Central Acetabular Impingement Is Associated With Femoral Head and Ligamentum Teres Damage: A Cross-Sectional Matched-Pair Analysis of Patients Undergoing Hip Arthroscopy for Acetabular Labral Tears.

PURPOSE: The primary purpose of this study was to report the prevalence of femoral head articular damage in patients with a central acetabular osteophyte (CAO) that was identified during hip arthroscopy and compare it with that in a matched control group without a CAO. A secondary purpose was to identify rates of coexisting intra-articular pathology in both patient groups.

METHODS: Intraoperative data were collected prospectively on all hip arthroscopy patients at our institution between 2008 and 2015. The inclusion criteria for this study were CAOs identified during hip arthroscopy for a labral tear and/or femoroacetabular impingement. The exclusion criteria were Tönnis grade greater than 0, previous hip conditions, and prior surgical interventions. The matched control group was selected based on sex, age ± 5 years, body mass index, and Workers' Compensation claim at a 3:1 ratio and comprised patients who underwent hip arthroscopy for a labral tear and/or femoroacetabular impingement without a CAO. The size and location of labral tears and chondral lesions were recorded in square millimeters with a 5-mm probe and by the clock-face method.

RESULTS: The CAO group consisted of 126 patients, who were matched to 378 patients in the control group. Femoral and acetabular chondral damage grades were significantly different between the 2 groups (P < .001). Of patients with CAOs, 55% had femoral head chondral damage compared with 24% of the control patients. The mean size of femoral chondral damage was 3.2 cm2 in the CAO group and 1.7 cm2 in the control group. The mean size of acetabular chondral damage was 1.7 cm2 in the CAO group and 1.2 cm2 in the control group. Both femoral and acetabular chondral damage sizes were significantly larger in the CAO group (P ≤ .007). The prevalence of ligamentum teres tears was significantly different between the 2 groups (P < .001). There were no statistically significant differences in the types of labral tears between the 2 groups (P = .625).

CONCLUSIONS: This study showed that patients with CAOs had a significantly higher prevalence of femoral chondral damage and ligamentum teres tears than matched controls.

LEVEL OF EVIDENCE: Level III, comparative study.