As a result of a lack of blood supply to a bone, osteoonecrosis results in the death of bone tissue, causing the bone to collapse and lose its shape and function. There are a variety of factors that can cause osteoonecrosis, such as trauma, medication, alcohol, and disease. It is most common in the hip, knee, shoulder, and ankle. Osteonecrosis can cause pain, stiffness, and difficulty moving the affected joint. Depending on the severity and location of the bone damage, osteoonecrosis can be treated conservatively or surgically. It can be diagnosed through physical examination, blood tests, and imaging tests. Keeping a healthy lifestyle and avoiding risk factors are two ways to prevent osteoonecrosis.
Causes
An osteonecrosis occurs when the blood flow to a bone is interrupted or reduced, preventing the bone from receiving oxygen and nutrients.
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An injury to the bone or the joint, such as a fracture, dislocation, or surgery, that damages the blood vessels and reduces blood supply to the bone.
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Medications such as corticosteroids, anticoagulants, or bisphosphonates can affect blood clotting, bone metabolism, or blood vessel function, increasing the risk of osteonecrosis.
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Abuse of alcohol can cause fatty deposits to build up in blood vessels, narrowing them and reducing blood flow to bones.
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A condition that impairs blood circulation, the immune system, or bone health, and predisposes to osteonecrosis, such as sickle cell anemia, lupus, diabetes, or HIV.
Symptoms
There may be no symptoms of osteonecrosis in its early stages, and the condition may be detected incidentally through an X-ray or another test. As the condition progresses, symptoms may include:
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A mild or severe pain in the affected bone or joint, which may worsen with activity or weight-bearing.
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A visible or palpable swelling or inflammation in the affected area.
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The ability to perform daily activities or movements may be limited by stiffness or reduced range of motion in the affected joint.
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The bone may collapse or deform when it loses strength and shape, causing the joint to become unstable or misaligned.
Diagnosis
Medical history, physical examination, laboratory tests, and imaging tests are used to diagnose osteonecrosis. A doctor will ask the patient about the symptoms, the duration of the symptoms, his or her medical history, and family history. The doctor will also conduct a physical examination, including:
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Checking for swelling, deformity, or tenderness in the affected bone or joint.
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Feeling for lumps, bumps, or crepitus on the affected bone or joint.
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Checking the affected bone or joint for pain, stiffness, or reduced movement.
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Assessing the nerve and vascular function of the affected limb for signs of compression.
Some laboratory and imaging tests may also be ordered by the doctor, including:
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Tests that measure blood cell counts, calcium, phosphate, alkaline phosphatase, and other markers of bone health.
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Tests of urine can measure calcium, phosphate, and other substances reflecting bone turnover and kidney function.
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Bone structure can be determined by X-rays, as well as the presence and location of bone damage.
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An MRI can detect early signs of osteonecrosis before they are visible on x-rays by showing the soft tissues and blood vessels.
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Cross-sectional images of the bone and joint can be obtained with a CT scan, which reveals the extent and severity of bone damage.
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During a bone scan, the metabolic activity of the bone and joint can be assessed, as well as hidden areas of osteonecrosis.
Treatment
There are a variety of treatments for osteonecrosis, depending on the cause and severity of the condition, as well as the patient's overall health. Treatment options include preserving bone and joint function, preventing or delaying bone collapse or joint replacement, and preventing or delaying joint replacement.
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Non-surgical conservative treatment methods include:
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Rest and activity modification, such as avoiding or limiting activities that cause or worsen pain, such as running, jumping, and twisting.
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Drugs that relieve pain and inflammation, such as nonsteroidal anti-inflammatory drugs (NSAIDs), or drugs that improve bone health and blood flow, such as bisphosphonates, statins, or anticoagulants.
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Working with a physical therapist to learn exercises and techniques that strengthen the muscles and tendons around the joints and improve their mobility and stability.
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A low-voltage current is applied to the affected bone, stimulating bone healing and blood circulation.
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Treatments involving invasive methods, such as:
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Drilling holes into the affected bone relieves pressure and pain, and increases blood flow to the bone.
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By bone grafting, healthy bone tissue is transplanted from another part of the body or from a donor, filling holes or defects in the affected bone, and promoting bone regeneration.
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The osteotomy procedure involves cutting and reshaping the bone in order to improve the alignment and function of the joints.
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In joint replacement, the damaged bone and cartilage are removed and replaced with metal, plastic, or ceramic artificial parts, restoring the joint's function and mobility.
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Prevention
There are some measures that can be taken to reduce the risk or severity of osteonecrosis, such as:
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Keeping the blood supply to the bones healthy by avoiding or limiting risk factors, such as trauma, medication, alcohol, and disease.
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In case of bone or joint pain, swelling, or deformity, seek medical attention immediately.
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Osteonecrosis should be treated and monitored according to the doctor's instructions.
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Consuming a balanced diet rich in calcium, vitamin D, and other nutrients that support bone health.
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Under the supervision of a doctor or a physical therapist, exercise should be done regularly to strengthen bones and muscles, and improve joint function and blood flow.
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Preventing falls and injuries by using safety equipment, avoiding slippery surfaces, or removing obstacles.
