The frequency of the bony parameters of femoroacetabular impingement syndrome in young asymptomatic individuals: a computed tomography study

Abstract

Objectives: Femoroacetabular impingement syndrome is a painful disorder of the hip formed by movements in the hip joint between the femoral head-neck junction and the acetabular edge. The aim of this study was to determine the prevalence of radiological femoroacetabular impingement syndrome findings in a young, asymptomatic Turkish population. Methods: A total of 1000 abdominal pelvic CT images were collected from patients aged between 18–40 years. Measurements were taken on the CT images of the alpha angle and femoral head offset as signs of cam-type deformity, and of the acetabular version angle and center-edge angle as signs of pincer-type deformity. Results: Femoroacetabular impingement syndrome was determined in 2.3% of the individuals. Pincer type deformity was determined in 56.5%, being 83.3% in females and 47.1% in males. The cam-type deformity was present in 43.5% of all cases, being in 16.7% of the females and in 52.9% of the males. No difference was determined between the genders in respect of alpha angle which is >55°. A head-neck offset which is <8 mm was at a higher rate in females (13.3%) than males. An acetabular anteversion angle which is <15° and centre-edge angle which is >40° was more in males than females at a rate of 11% and 25.2% respectively. Conclusion: The results of this study showed that the incidence of cam-type deformity in the adult males and the incidence of pincer-type deformity in the adult females were lower in the asymptomatic Turkish population than previously reported in literature.