Osteoarthritis, or degenerative arthritis, is a natural process that occurs with aging and represents deterioration of joint cartilage (the cushioning between our bones). I tell my patients there are 3 things in life we cannot avoid: death, taxes and arthritis. Thumb arthritis is the second most common type of arthritis in the hand behind arthritis involving the last joint in our fingers.
Thumb arthritis is also known as basal joint arthritis, rhizarthrosis, carpometacarpal (CMC) arthritis or trapeziometacarpal (TMC) arthritis. The thumb joint is normally covered with a smooth layer of cartilage providing cushioning and a smooth surface to allow the base of the thumb to interact with a bone in the wrist (trapezium) (fig.1). With TMC arthritis, the smooth covering of the bone begins to wear away creating a rough surface leading to damage to the joint. The roughened edges of the bone may lead to new bone growth (bone spurs) that you can felt through the skin.
This condition is more common in women and typically symptoms begin after the age of 40 years old. There is evidence of genetic predisposition to this type of arthritis. Also, previous trauma including fractures or sprains can predispose individuals to earlier arthritic changes of the thumb joint. Certain occupations and activities that place repetitive stress on the thumb may also contribute to damage of the TMC joint (i.e., dental hygienist). There are conditions that will preferentially affect cartilage structure and function, these include rheumatoid arthritis and lupus.
Individuals with TMC arthritis may begin to notice discomfort with certain daily activities. Most common activities reported to increase discomfort at the thumb joint include opening jars, grasping and turning doorknobs and pinching activities (e.g. turning car keys or buttoning a shirt). As the arthritic changes progress the pain may increase and be associated with weakness, decreased range of motion and the development of bone spurs which may cause the thumb joint to look enlarged.
Diagnosis of TMC arthritis is largely clinical. Individuals usually present with symptoms as described above and have provocative exam findings consistent with the condition. X-rays are not always necessary, and do not correlate with symptoms. Treatment is largely guided by symptoms, not by the appearance of the TMC joint on x-ray.
Treatment options are based on the severity of symptoms and often requires not just one intervention, but multiple interventions used in concert. Nonoperative treatment options include: A short course of an anti-inflammatory medication, prescription or over-the-counter topical anti-inflammatory medications (e.g. arnica, topricin, emu oil), day and nighttime bracing, avoidance of exacerbating activities, hand therapy, steroid injections, acupuncture and ice.
When nonoperative treatments fail to provide enough symptom relief, surgical options are available. The most common procedure is the partial or complete removal of the trapezium (fig.1), a bone in our wrist, along with cushioning/suspending the thumb joint using a variety of different techniques. With the removal of the trapezium there is no more bone on bone irritation. Recovery after thumb surgery ranges from 8 weeks to a year and requires the guidance and care of a certified hand therapist.
Thumb arthritis is a progressive condition, our genetics, occupations and activities dictate its course. Just because the condition is progressive does not mean it cannot be slowed down; providing meaningful symptom relief is the ultimate goal.