Osteonecrosis is the death of an area of bone that occurs when its blood supply is interrupted. This loss of blood flow can cause bone tissue to die and lead to symptoms such as pain, stiffness, swelling, and severe osteoarthritis.
Osteonecrosis most often affects the ends of long bones, such as the head of the femur in the hip or the humerus in the upper arm. It can also affect the knees, ankles, wrists, or jaw.
Osteonecrosis is also known as avascular necrosis or aseptic necrosis. Treatment is guided by an orthopedic specialist and may include medications, rest, physical therapy, or surgery.
Main symptoms
The main symptoms of osteonecrosis are:
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Pain in the affected bone, even at rest, that gets worse over time;
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Stiffness and difficulty moving the affected limb;
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Swelling in the affected area;
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Difficulty walking or carrying out everyday activities.
Symptoms of osteonecrosis develop as blood circulation to the bone worsens and the amount of bone damage increases.
It is important to consult an orthopedic specialist if symptoms of osteonecrosis develop so that the condition can be diagnosed and the most appropriate treatment can be started.
Confirming a diagnosis
Osteonecrosis is diagnosed by an orthopedic specialist based on symptoms, medical history, any history of trauma or medication use, a physical examination, and imaging tests.
The doctor may order tests such as an X-ray or MRI of the affected area.
These tests can help confirm osteonecrosis and rule out other conditions that may cause similar symptoms, such as rheumatoid arthritis, tumors, or osteomyelitis.
Is osteonecrosis serious?
Osteonecrosis can be serious, especially if it is not diagnosed and treated promptly.
This is because interrupted blood flow to the bone can cause complications such as collapse or destruction of the joint, arthritis, or the need for joint replacement surgery.
Osteonecrosis can also cause chronic pain and interfere with everyday activities and quality of life.
Possible causes
The main causes of osteonecrosis are:
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Bone trauma;
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Hip dislocation or fracture of the femoral head;
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Chemotherapy or radiation therapy;
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Long-term use of high-dose corticosteroids;
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Heavy alcohol use or smoking;
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Treatment with bisphosphonate medications, such as zoledronic acid.
Osteonecrosis can also develop after bone surgery or as a result of conditions that affect blood clotting or circulation, such as sickle cell disease, liver failure, cancer, or rheumatic diseases.
Other causes include extravascular compression within the bone, such as swelling in the bone marrow, bleeding, or displacement of bone fragments after a fracture.
Types of osteonecrosis
The main types of osteonecrosis are:
1. Osteonecrosis of the femoral head
Osteonecrosis of the femoral head can be caused by physical trauma to the bone, radiation therapy, corticosteroid use, or alcohol consumption.
It can also develop due to conditions that cause extravascular compression within the bone.
This type of osteonecrosis may not cause symptoms in its early stages.
However, as the blood supply to the femoral head becomes reduced or interrupted, hip pain may develop. The pain may get worse when walking or climbing stairs and improve with rest.
2. Osteonecrosis of the hip
Osteonecrosis of the hip is commonly a complication of hip dislocation when treatment is not performed promptly, within the first 6 hours.
This can interrupt the blood supply to the femoral head, causing this part of the bone to die and the joint to collapse. Symptoms may include hip pain, pain in the groin or buttocks, hip stiffness, or difficulty walking.
This type of osteonecrosis is commonly associated with trauma or may occur after hip replacement surgery, for example.
3. Osteonecrosis of the jaw
Osteonecrosis of the jaw is caused by reduced or interrupted blood flow to the jawbone, which plays an important role in opening and closing the mouth and in chewing.
This type of osteonecrosis is commonly associated with tooth extraction or the placement of dental grafts or implants and may cause symptoms such as jaw pain, swelling, or heaviness.
In addition, bisphosphonate medications such as zoledronic acid or pamidronate can increase the risk of osteonecrosis of the jaw.
4. Osteonecrosis of the knee
Osteonecrosis of the knee can be caused by knee dislocation, a stress fracture, corticosteroid use, lupus, or frequent and excessive alcohol consumption.
Some medications used to treat HIV may also increase the risk of osteonecrosis of the knee.
The most common symptoms of this type of osteonecrosis are knee pain (specifically inside the knee) and difficulty standing or moving the affected knee.
5. Osteonecrosis of the shoulder
Osteonecrosis of the shoulder is usually caused by trauma to the humerus, the bone of the upper arm.
This type of osteonecrosis can cause throbbing shoulder pain that may radiate to the elbow, as well as reduced range of motion in the shoulder and arm.
6. Osteonecrosis of the talus
Osteonecrosis of the talus affects the bone in the foot that connects with the two bones of the lower leg, the tibia and fibula.
This type of osteonecrosis can develop after a talus fracture or be associated with corticosteroid use or sickle cell disease, for example. It may cause deep ankle pain or swelling.
7. Osteonecrosis of the lunate
Osteonecrosis of the lunate, also known as Kienböck disease, affects the lunate bone in the wrist and may be associated with trauma, lupus, sickle cell disease, or cerebral palsy.
This type of osteonecrosis may cause wrist pain, swelling, stiffness, or difficulty moving the wrist.
Treatment options
Treatment for osteonecrosis should be guided by an orthopedic specialist and varies depending on the location of the affected bone.
The main treatments for osteonecrosis are:
1. Medications
Pain relievers and anti-inflammatory medications may be prescribed to help relieve pain and swelling.
If osteonecrosis is associated with bisphosphonate use, the doctor may recommend stopping the medication.
2. Rest
Resting the affected joint may also be recommended to relieve pain and support recovery.
The doctor may also recommend using crutches or a wheelchair for several months to reduce pressure on the hip joint, femoral head, knee, or ankle.
3. Physical therapy
Physical therapy is an important part of recovery from osteonecrosis, and treatment may vary depending on the type and severity of the condition.
Physical therapy may include muscle-strengthening exercises, joint mobilization, and stretching. These measures can help reduce the risk of complications in the affected area, such as fractures, and may help avoid the need for joint replacement surgery.
Devices such as electrical stimulation units may also be used to help control pain and strengthen muscles.
4. Surgery
Surgery may be recommended in more severe cases of osteonecrosis.
Different surgical techniques may be used, including core decompression, bone grafting, or reshaping of the affected bone.
Joint replacement surgery, such as hip, shoulder, or knee replacement, may also be recommended.
