Glossary
Bone marrow oedema on MRI
Quick answer
Bone marrow oedema is a bright, fluid-like area inside the bone on MRI. It means the bone is irritated, from a bruise after injury, overload, a stress fracture or arthritis. It is a description, not a diagnosis, and the cause decides treatment, explains Dr. Pablo Gelber, knee surgeon at Aman Hospital in Doha.
What it is
Bone is filled with marrow, which normally looks fairly uniform on MRI. When the bone is injured or overloaded, extra fluid and tiny areas of damage show up as a bright patch. X-rays cannot see this, so bone marrow oedema is found only on MRI.
It can feel like a deep, aching pain that is worse with standing or walking, and sometimes at night.
What it tells the surgeon
The pattern and location are clues. After a twisting injury, bruises on the outer thigh bone and back of the shin bone are typical of an ACL tear. After a kneecap dislocation, bruises appear on the inner kneecap and outer thigh bone. In runners and military recruits, a line within the oedema may be a stress fracture. In older knees, oedema beneath worn cartilage is linked to arthritis pain.
Sudden severe pain with oedema in an older patient, without injury, can point to a subchondral insufficiency fracture, which needs protected weight-bearing.
How it is treated
Treatment is aimed at the cause. Bone bruises usually settle over weeks to a few months with reduced impact and gradual return to activity. Crutches may be used for a period when pain is high. Follow-up MRI is only needed if symptoms do not improve.
Frequently asked questions
Is bone marrow oedema the same as a fracture?
Not always. It often means a bone bruise, but it can accompany a stress or insufficiency fracture. Your surgeon looks for a fracture line and matches it with your symptoms.
How long does bone marrow oedema take to settle?
It varies. Many bone bruises improve over a few weeks to a few months, while oedema linked to arthritis may come and go.
Related
