Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome: Part 1 - Definitions, terminology, taxonomy and imaging outcomes

H. Paul Dijkstra, Sean McAuliffe, Clare L. Ardern, Joanne L. Kemp, Andrea Britt Mosler, Amy Price, Paul Blazey, Dawn Richards, Abdulaziz Farooq, Andreas Serner, Eugene McNally, Vasco Mascarenhas, Richard W. Willy, Jason L. Oke, Karim M. Khan, Sion Glyn-Jones, Mike Clarke, Trisha Greenhalgh

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


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.

Original languageEnglish
Pages (from-to)325-341
Number of pages17
JournalBritish Journal of Sports Medicine
Issue number6
Early online dateDec 6 2022
StatePublished - Mar 2023


  • Athletes
  • Consensus
  • Hip
  • Osteoarthritis
  • Sports medicine


Dive into the research topics of 'Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome: Part 1 - Definitions, terminology, taxonomy and imaging outcomes'. Together they form a unique fingerprint.

Cite this