I have started to develop pain in my right thumb that the doctor calls osteoarthritis. I've had carpal tunnel in that hand for several years. Could the thumb joint be breaking down now that the carpal tunnel has been there so long?
A recent study of 300 patients treated for trigger finger and carpal tunnel syndrome was done looking for a direct link between the two. In fact, they found that patients with more than one trigger finger were three times more likely to develop carpal tunnel syndrome in the same hand as someone with only one trigger finger.
Though you didn't ask specifically about trigger finger, the study is important in answering your question. They also looked at other factors that might be linked with carpal tunnel syndrome. Age, sex (male versus female), and tobacco use were evaluated as possible risk factors. Rheumatoid arthritis, gout, and the presence or absence of thumb osteoarthritis were also examined.
The most common risk factor for carpal tunnel syndrome was diabetes. And now according to this list, we can add trigger finger to that list. But these other variables (gout, tobacco use, age, sex, and thumb arthritis) were not found to be statistically significant.
Knowing the anatomy of the carpal tunnel is helpful when looking at other hand problems that might come before or after carpal tunnel as a part of the whole picture. The carpal tunnel is created by the wrist bones forming an arch around the soft tissues of the wrist (e.g., around the ligaments, nerves, blood vessels, fascia, tendons).
Anything that decreases the space in the tunnel for these soft tissues can put pressure on the median nerve resulting in wrist and hand pain, numbness, and tingling common symptoms of carpal tunnel syndrome. It may be that thickening of the synovium (fluid and lining around the tendons) that causes trigger finger is a contributing factor to carpal tunnel syndrome.
Patients with trigger finger also have thickening of the fibrous cartilage around the pulley system that helps the flexor tendons move the fingers. This pathologic change in the anatomy may help explain why carpal tunnel syndrome follows the formation of trigger fingers. More study is really needed to understand the full implications of the anatomy and pathology that leads to combined hand conditions such as osteoarthritis of the thumb, trigger finger, and carpal tunnel syndrome.
Lauren E. Wessel, BSE, et al. Epidemiology of Carpal Tunnel Syndrome in Patients with Single Versus Multiple Trigger Digits. In The Journal of Hand Surgery. January 2013. Vol. 38A. No. 1. Pp. 49-55.
*Disclaimer:* The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.