Bone Marrow Oedema
What is Bone Marrow Oedema?
Bone marrow oedema occurs when fluid builds up in the bone marrow and is typically a response to an injury, such as a fracture or conditions such as osteoarthritis. Although pain is the major symptom, bone marrow oedema differs in terms of its causal mechanisms, underlying disease, as well as treatment and prognosis.
Bone marrow oedema (BMO) is typically identified via MRI or ultrasound when a patient has another condition or pain in or around the bone. Most frequently, they occur in the hip, knee, ankle, or foot but can occur in all bones.
It`s a relatively frequent disease, in a recent study of patients with foot and/or ankle pain the prevalence of bone oedema in MRI was 23%. There, the average patient was male, aged approximately 50, with traumatic or degenerative talus bone oedema.
In many cases, the liquid inside the bone will go away with time, therapy, and pain medication, such as nonsteroidal anti-inflammatory drugs (NSAIDs). However, waiting for the oedema to go away by itself can take a long time, which is especially concerning for professional athletes, but also frustrating for regular patients. From practical cases, we know that exclusively focusing on avoiding load and exercises, unfortunately only brings limited success. Therefore, a better approach is needed and has been investigated in recent research groups.
DIAGNOSIS AND TREATMENT
Painful BMO can occur spontaneously or secondary to various, underlying diseases. Therefore, the detection of oedema in the bone marrow is important in managing symptoms of arthritis, stress fracture, cancer, or infection. It can indicate where the pain started and how strong the bones are, which in turn will affect the treatment choice.
Common causes of bone marrow oedema include:
- Injuries: such as plantar fasciitis or tendinitis.
- Stress fractures: Stress fractures occur with repetitive stress on the bones. This can occur due to physical activity such as running, competitive dancing, or weightlifting. The fractures are characterized by bone oedema and fracture lines.
- Arthritis: Bone oedemas are relatively common in those who have both inflammatory and noninflammatory arthritis. It’s usually due to a cellular infiltrate within the bone which compromises bone cell function and appears as the disease gets worse together with loss of cartilage.
- Cancer: Metastatic tumours can produce a higher water production in bone. This oedema will appear in ultrasound or MRI. Radiation treatment can also cause oedemas to occur.
- Infection: Swollen tissues can cause increased water in the bone. The oedema will typically go away after the infection is treated.
The most important therapeutic measure is the research into the cause of the bone marrow oedema or the stress reaction/ stress fracture of the bone. Thus, triggering events, unaccustomed stress or incorrect stress should be investigated.
Initial treatment is symptomatic with restricted weight bearing, analgesics, and physiotherapy. In addition, corticosteroids, bisphosphonates, and prostaglandin inhibitors are used. Although BMO is usually self-limiting, previous conservative therapy has not been successful in shortening the course of the disease.
Shock wave therapy (SWT) has also shown to be a promising addition for a conservative treatment approach. Practical evidence shows its effectiveness in various orthopaedic diseases (Kienböck’s disease, plantar fasciitis, osteitis pubis, osteonecrosis of the femoral head). In general, shock wave therapy promotes the self-healing powers of the tissue and can therefore be a useful tool in managing underlying diseases or other, relevant symptoms.
Specifically, in bone tissue, this means the stimulation of osteoblasts and periosteum cells and the differentiation of stem cells. It is assumed that there is an increased secretion of nitric oxide synthase and vascular endothelial growth factor, which could lead to increased angiogenesis. In addition, the periosteum is stimulated and the activity of osteoclasts is reduced. To summarise, shock wave therapy promotes the treatment of the underlying causes around the pathology of bone marrow oedema, to activate the bone structure to heal itself.