Radiographic findings of femoroacetabular impingement in capoeira players

Purpose: Capoeira is a Brazilian martial art that requires extreme movements of the hip to perform jumps and kicks. This study evaluated a group of capoeira players to assess the prevalence of femoroacetabular impingement (FAI) in athletes practicing this martial art. Methods: Twenty-four experienced capoeira players (14 men, 10 women) underwent a diagnostic assessment, including clinical examination and standard radiographs of the pelvis and hips. The α-angle, head-neck offset, crossover sign, acetabular index, lateral centre-edge angle, and the Tönnis grade were assessed using the radiographs. Clinical relationships for any radiographic abnormalities indicating FAI were also evaluated. Results: Four subjects (17 %) reported pain in their hips. Forty-four hips (91.7 %) had at least one radiographic sign of CAM impingement, and 22 (45.8 %) had an α-angle of more than 60°. Eighteen hips (37.5 %) had at least one sign of pincer impingement and 16 (33.3 %) a positive crossover sign. Sixteen hips (33.3 %) had mixed impingement. There was a significant positive association between having an α-angle of more than 60° and the presence of groin pain (P = 0.002). A reduced femoral head-neck offset (P < 0.001) and an increased α-angle on the anteroposterior radiograph (P = 0.008) were independently associated with a higher Tönnis grade. Conclusion: High prevalence of radiographic CAM-type FAI among these skilled capoeira players was found. In these subjects, a negative clinical correlation for an increased α-angle was also detected. Additional caution should be exercised whenever subjects with past or present hip pain engage in capoeira. Level of evidence: Diagnostic, Level III.