Does cam morphology size and location affect self-reported burden in football players with femoroacetabular impingement syndrome?

      Introduction: Diagnosis of femoroacetabular impingement (FAI) syndrome requires hip and/or groin (hip/groin) pain, positive clinical signs, and cam and/or pincer morphology. Cam morphology most often occurs in the anterosuperior region and is better visualised using a Dunn 45° radiograph than an anteroposterior pelvis (AP) radiograph. The relationship between anterosuperior (Dunn 45°) or superior (AP) cam morphology size and reported burden is unknown in people with FAI syndrome who do not seek surgery. Therefore, we aimed to investigate the relationships between cam morphology size and scores for the Copenhagen Hip and Groin Outcome Score (HAGOS) and International Hip Outcome Tool-33 (IHOT-33) in football players with FAI syndrome.
      Methods: One hundred and eighteen sub-elite football players (12 women) with FAI syndrome (>6months of hip/groin pain, positive flexion-adduction-internal rotation test, and cam morphology) completed HAGOS and IHOT-33 questionnaires. All participants were aged 18 to 50-years-old and free from hip osteoarthritis and acetabular dysplasia. Participants underwent an anteroposterior (AP) pelvis and Dunn 45° radiograph. An alpha angle ³60° determined anterosuperior (Dunn 45°) and superior (AP pelvis) cam morphology to be present. Linear regression models were used to investigate the relationships between alpha angle (independent variable – assessed separately using AP and Dunn 45° radiographs) and IHOT-33 and HAGOS scores (dependent variables – score of 0 to 100).
      Results: In total, 110 (93%, 9 women) and 77 (65%, 8 women) participants had cam morphology when assessed using the Dunn 45° and AP radiographs, respectively. Larger anterosuperior alpha angles were associated with worse scores for the IHOT-Total, IHOT-Symptoms, IHOT-Job, and IHOT-Social subscales (unadjusted estimate range -0.555 to -0.321 (95% confidence interval -0.899 to -0.044), P=0.002 to 0.024, R2=0.049 to 0.089). Superior alpha angles were not related to any scores.
      Discussion: Football players with larger anterosuperior, but not superior, cam morphology reported worse burden on all IHOT-33 scores, except the IHOT-Sport. Larger cam morphology identified using the Dunn 45° radiograph might have greater clinical relevance in football players with FAI syndrome, than the AP radiograph; however, further prospective studies are needed to discern importance of these findings over time. R2 values suggest that other physical and non-physical factors also contribute to reported burden in football players with FAI syndrome.
      Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.