Hip Arthroscopy and the Continuum of Joint Degeneration: Outcomes, Indications, and Long-Term Perspectives.

Abstract

Femoroacetabular impingement syndrome (FAIS) has emerged as a major cause of hip pain and dysfunction, particularly in young and middle-aged patients. The abnormal morphology of the femoral head–neck junction and/or acetabular rim predisposes to labral and cartilage damage, increasing the risk of early hip osteoarthritis (OA). Uncertainties remain regarding long-term joint survivorship after hip arthroscopy, the impact of preexisting OA, outcomes in subgroups such as labral ossification (LO), and complications such as iliopsoas impingement (IPI) after total hip arthroplasty (THA).The overall purpose of this thesis was to evaluate outcomes after hip arthroscopy in different patient populations with FAIS, to explore long-term functional benefits and risks of disease progression, and to critically examine trends in outcome reporting in the FAIS literature. The first study focused on patients with FAIS and mild to moderate OA (80 hips, 75 patients). At 10 years, 41% had progressed to THA, particularly those with preoperative Tönnis grade 2 changes, who had more than threefold higher risk of arthroplasty compared with grade 1. Non-THA patients reported substantial and durable improvements in function, highlighting that hip arthroscopy may delay but not prevent OA progression. The second study investigated 10-year outcomes in a large group of 128 patients (151 hips) treated arthroscopically for FAIS. Statistically and clinically significant improvements in international Hip Outcome Tool 12 (iHOT-12) and other patient reported outcome measures (PROMs) were observed at long-term follow-up, with 83% patient satisfaction. The method survivorship, defined as avoidance of THA, was 77%, indicating sustained functional benefit for most patients. The third study assessed arthroscopic iliopsoas tenotomy for IPI after THA (13 hips). At two years follow-up, most PROMs improved, and 83% of patients reported satisfaction, supporting the procedure as a safe and effective option for carefully selected patients with post-THA groin pain. The fourth study evaluated outcomes in patients with FAIS and LO. At two years, 25% had already undergone THA, yet the remaining patients reported significant functional improvement across all PROMs. In the fifth study, a systematic review of 196 clinical studies on FAIS surgery published between 1999 and 2020 demonstrated a 20-fold increase in publications, with hip arthroscopy as the predominant surgical technique. The modified Harris Hip Score (mHHS) was the most frequently used PROM.