About Avascular Necrosis AVN
About Avascular Necrosis AVN diagnosis

Avascular Necrosis AVN diagnosis

Here is an overview of AVN symptoms, initial diagnosis and a short explanation of what has happened inside the joint.

Typical AVN Symptoms

The symptoms of Avascular Necrosis of the hip, knee or any affected joint can present themselves at different times depending on the activities a person is carrying out at any given time. The description of the symptoms in the most general sense is that a person will experience hip, knee or other joint pain.

AVN symptoms can easily be confused with many other conditions.

These symptoms are often presented as follows:

  • Persistent (chronic) pain.
  • Disrupted sleep.
  • Prescribed medication giving only limited pain relief.
  • Difficulty ascending or descending stairs.
  • Increased pain when getting up from sitting, or sitting down from standing.
  • Unable to follow normal activities due to pain.

Initial diagnosis

During this time these symptoms will be discussed with your GP, as the problems and pains do not improve, your GP will then arrange for a referral to a Consultant Orthopaedic Surgeon (OS).

On the first consultation, the OS will make a general examination; checking the range of joint movements, alignment issues and in some detail understanding your symptoms.
X-rays and an MRI scan will follow and the results of these will help the OS make his diagnosis.
It may take a subsequent referral for the final diagnosis to be made as many other conditions give similar symptoms.

Your GP will be notified and will take care of pain management and control. Your GP will be your first point of contact for any changes in your symptoms.

What has happened inside the joint

The reduced blood supply has allowed the bone at the joint site to start to die. This results in fluids and gases building up pressure within the bone, giving the chronic pain.

This can be observed as Bone Marrow Oedema on MRI scans but these oedema are not normally evident on X-rays. The pains will continue until the fluids and gases from the necrosis are finally absorbed into the body, this process can take many months.

Throughout all this the pain levels can fluctuate, causing confusion for the sufferer as to what is going on.

This dying or dead bone is now structurally vulnerable. For both hips and knees as major weight-bearing joints, they will be under mechanical stress from our normal body and limb movement, the affected bone then starts to break up, these ‘breakaway’ areas are known as lesions. Additional pain is observed as partial joint collapse takes place, finally the joint collapses.

Additionally, for many people during this process the mechanical joint alignment can be compromised, in the cases of AVN in the hips, knees or ankles it can result in “turn-in” or “turn-out” of the joint. This “turn-in” or “turn-out” of the joint will often create a pronounced limp or uneven gait, which is separate to a limp caused by the pain.


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