5 years. The average follow-up was 10.2 years. The socket was placed at the level of the true acetabulum, and a femoral shortening osteotomy was performed. The average Harris hip score before surgery was improved from 56 to 85 points at the final follow-up. Revision was performed in 4 hips due to loosening of the femoral component in 1 hip and osteolysis in 3 hips. The midterm outcomes of THA in patients with Crowe type IV developmental dysplasia were satisfactory. The severity of low back pain was significantly reduced after THA.