Primary total hip arthroplasty (THA) in patients with incomplete hip abductor tears: does hip abductor repair improve outcome?

Introduction: Incomplete tears of the hip abductor insertion can coexist with primary hip osteoarthritis. The aim of this investigation was to test the hypotheses that: 1) the outcome of patients undergoing primary THA using a direct anterior approach would be inferior when hip abductor pathology was present; and 2) in the presence of incomplete tears, the transgluteal approach with hip abductor repair delivers a superior outcome compared to the direct anterior approach. Patients and Methods: Forty patients underwent MR imaging of the hip abductor insertion prior to THA. The grade of abductor tears was assessed, the approach used for THA was recorded, and pre- and postoperative one-year outcome scores (WOMAC, HHS) were recorded. Results: Twenty patients showed a normal appearance of the hip abductor insertion and THA was performed using the direct anterior approach (group 1). In 20 patients partial tears of the hip abductor insertion were recognized. Eight of them had THA through a direct anterior approach (group 2) and twelve through a transgluteal approach with repair (group 3). All patients improved after surgery. Overall the WOMAC improved from 6.1 to 2.1 points and the HHS from 46 to 87 points. A significantly higher benefit in terms of the HHS was achieved in patients of group 1 (p = 0.045). No significant differences were recorded between group 2 and group 3. Conclusions: Improvement in outcome scores after THA using the direct anterior approach was inferior in the presence of partial hip abductor tears. The repair of partial hip abductor tears was not associated with superior clinical results.