Avascular necrosis (AVN) can occur when the blood supply to ball of the hip (the femoral head) is disrupted – either on a temporary or permanent basis.
Without a supply of blood, the affected bone and the tissue that surrounds it can gradually begin to deteriorate. This can cause the bone itself to change shape which is partly responsible for the joint stiffness that people often experience. It can also result in hip osteoarthritis.
The basic anatomy of the hip joint is shown below:
AVN is a condition that causes hip pain in young-to-middle-age adults. It’s often referred to as idiopathic, which means that it doesn’t have any clear cause. There are many possible reasons for the blood supply to be disrupted in this way but in the majority of cases it is not possible to pinpoint an exact cause.
However, it can be linked with the following:
• Drinking too much alcohol
• Using steroids which may be needed, for example, in the management of cancer conditions or asthma
• Sickle cell disease
• Radiotherapy
• Injury such as a particularly bad fracture or a difficult bone infection.
Some people may have no symptoms in the early stages of avascular necrosis. As the condition worsens, affected joints might hurt only when putting weight on them. Eventually, you might feel the pain even when resting. In those who do have symptoms, these could include:
• Deep pain in the groin and/or buttock and side of the hip. It can sometimes cause pain down the thigh to the knee
• Hip stiffness- this can cause difficulty putting on socks and shoes and cutting your toe-nails
• Pain at rest may be present
• Pain on walking- sometimes causing a limp
• Pain on sitting, bending forwards or squatting
• Hip pain and stiffness first thing in the morning
The condition is diagnosed by x-ray. X-rays will usually show AVN if it has been present for an extended period of time. In the very early stages, it may not show up on X-rays even though you are having pain. In the advanced stages, the hip joint will be very arthritic, and it may be hard to tell whether the main problem is AVN or advanced osteoarthritis of the hip. Either way, the treatment approach will be very similar.
In some cases you may have a bone scan or magnetic resonance image (MRI).
Your doctor or surgeon will use these imaging studies in order to plan the best treatment approach for you. They will look at where the damage has occurred, the shape of the bones and determine if any osteoarthritis changes have developed.
Once AVN has occurred, the treatment choices are determined by the changes within the hip joint and your symptoms. Other factors that guide treatment decisions include your age, activity level, general health including any specific health problems present. If AVN is detected early, non-surgical treatment may be an option. Non-surgical treatment may involve using medication and physiotherapy.
Non-surgical treatment will involve:
• Relief of symptoms
• Prevention of disease progression
• Improvement of function
Treatment strategies may include:
Walking aids A large aim of non-operative treatment is to decrease the load through the hip joint. This is usually done by using crutches or a walking aid.
Your physiotherapist will instruct you on how to properly use these devices. By using crutches or other walking aid, the load through the hip joint will be decreased.
Education
This involves learning more about your hip AVN and how it affects you. Gaining a greater understanding of what movements and positions aggravate your symptoms and modifying these can help in managing your symptoms.
Your therapist can discuss activity modifications that are specific to your functional level.
Exercise
It is important that exercises should:
• Strengthen the muscles around the hip joints, leg muscles and the trunk.
• Maintain the movement in your hip joints
• Work on aerobic fitness for your cardiovascular health through increasing your heart rate and making you short of breath.
Exercises that put less load through the hip joint are recommended. This could include water based exercises or stationary cycling.
Your therapist can you give you specific advice and exercises tailored to your needs
Weight Management
Increased weight can place more load through your hip joint and aggravate your symptoms. Losing weight could reduce your pain and other symptoms. Following a balanced, healthy diet together with regular exercise is a great start to losing weight.
The Association of UK dieticians provide some useful information on diet and weight loss and diet with osteoarthritis.
The NHS website has a weight loss plan to help you manage your weight.
The NHS website also provides support on smoking cessation and lifestyle changes to support your health on the ‘Live well’ pages.
Surgical Management
Medication may help to reduce pain but will not reverse the AVN. Your surgeon may discuss if surgery is a potential treatment option for you. The main surgical option is a total hip replacement (THR) which involves replacing the head of the femur and relining the socket. Your surgeon will discuss the risks and benefits of surgery specific to your situation.
Physiotherapy after surgery is also a key component for recovery. It will start immediately on the day of or the day after surgery.
For more information on the post-operative management following a total hip replacement.
As well as managing your weight there are other ways you can try to reduce the strain through your hip joint.
Pacing your activities Try to break your activities into smaller, more manageable chunks and take regular rest breaks in between as needed.
Stairs Use a handrail for support when going up and down stairs. Using the stronger leg first to lead the movement going up the stairs and the sore hip leading when going down to reduce the strain on the sore hip. Your therapist can advise you on this technique
Sitting position Try to sit with the hips slightly higher than the knees, using a wedge shaped cushion or sitting in a higher chair can help this. Try to avoid sitting for long periods, so getting up and moving around regularly will help.
Special equipment There can be special equipment and aids that can make doing your daily jobs easier and keep you as independent as possible. For example, there are devices that can assist with putting on your shoes and socks if you have difficulty bending the hip. Your therapist can discuss special equipment options with you tailored to your needs.
Sleeping If you prefer to sleep on your side, a pillow between your knees can support the hips. If you prefer lying on your back, you could try a pillow under the knees to support the hips.
Mood In some people, living with pain can affect mood, making them feel depressed, low or anxious.
It is important to discuss these feelings with GP who may be able to offer advice and support or refer you to other services that can help.
There are other options that can help in the management of your symptoms:
Painkillers: Paracetamol can be used to help with pain but your doctor may prescribe a stronger pain medication or creams if needed.
Please speak to your doctor about all the medication that you are taking.
For further information please contact: Physiotherapy Department: 020 8909 5820
Gibbs et al. Recommendations for the management of hip and knee osteoarthritis: A systematic review of clinical practice guidelines. Osteoarthritis Cartilage. 2023 Oct;31(10):1280-1292
Lespasio MJ, Sodhi N, Mont MA. Osteonecrosis of the Hip: A Primer. Perm J. 2019;23:18-100. doi: 10.7812/TPP/18-100. PMID: 30939270; PMCID: PMC6380478.
Klumpp R, Trevisan C. Aseptic osteonecrosis of the hip in the adult: current evidence on conservative treatment. Clinical Cases in Mineral and Bone Metabolism. 2015;12(Suppl 1):39–42. (level 2a)
NICE guidance: Obesity, identification, assessment and management
NICE guidance: Osteoarthritis in over 16s: diagnosis and management
Page last updated: 24 June 2025