The morphologic characteristics and range of motion in the hips of athletes and non-athletes

The cam deformity may cause impingement and probably leads to osteoarthritis of the hip. The aetiology of the cam deformity is incompletely understood. Vigorous training during skeletal growth can lead to the development of cam and symptoms of femoro-acetabular impingement and subsequent osteoarthritis of the hip. The purpose of this study was to compare the radiographic characteristics and range of motion between a group of athletes and a non-athletic control group. Thirty-two male athletes (17 soccer players and 15 ice-hockey players) and thirty non-athletes, used as a control group, were examined clinically and radiographically. Hip range of motion was measured and the FADIR and FABER tests were performed. Standard radiographs of both hips were taken. The centre-edge angle, alpha angle, caput-collum-diaphysis angle, head-neck offset and Tönnis grade were registered. The athletes had a higher Tönnis grade (right P =  0.009, left P =  0.004), more pain on the FADIR test (right P =  0.006, left P =  0.001) and lower ROM in internal (right P =  0.003, left P =  0.025) and external rotation (P < 0.001). A superiorly placed cam deformity (seen on an AP pelvis view) was correlated with reduced external rotation (right P =  0.001, left P =  0.004) and mild osteoarthritis (Tönnis grade 1), (P =  0.015, left P =  0.020), while a more anteriorly placed cam deformity (seen on a modified Lauenstein view) was correlated with reduced internal rotation (right P =  0.029, left P =  0.013). A lower range of motion, more osteoarthritic changes and more pain were found in the athletes than the controls. The control group had more cam deformities than previously reported.