Do you live with Avascular Necrosis (AVN)/Osteonecrosis (ON)? How has it affected your life? What advice do you have for others? Please share in the comment section below this post.
What is Avascular Necrosis?
Avascular necrosis (also osteonecrosis, bone infarction, aseptic necrosis, ischemic bone necrosis, and AVN) is a disease where there is cellular death (necrosis) of bone components due to interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses. If avascular necrosis involves the bones of a joint, it often leads to destruction of the joint articular surfaces.
In the U.S., how many people live with AVN/ON?
About 10,000 to 20,000 people develop avascular necrosis of the head of the femur in the US each year. When it occurs in children at the femoral head, it is known as Legg-Calvé-Perthes syndrome.
What is it like to live with AVN?
Everyone with AVN is affected differently, depending on where the AVN is located, and at what stage it is in. In early stages, it can resemble soreness or cause limping, if it is located in the hips. If not treated early, AVN can progress quickly and surgery may result. Once the bone has deteriorated, it is difficult to return the affected bone to normal. As its worst, the bone will collapse or become arthritic.
For many who live with AVN, it physically limits them in their daily life.
What are the known causes?
There are many theories about what causes avascular necrosis. Proposed risk factors include, chemotherapy, alcoholism, excessive steroid use, post trauma,caisson disease (decompression sickness),vascular compression, hypertension, vasculitis, arterial embolism and thrombosis, damage from radiation, bisphosphonates (particularly the mandible), sickle cell anaemia, Gaucher's Disease, and deep diving. In some cases it is idiopathic (no cause is found). Rheumatoid arthritis and lupus are also common causes of AVN. Prolonged, repeated exposure to high pressures (as experienced by commercial and military divers) has been linked to AVN, though the relationship is not well-understood.
How is it diagnosed?
Orthopaedic doctors most often diagnose the disease except when it affects the jaws, when it is usually diagnosed and treated by dental and maxillofacial surgeons.
In the early stages, bone scintigraphy and MRI are the diagnostic modalities of choice. In the early stages of avascular necrosis, X-rays usually appear normal and do not pick up on damage from AVN.
How is it treated?
A variety of methods are now used to treat avascular necrosis,the most common being the total hip replacement, or THR. However, THRs have a number of downsides including long recovery times and short life spans. THRs are an effective means of treatment in the geriatric population; however, doctors shy away from using them in younger patients due to the reasons above. Some doctors also prescribe bisphosphonates (e.g. alendronate) which reduces the rate of bone breakdown by osteoclasts, thus preventing collapse (specifically of the hip) due to AVN. Other treatments include core decompression, where internal bone pressure is relieved by drilling a hole into the bone, and a living bone chip and an electrical device to stimulate new vascular growth are implanted; and the free vascular fibular graft (FVFG), in which a portion of the fibula, along with its blood supply, is removed and transplanted into the femoral head. Progression of the disease could possibly be halted by transplanting nucleated cells from bone marrow into avascular necrosis lesions after core decompression, although much further research is needed to establish this technique.