Avascular Necrosis of the Hip in Primary Care

Avascular necrosis, or osteonecrosis of the femoral head, is a debilitating condition which leads to the destruction of the hip joint due to an interruption in the blood supply to the bony region and is most commonly due to trauma. The case discussed here has been highlighted as it presented as non-traumatic osteonecrosis of the femoral head with an absence of risk factors in a healthy adult male. A 37-year-old male presented with a 4-month history of recurrent left hip pain, which worsened with initiation of movement and weightbearing on the affected side. The patient was overweight but normotensive with a full range of movement of the hips bilaterally. There were no abnormalities detected on initial X-ray images of the left hip. However, due to the persistent pain and sclerotic changes in a subsequent X-ray, a magnetic resonance image of the bilateral hips was obtained, leading to the diagnosis of osteonecrosis of the bilateral femoral heads. Due to the lack of improvement with physiotherapy and analgesia, the patient was subjected to conservative surgery of the symptomatic left hip with concurring evidence of avascular necrosis based on intraoperative anatomical biopsy. This case emphasizes the importance of identifying underlying issues during history taking and physical examination in adults without risk factors. The early diagnosis of osteonecrosis assists in preventing joint collapse and can delay the requirement of joint replacements. High levels of suspicion are necessary to instigate investigation in persistent cases without the presence of risk factors.