Bone marrow oedema is swelling or fluid build-up within the bone marrow. Often, oedema is detected by imaging such as MRI. So what is subchondral bone marrow oedema, and how should you manage it?

What is subchondral bone marrow oedema?

The bone marrow is the spongy part of the centre of bones. It is involved in producing new red and white cells in the blood. A build-up of fluid in the bone marrow is often termed bone marrow oedema. Oedema usually occurs due to an injury such as a fall or pathological conditions such as osteoarthritis or tumours.

How to diagnose bone marrow oedema  

doctors looking at x-ray of bone marrow oedema

Generally, we diagnose fluid build-up in the bone marrow on imaging such as MRI. However, other imaging such as X-rays or CT can sometimes help make a specific diagnosis.

There are many causes of bone marrow edema, but the most common causes include the following:

Osteoarthritis 

Osteoarthritis occurs when the cartilage becomes damaged due to degeneration and inflammation. Bone oedema is often a sign that your osteoarthritis has gotten worse.

Studies suggest that the presence of oedema means worse symptoms and a higher chance of progression than cases without oedema.

Acute injury

An acute injury such as a fall or a twist can lead to bone marrow bruising or acute fracture. Fluid build-up or release can occur secondary to bleeding, fibrosis (scar tissue), or necrosis (tissue death). This fluid in the bone can last long, meaning pain from a bone bruise can last for many months.

Stress fractures 

Repeated and sustained impact on bone can weaken, leading to microfractures and fluid build-up in the bone marrow. This oedema is a stress response or fracture due to excessive physical activity such as running, football, or netball.

Tumours 

Tumour growth leads to fluid build-up and bone weakening. One particular tumour that causes intense bone marrow oedema is osteoid osteoma.

Infection 

Infection leads to acute inflammation and fluid build-up in the bone marrow.

Primary 

Sometimes, oedema forms for no known reason. This oedema is often termed primary bone marrow edema of unknown cause or transient migratory osteoporosis. Generally, this condition affects the hips, knees, ankle, and feet. Overall, it is essential to rule out the other causes of bone marrow oedema.

Treatment of bone marrow oedema 

vitamin D foods for bone marrow oedema

If the cause is due to trauma such as a fall, then treatment consisting of rest, ice, and NSAIDs will reduce swelling. Generally, most cases settle between 4-and six months. But sometimes, swelling can last for greater than a year.

We recommend rest using a walking aid or crutches in primary bone oedema (with no known cause). Also, ice and simple analgesic tablets will help. Generally, we perform routine checks of bone density and blood tests such as inflammatory markers and Vit D. There is a link between bone oedema and Vit D deficiency.

In addition, improving general lifestyle factors such as stopping smoking, increasing calcium intake, and reducing alcohol intake can help.

Other frequently asked questions:

Is there a link between pregnancy and primary bone oedema?

Yes. Often, primary bone marrow oedema affects women late in pregnancy. More commonly, it affects the hip joints and the knees and ankles.

How long does primary bone oedema last? 

Typically, symptoms last for 3-6 months. Sometimes, symptoms can recur or move to another joint.

Are injections indicated for bone marrow oedema?

Generally not. However, in severe cases, we might consider intravenous bisphosphonates. In addition, if bone oedema occurs in the knee, we may consider a hyaluronic acid injection into the joint.

Osteoid Osteoma on MRI: What do we see? 

Osteoid Osteoma is a benign bone tumour that occurs often in the pelvis or lower limb. Generally, pain is worse at night and better during the day. Also, Asprin or Ibuprofen reduces pain sometimes completely. Osteoid Osteoma can be tricky to detect on MRI. Sometimes, Osteoid Osteoma presents just with a small area of bone marrow oedema or can be completely missed. We often need other tests, such as CT scan, to find the small core or nidus.

Final word from sportdoctorlondon

Bone marrow oedema is often found on MRI scans. Therefore, it is essential to find out the cause of oedema so treatment can be effective.

Dr. Masci is a specialist sport doctor in London. 

He specialises in muscle, tendon and joint injuries.