A tiny ‘jellybean’ implanted in the thumb joint could relieve the pain and immobility of hand arthritis, according to new research. The prosthesis, made from the same clear gel material as disposable contact lenses, takes just 30 minutes to insert and has also been shown to increase grip strength.
In those with arthritis, the smooth cartilage that usually lines the tiny joints of the hand wears away.
This can be particularly pronounced in the main thumb joint, located just above the wrist and allows the thumb to rotate. Without cartilage, the bones grind together causing inflammation and pain.
The jellybean implant does not replace the joint but sits between the ends of the thumb bones, acting as a cushion. As it stops the bones coming into contact with each other, the thumb can move freely without causing pain.
Previously, patients with severe hand arthritis may have been offered joint fusion. Also called arthrodesis, this procedure fuses the two bones that make up the painful arthritic joint using metal plates, screws or wires.
Recovery can take weeks or even months and patients will lose the ability to move the thumb freely, though the surgery means pain and swelling are greatly reduced.
Another surgical option involves removing one of the arthritic bones at the base of the thumb – a trapeziectomy. Although this also relieves pain and maintains movement, grip strength still remains poor.
The jellybean implant, however, relieves pain and preserves normal movement.
Osteoarthritis of the thumb is estimated to affect eight to 12 per cent of adults and as many as a third of women over 55. Also known as basal thumb arthritis, symptoms include pain, swelling, stiffness, deformity, loss of motion and weakness, making even simple tasks such as turning doorknobs difficult.
In the early stages, the arthritis can be treated with painkillers, splints and injections. But in many cases the disease progresses to the point where little or no cartilage is left, leaving the sufferers with painful bone-to-bone contact.
Implantation takes less than one hour and starts with a small incision a few inches long, to expose the joint. Damaged cartilage is then removed and the Cartiva is inserted into the base of the thumb.
