Avascular Necrosis (AVN)

This is a condition where the blood supply to the femoral head (ball in the socket) is not sufficient enough and the bone starts to break down. We often don’t know why this happens to an individual patient but there are a number of things which are linked to AVN, including:

• Steroids
• Alcohol excess
• Previous trauma/ injury
• Blood clotting disorders
• Sickle Cell Disease

This condition can be very painful even before there are any signs on an xray. Therefore, we will often arrange an MRI scan to identify this as the cause. Initially there is just inflammation in the bone, and it progresses to where the bone in the femoral head collapses.

Depending on how far the condition has progressed there are a variety of treatments. These may include:

• Medications including Bisphosphonates (+/- vitamin D) – this has been shown in some patients to prevent the progression of the disease and reduce pain. The current evidence is based on populations in India and Japan and may not be as effective in a Bristol-based population.
• Core Decompression – this is a procedure designed to reduce pain, but with no evidence that it changes the progression of the disease. This is a daycase operation when a channel around 6mm wide is drilled into the bone under xray guidance to ‘decompress’ the bone. This will only occasionally be appropriate, when the disease is proven but there is no ‘collapse’ of the femoral head bone.
• Total Hip Replacement (link to information about THR) - once the bone has started to collapse there are no other reliable treatments other than a hip replacement (the alternative is simply managing your symptoms with painkillers, walking sticks and reduced activity).