Associations Between Hip Cartilage Lesions and Morphologic Parameters of Bony Structures in a Cohort of Asian Patients with Labral Tears Measured Using a Computed Tomography-Based Software System.

Abstract

Objective: This study aimed to investigate the associations between hip cartilage lesions and bony morphologic parameters in the hip joints using a computed tomography-based software system.

Methods: Seventy-nine symptomatic hips that underwent hip arthroscopic labral preservation surgery were enrolled in this study. Bony structural morphologic parameters were subsequently assessed via a computed tomography-based software system. The indices included the femoral neck anteversion (FNA), alpha angle (AA) at each o'clock position of the femoral head, lateral center edge angle (LCEA), and 3 dimensional acetabular coverage (3D-AC). Cartilage damage was confirmed arthroscopically and classified according to the Multicenter Arthroscopy of the Hip Outcome Research Network (MAHORN) classification as well as the International Cartilage Repair Society (ICRS) classification.

Results: Of the 79 hips, 41 patients were male, and 38 were female, with a mean age of 39.1 years ± 16.1 years (11-78). The mean LCEA was 27.6° ± 8.6° (range 7° to 46°), and the mean FNA was 22.9° ± 14.4° (range -2° to 63°). Grade 4 or 5 MAHORN acetabulum cartilage lesions were observed in 10 hips (13%), while femoral head cartilage lesions with ICRS grade of 3 or 4 were found in 10 hips. Patients with MAHORN grade 4 or 5 cartilage lesions had significantly greater FNA compared to those with MAHORN grade 0 to 3 lesions (32.6° ± 10.3° versus 21.4° ± 14.4°, p = 0.009). Although patients with MAHORN grade 4 or 5 lesions had greater AA at the entire o'clock of the femoral neck, the difference was not statistically significant. Patients whose FNAs were 26° or larger had a 6.2-fold greater odds ratio (95% CI, 1.2-31.5) of acetabular cartilage damage than those whose FNAs were less than 26° (p = 0.015).

Conclusion: The use of computed tomography-based software provided detailed insights into bony abnormalities reinforcing its utility in evaluating hip joint pathologies and their relationship with cartilage lesions.

Level of evidence: Level III.