Avascular necrosis of the hipBMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l2178 (Published 30 May 2019) Cite this as: BMJ 2019;365:l2178
- Jonathan N Lamb, clinical research fellow and orthopaedic specialist trainee1,
- Colin Holton, consultant orthopaedic hip surgeon2,
- Philip O’Connor, consultant musculoskeletal radiologist3,
- Peter V Giannoudis, professor of orthopaedic trauma surgery and honorary consultant orthopaedic trauma surgeon2 4
- 1Leeds Institute of Rheumatic and Musculoskeletal Medicine, School of Medicine, University of Leeds, Leeds, UK
- 2Academic Department of Trauma & Orthopaedics, School of Medicine, University of Leeds, Leeds General Infirmary, Leeds, UK
- 3Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK
- 4NIHR Leeds Biomedical Research Centre, Chapel Allerton Hospital, Leeds, UK
- Correspondence to J N Lamb
What you need to know
Common risk factors for AVNFH are alcoholism, use of steroids, chemotherapy and immunosuppressant medication, and sickle cell anaemia
Consider MRI scan of the hip and referral to an orthopaedic team if a patient has a painful hip for longer than six weeks with normal radiographs
Early treatment improves the chances of hip survival by up to 88% at seven years
A 36 year old woman presents to her GP with a history of left groin pain radiating to the knee. The pain is severe, worse on walking, and associated with a limp. The patient revisits the GP a year later with persistent pain despite analgesia. Plain radiographs of the hip and knee show slight narrowing of the hip joint space with no other features and she is referred to a secondary care orthopaedic clinic. A magnetic resonance imaging (MRI) scan of the hip shows classic features of avascular necrosis of the femoral head (AVNFH) with collapse.
What is avascular necrosis of the femoral head?
Osteonecrosis of the femoral head (AVNFH) causes loss of integrity of subchondral bone structure due to abnormal microcirculation. The underlying pathogenesis is unclear1; risk factors are likely to affect microcirculation in some way but this has not been confirmed by research. The common end point is abnormal microcirculation and necrosis. Subchondral bone subsequently collapses, which leads to progressive secondary arthritis.
Mean age of presentation in the UK is 58.3 years, with a prevalence of two per 100 000 patients.2 On average, AVNFH occurs earlier in life than typical osteoarthritis. It is more common in men and the highest prevalence is in men aged 25 to 44 and women aged 55 to 75.3 In the UK it is the third most common indication for total hip replacement in people under 50.4
The following factors are associated with an increased risk of …