About Avascular Necrosis
Avascular necrosis (AVN) is a condition where bone tissue dies due to a lack of blood supply, leading to joint pain, bone destruction, and loss of joint function.
Non-modifiable risk factors (risk factors a person cannot change) for AVN include:
- Trauma: Injury to a joint or bone can disrupt the blood supply and increase the risk of AVN.
- Age: AVN can occur at any age, but it is more common in people between the ages of 30 and 60.
- Gender: AVN affects both men and women, but certain conditions like systemic lupus erythematosus (SLE) have a higher prevalence in women, increasing their risk of developing AVN.
- Underlying diseases: Certain medical conditions like systemic lupus erythematosus (SLE), sickle cell disease, HIV infection, Gaucher's disease, pancreatitis, and alcoholism can increase the risk of AVN.
Modifiable risk factors (risk factors a person possible can change) for AVN include:
- Steroid usage: The use of corticosteroid medications, such as prednisone, is one of the most significant risk factors for AVN. These medications can disrupt the blood supply to the bones and increase the risk of bone tissue death.
- Excessive alcohol consumption: Heavy alcohol use can weaken bones and impair blood flow, increasing the risk of AVN.
- Smoking: Smoking damages blood vessels and reduces blood flow to the bones, making smokers more susceptible to AVN.
- Obesity: Being overweight or obese puts extra stress on the joints, which can lead to decreased blood flow and increase the risk of AVN.
- Long-term use of bisphosphonates
It's important to note that while non-modifiable risk factors cannot be changed, understanding them can help identify individuals who may be at higher risk for AVN. Modifiable risk factors, on the other hand, can be addressed through lifestyle changes or medical interventions to reduce the risk of developing AVN.
By recognizing these causes and risk factors for AVN, healthcare professionals can provide appropriate guidance and interventions to individuals who may be at increased risk.
In the early stages of AVN, a person may not have any symptoms. However, as the condition progresses, they may start to experience pain. AVN can affect any joint. It most often affects the hip, but may also occur in the ankles, knee, shoulders, and jaw.
Here are the common symptoms of avascular necrosis:
- Pain, particularly if AVN affects weight-bearing joints. At first, most people start to feel pain when they bear weight on the affected joint, but later, the joint may feel painful during rest.
- Stiffening joints
- A loss in the range of motion
- A sudden increase in pain if the end of the bone collapses
- Arthritis
In more severe cases:
- Debilitation or weakness
- Persistent pain
To diagnose avascular necrosis, healthcare professionals may perform the following examinations, tests, and procedures:
Medical History: Doctors will ask about your symptoms and medical history to understand your overall health and any potential risk factors for avascular necrosis.
Physical Examination: During a physical examination, healthcare providers will look for physical signs of the condition, such as pain, swelling, or the presence of masses in the affected area.
Imaging Tests: Various imaging tests are used to diagnose avascular necrosis and determine its severity. These include:
- X-rays: X-rays provide initial information and help rule out other causes of joint pain.
- Magnetic Resonance Imaging (MRI): MRI scans are highly sensitive and commonly used to detect signs of avascular necrosis before symptoms appear. They provide detailed images of the bone, allowing doctors to assess the extent of bone damage.
- Computed Tomography (CT) Scan: CT scans also provide detailed images of the bone and can be used to evaluate the stage or severity of avascular necrosis.
Additional examinations, tests, and procedures may be performed to determine the stage or severity of avascular necrosis:
- Steinberg Classification System: Avascular necrosis can be classified into seven stages using the Steinberg classification system. This classification is based on radiological findings from X-rays, MRI scans, and bone scans. The stages range from normal or non-diagnostic radiographs (stage 0) to advanced degenerative changes (stage VI).
- Dorr Classification: The Dorr classification system is used to assess proximal femoral morphology in avascular necrosis. It helps determine the shape and thickness of the femoral bone using radiological images. The classification includes three types: type A with thick cortices, type B with proximal bone loss, and type C with substantial cortical thickness loss.
It's important to note that these additional examinations, tests, and procedures may not be necessary for every individual with avascular necrosis. The specific diagnostic approach will depend on your symptoms, medical history, and the assessment made by your healthcare provider.
The goals of treatment for AVN are to prevent disease progression, relieve pain, and restore joint movement and mobility. Treatment options include:
Medication:
- Nonsteroidal anti-inflammatory drugs (NSAIDs) to help relieve pain. NSAIDs are available over-the-counter or with a prescription.
- Osteoporosis drugs may potentially slow progression of AVN
- Medications to help prevent blockages or clots in blood vessels so blood can get to the bone. These may include cholesterol-lowering medications and anticoagulants.
Therapies:
- Physical therapy or rehabilitation: This treatment focuses on exercises that improve joint motion and strengthen the muscles around the affected joints. For example, circular movements of the hip while holding onto something can help improve joint mobility and reduce pain. Canes or crutches to aid walking may also be helpful.
Therapeutic procedures:
- Total hip arthroplasty (THA): This involves replacing the damaged hip joint with an artificial joint. Other joints may be replaced, such as knee replacements.
Health behavior changes:
- Lifestyle modifications: Making certain changes in lifestyle can help prevent AVN or slow down its progression. These include:
- Consuming alcohol in moderation: Excessive alcohol consumption is a risk factor for AVN, so it's important to limit alcohol intake.
- Quitting smoking: Smoking is another risk factor for AVN, and quitting smoking can help improve blood flow to the bones.
- Discussing alternatives to corticosteroids: If you are taking corticosteroid medications, discussing alternatives with your doctor may help reduce the risk of developing AVN.
It's important to note that treatment options may vary depending on factors such as age, stage of disease, which bone is affected, and the extent of damage to the bone. Nonsurgical treatments like physical therapy and medication may be effective in early stages or when AVN only affects a small area. However, advanced forms of AVN or involvement of weight-bearing bones like the hip or knee may require surgical intervention like THA. Always consult with a healthcare professional for personalized advice. Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Medication side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.
Remember, early intervention and addressing risk factors can greatly improve outcomes for individuals with AVN.
As avascular necrosis progresses, it can cause debilitation and weakness, persistent pain, and destruction of the joint beyond repair. In some cases, the joint may need to be replaced. The outlook for avascular necrosis is often negative, regardless of early treatment. In fact, 59% of people without symptoms later develop symptoms or experience bone collapse.
It's important to note that while these treatments can help manage symptoms and improve function, they typically do not slow down the progression of avascular necrosis.
In terms of complications, avascular necrosis can lead to immobility and disability if left untreated or if it progresses to a severe stage. Joint replacement surgery may be necessary in some cases.