Many people are all too familiar with the aches and pains of arthritis, but what exactly is arthritis? One common misconception is that arthritis is the result of something that grows in or on a joint over time. If that were the case, curing arthritis would be as simple as removing the unwanted “growth”. Unfortunately arthritis is not caused by anything growing on the joint, but rather a wearing away of the joint’s protective coating known as cartilage.
The basic definition of arthritis is inflammation of a joint. There are many different types of arthritis, but the most common and the one treated primarily in sports medicine is osteoarthritis (OA). OA is the gradual wearing away or degeneration of a special cartilage called articular cartilage that covers the ends of bones in a joint. It is most commonly seen in weight-bearing joints including the knee, hip, spine, and feet. It is also common in the hand. Risk factors that contribute to early development and continued proliferation of OA include increasing age, gender (OA is more prevalent in women than men), genetic predisposition, obesity, joint injury, excessive mechanical stress, and structural malalignment and muscle weakness.1
Articular cartilage or hyaline cartilage is a highly specialized connective tissue that provides a smooth, lubricated surface for articulation and facilitates the transmission of loads with little to no friction.2 It is highly resistant to shear and compressive forces making it highly resilient to a harsh biomechanical environment. Also, unlike other tissues, articular cartilage has no blood vessels, nerves, or lymphatics. This allows painless motion even with significant impact activity, but also means it has a limited capacity for healing and repair.
As this articular surface wears away either due to age, injury or other causes, more of the underlying bone is exposed, which has millions and millions of nerve endings. Consequently, the more areas of bone that are exposed, the more symptoms of inflammation such as pain, swelling, stiffness, and loss of motion are possible. Also, as this cartilage wears away, it breaks open and frays which causes the surfaces to become rough and coarse instead of smooth and slick. This translates into symptoms of popping, clicking, and catching. Eventually, loss of function and muscle atrophy can occur.
Even though articular cartilage does not have the ability to repair itself once damaged, there are still several treatment options for OA. The most basic form of treatment is to reduce risk factors. Weight loss, activity modification, and strengthening the musculature around the affected joint are some examples of this. Pharmacological management includes anti-inflammatory medications (both oral and topical), cortisone injections, and viscosupplementation injections. Physical therapy can also be beneficial in maintaining motion and strengthening muscles. The gold standard for surgical management of severe OA is joint replacement, but this is usually only recommended when other more conservative treatments have failed. There are arthroscopic surgical options for articular surface loss or injury. However, candidates for these procedures are usually young adults who have only one or two small areas of articular cartilage damage with little diffuse joint involvement. Newer treatments are also available including use of stem cells and platelet rich plasma (PRP) injections (see Dr. Chad Price’s blog post “What’s the Deal with Stem Cells?” for more information).
Our providers can help diagnose and recommend appropriate treatment options to reduce or eliminate the symptoms caused by OA. Please feel free to schedule an appointment with one of our providers if you have any questions regarding osteoarthritis or would like to pursue treatment.
Jocelyn Rollins, ANP-BC
1. Center for Disease Control and Prevention, Division of Population Health. (2014, April 4). Osteoarthritis: Risk Factors. Retrieved October 16, 2014, from http://www.cdc.gov/arthritis/basics/risk_factors.htm
2. Fox, A. J., Bedi, A., & Rodeo, S. A. (2009). The Basic Science of Articular Cartilage: Structure, Composition, and Function. Sports Health: A Multidisciplinary Approach, 1(6), 461-468. doi: 10.1177/1941738109350438