Hear the word “arthritis” and you may automatically think of hips or knees. Osteoarthritis (OA) at the base of the thumb is just as common, but has not been studied as much. In fact, when Lisa Mandl, MD, MPH, a rheumatologist at Hospital for Special Surgery in New York City, first started seeing patients in the clinic, she was surprised at the number of people - mostly older women - who came to her complaining of severe pain at the base of the thumb.

Even though the patients had sought relief from cortisone injections, splints, physical therapy and non-steroidal anti-inflammatory medications, they were still experiencing pain severe enough to wake them at night. The only option left was surgical repair of the joint, an option most of Dr. Mandl’s patients were not ready to accept. 

“Hand OA is, to some extent, overlooked because we don’t walk on our hands,” says Jeffrey Katz, MD, professor of Medicine and Orthopedic Surgery at Brigham and Women's Hospital, one of Dr. Mandl’s longtime mentors.

Although knee and hip OA can literally knock people off their feet, the disability from hand problems is “more subtle but it’s very striking,” says Dr. Katz.

Dr. Mandl says she has seen patients who are otherwise healthy, but their terrible thumb pain is ruining their lives.  “It struck me how they’d waited to retire and play with the grandkids, and then couldn’t do it.”

Dr. Mandl set out to learn everything she could about carpometacarpal OA. She read everything in the medical literature only to learn that not much is known about this type of arthritis.

The carpometacarpal (CMC) joint is at the base of the thumb, where the thumb attaches to the hand. Like arthritis in the hip or knee, the pain comes when the cartilage wears away so much that bone rubs against bone. As with OA of the knee and hip, CMC OA is more common in women than men. By age 80, up to 80 percent of women are affected.

CMC OA interferes with daily activities in kitchen, around house, in people who do keyboard work, or assembly work or need to use power tools.

Dr. Katz expects the prevalence of hand OA to only worsen as the older population stays more active and stays in the workplace longer. “It’s one of those older worker problems,” he explains. “As the workplace ages, we need to develop work tasks and equipment with the understanding that more workers will have this problem.”