Is Labral Size Predictive of Failure with Repair in Hip Arthroscopy? A Review of 571 Cases

Abstract

The purpose is to assess whether labral size is predictive of labral repair failure or demonstrates association with patient outcomes post-hip arthroscopy. A retrospective chart review was performed for patients undergoing arthroscopic hip labral repair from April 2009 to July 2015. Labral size was measured in 4 quadrants (antero-inferior, antero-superior, posterior-superior, and posterior-inferior). The average size across torn labral segments was assessed for statistical significance with labral repair failure as determined by patient reported outcomes (PROs) and need for additional surgery. Outcomes were evaluated for any continuous correlation as well as significant differences between classes of labral sizes derived from quartile and decile ranges. Included hips were those from patients between the ages 18 and 55 with 2-year postoperative follow up and lateral center edge angles (LCEA) between 25-40°. Exclusion criteria included less than 2 year follow up, Tonnis osteoarthritis grade ≥ 2, coxa profunda or protrosio, previous hip surgeries, pediatric hip conditions such as Perthes and slipped capital femoral epiphysis, avascular necrosis, and certain surgical factors such as labral debridement or reconstruction, and peri-trochanteric or deep gluteal space procedures. A total of 571 hips were included in the study. The mean labral width of involved quadrants was 5.35 ± 1.40 mm. Labral width averages did not show significant difference between those requiring revision versus those not requiring revision (p= .4054). There was no significant correlation between labral width and the change in preoperative and 2-year postoperative iHOT (R2 = 0.05780), mHHS (R2 = 0.19826), or NAHS (R2 = 0.23543) outcome scores. Those with labral sizes in the upper decile of our cohort showed significantly decreased improvement in the iHOT (p= .0287) and NAHS (p= .0490) when compared to the middle 50% of labral sizes. No significant differences in outcome scores were found for the bottom decile, bottom quartile, or upper quartile groups compared to middle 50%. Labral size did not predict clinical outcomes or need for revision in the majority of patients in our cohort. Hypertrophic labrums in the largest 10th percentile, or a size of 7.3 mm or greater, demonstrated lower postoperative outcome scores. This may suggest that patients with extremely large labrums may not improve after arthroscopy to the same degree as those with more normally sized labrums. However, for the majority of patients it is reasonable to suggest differences in labral size should not alter the treatment plan if morphology is otherwise standard. The reported poor outcomes associated with hypoplastic or hypertrophic labra may be due to associated factors rather than labral size alone.