Osteonecrosis

Osteonecrosis, also known as avascular necrosis, is a condition characterised by death of bone and the surrounding cartilage. This occurs in both the hip (the femoral head) and the knee.

It can be caused by several factors including:

• Excess alcohol use
• Trauma such as fracture of the neck of the femur
• Malalignment such as excessive pressure through part of the knee
• Idiopathic meaning without identifying cause
• Some medications and medical conditions

Hip osteonecrosis causes gradual deterioration of the femoral head, being the ball of the ball and socket joint. In younger populations, this has been treated with joint-preserving procedures such as core decompressive drilling and revascularisation. These have limited scope due to poor success rates, especially given hip replacement is an option and is so successful.

It is important to consider the cause of osteonecrosis for each individual patient and optimise preventative strategies. This can minimise the progression of early osteonecrosis, and also considers the risk of the other limb developing the same condition.

Not all osteonecrosis conditions require surgery.