Clinical and radiographic predictors of intra-articular hip disease in arthroscopy.

BACKGROUND: The arthroscopic treatment of intra-articular hip disease and associated structural abnormalities continues to evolve. Nevertheless, contemporary diagnostic tools have significant limitations in predicting severity of disease preoperatively.

HYPOTHESIS: Clinical characteristics and radiographic parameters correlate with and predict intra-articular disease patterns in patients undergoing hip arthroscopy.

STUDY DESIGN: Cohort study; Level of evidence, 3.

METHODS: In sum, 355 hips in 338 patients undergoing hip arthroscopy by a single surgeon were retrospectively reviewed. Clinical characteristics and radiographic findings (on anteroposterior pelvis and frog lateral radiographs) of mild dysplasia, cam, and pincer-type femoroacetabular impingement were compared with intraoperative labral and chondral disease patterns.

RESULTS: Labral tears were present in 90.1% of hips, and acetabular cartilage lesions were present in 67.3%, including 41.7% with grade 3 or 4 chondromalacia. Multivariate logistic regression analysis found male sex, older age (<30, 30-50, >50 years old), Tönnis osteoarthritis grade, and alpha angle >50° on frog lateral radiograph to be independently associated with increased risk of grade 3 or 4 acetabular chondromalacia (all P < .001). Insidious onset of pain (in contrast to acute onset) was independently associated with the presence of acetabular chondromalacia (P = .002). Cam-type femoroacetabular impingement (alpha angle >50°) was strongly associated with more severe labral disease (P < .001). Findings of acetabular dysplasia and pincer femoroacetabular impingement did not remain significantly associated with acetabular chondral disease in the multivariate analysis.

CONCLUSION: Several clinical and radiographic characteristics--most notably, male sex, older age, Tönnis grade, and elevated alpha angle--are associated with more severe intra-articular hip disease. The recognition of these associations between clinical and radiographic characteristics and hip disease patterns is important for patient selection, surgical planning, and patient counseling.