Avascular Necrosis of the Hip
When blood flow to the head of the thigh bone drops, the bone weakens and can collapse. Early diagnosis makes joint-preserving treatment possible.
Avascular necrosis (osteonecrosis) is the death of bone tissue caused by a loss of blood supply. In the hip it most often affects the head of the thigh bone. Bone that has lost its blood supply weakens over time, collapses under load and the joint surface is damaged. The condition often affects adults aged 30-50 and can involve both hips.
What causes avascular necrosis?
- Long-term or high-dose corticosteroid use
- Excessive alcohol consumption
- Hip fractures and dislocations
- Sickle cell disease and some other blood disorders
- Clotting disorders, some autoimmune diseases and decompression sickness
- In some patients no clear cause is found
Symptoms
In the early stage there may be no symptoms. As the disease progresses, pain starts in the groin, hip or front of the thigh. At first it comes with weight bearing, later also at rest and at night. Hip movement, especially turning inwards, may become limited, and a limp may develop.
Diagnosis
X-rays can look normal in the early stage. MRI shows the disease earliest and defines its extent. The stage of the disease, especially whether the femoral head has collapsed, directly determines treatment. In patients with risk factors, assessing the other hip is also recommended.
Treatment options
Early stage: joint-preserving treatment
- Reducing risk factors: Adjusting corticosteroid doses where possible and stopping alcohol.
- Core decompression: A narrow channel is drilled into the femoral head to reduce pressure inside the bone and encourage new blood vessels. In suitable patients, bone graft or cells obtained from bone marrow can be placed in the channel.
- Protected weight bearing and physiotherapy: Using crutches for a period and keeping the hip muscles strong.
Advanced stage: hip replacement
When the femoral head has collapsed and the joint surface is damaged, a hip replacement is performed to relieve pain and restore movement. It is a reliable and widely used treatment for advanced avascular necrosis.
After treatment
After core decompression, partial weight bearing with crutches is continued for a few weeks and the bone is monitored with regular MRI scans. Recovery after hip replacement follows the process described on our hip replacement page.
Who is at risk?
People who need long-term steroids (for example for rheumatic diseases, after organ transplantation or for some lung diseases), those who drink alcohol regularly and those who have had a hip fracture are at risk. In these people, early assessment when groin pain starts means the disease can be caught while joint-preserving treatment is still possible.
Frequently asked questions
Can early avascular necrosis heal without surgery?
Some very small lesions that cause no symptoms can be monitored. In most patients, however, the disease tends to progress, and joint-preserving procedures in the early stage aim to delay collapse.
Can both hips be affected?
Yes. Especially when steroids or alcohol are the cause, both hips can be involved. This is why the other hip should also be checked with MRI.
Can young people have a hip replacement?
In advanced necrosis with severe pain and stiffness, hip replacement can also be done in young patients. It is chosen when joint-preserving options are no longer enough.
Should I stop my steroid treatment?
Steroids should not be stopped without the doctor who prescribed them. If needed, a dose adjustment is planned together with that specialist.
The information on this page is general and does not replace an examination. An examination is needed to decide which treatment suits you.