Bone Dry: Learning More about Osteonecrosis
Originally published in Prime (2022)
For the original article, please click here.
In this interview, Dr Lai talks about osteoneocrosis.
In osteonecrosis or avascular necrosis, there is loss of blood flow to part of a bone. This results in the death of bone cells as well as breakdown and collapse of the adjacent joint. Osteonecrosis often develops around the hip, knee and shoulder joints, leading to joint damage and arthritis. Less often, the bones of the ankles and hands are affected.
There are a number of different causes for osteonecrosis. They include the following:
Idiopathic - In the majority of patients, the cause is unknown.
Injury - Fracture or dislocation of the hip can damage the blood vessels, leading to osteonecrosis of the hip.
Corticosteroids - These medicines, commonly used to treat asthma, rheumatoid arthritis and systemic lupus erythematosus (lupus), and which may be found in Chinese medicines, increase the risk of osteonecrosis when they are used for long periods at high doses.
Alcohol - Overuse of alcohol can cause fat cells to build up in the bone marrow and can increase cortisol (a hormone that can cause blood vessels to narrow) levels in the blood. Together, these may decrease blood flow to the bone and lead to osteonecrosis
Medical Conditions-Certain medical conditions, such as sickle cell disease, polycythaemia, decompression sickness or Caisson disease in deep sea divers, lupus and radiation treatment, can cause osteonecrosis.
The time it takes to go from start of symptoms to a loss of joint function varies from person to person. This can range from a few weeks to more than a year. Acute pain may also suddenly develop if the subchondral bone fractures and collapses
Except in the very early stages of the disease, most cases can be diagnosed with an x-ray. Another method of diagnosis is through Magnetic Resonance Imaging (MRI) scans. An MRI scan can detect early signs of osteonecrosis even before they are seen on an x-ray. In some cases, diagnosis can be made even before the patient starts experiencing symptoms. MRIs can assess and evaluate the degree of bone damage and the overall structure of the joint better than a normal x-ray.
The goal of treatment for osteonecrosis is to preserve normal joint function for as long as possible. If the disease is caught early, the bone is not weight-bearing and the damaged area is small, the bone may heal on its own. In this case, your doctor may recommend one or more non-surgical treatment options to you.
However, in most cases, treatment is likely to involve surgery. In the early stages of disease, surgical procedures will focus on preserving your normal joint. In the late stages of disease, patients may need a total joint replacement of hip, knee or shoulder to restore normal joint function.
In general, the appropriate treatment is evaluated based on the:
The patient's age.
The stage of the disease.
The affected bone and the amount of damage present.
Some of the common symptoms that osteonecrosis patients following factors: may observe include the following:
Pain in the groin or buttocks area in hip involvement, around the knee or shoulder.
Pain when weight is put on the affected joint, sometimes even at rest. Over time, the joint will stiffen and lose its range of motion as osteoarthritis sets in.
Non-surgical approaches may help patients manage their symptoms of osteonecrosis, but generally, they do not cure the disease or slow its progression. Your doctor may recommend one or more of the following non-surgical options to you for disease management, including:
Anti-inflammatory medicines, such as celebrex, arcoxia, ponstan or indomethacin, to reduce pain and swelling. Physical therapy to strengthen muscles, and reduce joint tenderness and stiffness.
Use of a cane or crutches- if the bone is weight bearing- to provide support, and help relieve pain and weakness when walking.
Corticosteroid injections to reduce pain and swelling
Most people with osteonecrosis will eventually need surgery to treat the disease as it progresses. There are two main types of surgery which can be done: core depression surgery and osteotomy. These are aimed at preserving the joint. However, if these surgical options fail or if the diseased bone has already collapsed, you may need joint replacement surgery instead. The different types of surgery are:
1. Core decompression surgery
This is the most common surgery for osteonecrosis of the hip in the early stages of disease. It involves drilling one or more narrow shafts through the bone to decrease the pressure within the bone. This procedure helps to relieve pain and slow disease progression.
Core decompression can be combined with bone grafting to improve bone healing and prevent collapse of the joint. The bone in the bone graft can be taken from the patient or from a donor, or it can be totally synthetic. In certain situations, a section of healthy bone from another part of the body is transplanted along with its blood supply to bring blood supply and healing to the area of osteonecrosis.
When the affected portion of hip bone has collapsed, an osteotomy can be done to reorient the position of the remaining hip bone so that healthy bone is now in the weight bearing position of the hip joint. This recreates a new joint surface, reducing pain and improving the motion of the hip joint. This procedure was first described by Dr Yoichi Sugioka in 1978.
3. Total joint replacement
If the bone in the joint has collapsed and is severely damaged, the joint will need to be replaced with an artificial joint. Total joint replacements relieve pain and improve the range of motion of the affected joint, bringing it back to normal. Current hip and knee replacements can last for 20 years or more, especially if ceramic-on-ceramic articulations are used in the hip joint. This allows the patient to lead a normal lifestyle without pain and stiffness.