Osteoarthritis is usually thought of as an age-related process.
Within a joint, you have a tough slippery tissue called cartilage that covers the surface of the bones. This cartilage is there to protect the bones, help the bones to move against each other freely and to cushion the joint. Over the years, the cartilage gets thinner and the surface becomes less smooth. This can cause the joint to feel stiff, and you may notice creaking sounds when moving.
When the cartilage becomes worn, the body tries to repair the tissue, which causes all of the tissues in the local area to become more ‘active’. Despite changes to the joint, this repair process usually allows the joint to function normally without pain. This means that despite us all developing osteoarthritic changes in our joints as we get older, it does not mean that every joint will be painful or stiff.
Unfortunately, this repair process does not always work well, which means structural changes to the joint can end up causing pain, stiffness and/or swelling. Examples of changes that can happen to a joint:
· Extra bony spurs develop at the edge of a joint (called osteophytes). These can restrict movement or rub against other soft tissue structures.
· The soft tissue structure that lines the joint (call synovium) can become thicker and produce more joint fluid (synovial fluid), causing the joint to swell or appear larger.
· Soft tissue structures that support the joint may become weaker.
The risk of developing osteoarthritic symptoms can be down to many different factors, including:
· Age – symptoms of osteoarthritis can develop any time after the late 40s. This is because the body becomes less good at repairing itself the older it is.
· Gender – osteoarthritis is more common in women. Women also tend to develop more severe symptoms.
· Obesity – being overweight can put extra pressure through your weight bearing joints, such as your hips and knees. However, being overweight also raises the levels of inflammation in the body, which can make osteoarthritis worse in any joint.
· Injury or operations – any trauma to a joint, through injury or surgery, can increase the chance of developing osteoarthritis in a joint.
· Joint abnormalities – some people are born with joint abnormalities (eg perthe’s disease in the hip), which can lead to earlier and more severe osteoarthritis occurring within a joint.
· Genetics – some people are more likely to develop symptoms of osteoarthritis purely because of the genes they have inherited, which could affect structures like collagen that support a joint.
· Other disease – Other joint diseases can result in more severe osteoarthritic changes or symptoms, these could include rheumatoid arthritis or gout. Other diseases such as diabetes can also contribute to more severe osteoarthritic symptoms.
· Weather – although this doesn’t contribute to any structural joint changes, many people say that their osteoarthritis feels worse when the atmospheric pressure drops – for example, during cold, damp or rainy weather.
· Diet – again diet does not cause any structural change within a joint, but some people find that certain food groups can either make their symptoms feel better or worse.