High satisfaction and low conversion rate to total hip arthroplasty after hip arthroscopy for femoroacetabular impingement syndrome and risk factors affecting survival at long-term follow-up.

Purpose: Studies evaluating the long-term survival rate, patient satisfaction, and conversion to total hip arthroplasty (THA) are limited. The aim of this study was to evaluate satisfaction and hip survival at a minimum 10-year follow-up in patients following hip arthroscopy for femoroacetabular impingement syndrome (FAIS).

Methods: A total of 164 patients underwent hip arthroscopy for FAIS between 2007 and 2012; of these, 76 (49 men and 27 women; mean age, 40.7 ± 11.2 years; range, 15-69 years) patients could be clinically examined or reached by phone or email and included in the study. Prospectively collected data of these patients who followed for a minimum of 10 years were retrospectively analysed. Patients who had previous trauma or surgery on the hip or were younger than 15 years were excluded. Of the 76 patients, 37 (48.7%) had mixed type, where 29 (38.2%) had cam and 10 (13.2%) had pincer type FAIS. Patient demographics, Tonnis grade for osteoarthritis and intraoperative findings were reviewed. Outcome measures of interest included reoperations (re-arthroscopy, conversion to THA), patient satisfaction, ability to return to sports, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), modified Harris Hip Score (mHHS) and some possible factors associated with conversion to THA.

Results: The mean follow-up was 12.4 ± 1.8 (10-16 years). Twenty-one per cent required conversion to THA, with a mean time requiring THA of 4.8 ± 1.7 years (2-8 years). Mean age of the patients requiring THA was 47.8 ± 8.2 years. Two (2.6%) patients required re-arthroscopy. Fifty-eight (76.3%) patients did not undergo any revision surgery or other treatments. Forty-seven (61.8%) patients were completely satisfied with the results, where 5 (6.6%) patients were very satisfied and 4 (5.3%) patients were satisfied. Overall satisfaction rate was 73.7%. Mean postoperative mHHS score was 76.5 ± 15.5 and the mean WOMAC score was 84.0 ± 16.0. Return-to-sports rate was 85%, and the return to the old sport level was 67.1%. Age over 40 years (p = 0.004), a Tonnis Grade >1 (p < 0.001) and a full-thickness acetabular chondral lesion (p = 0.001) were identified as factors for failure and conversion to THA.

Conclusions: Hip arthroscopy for FAIS resulted in high satisfaction of patients who did not eventually require THA. Higher rates of conversion to THA were seen in older patients, patients treated with higher Tonnis grade and full-thickness acetabular chondral lesions.

Level of evidence: IV, Case Series.