Avascular necrosis is a death of bone tissue caused due to inadequate blood supply and the condition is also called osteonecrosis. This condition is categorised by small breaks in the bone and the bone subsequently collapses. While a broken bone can hinder the blood flow to a part of the bone. Avascular necrosis is linked with chronic use of high dose steroid medications and excessive consumption of alcohol. This condition can affect any person, but it is most common among people between 30 to 50 years.
Symptoms
Most people do not show any symptoms in the initial stages of avascular necrosis. However, as the condition aggravates, the affected joint may hurt a person when they put weight on it and feel intense pain while lying down.
Pain may be mild to severe, and it gradually develops. Pain associated with osteonecrosis of the hip might be the centre of the groin, thigh, or buttocks. Asides from the hip, the region’s most probably to be affected include shoulder, knee, hand, and foot. In a few people, avascular necrosis affects bilaterally including both hips and knees.
Causes
This condition develops when the blood flow to a bone is reduced, and it can be caused due to:
Joint or Bone Trauma: Any injury, like a dislocated joint, may damage nearby blood vessels. Cancer treatments including radiation can also weaken the bones and damage blood vessels.
Blood Vessels Blockage: Fat deposits in the blood vessels can block small blood vessels, which reduces the blood flow to the bones.
Medical Conditions: Certain health conditions such as sickle cell anaemia and Gaucher’s disease can also reduce blood flow to the bones.
In about 25% of people, the exact cause is unknown.
Risk Factors
Trauma or any injury like hip dislocation or fracture can harm the nearby blood vessels and lessen the blood flow to the bones.
High use of steroids is one of the most common risk factors for avascular necrosis.
Excessive consumption of alcohol can cause fatty deposits to form in the blood vessels.
Long-term use of certain medications can increase bone density that may lead to the development of osteonecrosis of the jaw. It is a rare complication observed in a few people who are treated with high doses of cancer medications.
Radiation therapy for cancer can also weaken the bone. Organ transplantation, mainly kidney transplant is also linked with avascular necrosis.
Medical conditions related to avascular necrosis include:
Gaucher's disease
HIV/AIDS
Systemic lupus erythematosus
Sickle cell anaemia
Also Read: 5 Effective Ways To Build Healthy Bones - Infographic
Complications
If left untreated, avascular necrosis can worsen with time and eventually bone may collapse. Furthermore, it can also lead to bone losing its smooth shape and leading to severe arthritis.
Diagnosis
The doctor will thoroughly examine the patient and would press around the joints for assessing any tenderness and may also move the joints through several positions to check if the patient range of movement has been minimised. Some of the tests recommended by the doctor include:
Imaging Tests
Most disorders associated with the bones can cause joint pain, where imaging tests can aid the doctor to pinpoint the source of pain, which include:
X-rays can disclose the changes that develop in the later stages of avascular necrosis, while early stages X-rays appear normal.
MRI and CT scan produce complete pictures of the bone that can reveal any minor changes in bone, which may indicate avascular necrosis.
A bone scan is a procedure where minimal amount of radioactive material is injected into the vein, that travels to the regions of the bones that are damaged and reveal as bright spots on the imaging plate.
Also Read: Bone Density Test: Procedure, Risks, Results
Treatment
The main objective of treatment is to avert further bone loss.
Medications: The doctors prescribe medications in the early stage of avascular necrosis to alleviate pain, improve blood flow, prevent blockage, and enhance bone health.
Rest: Proper rest will lessen the burden on the affected bone and can slow the damage. The doctor may advise the patient to restrict physical activity or use crutches to keep weight off the joint.
Exercises: A physical therapist will teach the patient certain exercises to improve the range of movement in the joint.
Electrical Stimulation: Electrical currents may help the body to make new bones and to replace the damaged ones. It is used during surgery and placed directly to the damaged area.
Surgery: Certain surgical procedures are also done to stimulate the production of healthy bone tissue and blood vessels such as core decompression, bone grafting, bone reshaping, joint replacement, and regenerative medical treatment.
