Characterizing the Prevalence of Cam-Type Hip Impingement in Women’s Professional Ice Hockey Players

Abstract

PURPOSE: Recent studies have demonstrated an increased prevalence of femoroacetabular impingement (FAI) in elite men's ice hockey players, yet little is known about the hips of players in the National Women’s Hockey League (NWHL). The primary purpose of this study was to determine the prevalence of radiographic cam-type FAI in women’s professional ice hockey players. The secondary purpose was to analyze the relationship between the presence of cam deformity and hip ROM; clinical impingement signs; and age of menarche. METHODS: Clinical, radiographic and demographic data were collected for NWHL players during pre-participation physicals. Alpha angles were measured on 45° Dunn radiographs, with alpha angles >55° defined as cam-positive. Spearman correlations were performed to analyze the relationship between alpha angle and both ROM measurements and menarchal age. Players were grouped into those with and without cam lesions and group differences were assessed using the student's t-test. RESULTS: Twenty-seven athletes were included. Nineteen (70%) had alpha angles >55°; 14 (52%) had bilateral cam deformity. Average menarchal age was 13.9 ±1.5 years. There was a significant association between age of menarche and alpha angle (right hips, p=0.01; left hips, p=0.04). There was no significant association between alpha angle and either hip ROM or clinical impingement signs. CONCLUSION: This study suggests that elite female ice hockey players have a higher prevalence of cam-type morphology than the general population. The positive association between alpha angle and age of menarche lends additional support to the etiological hypothesis of the cam lesion resulting from activity-related stress at the proximal femoral physis; players with earlier menarche (and therefore earlier physeal closure) seem to be less vulnerable to the development of cam deformity of the proximal femur. Thus, professional women’s ice hockey players have a high risk of developing cam-type morphology of the proximal femur, although each player’s age of menarche may mediate her individual risk for cam lesion development.