Osteoarthritis is the most common form of arthritis and it’s affecting more and more Canadians every year. It’s estimated that by 2035, one in four Canadians with be diagnosed with osteoarthritis – a disease of the whole joint that leads to the breakdown of joint cartilage and the underlying bone.
Osteoarthritis (OA) is sometimes described as degenerative or “wear-and-tear” arthritis. Recent studies suggest there may be an inflammatory component to OA, so it may not just be age-related or caused by overuse. In normal joints, cartilage – the tough elastic material that covers and protects the ends of bones – acts as a cushion and provides a smooth, gliding surface for joint motion. OA causes the cartilage to break down, leading to pain, swelling, and problems moving the joint. As it worsens over time, the cartilage wears away and bone rubs against bone, causing joint damage and increased pain.
OA usually progresses slowly over months or years and early symptoms tend to come and go. It commonly affects the knees, hips, first toes, wrists, thumbs, fingers, and spine. As damage progresses, symptoms can become more constant, occurring at rest and disturbing sleep.
There are a number of methods for classifying the clinical severity of OA, which is important in directing appropriate treatment. The most commonly used is Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) that assesses OA based on pain, stiffness, and physical function.
There are also different methods for determining the severity of OA through imaging.The Whole-Organ Magnetic Resonance Imaging Score (WORMS) method provides a whole-organ assessment of OA using MRI to look at 14 different features of soft tissue within the joint, such as articular cartilage integrity, subarticular bone marrow abnormality, subarticular cysts, etc.
As X-ray is more readily available, the Kellgren-Lawrence grading scale is routinely used to gauge OA disease severity. It is determined by assessing joint space narrowing and bony growths, and is divided into five stages – stage 0 to 4.
STAGE 0 – Joint is healthy and there are no signs of OA.
STAGE 1 – Some development of bony growths (bone spurs) within the joint. At this stage, there is only minor wear on joint components and you rarely experience pain or discomfort.
STAGE 2 – This is considered mild OA. X-rays will show larger bone spurs, but cartilage is still thick enough to prevent the bones from rubbing against one another. Synovial fluid, which helps lubricate and cushion joints, is typically still present at sufficient levels for normal joint motion. It’s often at this stage where you may first begin experiencing symptoms. They could include pain after a long day of walking or running, greater stiffness in the joint when it’s not used for several hours, or tenderness when kneeling or bending.
STAGE 3 – Classified as moderate OA, cartilage between bones shows obvious damage and thinning so the space between the bones begins to narrow. You may experience frequent pain when using the joint, or stiffness after long periods of inactivity or when waking up in the morning. Joints may swell after extended periods of motion, as well.
STAGE 4 – At this stage, OA is considered severe and you may experience great pain and discomfort when using the affected joint, or during rest. The joint space between bones is dramatically reduced and the cartilage is often completely gone, leaving the joint stiff and possibly immobile. Synovial fluid can be decreased dramatically, no longer reducing the friction between the bones, or can be increased, limiting range of motion of the joint.
Osteoarthritis is a chronic (long-term) disease and, although there is no cure, treatment can help reduce your symptoms and make it possible for you to lead a full and active life. Studies suggest treatment in early stages of the disease is the most effective way to prevent progression. In most cases, you can manage mild to moderate arthritis symptoms for many years with a treatment plan. It’s also important to thoroughly discuss all your option with your health care practitioner, especially in the later stages of the disease.
For more information on Image-Guided Pain Therapy injections, please speak to your health care practitioner.
Arthritis Foundation (2018) Osteoarthritis: Prevention, causes and treatments. www.arthritis.org. Accessed November 14, 2018.