How Serious Is Bone Marrow Edema?

Doctor looking at mri
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Bone marrow edema is a term used to describe the build-up of fluid (edema) in the bone marrow. While the term is still frequently used by clinicians, it is more commonly referred to today as a bone marrow lesion.

Bone marrow edema is a condition that can be identified on an ultrasound or magnetic resonance imaging (MRI) scan and is often associated with osteoarthritis, a fracture, or joint injury.

Bone Marrow Edema in Osteoarthritis

The development of bone marrow edema in osteoarthritis is usually indicative of a worsening condition.

In addition to the accumulation of fluid, subchondral cysts can often be spotted on an MRI. This is when the damage done to the cartilage begins to harden and form fluid-filled sacs (cysts) within the joint. This causes the joint space to narrow and the cartilage to further wear away, causing​ a bone to rub against bone.

As more and more cartilage is lost, the underlying nerve receptors become increasingly exposed, leading to pain and the increasing loss of mobility. This is especially true in cases of knee osteoarthritis. An underlying knee misalignment only worsens the condition, adding structural stress to already inflamed joints.

Bone marrow edema in persons with osteoarthritis is associated with poor outcomes. When compared to people without edema, those with edema are likely to see their condition deteriorate quickly, often over the course of 15 to 30 months.

Bone Marrow Edema in Injury

Bone marrow edema is commonly seen with fractures and other serious bone or joint injuries, especially those involving the spine, hip, knees, or ankle. Within the context of an injury, the term is relatively non-specific and may refer to an accumulation of fluid or blood or the build-up of fluids resulting from fibrosis (scarred tissue) or necrosis (tissue death).

Some of the more common causes of bone marrow edema include:

  • Stress fractures of the foot, hip, ankle, or knee in which repetitive impact places undue strain on a weight-bearing joint
  • Anterior cruciate ligament (ACL) tears, usually complex rather than simple, which manifest with bruising and synovitis ("water on the knee")
  • Vertebral compression fractures, often associated with advanced age, where the bones of the spine begin to crumble and collapse
  • Bone tumors in which the accumulation of fluid can help undermine the structural integrity of a bone and increase the risk of a fracture
  • Dislocation of the hip in which the diminished blood supply to the bone can cause osteonecrosis (bone death)

While some types of bone marrow edema are difficult to treat, those associated with traumatic injury or repetitive motion can often be resolved with rest, nonsteroidal painkillers, and physical therapy. Severe cases may require steroid injections or surgery.

Bone marrow edema can be a confusing condition, affecting some people differently than others. While it tends to resolve within four to 12 months following an injury, up to 15 percent of cases will persist for two years or more, even among those in otherwise perfect health.

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View Article Sources
  • Eriksen, E. "Treatment of bone marrow lesions (bone marrow edema)." Bonekey Rep. 2015; 4:755. DOI: 10.1038/bonekey.2015.124.
  • Kothari, A.; Guermazi, A.; Chmiel, S. et al. 'Within-subregion relationship between bone marrow lesions and subsequent cartilage loss in knee osteoarthritis." Arthritis Care Res. 2010; 62(2):1988-203. DOI: 10.1002/acr.20068.