Accessibility Tools

What is Bone Marrow Edema Syndrome of the knee?

Bone marrow edema syndrome of the knee is a condition characterized by a group of symptoms including bone pain and bone marrow edema in the knee joint. The condition can be often detected on an ultrasound or magnetic resonance imaging (MRI) scan and is commonly associated with fracture, joint injury, or osteoarthritis. It can also be associated with osteomyelitis (bone infection), which can be seen in an MRI as well. 

Bone marrow is a spongy, soft tissue that is found in the center of most bones. It comprises of blood stem cells, which are special cells that in due course become white blood cells, red blood cells, or platelets.

Edema is the swelling that occurs due to fluid buildup in a specific body region. Bone marrow edema is the buildup of fluid within the bone marrow. Bone marrow edema is also referred to as bone marrow lesion.

Causes of Bone Marrow Edema of the Knee

Bone marrow edema of the knee may develop due to the following conditions:

  • Knee ligament injuries
  • Trauma to the knee bone, including bone bruises and broken bones
  • Degenerative joint diseases, such as osteoporosis or osteoarthritis.
  • Synovitis (inflammation of the synovial membranes that line the joints)
  • Avascular necrosis (death of bone tissue) 
  • Bone infection
  • Bone tumor (in rare cases)

Symptoms of Bone Marrow Edema of the Knee

Bone marrow edema of the knee may or may not cause symptoms. If it does, localized knee pain is usually the main indication. You may also notice swollen joints, also known as joint effusion. In general, some of the common symptoms of bone marrow edema in the knee include:

  • Recurrent tenderness and pain
  • Swelling of the knee area
  • Bruises around the knee
  • Inability to weight-bear on the knee
  • Varying level of pain, from mild to moderate, depending on the trauma and severity

Diagnosis of Bone Marrow Edema of the Knee

Bone marrow edema of the knee may or may not cause any symptoms. It is usually diagnosed when a patient has another condition or pain in or around the knee. In order to diagnose the condition, your physician may conduct the following:

  • A thorough physical examination of the knee to look for signs of edema and pain
  • A review of your medical history
  • Blood tests to look for inflammatory agents in the body
  • Ultrasound and MRI scans as bone marrow edema do not show up on an X-ray or CT scan
  • A bone biopsy, in some instances, to rule out other serious conditions such as cancer and to obtain a more precise diagnosis

Treatment for Bone Marrow Edema of the Knee

Mild to moderate cases of bone marrow edema of the knee can be treated with conservative treatment measures such as physical therapy/rehabilitation protocol, application of ice to the affected area, ample rest to the knee lasting for several months, nonsteroidal anti-inflammatory drugs (NSAIDs) such as acetaminophen and ibuprofen to ameliorate pain and swelling, and use of assistive devices such as a cane or crutch for walking can also help subside the edema and facilitate recovery.

For more severe cases, your physician may recommend a surgery called core decompression surgery. This surgical procedure is performed under anesthesia and involves drilling tiny holes into the affected portion of the bone to release pressure and ease pain. Drilling of tiny holes also enables the affected portion of the bone to experience increased blood flow, formation of fresh blood vessels, and natural bone healing. Your surgeon may then fill the drilled holes with bone graft material or bone marrow stem cells to stimulate normal bone marrow growth.

Another surgical option for bone marrow edema of the knee is called subchondroplasty. This is a minimally invasive procedure that is performed to repair chronic bone marrow lesions by filling them with a bone substitute material (BSM). The artificial substitute is then slowly resorbed and replaced with healthy bone, repairing the bone defect. Subchondroplasty also resolves the associated edema. This is a procedure that is especially effective for patients with osteoarthritis of the knee (wear and tear of the cushioning cartilage tissue between the bones). During this procedure, an X-ray is first used to determine the site of the edema. The patient is then sedated, and a tiny needle is used to inject a paste into the region of the edema. The paste eventually hardens and offers more density and strength to the bone. By improving bone strength, it enables the bone to manage osteoarthritis and pain of the edema.