Radiological Assessment of Femoroacetabular Impingement Morphology Using Computed Tomography in Asymptomatic Young Population.

Abstract

Background Femoroacetabular impingement is regarded as precursor of osteoarthritis. Various studies have discussed the prevalence of femoroacetabular morphology but only few studies have been done on asymptomatic population using cross-sectional imaging. Objective To determine the prevalence of femoroacetabular impingement morphology in young asymptomatic population on computed tomography. Method This cross-sectional study was done in 200 individuals who underwent computed tomography for abdominal pathologies without any symptoms of hip pain, hip pathology or osteoarthritis. Multiplanar images were reformatted and assessed for the presence of parameters associated with femoroacetabular impingement; alpha angle greater than 55°, femoral head-neck offset less than 8 mm, angle of acetabular version less than 15°, lateral center edge angle greater than 40°. Result At least one of the femoroacetabular impingement morphology was detected in 162 hips. The prevalence of abnormal hip joint was higher in male patients than in female patients (47.3% vs 31.8%). Prevalence of cam morphology was 14.5%, pincher was 17.5% and mixed morphology was 8.5%. Prevalence of cam and mixed morphology were common in male hips however there was no statistically significant difference in prevalence of pincher morphology between male and female hips. Conclusion Femoroacetabular morphology was noted with high frequency in asymptomatic young population on computed tomography. Diagnosis of femoroacetabular impingement syndrome should be based on combination of clinical and radiological findings.