Prevalence, topographic and morphometric features of femoral cam-type deformity: changes in relation to age and gender

Femoroacetabular impingement (FAI) syndrome is a frequent cause of pain and in recent years considered to be a precursor of premature hip osteoarthritis. The structural abnormalities which characterize FAI syndrome, such as the cam-type deformity, are associated with morphological alterations that may lead to hip osteoarthritis. The aim of this study was to determine the prevalence and topographic and morphometric features of the cam deformity in a series of 326 femur specimens obtained from a Mexican population, as well as changes in prevalence in relation to age and gender. The specimens were subdivided into groups according to gender and age. A standardized photograph of the proximal femur of each specimen was taken, and the photograph was used to determine the alpha angle using a computer program; the location of the lesion was determined by quadrant and the morphometric characteristics were determined by direct observation. The overall prevalence of cam deformities in the femur specimens was 29.8 % (97/326), with a prevalence by gender of 35.2 % (64/182) in men and 22.9 % (33/144) in women. The mean alpha angle was 54.6° ± 8.5° in all of the osteological specimens and 65.6° ± 7.5° in those specimens exhibiting a cam deformity. Cam deformities were found topographically in the anterior–superior quadrant of the femoral head–neck junction in 86.6 % (84/97) of the femurs. Deformities were found in 28.2 % of the right femurs and 31.3 % of the left femurs. The prevalence of cam deformity was higher in the femur specimens of young men and in those of middle-aged and older women. There were no significant differences in this deformity in relation to the alpha angle according to age and gender.