Arthroscopic treatment of femoroacetabular impingement shows persistent clinical improvement in the mid-term.

INTRODUCTION: The concept of femoroacetabular impingement (FAI) and the indication for surgical intervention have been established in the last decade. Despite promising short-term results and emerging arthroscopic techniques, it remains unclear whether patients benefit from surgical correction in the mid- to long-term and whether progressive joint degeneration can be prevented.
MATERIALS AND METHODS: A retrospective study of our first 50 consecutive patients who underwent arthroscopic correction for FAI was conducted. The modified Harris hip score (mHHS) was assessed preoperatively and at final follow-up. In addition, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and a subjective hip value (SHV) were added at final follow-up. Degenerative changes according to Kellgren and Lawrence scale and the α angle were analyzed preoperatively and on the most recent radiograph.
RESULTS: Of a total of 50 patients, 44 (24 male, 20 female) with a mean age of 34.3 years (17-65) were available with complete follow-up. Of these 44 patients, 39 were treated with correction of the femoral offset for isolated cam deformity, 5 with additional focal pincer correction and partial labral resection. After a mean follow-up of 66.3 ± 14.5 months the mHHS had improved significantly from 67.2 ± 6.4 preoperatively to 86.4 ± 13.5 (p < 0.001). The WOMAC score (converted to 0 = best/100 = worst) resulted in mean indices for the subcategories pain, stiffness and function of 11.8 ± 16.5, 12.2 ± 17.8 and 9.1 ± 16.1. The SHV was reported with a mean of 77.7 ± 21.8 % at final follow-up. The α angle was reduced significantly from 57.2° ± 10.1° to 46.3° ± 7.4° (p < 0.001). The Kellgren and Lawrence score showed a non-significant trend from 2.0 ± 0.8 preoperatively to 2.2 ± 0.9 in the most recent radiograph (p = 0.46). 5 patients had been converted to a total hip arthroplasty a mean of 28 ± 7.1 months postoperatively. These patients were significantly (p < 0.01) older with a mean age of 49.8 ± 7.8 years and showed significantly higher present osteoarthritic changes with an average Kellgren and Lawrence score of 2.6 ± 2.5 before FAI correction (p < 0.01).
CONCLUSIONS: Arthroscopic correction of femoroacetabular impingement results in a persistent clinical improvement without significant progression of degenerative changes in the majority of patients. The indication for surgery should be established cautiously when degenerative changes are present. LEVEL OF EVIDENCE: Level IV, Case series with no comparison group.