|A femoral head with AVN|
Sadly the femoral head has died but to give NGH their due they said it might, and they have me booked in for Wednesday 15-June as a trauma patient rather than an elective surgery patient. Then another week or so in hospital and another six weeks of taking life easily - I think I'll just write 2016 off!
The document from which the above image came is here and is really worth reading - there's a number of causes of AVN - mine is due to trauma only!
Why do I have this problem?
There are many causes of AVN. Anything that damages the blood supply to the hip can cause AVN. Injury to the hip itself can damage the blood vessels. Fractures of the femoral neck (the area connecting the ball of the hip joint) can damage the blood vessels. A dislocation of the hip out of the socket can tear the blood vessels. It usually takes several months for AVN to show up, and it can even become a problem up to two years following this type of injury.
Some medications are known to cause AVN. C Corticosteroids (cortisone) such as prednisone or methylprednisolone are the most common drug known to lead to AVN. This is usually only a problem in patients who must take cortisone every day due to other diseases, such as advanced arthritis, or to prevent rejection of an organ transplant.
Sometimes there is no choice, and cortisone has to be prescribed to treat a condition, knowing full well that AVN could occur. AVN has not been proven to be caused by local injection with cortisone, such as one or two injections into joints to treat arthritis or bursitis. But some patients have developed AVN within the first month of taking these drugs orally (pills by mouth). Patients taking both corticosteroids and statin drugs (cholesterol-lowering medications) seem to have the greatest risk for developing femoral head osteonecrosis.
A clear link exists between AVN and lifestyle choices such as smoking and alcohol abuse . Smoking causes blood vessels to constrict or narrow thereby limiting the amount of blood flow to an area such as the hip with its already limited backup supply. Excessive alcohol intake somehow damages the blood vessels and leads to AVN. Deep sea divers and miners who work under great atmospheric pressures also are at risk for damage to the blood vessels. The pressure causes tiny bubbles to form in the blood stream which can block the blood vessels to the hip, damaging the blood supply.
Then there is a long list of other diseases and conditions that are associated with increased incidence of femoral head osteonecrosis. These are referred to as nontraumatic causes. For example, there is a link between osteonecrosis and more commonly known problems like leukemia, sickle cell diseases, and HIV infection and less well-known diseases such as Gaucher disease, hyperuricemia (a condi- tion commonly called “gout”), and Caisson's disease.
What does AVN feel like?
The first symptom of AVN is pain when weight is placed on the hip. The pain can be felt in the groin area, the buttock area, and down the front of the thigh. As the problem progresses, the symptoms include development of a limp when walking and stiffness in the hip joint. Eventually, the pain will also be present at rest and may even interfere with sleep. (I certainly am disturbed by the pain at night and when resting.)