Total hip arthroplasty for high-riding hips: A retrospective analysis of 79 cases and proposal of a new classification

Abstract

Purpose: Total hip arthroplasty (THA) for high-riding hips is a complex procedure and the requirement for subtrochanteric osteotomy (STO) is an important decision that needs to be taken preoperatively. STO renders this complex surgery even more complicated and there are no guidelines to determine the STO requirement. In this study, the outcomes of THA for patients with high-riding hips were evaluated and a practical classification system is proposed to predict any osteotomy requirement. Methods: A retrospective evaluation was made of 79 hips of 76 patients who underwent THA for high-riding hip dysplasia. The amount of shortening in patients with STO and in patients without STO was compared. All patients were evaluated in respect of Harris hip score, operating time, erythrocyte suspension need, and actual limb length discrepancy. Preoperative radiographs were classified into four types according to the ratio of the distance between the lesser trochanter and the ischial tuberosity with pelvic height (LT-IT/P) to grade the degree of dislocation. Results: The mean follow-up was 30 ± 6.54 months. STO was applied to 47 (60%) hips and not to 32 (40%). There was no statistically significant difference between the groups in respect of the functional scores. STO prolonged the operating time and increased the need for blood transfusion ( p = 0.026, p 0.3 (type 3), a shortening osteotomy will most likely be required. The rate of complications is increased if LT-IT/P is >0.4 (type 4). Conclusion: STO adjunct to THA increases the rate of complications. This practical classification system may guide the surgeon in the decision of whether an STO should be added to the procedure or not. Level of evidence: Level III, clinical trial