When one ages, it is not uncommon to hear complaints of body aches and painful joints from the elderly. Just like any machine which undergoes wear and tear over a period of time, so does our body. But what makes us special is that our body also has its own repair system. Osteoarthritis is a dynamic phenomenon which involves destruction and repair of the cartilage tissues in the joints. Over time, these cartilage tissues which act as lubricants in the joints of our bodies become exhausted due to several causes, and many people have a higher tendency of developing this condition sooner than he or she should.
Osteoarthritis, being the most common disorder of the bone, most often involves the weight-bearing joints – the hip, knees, neck, and spine. There are many other common areas such as the finger joints which are also affecting many patients. We need to first understand how what is within the joint in order to be able to identify the trigger of the problem and manage it appropriately.
What forms the joint and how does osteoarthritis occur?
A joint is a connection between two bones. Within the joint space, it consists of articular cartilage embedding the bones acting like paddings to protect the bone, synovial fluid filling the joint space, synovial membrane and a fibrous joint capsule which envelopes the joint space as a whole. The synovial fluid is important because it provides nutrient to the articular cartilage which is not supplied by any blood vessels. It is also important in its mechanical function as a shock absorber when mechanical stress is applied to that particular joint. When these tissues and substance within the joint cavity is lost due to wear and tear, the two bones come into contact and the resulting friction between them causes pain and immobility to the affected patient.
As mentioned earlier, this condition involves both destruction and repair. When there is erosion of the tissues and substance in the joint, the body compensates by repairing the site and forming new bones and releasing inflammatory cells are formed to prevent further damage. Hence, bony formation around the joint, termed subchondral cyst, and bone spurs, which is known as osteophytes, appears in radiograph films showing evidence of osteoarthritic changes. Inflammation causes swelling and pain.
What are the 7 common risk factors contributing to osteoarthritis?
Osteoarthritis affects mostly adults who are approaching the advanced age. Studies show that more than half the population of age above 65 years old has evidence of osteoarthritic changes. The prevalence of the disease progressively increases with age. Even though it is a disease that commonly affects the elderly, there are also minorities of younger patients between ages of 30 to 40 years old who are diagnosed with osteoarthritis due to other risk factors.
Weight-bearing joints are one of the most common sites affected by osteoarthritis as mentioned before. Thus, the weight of the patient obviously plays a role in the progress of developing the disease. Carrying more weight means increasing mechanical stress to the bones and joints, such as the hips and the knees. However, this risk can be prevented through efforts of losing weight in order to reduce the stress to the bones and joints.
Female has a higher risk of developing osteoarthritis. Especially in conjunction with the risk of advance age when menopause approaches. However, the exact explanation for the role of hormonal changes in menopausal women with osteoarthritis is not known.
Any previous insults to the bones and joints increase the risk of developing osteoarthritis. It can be any sort of trauma, such as from a motor-vehicle accident, sports injury or a fall. Also, repetitive stresses caused to the particular joint due to occupation or sports disrupt the biomechanical system of the bones and joints, resulting in premature degeneration and chronic damage to the joint.
Muscles provide neuromuscular protection to the bones and joints. When this protection is affected due to the dysfunction of the muscles, this causes the increase of joint motion because the muscles are unable to aid in lifting the weight of the bone. Eventually, osteoarthritis develops due to overworking of the joint.
Research studies have successfully identified few genes that are associated with osteoarthritis. Notably the frizzled-related protein (FRZB) gene, and the asporin (ASPN) gene.
People who are born with abnormal joint formation or cartilaginous deformity have high tendency of developing osteoarthritis. For example, patients with congenital hip dysplasia or unequal leg lengths are more prone to developing osteoarthritis at an earlier age.