Clinical Opal #13 - 41 year old with hip pain
The pain has been present for a couple of months and is worse on weight bearing. She denies any previous hip problems and there is no history of trauma. There is no night pain nor other red flags on history.
She has seen the physio on a couple of occasions, but the pain is no better. Physical examination is unremarkable.
What rare but serious condition must be considered in your assessment of Zoe’s pain?
One important and ‘not to be missed’ condition to consider in Zoe’s case is avascular necrosis of the femoral head (AVNFH).1 AVNFH is characterised by loss of integrity of subchondral bone due to abnormal microcirculation. The underlying pathogenesis is unclear, but the common end point is bone necrosis and death, which leads to osteoarthritis. AVNFH is one of the commonest reasons for hip replacements in younger people. Thus, the early recognition and treatment of AVNFH is critical.
The mean age of presentation is 58 years and it is more common in men. There are a range of risk factors, including hyperlipidaemia, family history, cigarette smoking, alcohol abuse, obesity, coagulopathies, and steroid or immunosuppressant use. Diagnosis is made by MRI and surgical intervention is usually required.
AVNFH is commonly missed for a range of reasons:
- it is rare and often not considered
- physical examination is often normal
- x-rays in the early stages are often normal
- pain is commonly misattributed to non-specific hip pain.
Thus, in order to reduce the likelihood of a missed or delayed diagnosis, always consdier AVNFH in patients presenting with hip or groin pain, especially when younger and/or with coexisting risk factors.
References
- Lamb J et al,. Avascular necrosis of the hip. BMJ 2019;365:l2178 doi: 10.1136/bmj.l2178
Medcast ‘Not to be missed’ course
AVNFH is a classic example of a ‘not to be missed’ condition in general practice – one which is prone to diagnostic delay but also with potentially serious consequences.
It follows that these 'not to be missed' conditions must be reliably identified and managed. But while having a sound clinical knowledge is essential, application of effective clinical reasoning and diagnostic strategies is just as important.
The Medcast 2022 'Not to be missed' webinar series is a unique blend of clinical updates, practical wisdom and diagnostic reasoning, covering a range of high-risk general practice presentations and conditions from ectopic pregnancy to temporal arteritis. This month, Professor Josh Davis will cover a range of infectious disease presentations. We look forward to seeing you there.
Simon is a GP based in Newcastle, NSW, and a senior medical educator with Medcast. He also has medical education roles with the RACGP and GPSA.
Over the past three decades, Simon has worked in clinical and educational roles in NSW and the NT, as well as in the Republic of Ireland. He has published over 75 peer reviewed journal articles, and in 2018 received the RACGP Corliss award for his contribution to medical education.
Simon is passionate about high quality education and training. He has particular interests in GP supervisor professional development and the rational use of tests and medicines. He is a proud member of Doctors for the Environment. He spends his spare time drinking craft beer and pretending that he is a musician in the Euthymics, an all-GP band.
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