Pinching and pulling, pressing and picking, typing and texting: these are just a few of the myriad uses of the hand’s most mobile joint, the thumb. But researchers at Johns Hopkins Hospital have found that the movement we take so much for granted in this versatile joint may come at a cost.
W. P. Andrew Lee, a surgeon in the Department of Plastic and Reconstructive Surgery, marvels at the utility of the thumb in a video interview with Hopkins. He notes that it must be able to turn nearly three hundred and sixty degrees to achieve its full range of motion and that in the entire human body, the thumb’s basal joint is the most flexible and versatile. This mobility is apparent in the many tasks people perform which would seem unimaginable without the thumb: twisting a joystick in an intense video game battle, gripping a handlebar while biking through heavy lanes of traffic or even participating in thumb wars with friends. In fact, the Orthopedics Department at the University of Washington reports that the thumb alone accounts for 40 percent of total hand function.
After decades of use, however, the frequent wear and tear that the thumb inevitably encounters manifests itself into a disease that usually conjures to mind childhood remonstrations to drink more milk or grandma’s recent reconstructive hip surgery: osteoarthritis.
Osteoarthritis of the thumb, or basal joint arthritis, usually occurs in patients in their fifties and sixties, often initially showing up as discomfort in the thumb and degenerating over a span of months or even years into debilitating pain. The disease is characterized by degeneration of cartilage in the carpometacarpal joint, and symptoms include tenderness and swelling in the joint, as well as clear visual deformity.
Lee notes that his patients afflicted with basal joint arthritis have thumbs with joints that are not functioning smoothly. The arthritis affects a person’s ability to twist, push and perform tasks that require manual dexterity; the pain associated with osteoarthritis is often so extreme that the patient stops using the thumb altogether. That’s when someone like Lee usually steps in.
Care for a thumb afflicted with osteoarthritis usually begins with a soft splint attached to the thumb to restrict its movement. The other fingers of the hand, in this case, are free to move. If the thumb does not improve with this treatment, which may also include medication and corticosteroid injections, surgery is usually the next step.
The particular surgery Lee performs, arthroplasty, involves removing a bone in a wrist that grinds against other bones in the hand to cause pain. The space in which the bone was located is filled with a tendon, suspending the joint and thus allowing it to function normally after surgery and healing. Other procedures for rectifying basal joint arthritis involve fusing joints, which decreases pain but also increases the mobility of the thumb, or repositioning the bones in the carpometacarpal joint.
During healing, the patient must wear a splint for six weeks to support the thumb and participate in two to three months of hand therapy. Treatment is usually highly successful, with a success rate of 90 to 95 percent as reported by the CV Starr Hand Surgery Center.
The occurrence of basal joint arthritis will last as long as people continue using their thumbs. As teens type and text repetitively, adults work longer before retirement, and people find more and more creative uses for their hands, they should take care to ensure not only the health of their hips and knees but also the tools with which they press, pull, touch caress — in short, communicate.
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