Predictors of Clinically Suspected Intra-articular Hip Symptoms and Prevalence of Hip Pathomorphologies Presenting to Sports Medicine and Hip Preservation Orthopaedic Surgeons.

PURPOSE: The first purpose of the study was to evaluate the prevalence of various radiographic parameters and pathomorphologies for patients presenting with the diagnosis of hip pain. The second purpose of this study was to identify those pathomorphologies and radiographic parameters that were predictive of clinically suspected intra-articular and hip joint-related symptoms.

METHODS: A total of 998 hips (499 patients, 228 males, 271 females, mean age 38 years) presented to 2 orthopaedic surgeons with the diagnosis of hip pain. Patients were retrospectively identified as intra-articular and hip joint-related symptoms or extra-articular and non-hip joint-related symptoms based on history, examination, injection response, and diagnosis listed on clinical notes. A detailed morphologic evaluation of anteroposterior and 45° modified Dunn lateral radiographs of both hips was performed for all patients.

RESULTS: The presence of at least 1 finding consistent with femoroacetabular impingement (FAI) was noted in 96.6% of patients (89.9% of hips) and was bilateral in 83%. The prevalence of dysplasia was 10.6% in patients (6.7% of hips) and was bilateral in 2.8%. Cam-type morphology was more common in males (P < .001). Profunda and protrusio were more common in females (P < .001). Acetabular retroversion was more common in males (P = .02). Fifty-seven percent of hips (564/998) were diagnosed clinically with intra-articular and hip joint related symptoms. Cam-type FAI, mixed-type FAI, increasing alpha angle, and increasing Tönnis grade were independent predictors of clinically suspected intra-articular and hip joint symptoms (P < .001), whereas isolated Pincer-type morphology was not.

CONCLUSIONS: FAI is highly prevalent (96.6%) and frequently bilateral (83%) in patients presenting to an orthopaedic clinic with hip pain. Cam-type morphology and acetabular retroversion are more frequent in men, whereas profunda and protrusio are more frequent in women. Cam-type morphology, increasing alpha angle (larger cam morphology), and increasing Tönnis grade were highly predictive of clinically suspected intra-articular symptoms, whereas isolated pincer-type morphology was not.

LEVEL OF EVIDENCE: Level III, case-control study.