This essentially stands for loss of blood supply to the ball of hip joint. The reason for the ball of hip joint getting affected is mainly to do with the pattern of supply. The normal sequence of events following the blood supply cut off is due to the changes in the structure and the make up off the bone. The weakening of the structure of the bone takes place over few months and sometimes even years. It loses its inherent architecture and can collapse under the weight of the body or the force on the bone itself. As most of these areas are within the joint, they can actually cause disruption of the smooth articular surfaces of the bone leading to prolonged problems and complications. The bone however can revascularize, itself which is to say that the blood supply can start again but the period in which it will start is not very certain but there is no doubt about the capacity of the bone to regenerate. If the bone however collapses in the meanwhile, then arthritis would be inevitable.
The age of onset of symptoms can be very variable depending on the moon involved and the cause for the am we in. hey yes much more common in the younger age group the consequence this is can also be significant in that age group.
Symptoms of AVN
In its early stages, AVN may not cause symptoms. As blood cells die and the disease progresses, symptoms may occur in roughly this order:
- Mild or severe pain in or around the hip joint; groin pain
- Groin pain may spreads down to the knee
- Pain occurs when the joint in under pressure that means while standing and walking
- This pain may be severe enough to limit movement
Pain may dramatically increase in intensity because of tiny breaks in the bone, called microfractures. These can cause the bone to collapse. Ultimately, the joint may break down and develop arthritis.
The time between the first symptoms and the inability to move a joint varies. In general, it ranges from a few months to more than a year. Symptoms may appear bilaterally, meaning on both sides of the body.
Causes and risk factors for the condition
Injury around hip like fracture neck of femur and hip dislocation slows or stops blood flow to the ball of hip joint is the main cause of AVN. Other common risks and causes of AVN are:
- Drinking too much alcohol
- Taking high doses of corticosteroids for a long time, such as prednisone or cortisone, because they can increase fatty substances (lipids) in the blood, which can block arteries
Some fewer common causes of AVN include:
- Decompression sickness and caisson disease, a condition caused by the rapid release of nitrogen into the blood among deep sea divers.
- Chemotherapy or radiation
- High cholesterol, high triglycerides, or both
- Gaucher’s disease
- HIV infection
- Organ transplants, especially a kidney transplant
- Sickle cell anaemia or other blood disorders
Sometimes no symptoms could be found to be the cause of AVN. This condition is called idiopathic AVN.
Men develop AVN more than women unless the cause is injury or lupus. It most often affects people aged between 30-60 yrs. of age. But people of any age can develop AVN.
Prognosis for Avascular Necrosis
More than half the people with this condition need surgery within 3 years of diagnosis. If a bone collapse in one of the joints, it is very likely to it happen in another as well.
Patients outcome depends on several factors, like
- Disease stage at the time of diagnosis
- If there is an underlying condition
Patients are less likely to do well if:
- Age is over 50 yrs.
- Stage III or higher when diagnosed.
- More than a third of the bone’s weight-bearing area is involved.
- Damage goes past the end of the bone.
- Long history of cortisone treatments.
Treatment for Avascular Necrosis
The goals of treatment for AVN are to improve or ensure function of the affected joint, stop the progression of bone damage, and reduce pain.
The best treatment will depend on a number of factors, including:
- Stage of the disease
- Location and amount of bone damage
- Cause of AVN
If the cause of avascular necrosis is identified, treatment will include efforts to manage the underlying condition. For example, if AVN is caused by blood clots, a medication to dissolve clots is used. If inflammation of the arteries is responsible, anti-inflammatory medicines are used.
If avascular necrosis is caught early, treatment may involve taking medications to relieve pain or limiting the use of the affected area. If hip, knee, or ankle is affected, crutches may be necessary to take weight off the damaged joint. Range-of-motion exercises to help keep the affected joint mobile.
While these nonsurgical treatments may slow the progression of avascular necrosis, most people with the condition eventually need surgery.
Surgical options include:
- Core decompression, along with Bone grafts, or BMAC
- A procedure that involves drilling inside of the bone to relieve pressure and allow formation of new blood vessels to initiate new bone formation and replace the damaged bone
- Osteotomy, a procedure that involves cutting the bone and changing its alignment to relieve stress on the damaged bone or joint
- Vascularized bone graft a procedure that uses the patient’s own tissue to rebuild diseased or damaged hip joints; the surgeon first removes the bone with the poor blood supply from the hip and then replaces it with the blood-vessel-rich bone from another site, such as the fibula, the smaller bone located in the lower leg.
- Total joint replacement, which involves removing the damaged joint and replacing it with a synthetic joint.