Avascular necrosis of the hip is when bone tissue dies due to a lack of blood supply. It is also called Osteonecrosis of the hip; it can lead to tiny breaks in a bone and a bone’s eventual collapse. 

A broken bone or a dislocated joint can interrupt the blood flow to a specific section of bone. Avascular necrosis of the hip is also caused due to long-term use of high-dose steroid medications and excessive alcohol consumption. 

Anyone can be affected by it, but the condition is most common amongst the people between ages of 30 to 50. Every year over 20,000 people suffer from this. In many cases, both the hips are affected. Men are more likely to be affected by osteonecrosis than women. 

Anatomy 

Our hip is a ball-and-socket joint. The socket is the acetabulum, which is a concave part of the large pelvis bone. The ball is the femoral head, which is the upper end of the femur bone (thighbone). The surface of the ball and socket joint is covered with articular cartilage, a burnished, smooth substance that protects the bones and also enables them to move easily over each other. 

Avascular necrosis of hip occurs in the femoral head, which is the ball of ball-and-socket hip joint. Risk Factors It is not always known what causes the lack of blood supply in the joint, but doctors have identified a number of risk factors that can make it more likely for someone to develop osteonecrosis: 

  • Injury: Hip dislocations, hip fractures, and other injuries to the hip can damage the blood vessels and impair circulation of blood to the femoral head. 
  • Excessive alcohol use: Overconsumption of alcohol excessively can cause fatty deposits to form in the blood vessels and can elevate cortisone levels, resulting in a decrease of blood supply to the bone. 
  • Corticosteroid medicines: Many diseases, like asthma, rheumatoid arthritis, and systemic lupus erythematosus, and many more are treated with steroid medications. Although it is not exactly known why and how can these medications lead to Avascular necrosis, research shows that there is a connection between the disease and long-term use of corticosteroid. 
  • Medical conditions: Osteonecrosis is associated with other diseases, like Caisson disease (diver’s disease or “the bends”), sickle cell disease, myeloproliferative disorders, Gaucher’s disease, systemic lupus erythematosus, Crohn’s disease, arterial embolism, thrombosis, and vasculitis. 

Symptoms 

Avascular necrosis symptoms develop in different stages. Hip pain is typically the very first Avascular necrosis symptom. This may further lead to a dull ache or throbbing pain in the groin or buttock area. As the disease progresses, it becomes more and more difficult to stand and put weight over the affected hip, and moving the hip joint turns painful. It may take from several months or even a year for the disease to progress. It is important to diagnose Avascular necrosis symptoms early, because some studies show that early treatment is associated with better outcomes. How is Avascular necrosis of hip diagnosed? Along with a complete report of medical history and physical exam, you may have one or more of the following tests: 

  • X-ray: This test uses invisible electromagnetic energy beams to create images of internal tissues, bones, and organs onto a film. 
  • Computed tomography scan (also known as CT or CAT scan): A CT scan shows the details of the bones, the muscles, the fat, and the organs. CT scans are generally more detailed than normal X-rays. 
  • Magnetic resonance imaging (MRI): These tests use large magnets, radiofrequencies, and also a computer to create detailed images of the organs and structures within the body. 
  • Radionuclide bone scan: This nuclear imaging technique uses a very small amount of radioactive material, which is further injected into the blood and is detected by a scanner. This test shows the blood of flow to the bone and cell activity within the bone. 
  • Biopsy: A procedure in which the tissue samples are removed from the body for an exam under a microscope. It’s done to find the cancer cells or other abnormal cells or remove the tissue from the affected bone. 
  • Functional evaluation of bone: Tests that usually involves a surgery that measures the pressure inside the bone. Avascular necrosis treatment without surgery There are treatments for avascular necrosis. There are both types of treatments with surgery and without surgery. Avascular necrosis treatment without surgery can be done using medication and therapy. Some of the Avascular necrosis treatment without surgery using drugs and exercises are,• Nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil, Motrin IB, 

others) or naproxen sodium (Aleve) might help one relieve the pain associated with the avascular necrosis. 

  • A physical therapist can teach you exercises that help in maintaining and improving the range of motion in your joint.