Introduction
Extensive chondral and labral damage have, independently, been shown to be associated with poorer outcomes following hip arthroscopy(HA) for femoroacetabular impingement(FAI). The extent of damage to the chondrolabral junction(CLJ) transition zone and consequential association with mid-term outcomes is less well reported.
Methods
A prospective institutional hip preservation registry was reviewed for patients undergoing HA for isolated pincer or mixed FAI between 2015-2019. Two groups were established based on the type of labral repair performed: Cuff Repair (Group A) vs Loop Repair (Group B). The choice of repair was determined by the integrity of the CLJ, thus eligible cases from the Group A consisted of those with an intact CLJ, while eligible cases from Group B consisted of those with complete CLJ separation. 1:1 case-control matching was performed based on gender and age±5 years. Exclusion criteria: Tonnis>1, dysplasia (LCEA/ACEA <25o), concomitant hip pathologies, bilateral patients where both repair types were performed for separate hips. Patient-reported outcomes(PROs), minimal clinically important difference(MCID), symptom burden(SB), rate of revision arthroscopy and conversion to THA was evaluated between groups at 5-years post-op.
Results
1,049 HA cases were operated on during the study period. 252 met inclusion for Group A; 110 for Group B. Following 1:1 matching, 97 cases were included in each group; 92% Male, mean age 32.5±9.7 (p=0.082). Bony prominences were larger for Group B compared to Group A (LCEA 37.4o vs 35.2o, p=0.006; ACEA Most Anterior, 47.1o vs 44.0o, p<0.005; AA Dunn 67.2o vs 50.8o, p<0.001; AA AP view 74.0o vs 51.4o, p<0.001), indicating progression of FAI. ACEA Sourcil was similar between groups (35.9o vs 34.7o, p=0.192). No difference in rates of repeat HA (6.5% Group A vs 5.0% Group B, p=0.743), or conversion to THA (0.0% Group A vs 3.8% Group B, p=0.245) between groups. PROs were similar pre-operatively: mHHS, p=0.491; UCLA, p=0.501; SF36, p=0.506; WOMAC, p=0.338; and post-op for UCLA (9(7-10) A vs 9(6-10) B, p=0.208), SF36 (89(81-95) A vs 87(73-92) B, p=0.220), WOMAC (4(1-10) A vs 7(2-21) B, p=0.121). At 5-years post-op mHHS was higher for Group A compared to Group B: (100(96-100) vs 96(83-100), p=0.007).
Cohort-specific MCID thresholds were 8.3, 1.3, 8.8, 8.4 for mHHS, UCLA, SF36, WOMAC.
MCID achievability was similar between groups: mHHS, 88% vs 78%, p=0.182; UCLA, 77.1% vs 58.7%, p=0.056; SF36, 58.1% vs 50.0%, p=0.432; WOMAC, 76.5% vs 57.5%, p=0.086, for Group A and B respectively.
Symptom burden was similar between groups pre-operatively (5.5±2.6 vs 6.0±3.1, p=0.285) and 5-years post-op (3.1±3.5 vs 3.7±3.1, p=0.340) for Group A and B respectively. The MCID for SB resolution was achieved at similar rates for both groups: 60% (A) vs 62% (B), p=0.842.
Conclusion
At 5-years post-op there is a significant improvement in all PROMs. The integrity of the CL junction and subsequent repair does not appear to impact post-op PROMs, ability to achieve MCID or survivorship, in this matched cohort. Although Group B represented pathological progression intraoperatively and on imaging, with Tonnis grades <2 such progression seems not to impact surgical outcome at this time point.