Millions of people are affected by arthritis, so it has become a familiar term. However, many of my patients who are afflicted with this diagnosis really have no idea what is going on inside their joints and causing their pain/dysfunction. Here is a little rundown on this very common problem.Arthritis is generically defined as joint inflammation that is accompanied by pain, swelling, stiffness, and deformity. There are several types, including osteoarthritis (also called degenerative arthritis or degenerative joint disease), rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. Rheumatoid arthritis is a chronic systemic disease that involves many joints on both sides of the body. Ankylosing spondylitis
is a chronic disease of the spine that causes inflammation between the vertebrae and eventually fusion of these bones. Psoriatic arthritis is an autoimmune disease affecting the joints and is associated with psoriasis (a skin disorder).
The most prevalent type of arthritis is osteoarthritis (OA), which is progressive cartilage deterioration in a synovial joint. Synovial joints are joints in your body that contain articular cartilage and a lubricant called synovial fluid (spine, knees, hips, ankles, shoulders, elbows, fingers, etc). In the early stages of the development of OA, there is often pain and swelling in the joint. The swelling (joint effusion) is a sign of
inflammation and is usually an overproduction of synovial fluid or blood inside the joint. Joint inflammation often occurs when you increase your activity level or do things your body isn’t accustomed to (think of being really sore after doing yard work or walking all day while on vacation). Inflammation is the body’s attempt to repair damaged tissue, but this extra fluid causes uncomfortable pressure within the joint capsule. This discomfort can decrease your willingness to move and cause stiffness. Over time, these frequent
episodes of pain and lack of movement into certain ranges causes an increased stiffness in the joint and surrounding muscles. When you don’t move, there is not enough synovial fluid being generated to bathe and lubricate the cartilage, so over time, the cartilage lacks proper nutrition and gets destroyed. When the cartilage is weakened in this way, it can no longer withstand stress so it will thin out or split and cause the underlying bone to be exposed. The body attempts to repair the area where cartilage is damaged by producing more bone cells. This can lead to bony remodeling and overgrowth at the margins of a joint called bone spurs (osteophytes). Bone has a ton of pain receptors, so if pressure is applied to a bone and there is no cartilage to absorb the force, you feel pain.
Primary OA has no known cause, but is correlated with aging and heredity. Secondary OA is a result of injury to a joint such as a fracture, repetitive joint use (such as with some exercise or occupational activities), obesity, or metabolic disease that weakens the bones (such as osteoporosis). Even though OA is associated with aging, it does not appear to be an absolute or normal part of aging. Therefore, not every elderly person
develops OA, and OA can be present in young people. The increased incidence and prevalence of OA with age is likely due to several changes that occur naturally with aging. These include:
- Decreased ability of chondrocytes (bone cells)to stimulate repair
- Increase in the laxity of ligaments around joints, thus making them more unstable and therefore, more easily injured
- Less shock absorption around a joint due to weak muscles and slower neurologic response times
- Hormone replacement therapy (women receiving hormone replacement therapy have lower prevalence of OA)
- Obesity
- Genetics and family history
- Activity level (strenuous, high-intensity, and repetitive exercise, both sport and occupational, is associated with the development of OA, but there is not an increased incidence with moderate exercise)
- Occupation (repetitive motions such as knee bending, carrying loads of 25lbs or greater, and use of tools that create a lot of vibration)
- Muscle loss
- Trauma (previous traumatic injury to a joint often leads to the development of OA)
If you have any questions about Arthritis, please contact me at Erin@JointVenturesPT.com.
Sources:
Taber’s Cyclopedic Medical Dictionary, 20th edition, Copyright 2005.
Therapeutic Exercise Foundations and Techniques, 4th edition, Kisner, C; Colby, L.A;
Copyright 2002.
Orthopedic Examination, Evaluation, and Intervention; Dutton, Mark; Copyright 2004.