Flexor Tendon Injury

What it is

Muscles in the forearm become cord-like tendons that attach to the bones of the hand. The flexor tendons on the palm side let you bend your fingers and thumb and make a fist. When one is cut or torn, the finger cannot bend at the affected joint.

What causes it

Most flexor tendon injuries come from cuts to the hand, wrist, or forearm, and even a small cut in the wrong place can divide a tendon. Less often, a tendon pulls off the bone (see jersey finger), wears through and ruptures, or separates where it joins the muscle.

Symptoms

• Inability to bend one or more joints of a finger or thumb
• Numbness, tingling, or heavy bleeding, since nerves and arteries run right beside the tendons

See a physician promptly for any cut that changes how your hand moves or feels.

Treatment

Cut flexor tendons do not heal by themselves, so surgery is usually needed to bring the tendon ends back together. Injured nerves and arteries are repaired at the same time. These injuries are easier to repair soon after they happen.

Recovery

After surgery, a protective splint and a structured hand therapy program are essential. Following the therapy instructions closely helps prevent the repair from pulling apart. Scarring and stiffness are common, and a second procedure to free up the tendon is sometimes needed. Many people do well, but full recovery takes several months.