Avascular Necrosis Of the HIP
Avascular necrosis of the femoral head is a type of osteonecrosis due to disruption of blood supply to the head of femur. It can occur due to a variety of causes, either traumatic or atraumatic in origin. An injury, such as a dislocated joint, might damage nearby blood vessels. It leads to tiny breaks in the bone and the bone’s eventual collapse occurs of the femoral head. Anyone can be affected, but the condition is most common in people between the ages of 30 and 50.
In More than ninety percent of cases the cause is unknown and called as Idiopathic Avascular necrosis of the head. In the remaining ten percent approximately, the causes may be attributed to Alcohol intake, Steroid intake, or is even found in some types of anemia ( sickle cell anemia).It is more prevalent in some part of India (some parts of Maharashtra) so genetic attribution is also there.
Risk factors for Osteonecrosis
- Post Solid organ transplantation
- Renal Failure
- Inflammatory Bowel Disease
- Systemic lupus erythematosus
Symptoms of Avascular Necrosis of Femoral Head
- Minimal early joint pain.
- Increased joint pain as bone and joint begin to collapse.
- Limited range of motion due to pain
- Sometimes Knee Pain may also be a symptoms of Hip problem
The history and clinical examination are particularly important and moreover the aetiology or the cause should be found. Diagnosis is made by pairing the clinical presentation with appropriate imaging. Imaging can include x-rays, radionuclide bone scanning, and magnetic resonance imaging (MRI). The use of imaging in the context of the patient’s symptoms can help guide appropriate treatment.
Stages of AVN Femoral head
Stage 1 has a normal x-ray, but MRI reveals the dead bone. Stage 2 can be seen on regular x-ray but there is no collapse of the femoral ball. Stage 3 shows signs of collapse (called a crescent sign) on x-ray. Stage 4 has collapse on x-ray and signs of cartilage damage (osteoarthritis)
The most asked question is -Is AVN curable?
The answer is – it depends on the stage of presentation.
While these nonsurgical treatments may slow down the avascular necrosis, most people with the condition eventually need surgery. Surgical options include: Core Decompression , Bone grafts, (vascularised or strut grafts), Muscle pedicle bone grafts . The prognosis / fate remains guarded but yes in early stages Femoral Head salvage should always be tried.
Nowadays Tissue-Targeted Cell Therapies
For Treatment of Degenerative Diseases especially for AVN is also an option but the conservative or salvage procedures work only in early stages. Eventually if these fails there is always option of Total Hip Replacement.
Core decompression prevents osteonecrosis from progressing to severe arthritis and the need for hip replacement in some cases. This depends upon the stage and size of the osteonecrosis at the time of the procedure.
Core decompression achieves the best results when osteonecrosis is diagnosed in its early stages, before the bone collapses. In some of these cases, the bone heals and regains its blood supply after core decompression. It takes a few months for the bone to heal and, during this time, you will need to use a walker or crutches to avoid putting stress on the damaged bone.
Patients with successful core decompression procedures typically return to walking unassisted in about 3 months and have complete pain relief.
When osteonecrosis is diagnosed after collapse of the bone, core decompression is not usually successful in preventing further collapse. In this situation, the patient is best treated with a total hip replacement. Total hip replacement is successful in relieving pain and restoring function in many patients with osteonecrosis.
Total Hip Replacement
In total hip replacement, both the head of the femur and the socket are replaced with an artificial device.
If osteonecrosis has advanced to the point where the femoral head has already collapsed, the most successful treatment is total hip replacement. In this procedure, your doctor removes the damaged bone and cartilage, then positions new metal or plastic joint surfaces to restore the function of your hip.