Pain, swelling, and inflammation are the most common symptoms of knee arthritis (osteoarthritis). When traditional remedies such as lifestyle modifications, anti-inflammatory drugs, and the application of heat and ice aren't providing relief, injections may be placed directly into the knee to ease swelling and restore the joint's function. A newer type of injection involves alpha 2 macroglobulin, a naturally occurring protein found in blood plasma. Here's what you need to know about A2M injections for knee arthritis.
What is Alpha 2 Macroglobulin?
Alpha 2 macroglobulin is a major type of protein found in plasma, the colorless part of blood. It's believed that A2M helps minimize pain in the knee by deactivating certain enzymes that can break down cartilage cells. When cells in cartilage break down in the knee, the bones that connect to form the knee joint experience increased friction during movement, which causes tissues to become inflamed and nerves to become irritated.
How Do A2M Injections Work?
A2M is a broad spectrum multi-purpose protease inhibitor that deactivates three specific chemicals linked to cartilage breakdown. When these three chemicals are "trapped" by the A2M protein, the body can naturally eliminate them to prevent tissue damage. The injections are prepared by taking the patient's own blood and preparing an injection with a higher than normal amount of A2M. A local aesthetic is usually included to minimize discomfort.
The A2M injection will be placed directly into the affected part of the knee. Image tests are typically done to ensure that the injection is placed into the correct part of the knee. A fibronectin-aggrecan G3 complex test (FAC) may be done to determine if the knee joint will likely respond well to A2M therapy.
What Are the Possible Benefits of A2M Injections?
Clinical studies involving A2M injections suggest the treatment can provide noticeable and sustained relief from arthritis symptoms. According to the American Academy of Orthopaedic Surgeons, A2M injections may be considered when conservative treatments have failed to provide meaningful relief or when knee pain reaches a point where daily life is affected. The treatment isn't recommended for patients with bleeding disorders.
Highly concentrated A2M injections may provide sustained relief from knee arthritis, according to results from a Brown University and National Institutes of Health study. The reduction in inflammation may slow or stop the progression of OA (osteoarthritis) affecting the knee joint. Treatment with A2M injections may also benefit patients with knee pain due to arthritis by:
A2M injections are similar to platelet-rich plasma (PRP) injections in that a component of the patient's own blood is used for the treatment. As with PRP injections, A2M injections may allow patients to actively participate in physical therapy without pain, which can further allow the knee joint and supporting tissues, tendons, and muscles to heal. Since A2M injections contain a naturally occurring protein, the treatment is generally considered safe for most patients.