About ischemic necrosis of bone

What is ischemic necrosis of bone?

Osteonecrosis, also known as avascular necrosis, is a disease resulting from the temporary or permanent loss of the blood supply to the bones. Without blood, the bone tissue dies and causes the bone to collapse. If the process involves the bones near a joint, it often leads to collapse of the joint surface. This disease also is known, aseptic necrosis, and ischemic bone necrosis.

Although it can happen in any bone, osteonecrosis most commonly affects the ends (epiphysis) of long bones such as the femur, the bone extending from the knee joint to the hip joint. Other common sites include the upper arm bone, knees, shoulders, and ankles. The disease may affect just one bone, more than one bone at the same time, or more than one bone at different times. Orthopaedic doctors most often diagnose the disease.

The amount of disability that results from osteonecrosis depends on what part of the bone is affected, how large an area is involved, and how effectively the bone rebuilds itself. The process of bone rebuilding takes place after an injury as well as during normal growth. Normally, bone continuously breaks down and rebuilds--old bone is reabsorbed and replaced with new bone. The process keeps the skeleton strong and helps it to maintain a balance of minerals. In the course of osteonecrosis, however, the healing process is usually ineffective and the bone tissues break down faster than the body can repair them. If left untreated, the disease progresses, the bone collapses, and the joint surface breaks down, leading to pain and arthritis.

What are the symptoms for ischemic necrosis of bone?

In its early stages, AVN usually doesn’t have symptoms. As the disease gets worse, it becomes painful. At first, it might only hurt when you put pressure on the affected bone. Then, Pain may become constant. If the bone and surrounding joint collapse, you may have severe Pain that makes you unable to use your joint. The time between the first symptoms and bone collapse can range from several months to more than a year.

What are the causes for ischemic necrosis of bone?

Things that can make avascular necrosis more likely include:

  • Alcohol. Several drinks a day can cause fat deposits to form in your blood, which lower the blood supply to your bones.
  • Bisphosphonates. These medications that boost bone density could lead to osteonecrosis of the jaw. This could be more likely if you’re taking them for multiple myeloma or metastatic breast cancer.
  • Medical treatments. Radiation therapy for cancer can weaken bones. Other conditions linked to AVN include organ transplants, like kidney transplants.
  • Steroid drugs. Long-term use of these inflammation-fighting drugs, either by mouth or in a vein, leads to 35% of all cases of nontraumatic AVN. Doctors don’t know why, but longtime use of medications like prednisone can lead to AVN. They think the meds can raise fat levels in your blood, which lowers blood flow.
  • Trauma. Breaking or dislocating a hip can damage nearby blood vessels and cut the blood supply to your bones. AVN may affect 20% or more of people who dislocate a hip.
  • Blood clots, inflammation, and damage to your arteries. All of these can block blood flow to your bones.

What are the treatments for ischemic necrosis of bone?

Treatment goals for AVN are to improve the joint, stop the bone damage, and ease pain. The best treatment will depend on a number of things, like:

  • Your age
  • Stage of the disease
  • Location and amount of bone damage
  • Cause of AVN

If you catch avascular necrosis early, treatment may involve taking medications to relieve pain or limiting the use of the affected area. If your hip, knee, or ankle is affected, you may need crutches to take weight off the damaged joint. Your doctor may also recommend range-of-motion exercises to help keep the joint mobile.

  • Medications. If the doctor knows what’s causing your avascular necrosis, treatment will include efforts to manage it. This can include:
    • Blood thinners. You’ll get these if your AVN is caused by blood clots.
    • Nonsteroidal anti-inflammatory drugs (NSAIDs). These will help with pain.
    • Cholesterol drugs. They cut the amount of cholesterol and fat in your blood, which can help prevent the blockages that lead to AVN.
  • Surgery. While these nonsurgical treatments may slow down the avascular necrosis, most people with the condition eventually need surgery. Surgical options include:
    • Bone grafts. Removing healthy bone from one part of the body and using it to replace the damaged bone
    • Osteotomy. Cutting the bone and changing its alignment to relieve stress on the bone or joint
    • Total joint replacement. Removing the damaged joint and replacing it with a synthetic joint
    • Core decompression. Removing part of the inside of the bone to relieve pressure and allow new blood vessels to form
    • Vascularized bone graft. Using your own tissue to rebuild diseased or damaged hip joints. The surgeon first removes the bone with the poor blood supply from the hip, then replaces it with the blood-vessel-rich bone from another site, such as the fibula, the smaller bone in your lower leg.
    • Electrical stimulation. An electrical current could jump-start new bone growth. Your doctor might use it during surgery or give you a special gadget for it.

What are the risk factors for ischemic necrosis of bone?

Conditions associated with nontraumatic AVN include:

  • Decompression sickness, which causes gas bubbles in your blood
  • Diabetes
  • Gaucher disease, in which a fatty substance collects in the organs
  • HIV 
  • Long-term use of drugs called bisphosphonates to treat cancers like multiple myeloma or breast cancer, which can lead to AVN of the jaw.
  • Pancreatitis, inflammation of the pancreas
  • Radiation therapy or chemotherapy
  • Autoimmune diseases such as lupus
  • Sickle cell disease

Is there a cure/medications for ischemic necrosis of bone?

Ischemic necrosis of bone is a degenerative condition of the bone characterized by the death of cellular components of the bone secondary to an interruption of the subchondral blood supply. It is also known as aseptic necrosis, avascular necrosis, and osteonecrosis. It primarily affects the tips of the long bones at weight-bearing joints. The commonly affected sites are the hip, femoral head, knee, talus, and humeral head.

The treatment strategy is determined based on the site of necrosis and underlying etiology.
1. Hip
• Many patients may need total hip arthroplasty. However, joint salvaging procedures may help, as they have shown varying results.
• Core decompression, one of the joint salvaging procedures, is most effective in the early stages when lesions occur in a small area of the weight-bearing surface of the femoral head.
2. Knee
• Unicompartmental knee replacement provides a good outcome with short rehabilitation.
• When the lesion area is large, total knee replacement is more suitable.
• Intraosseous decompression can help shorter lesion areas.
3. Shoulder
• In the early stages, core decompression provides satisfactory outcomes.
• Humeral head resurfacing or hemiarthroplasty is preferred for moderate severity.
• And advanced disease requires total shoulder replacement.
4. Kienbock's Disease
• The early stage can be treated with either bone graft or procedures that offload the lunate.
• Immobilization, including external fixation, is an option for stages 1 and 2.
• Surgical options address the carpal collapse in stage 3, whereas advanced disease may require joint sacrificing procedures such as wrist arthrodesis.
5. Preiser Disease
• immobilization, cortisone injections, radial wedge osteotomy, and bone graft are in the early stages.
• Advanced stages may warrant arthroscopic debridement, scaphoid excision, proximal row corpectomy, or even arthrodesis.

In the hip: early stages are asymptomatic. Later stages may present referred pain in the buttock and thigh. Many patients have pain at rest. Others include stiffness and changes in gait,Knee: cute onset knee pain that occurs while weight-bearing and at night,Shoulder: pulsating pain with radiation to the elbow and a decreased active range of motion,Wrist: unilateral pain on the wrist's dorsal and radial aspects. Decreased range of motion, wrist swelling, and weakened grip strength
Necrosis in the tips of long bones,Kienbock's Disease,Preiser Disease

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