Bone Marrow Edema in the Knee
What is Bone Marrow Edema?
Bone marrow edema is a condition that occurs when excess fluids in the bone marrow build up and cause swelling. It is often caused in response to an injury, such as a broken bone or bruise, or a more chronic condition such as osteoporosis. Bone marrow edema most commonly occurs in the hips, knees and ankles. In this case, bone marrow edema of the knee is a main cause of localized knee and joint pain, and is only diagnosable via a Magnetic Resonance Imagining test (MRI).
It is usually caused by:
- Knee bone trauma of any kind, including broken bones and bone bruises.
- Joint disorders such as osteoarthritis or osteoporosis. In this case, the knee joint is lacking the cushion that cartilage provides, which can lead to easier fracture and wear on the bone. Subsequently, if a fracture of the bone occurs, the injured area becomes susceptible to edema.
- Avascular necrosis, or “bone death.” This is when a small portion of the bone dies, and can result in a painful bone marrow edema.
- Knee ligament injuries.
- A condition such as synovitis (an inflammation of the lining the joints, called synovial membranes).
- In rare conditions, bone tumor.
Symptoms of Bone Marrow Edema in the Knee
Bone marrow edemas may not bother you at all, or they may be painful and inconvenient. They can feel more intense than a muscular injury (for example, a muscle bruise) at times. A muscle is capable of swelling, which increases blood flow to heal the area. Unfortunately, bones are not capable of swelling, and thus the fluid (edema) that collects in the marrow can create intense pressure within the bone, resulting in more intense pain. In fact, in many osteoarthritic patients, it isn’t the lack of cartilage that’s causing them pain, but rather the pressure due to the edema.
Some of the most common symptoms of bone marrow edema include:
- Varying degrees of pain, from mild to moderate, depending on the severity and Trauma.
- Swelling of the knee area.
- Inability to put full pressure on the knee to walk.
- Recurrent pain and tenderness.
Treatment of Bone Marrow Edema in the Knee
Thankfully, most bone marrow edemas will settle down and heal on their own after the injury has subsided. For example, in some cases of osteonecrosis the bone will regenerate itself and heal the edema. Unfortunately, though, in the case of osteoarthritis, the edema may only get worse over time. In this case, treatment options may be explored.
Traditional treatments for bone marrow edema usually involve rehabilitation through physiotherapy and rest. Ice, medications such as ibuprofen or acetaminophen, and even a crutch or a cane can help as well. There is one drug-facilitated treatment that uses a bisphosphonate and vitamin D mixture to help increase bone density. When this treatment is delivered via intravenous, it is found to be quite effective in reducing pain and increasing density. Other drugs that usually treat the vascular system have been found effective for bone marrow edema, in that they encourage blood flow and treat any vascular abnormalities that may exist in the bone and marrow.
In some more challenging cases, core decompression may be used. This is a type of surgery where a surgeon drills a hole into the affected part of the bone allowing that area of the bone to experience increased blood flow, form new blood vessels, and heal.
Another option is subchondroplasty, which can be especially effective for osteoarthritis patients. In this procedure, an x-ray determines where the edema is. The patient is then sedated, and a small needle injects a paste into the area of the edema. The paste then hardens and provides more strength and density to the bone. By improving the strength of the bone, it will enable the bone to deal with the pain of the edema and of the osteoarthritis.
If you are experiencing knee pain don’t live with the pain, or wait weeks for an appointment. Contact our office, or book an appointment online with Dr. Goradia, Richmond’s knee and shoulder expert and sports medicine specialist.