Introduction: The purposes of this study were to describe: (i) short-term disease-specific patient-reported outcome scores (PROMs); and (ii) factors associated with reoperation or treatment failure in patients undergoing open hip preservation surgery for symptomatic extraarticular FAI.
Methods: Patients undergoing open hip preservation surgery for symptomatic extraarticular FAI were identified from a prospective, single-centre hip preservation registry (n = 51 patients; median clinical follow-up 24 [range 11-49] months). Hip-specific PROMs were assessed preoperatively, 6 months, and each year subsequently. Patients undergoing reoperation or treatment failure (<10 point improvement in iHOT-33 postoperatively) over the study period were identified. Preoperative associated factors were explored on a univariate basis.
Results: International Hip Outcome Tool-33 (iHOT-33) improved from 33 (standard deviation [SD] 18) to 62 (26) at most recent follow-up and 76% of patients improved by minimum clinically important difference (MCID). Harris Hip Score improved from 53 (15) to 75 (17) at most recent follow-up and 79% of patients improved by MCID. Hip Outcome Score (HOS) Sport improved from 45 (26) to 66 (28) at most recent follow-up and 60% of patients improved by MCID. Continued improvements in mean follow-up scores were seen from 1 year to 2 years. Overall, 7 patients underwent reoperation and 9 patients failed to improve by MCID. Preoperative HOS Sport was higher in patients experiencing reoperation or treatment failure (58 [SD 19] vs. 40 [SD 27] respectively; p = 0.03). No other associated demographic, physical examination, or radiographic factors were found.
Conclusions: Open treatment of extraarticular FAI results in short-term improvements in hip-specific PROMs in most patients. Higher HOS Sport scores were associated with reoperation or treatment failure. Longer-term follow-up is necessary to define maximum improvements in this challenging patient population.