Arthroscopic Hip Revision Surgery for Residual Femoroacetabular Impingement (FAI): Surgical Outcomes Compared With a Matched Cohort After Primary Arthroscopic FAI Correction.

BACKGROUND There are limited data reporting outcomes after revision arthroscopic surgery for residual femoroacetabular impingement (FAI). HYPOTHESIS (1) Revision arthroscopic FAI correction results in improved outcomes, but they are inferior to those of primary arthroscopic FAI correction. (2) Improved postrevision radiographic parameters are predictive of better outcomes. STUDY DESIGN Cohort study; Level of evidence, 3. METHODS Patients who underwent arthroscopic hip revision for residual FAI were reviewed. Pathomorphological findings, intraoperative findings, and preoperative and postoperative modified Harris Hip Score (MHHS), Short Form-12 (SF-12), and pain on a visual analog scale (VAS) values were evaluated. Outcomes after revision arthroscopic FAI correction were compared with outcomes of a matched cohort who underwent primary arthroscopic FAI correction. RESULTS A total of 79 patients (85 hips) with a mean age of 29.5 years underwent arthroscopic revision FAI correction (mean follow-up, 26 months). The labrum was debrided (27 hips), repaired (49 hips), or reconstructed (7 hips). Two labrums were stable and required no treatment. The results of revision arthroscopic FAI correction were compared with those of 220 age- and sex-matched patients (237 hips) who underwent primary arthroscopic FAI correction (mean follow-up, 23 months). The mean improvement in outcome scores after revision FAI correction was 17.8 (MHHS), 12.5 (SF-12), and 1.4 (VAS) points compared with 23.4 (MHHS), 19.7 (SF-12), and 4.6 (VAS) points after primary arthroscopic FAI correction. The mean improvement was significantly better in the primary cohort compared with the revision cohort (P < .01 for MHHS, SF-12, and VAS values). Good/excellent results were achieved in 81.7% of the primary cohort and 62.7% of the revision cohort (P < .01). Greater postoperative head-neck offset (P = .024), subspine/anterior inferior iliac spine (AIIS) decompression (P = .014), labral repair/reconstruction (P = .009), and capsular plication (P = .032) were significant predictors for better outcomes after revision surgery. CONCLUSION Arthroscopic hip revision surgery for residual FAI yielded significantly improved outcome measures, but these were inferior to those after primary arthroscopic FAI corrective surgery. Improved femoral head-neck offset after cam decompression, identification and treatment of subspine/AIIS impingement, labral preservation/reconstruction, and capsular preservation/plication may be paramount to achieve satisfactory outcomes.