Necrosis is the term used for denoting tissue death in the body. Death of tissue can occur due to insufficient blood supply or complete cut-off from blood supply. It can occur due to radiation, sudden injury and exposure to chemicals. The damage caused by necrosis is irreversible. If the tissue death occurs in the bone it is known as Avascular necrosis. It can cause tiny fractures inside the bone which may eventually cause bone collapse.
Blood supply to particular section of a bone would stop leading to avascular necrosis. In some cases the joint of particular bone gets dislocated causing necrosis. This can occur due to prolonged use of steroids and alcoholism. Often, the hip joint is affected by avascular necrosis and sometimes it can affect the upper leg, upper arm or knee bones. Bone needs continuous blood supply since it is a living tissue. Any interruption of blood can cause death of bone tissue. Avascualr necrosis is also called as osteonecrosis or aseptic necrosis.
Symptoms :
Pain in the joint is the only symptom of avascular necrosis. In the initial stages there will not be any sign, but as the disease progresses, the joint may get affected causing intense pain while making movements. Avascular necrosis does not occur overnight. It is a process that happens gradually causing tissue death in the bone. It might take months together or sometimes even a year for tissue death on the bone. It can affect hip joints, shoulder, upper arm or leg and even your foot. Severe pain is felt in the groin or thighs and you can feel the pain in both sides of the body.
Causes :
When normal blood supply to the bone is restricted or slowed down it can cause avascular necrosis. This can happen due to sudden trauma or injury and due to dislocation of joint. People who undergo hip joint surgery are prone to develop avascular necrosis. People who are taking chemo therapy for cancer can develop avascular necrosis since radiation can weaken the bones and joints interrupting regular blood supply.