Avascular necrosis of the hip – what can help

Avascular necrosis (AVN) of your hip is caused by reduced blood supply to the tissue at the head (ball) of your femoral (thigh) bone, which sits in your hip joint.

This lack of blood supply affects the healthy bone tissue in your femoral head, eventually causing the bone to break down. When the end of your femoral bone collapses, it loses its smooth shape and no longer moves in the hip joint socket properly, which can lead to osteoarthritis.

Also known as osteonecrosis, AVN most commonly affects the hips, which is what this article is about. However, you can also experience it in other areas like your jaw, shoulders, and knees

What are the symptoms?

Avascular necrosis (AVN) of the hip typically involves a gradual degeneration process, which means symptoms happen over a longer period of time and get worse as the condition progresses.

You may get symptoms including:

• increasing levels of pain (you may feel pain when you put weight on your hip joint that eases when you don’t)
• stiffness in your hip joint
• not being able to move properly
• difficulty walking, standing, or climbing stairs
• limping and changes to the way you walk
• secondary pain in your groin, thigh, or buttocks.

When to get emergency help

Seek medical help immediately if you think you have dislocated your hip joint or broken a bone.

What causes it?

Avascular necrosis (AVN) is more common among men than women, and usually affects those aged between 30 and 65.

These are types of causes behind AVN: traumatic and non-traumatic.

Traumatic AVN occurs following trauma or damage – such as a hip fracture or hip dislocation – which causes the blood flow to your femoral bone to be affected.

Non-traumatic cases of AVN are more common, and there are many causes, including:

• build-up of fatty deposits in your blood vessels, which can be caused by things like drinking too much alcohol
• smoking
• use of steroid medication, such as to manage a medical condition like asthma
• having cancer treatments that use radiotherapy
• health conditions such as sickle cell anemia, HIV, pancreatitis, diabetes, lupus, Crohn’s disease, and Gaucher disease
• having an organ transplant.

In some cases it may not be clear what’s causing your AVN.

When to see a doctor

Go back to the section ‘When to get emergency help’ to check which symptoms need immediate medical attention.

Otherwise, you should see your doctor if you have any of the following symptoms:

• ongoing pain in your hip (or any) joint
• hip pain that isn’t helped by resting or medication
• difficulty walking or moving because of your hip pain
• limping, but you don’t know why.

How is it diagnosed?

It’s important to receive a proper diagnosis for avascular necrosis (AVN) of the hip, as it’s thought that early treatment may help your condition in the long term. If left untreated, there is a high chance you may experience a breakdown of your affected joint that can’t be improved.

To check if you might have AVN, your doctor will discuss both your medical history and lifestyle to see if any factors might be increasing your risk of hip pain and bone degradation. They will also ask about your symptoms, such as how long you’ve been experiencing hip pain and if anything makes it better or worse.

Your doctor will then physically examine your hip, checking for range of movement, signs of tenderness, and seeing when pain occurs.

If your doctor suspects you have AVN, they will refer you for further tests to rule out other conditions and confirm a diagnosis. These may include:

• X-ray
• MRI
• CT scan
• bone scan
• biopsy
• blood test.

What are the treatments?

Treatment for avascular necrosis (AVN) of the hip depends on factors such as your medical history, for example, if you have a health condition that’s triggering AVN; symptoms; and how much your bone is damaged.

Your doctor may initially recommend at-home care and lifestyle changes, and outpatient treatments to help manage your symptoms. These could involve:

• taking over-the-counter pain medication (ask your doctor for advice on which is best for you)
• placing an ice or heat pack wrapped in a cloth or towel, on your affected joint for short periods (your doctor can tell you which one to use and how often)
• physical therapy – to help restore and maintain movement
• quitting smoking
• reducing your alcohol intake
• managing your weight
• using walking aids (such as crutches)
• treatment to manage a health condition
• electrical stimulation, to help encourage new bone growth
• medication such as treatment for osteoporosis or for lowering cholesterol; blood thinners, or drugs to open blood vessels and increase blood flow to the bone.

While these things can help minimize symptoms, they unfortunately do not generally stop AVN from progressing.

Eventually, you may need surgery to treat your AVN. This may include:

• core decompression, which involves drilling a hole in your affected bone to improve blood flow and ease pain
• a bone graft, which involves taking a small piece of bone from elsewhere in your body, or synthetic bone is used, and attaching it to your affected bone to encourage new growth
• osteotomy, which involves cutting your affected bone and reposition it so your body weight moves to other parts of the bone that are healthy and able to stand weight
• a joint replacement, which involves entirely replacing your affected joint with plastic or metal parts.

Can you prevent it?

It’s not always possible to stop AVN. However, certain steps may help reduce your risk, such as:

• not smoking, as this affects your blood vessels
• cutting down your alcohol intake, as this can impact new bone growth and cause fatty deposits to build-up in your blood vessels
• maintaining healthy cholesterol levels to stop tiny bits of fat blocking up your blood supply
• managing health conditions and speaking to your doctor about dosage of medications such as steroids
• keeping to a healthy weight to avoid putting your joints under too much pressure
• avoiding repetitive movements that put your joints under strain.