A novel arthroscopic classification of labral tear in hip dysplasia

Acetabular labral tears cause of pain in patients with symptomatic hip dysplasia. To date, no structured grading system has been developed to evaluate labral tears in these patients. The present study describes a new system of grading labral tears in patients with acetabular dysplasia.

The data of 66 patients who underwent hip arthroscopy for symptomatic hip dysplasia from March 2014 to February 2018 were reviewed. Labral tears were classified into four groups, based on the occurrence of chondrolabral junction (CLJ) disruption, capsulolabral recess (CLR) disruption, and labral displacement. Labral tears without instability were classified as grade 1 or 2. Partial delamination or blistering of the labrum with minimal fraying at the CLJ was classified as grade 1, whereas labral tears with CLJ disruption were classified as grade 2. Unstable labral tears with CLR disruption followed by CLJ disruption, but without labral displacement, were classified as grade 3, whereas unstable labral tears with CLR and CLJ disruption, but with labral displacement, were classified as grade 4. The radiological and clinical characteristics of patients in each grade were determined including by simple radiographs and MRI/MR arthrography, as were concomitant findings, including rupture of the ligamentum teres, articular cartilage damage, and presence of a paralabral cyst. The surgical options selected for each grade and clinical outcomes, including modified Harris hip scores (mHHS) and Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) scores, were evaluated. Spearman's correlation analyses were performed to assess whether labral tear grade correlated with baseline characteristics, the incidence of concomitant injuries, and the severity of osteoarthritis (OA). The Wilcoxon test for paired data was performed to compare treatment results with pain scores.

The study cohort included six men and 53 women of mean ± SD age 39.9 ± 13.0 years (range, 15-66 years). Of the 66 hips, seven (10.6%), 10 (15.2%), 30 (45.5%), and 19 (28.8%) were classified as grades 1-4, respectively. Symptom duration (P = 0.017), preoperative Tönnis OA grade (P < 0.001), cartilage damage (P < 0.001), and the presence of a paralabral cyst (P = 0.001) correlated significantly with baseline tear grade. In all groups, mHHS and WOMAC scores improved after surgical treatment.

Arthroscopic findings of labral tears in patients with hip dysplasia differed from the conventional classification. The classification system proposed in this study will likely be useful for determining the degree of labral tear in patients with hip dysplasia and for predicting treatment outcomes.