The Prevalence of Cam-Type Femoroacetabular Morphology in Young Adults and Its Effect on Functional Hip Scores

Pelvic computed tomography (CT) scans of forty five young adults were reviewed and the alpha angle was calculated. The patients were selected on the basis of an age of less than 40 years and the absence of any CT evidence of previous hip pathology. An alpha angle of >55° was considered positive for cam morphology. The non-arthritic hip score and the University of California Los Angeles activity score were completed by the selected group of patients.

The mean age of the individuals was 33 years (range, 20 to 40). The mean alpha angle at the superoinferior position of the anterosuperior quadrant of the femoral neck was 50.1° on the right side and 49.6° on the left. The prevalence of cam morphology was found to be 20% in the right hip and 17.7% in the left hip. There was a relatively higher prevalence of cam morphology in men.

We also compared the functional scores of patients with an alpha angle >55° and those with an alpha angle ≤55°. We found no statistically significant difference between the two groups for both scores.