Similar Rates of Survivorship and Marginal Clinical Impact of Routine Interportal Capsular Repair Versus No Repair at 5 Years After Arthroscopic Correction of Femoroacetabular Impingement.

PURPOSE: To (1) compare 5-year survivorship (avoiding repeat hip arthroscopy (HA)/total hip replacement conversion) between those undergoing routine capsular repair compared with where no repair was performed; (2) compare patient-reported outcome measures (PROMs) and achievability of metrics of clinically important improvement between these groups; and (3) evaluate the moderating influence of age and sex on outcomes.

METHODS: Review of prospectively collected data from an institutional hip preservation registry, of cases undergoing hip arthroscopy (HA) for femoroacetabular impingement between January 2011 and September 2018, with minimum 5-year follow-up, was undertaken. Cases undergoing routine interportal capsular repair (CR) were matched in a 1:1 ratio (age ± 2 years, sex, Tönnis grade) to hips with no capsular repair (NR). Exclusion criteria were dysplasia, Tönnis grade >1, age >50 years, and concomitant hip pathologies. Group survival was evaluated using Kaplan-Meier analysis and for levels of sex and age. Where revision surgery (repeat HA/total hip replacement) was avoided, PROMs (modified Harris Hip Score, University of California and Los Angeles Activity Scale [UCLA], Short Form 36 [SF-36]) were assessed at minimum 5 years, and proportion of cases achieving minimal clinically important difference (MCID) and substantial clinical benefit (SCB) determined.

RESULTS: In total, 285 CR cases were matched with 285 NR cases. The average age was 27.0 ± 5.9 years, and most patients (90%) were male. The overall total hip replacement rate was 0.7% (0.4% NR; 0.9% CR, P = .619) and was not significantly different between groups when adjusting for sex (χ2 = 0.474, P = .491), or age (χ2 = 0.463, P = .496). The overall repeat HA rate was 12.0% (12.9% NR; 11.1% CR, P = .538), which was not significantly different between groups when adjusting for sex (χ2 = 0.479, P = .489), or age (χ2 = 0.448, P = .503). Significant improvement in all PROMs was noted for both the NR and CR groups (P < .001 for all). At 5 years postoperatively, SF-36 was marginally greater for the NR group (P = .006, r = 0.169). No significant difference between groups at 5 years postoperatively were found: modified Harris Hip Score (P = .476), UCLA (P = .188). A greater proportion of CR cases achieved MCID in UCLA (69.4% vs 56.5%, P = .032, Φ = 0.131). MCID achievement rates were similar between groups for all other PROMs (P > .05). A greater proportion of patients in the NR group achieved SCB in SF-36 (54.0% vs 41.9%, P = .049, Φ = 0.127). SCB achievement rates were similar between groups for all other PROMs (P > .05).

CONCLUSIONS: Routine repair of an interportal capsulotomy makes no difference to survivorship at minimum 5 years post-HA compared with nonrepair, with marginal differences in PROMs, and achievability of MCID and SCB thresholds of clinically significant improvement. The impact of capsular management (repair/nonrepair) may be more apparent for specific patient cohorts rather than routine repair in all cases.

LEVEL OF EVIDENCE: Level III, retrospective matched comparative case series.