A new theory of joint function presented in a symposium at the 71st annual meeting of the American Academy of Orthopaedic Surgeons suggests that the development of osteoarthritis in the knee following an injury may be both predictable and preventable.
By examining the joint at the metabolic level, physicians may be able to identify those at risk for developing osteoarthritis in the future and take measures to stop the progress of the condition.
Posttraumatic osteoarthritis of the knee joint is one of the most common conditions managed by orthopedic surgeons worldwide. Currently, the most common approach is based on a structural view of joint function. MRIs and x-rays are typically used to analyze the structure of the bones, cartilage, and other tissues in the joint. However, the tissue homeostasis theory states that joints are more than mechanical structures - they are living, metabolically active systems. When damaged, joint tissues can begin to lose their homeostasis (the ability to maintain their metabolic equilibrium), which can eventually lead to the development of osteoarthritis.
Scott F. Dye, MD, originator of this theory and associate clinical professor of orthopedic surgery at the University of California in San Francisco, California, stated: "This loss of homeostasis may already be occurring at a time when traditional imaging studies, including MRI and x-ray, would show that the joint structures are normal. If we start imaging the knee for metabolic changes through the use of a study called a bone scan, we can identify the risk of osteoarthritis at a time when something can be done to prevent the development of overt degenerative changes. We can abort this subtle process that, if unchecked, can become an extremely painful condition for the patient."
Dye has found that following orthopedic treatment, such as reconstruction of the anterior cruciate ligament (ACL), patients may still develop osteoarthritis in the knee months or years later. This is because the knee's load transference capacity (or envelope of function) is rarely restored in an ACL reconstruction, even if seemingly normal structural and biomechanical characteristics are achieved.
If patients in this condition return to their usual activities too soon, thus loading their knee beyond its envelope of function, loss of homeostasis will begin to occur. If this loading of the joint continues over a prolonged period, it can result in overt degeneration of the joint tissues. Yet, if the joint is loaded within its envelope of function, the tissue homeostasis theory predicts that it is possible to maintain tissue homeostasis for the entire joint without the development of osteoarthritis. The principle of treatment is to maximize the envelope of function for a given joint or musculoskeletal system as safely and predictably as possible.
Article prepared by NewsRx.com