Many people present to the office with their MRI reports and worry that something is wrong with their bone marrow.
Bone Marrow Edema is simply a condition where fluid is found within the bone. It’s a very non-specific finding.
Bone marrow edema occurs for three main reasons.
The first is trauma. In response to direct impact or trauma the adjacent bone can form fluid . This edema is often not associated with a fracture on x-ray. It commonly can be Calciumled a bone bruise or occult fracture
The second most common cause of bone marrow edema is osteoarthritis. In a healthy knee, the bones are covered in cartilage. In an arthritic knee that cartilage has become thin, or absent. In that situation the underlying bone is under more stress. If the stress exceeds the capacity of the bone to support the weight then a stress reaction occurs. That stress reaction or fracture shows up as bone marrow edema.
“Osteonecrosis”: Osteonecrosis literally means “bone death”. That means that the blood supply to bone is compromised and a small portion of bone dies. It often presents as a large area of bone edema and it can be quite painful.
Does Bone Marrow Edema Hurt?
When soft tissues are injured, swelling often results.. Well.. bones are hard with little or no capacity to swell. Therefore, if there is fluid in the bone, the pressure inside the bone increases. When the pressure in the bone rises because of the edema, pain will occur. In many patients with osteoarthritis, especially those of you with very little swelling in the knee joint itself, it is likely that the bone marrow edema is the source of pain Usually a physical exam will show that you are more tender over the bone, as opposed to being tender over the joint where the two bones meet.
Does Bone Marrow Edema Need to be Treated?
After trauma, the bone marrow edema will often resolve on its own. In osteonecrosis, the bone marrow edema will also subside. In many cases of osteonecrosis the bone will grow new blood vessels and reform. Sometimes the area involved is too large, and it may not regrow. In these instances often the structural support of bone is compromised and the bony construct can collapse leading to osteoarthritis. Primary osteoarthritis on the other hand is a progressive condition. Sadly, it only gets worse over time. That means that the edema is unlikely to improve either. In cases of severe pain that is thought to be due to bone marrow edema, certain treatments might be indicated.
How is Bone Marrow Edema Treated?
The initial treatment of bone marrow edema is not very different from the treatment of most bruises. Rest, ice, medications, activity limitation, and possibly a crutch or a cane. In cases of trauma, and many cases of osteonecrosis, that will suffice. In some patients with bone marrow edema due to osteoarthritis, the pain might not improve. If the pain has not improved and your quality of life is suffering, you may prove to be a candidate for a procedure known as a subchondroplasty.
In a subchondroplasty procedure ,we use an X-ray machine to find the area of bone where the edema is present. A needle is placed (under anesthesia), and a calcium phosphate paste is injected. That paste will harden shortly thereafter providing the bone significantly more strength and support. By improving the strength of the bone, it will enable the bone to deal with the added stress due to the osteoarthritis. Often the procedure is performed with an arthroscopy to address the arthritic component of the problem within the joint itself. If the procedure is successful, and the bone is stronger, then the bone marrow edema can subside. Once the bone marrow edema subsides, pain relief can ensue.
The early clinical trials, and our experience shows this to be a safe and effective procedure. While arthroscopy alone has mixed results in the arthritic knee, subchondroplasty can offer increased success for patients hoping to avoid more aggressive treatments for osteoarthritis. We need more research, and more time to determine if this could be a long term solution for pain due to bone marrow edema.