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Welcome to day 3 of my 12 Top Hip Papers of 2023 series of miniblogs. If you missed Day 2, you'll find a link at the bottom of this page to take you back. For day 3, we'll be looking at key points from the The Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome - read on!

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3 of 12 Top Hip Papers of 2023 : The Oxford consensus on primary cam morphology and femoroacetabular impingement syndromes1

We've come a long way in our recognition and understanding of cam morphology and femoroacetabular impingement syndrome (FAIS), but are we all speaking the same language? This consensus builds on the original Warwick Consensus on FAIS. Inconsistencies in definitions, terminology, taxonomy and imaging assessments and criteria for identifying cam morphology can be problematic both in research and clinical management of FAIS.  How do you define cam morphology, and do you differentiate between primary and secondary cam morphology?

Study Aim:

  • This group of researchers and expert clinicians aimed to assess and improve the level of agreement on primary cam morphology definitions, terminology, taxonomy and imaging outcome measures.

What was done:

  • An expert panel — the Young Athlete’s Hip Research Collaborative — came to a consensus on a number of previously unresolved issues around cam morphology and femoroacetabular impingement syndrome, using online Delphi surveys and an online meeting.

Key Decisions:


  • Primary cam morphology is a cartilage or bony prominence (bump) of varying size at any location around the femoral head-neck junction of the hip.
  • It changes the shape of the femoral head from spherical to aspherical.
  • Primary cam morphology occurs commonly in athletes, particularly males.
  • Primary cam morphology develops during adolescence, as a normal response to load.


  • The term ’morphology’ is recommended, rather than negative terms like ’lesion’, ’abnormality’ or ’deformity’.


This agreement distinguished between primary and secondary cam morphology.

Primary cam morphology:

  • develops during skeletal maturation in young adolescents.
  • is a normal physiological response to high-load activity.
  • is largely benign.

Secondary cam morphology

  • develops secondary to primary hip disease or injury, e.g, slipped capital femoral epiphysis, Legg-Calve-Perthes disease, and deformity after fracture of the proximal femur.


  • This consensus recommended Magnetic Resonance Imaging (MRI) as the preferred imaging modality.
  • Radiologists should report a continuous alpha angle on radial MRI along the axis of the femoral neck.

Clinical Implications:

Clinicians should aim to keep up-to-date with refinement in definitions, terminology and taxonomy for FAIS and other conditions. This type of consensus improves clarity for clinicians, researchers and patients alike. Consistent language enhances understanding and reduces confusion and mixed messaging for patients.

Like to learn more about assessing and managing FAIS associated with primary cam morphology?

In this course, you can find detailed information on pathoaetiology, assessment and management of joint related hip pain, including FAIS, and many other conditions. To learn more, take the anterior hip pain online course, or join me in a face to face or practical anterior hip pain workshop.

This online course is included in Hip Academy and Hip Academy members receive discounts for online workshops.

I hope you enjoyed the infographics and key learnings from Day 3 of my 12 Top Hip Papers of 2023. There are 9 more papers in this series, so use the navigational graphics below, to see what other top papers and infographics I have for you!

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About Dr Alison Grimaldi

Dr Alison Grimaldi is a physiotherapist, researcher and educator with over 30 years of clinical experience. She has completed a Bachelor of Physiotherapy, a Masters of Sports Physiotherapy and a PhD, with her doctorate topic in the hip region. Dr Grimaldi is Practice Principal of PhysioTec Physiotherapy in Brisbane, a Fellow of the Australian College of Physiotherapy and an Adjunct Senior Research Fellow at the University of Queensland. She runs a global Hip Academy and has presented over 100 workshops around the world.