Of our major synovial joints, the knee and hip are most affected by osteoarthritis (OA). Although the exact cause of OA is unknown and probably varies somewhat from person to person, factors such as advanced age and mechanical injury to a joint are associated with the development of OA. As the condition progresses, articular cartilage begins to soften and demonstrate fibrillations (shown here). At the same time, the underlying bone may hypertrophy due to having to accommodate extra stress as the cartilage matrix becomes disrupted.
So, what can you do to help maintain cartilage health? There are a few things and they revolve around loading the cartilage appropriately in order to help optimize nutrient delivery to this tissue. First and foremost, excessive stress (increased height to weight ratio, excessive exercise without sufficient rest, etc) have been associated with early cartilage breakdown. On the flip side, inadequate loading of cartilage (sedentary lifestyle) and not using a joint through it’s full range of motion may impair nutrient delivery. Cartilage, unlike many other tissues, does not have a pump to deliver nutrients, so it relies on a special type of diffusion called imbibition. You can think of your articular cartilage like a sponge and in order for water, synovial fluid and nutrients to move in and out, the sponge must be squished (loaded) and then unloaded so that absorption can occur. This is why loading a joint appropriately throughout the day (this might mean losing a little weight or modifying your exercise program) and using our joints through a full range of motion are so important for maintaining cartilage health long-term.