Influence of femoroacetabular impingement on results of hip arthroscopy in patients with early osteoarthritis.

To ascertain whether better results could be obtained using hip arthroscopy, we retrospectively reviewed the radiographic and clinical aspects of anterior femoroacetabular impingement in 43 patients diagnosed with early osteoarthritis with acetabular labral tears who previously had arthroscopic treatment. The average followup was 50 months. The patients were divided into two groups: patients who had no osteoarthritis seen on simple radiographs, but had degenerative changes of the labrum and cartilage seen on magnetic resonance arthrograms and arthroscopy, and patients who had osteoarthritic findings seen on simple radiographs. Both groups were examined retrospectively for signs of anterior femoroacetabular impingement at the acetabulum and proximal femur. Postoperative improvement was evaluated using the Japanese Orthopaedic Association pain score. Six of 21 patients in Group I and 12 of 22 of patients in Group II showed radiographic evidence of femoroacetabular impingement. The score improved from 0.76 preoperatively to 2.38 postoperatively in Group I and from 0.75 preoperatively to 1.90 postoperatively in Group II. Arthroscopic débridement produced improved results seen during short-term and midterm followups. However, in patients with femoroacetabular impingement the results were considered inadequate. We found that arthroscopic treatment of osteoarthritis of the hip fails if there is detectable femoroacetabular impingement.