What is bone marrow oedema?
Bone marrow oedema is the name for a build-up of fluid inside the marrow space of a bone. The marrow space is the soft, spongy inner part of the bone, also known as bone marrow. An oedema is a swelling caused by fluid collecting in tissue. In the case of bone marrow oedema, that fluid is inside the bone itself.
How does bone marrow oedema develop?
This kind of fluid build-up usually happens when a bone is damaged or put under too much strain. A common cause is an injury, such as a bruise, a fracture, or a bone contusion. Repeated stress, like the kind that comes from sports involving lots of jumping or stop-and-go movements, can also irritate the bone and lead to bone marrow oedema. In some cases, the fluid build-up is linked to poor blood supply, inflammation, or conditions such as osteoarthritis.
At its core, bone marrow oedema means that the bone in the affected area is irritated or injured, and is responding with a swelling inside the marrow space. The oedema is often found by chance during a magnetic resonance imaging (MRI) scan, where it shows up as a bright area inside the bone.
Typical complaints and symptoms
Bone marrow oedema may or may not cause symptoms. Many people report pain that gets worse with activity and is sometimes felt even at rest. The joint or bone often feels tender to the touch, and there may be mild swelling or warmth in the surrounding area. Depending on where the oedema is located, for example in the knee, ankle, or hip bone, the pain can limit movement.
Sometimes bone marrow oedema causes no symptoms at all and is only discovered when an MRI scan is carried out for a different reason. In that case, the fluid build-up is called an incidental finding.
Is bone marrow oedema dangerous?
Many people feel worried when they first read about bone marrow oedema in their results. The idea of a swelling inside a bone can seem alarming at first. In most cases, however, bone marrow oedema is not a reason to panic. It is usually a temporary response by the body to overuse or injury. With the right treatment, the oedema often heals on its own.
That said, bone marrow oedema can sometimes be a sign that the bone has been more seriously damaged, or that there is a more significant underlying cause, such as a problem with blood supply, inflammation, or the early stages of bone necrosis (where bone tissue begins to die). This is why it is important to find out the exact cause and to keep an eye on how things progress.
Next steps and treatment options
Treatment for bone marrow oedema depends entirely on the underlying cause and how severe the symptoms are. In many cases, rest and reducing strain on the affected area is enough. This means avoiding sport and activities that put pressure on the bone. Sometimes the use of a walking aid or a splint is recommended to give the bone time to heal.
Pain-relieving and anti-inflammatory medicines may also be used. If symptoms are more severe, or if the oedema does not improve on its own, physical treatments such as cold therapy or targeted physiotherapy may be considered. In rare cases, for example when the blood supply to the bone is at risk or the oedema does not get better, further treatments may be needed. These can include specialist medicines to support bone structure, or in exceptional cases, surgery.
It is important not to return to full activity too soon. Going back to normal too quickly risks making the symptoms worse, or even causing lasting damage to the bone.
How long does healing take?
The time it takes for bone marrow oedema to fully resolve can vary a great deal. In straightforward cases, the oedema heals within a few weeks to a few months. Symptoms usually ease and the inside of the bone returns to normal. With larger oedemas, accompanying injuries, or long-term overuse, healing can take considerably longer. Regular check-ups, usually with MRI scans, help to monitor progress and to spot early on whether further steps are needed.
When should you seek medical advice?
Anyone with persistent, significant bone pain that does not improve with rest or gets worse with activity should see a doctor. Swelling, warmth, or restricted movement are also good reasons to seek professional advice. If bone marrow oedema has already been identified and the symptoms are getting worse or have been going on for a long time, it is worth getting a further assessment. This helps to make sure there is no more serious underlying cause and that healing is being supported as well as possible.
