PT - JOURNAL ARTICLE AU - H Paul Dijkstra AU - Sean Mc Auliffe AU - Clare L Ardern AU - Joanne L Kemp AU - Andrea Britt Mosler AU - Amy Price AU - Paul Blazey AU - Dawn Richards AU - Abdulaziz Farooq AU - Andreas Serner AU - Eugene McNally AU - Vasco Mascarenhas AU - Richard W Willy AU - Jason L Oke AU - Karim M Khan AU - Sion Glyn-Jones AU - Mike Clarke AU - Trisha Greenhalgh ED - , TI - Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome: part 1—definitions, terminology, taxonomy and imaging outcomes AID - 10.1136/bjsports-2022-106085 DP - 2023 Mar 01 TA - British Journal of Sports Medicine PG - 325--341 VI - 57 IP - 6 4099 - http://bjsm.bmj.com/content/57/6/325.short 4100 - http://bjsm.bmj.com/content/57/6/325.full SO - Br J Sports Med2023 Mar 01; 57 AB - Introduction Primary cam morphology is a mostly benign bony prominence that develops at the femoral head-neck junction of the hip, but it is highly prevalent in many athlete populations. In the small proportion of athletes for whom it is not benign, the resulting hip osteoarthritis can be debilitating. Clinicians, athletes, patients and researchers do not yet agree on important primary cam morphology elements. We aimed to ascertain and improve the level of agreement on primary cam morphology definitions, terminology, taxonomy and imaging outcome measures.Methods To collect and aggregate informed opinions, an expert panel—the Young Athlete’s Hip Research Collaborative—rated primary cam morphology definition, terminology, taxonomy and imaging outcome statements through an online Delphi exercise followed by an online meeting to explore areas of tension and dissent. Reporting followed Conducting and REporting DElphi Studies.Results A diverse and inclusive Delphi panel (n=65 for rounds 1 and 2, representing 18 countries; 6 stakeholder groups; 40% women) agreed on 35 of 47 statements in 4 domains, while surfacing areas of tension and dissent. This Delphi panel agreed on four key issues essential to moving research and clinical care forward around primary cam morphology. They agreed on: (1) definition, confirming its conceptual attributes (tissue type, size, location, shape and ownership); (2) terminology—use ‘morphology’ and not terms with a negative connotation like ‘lesion’, ‘abnormality’ or ‘deformity’; (3) taxonomy, distinguishing between primary and secondary cam morphology, and (4) imaging outcomes, a continuous bone/cartilage alpha angle on radial femoral head-neck MRI for primary cam morphology aetiology research.Conclusion This consensus provides athletes, patients, clinicians and researchers with a strong foundation to guide more precise communication, better clinical decision-making and higher value research about primary cam morphology and its natural history.