Avascular necrosis (AVN) of the Femoral Head

Technical Name: Avascular necrosis (AVN) of the Femoral Head

AKA Name: Osteonecrosis 

Short Summary:

Avascular Necrosis (AVN) of the hip is a condition affecting the small blood vessels around the femoral head (ball at the top of the thigh bone) so that there is reduced blood supply to this area.  This results in the bone cells with the head dying slowly and then progressively collapsing due to the collapse bone in the head (ball) disintegrating.  This results in pain and discomfort around the hip joint which commonly results in a restricted range of movement of the hip. 

What are the symptoms?

This is a rare condition that can affect any age group but is more common in those aged between 40 and 65 years old.  The symptoms are similar to those of hip arthritis with pain in the groin and lateral side of the hip and buttock region with any form of movement or weight bearing.  As the condition progresses the hip becomes more stiff and quality of life deteriorates.

There are several risk factors for developing this condition that include: -

  • Previous hip trauma including certain types of hip fracture (intracapsular neck of femur fracture) or hip dislocation.
  • Certain medications predominantly Steroids.
  • Alcohol dependence
  • Medical conditions such as inflammatory connective tissue disorders such as Gauchers Disease or Lupus.

How is it diagnosed?

A clear history is important detailing any risks factors but to confirm the diagnosis an x-ray is important.  When the condition is relatively advanced then changes in shape to the femoral head (collapse) are obvious however if presentation is earl enough then the subtle changes are only visible on an MRI scan.

How is it treated?

There are two main treatments available and the choice depends on the extent of the damage to the femoral head at the time of presentation.

  • Core-decompression – involves drilling one or more holes into the femoral head (ball of the joint) to reduce pressure the area that lacks blood supply and the aim is that this encourages new blood vessels to form.   This treatment is only successful if the condition is identified early before any collapse or changes in the femoral head are present.
  • Total Hip Replacement – once the femoral head has changed shape and collapsed significantly then the only option to improve the symptoms is to replace the damaged hip with replacement of the ball and the socket. 

Important: this information given above is only a guideline as is not complete.  For more information or to book an appointment please contact us.