Flexor and Extensor Tendon Injuries

Flexor tendons connect the flexor muscles in your forearm to the bones in your fingers and allow you to bend your fingers. There are two flexor tendons in each finger and one in each of your thumbs and they rest on the palm side of your hand very close to the skin. So they are easily susceptible to injuries such as cuts. A simple cut on the palm side of your hand can impact the tendons and thus your ability to move your fingers. Injuries to the flexor tendons include cuts, tears, completely severed tendons and having a tendon torn off the bone by a sudden pull. If a tendon is cut through, the part attached to the muscle will recoil back into the palm, preventing the finger from bending and preventing the tendon from healing on its own. If the tendon is partially cut or torn, the finger may still move, but the tendon could tear away later.

Aside from obvious open injuries like cuts, symptoms of an injured flexor tendon include the inability to fully bend a finger, stiffness, painful bending or opening of a finger, swelling over the joint closest to the fingertip or tenderness on the finger or palm of your hand. Applying ice and elevating the hand is a good immediate first aid procedure, and compression on the injured area can slow the blood flow to the injury. It is important for injuries to the fingers to be evaluated by a physician or hand surgeon and for any open wounds to be quickly cleaned and treated.

When the tendons are cut through, they need to be surgically reattached and sown together from the inside out. It is usually best to have the surgery as soon as possible after the injury. Your physician will recommend whether surgery is needed, how soon it should be performed and what particular surgical procedure is optimum to repair your flexor tendon injury.

Extensor tendons are located on the backside of your hand and fingers and are attached to muscles in your forearm and allow you to straighten your wrist, fingers and thumb. Because they lie right under your skin and sit directly on the bones, even a slight cut on the top your hand or fingers can injure them. Once injured, you are likely to have difficulty straightening your fingers, though you may indeed still be able to make a fist and grasp objects.

Injuries to the tendons are most often caused by a direct trauma to the back of the hand. Besides trauma, extensor tendons can also be impacted by an injury to the muscles that operate the tendons, or to the nerves that operate the muscles. Even arthritis at the wrist can wear down and eventually rupture the extensor tendons.

It is optimum to have any injury to the extensor tendons evaluated by a hand surgeon, and essential to have the injury cleaned, treated and evaluated by a physician within 12 hours. The sooner an extensor injury is treated, the better the odds are for full recovery. Tendons that are cut or split will need to be stitched together, thus requiring surgery. Tears to the extensor tendons caused by jamming your hand or fingers may simply be treated with a splint. Splints prevent the parts of the tendon still connected from pulling apart and should be worn continuously until the tendon is totally healed. Sometimes, in addition to an external splint, a pin is placed in the bone across the joint to act as an internal splint. After surgery, physical therapy is an essential part of the recovery process and most therapy programs last 4 to 8 weeks.

A single, clean cut that impacts the extensor tendons alone and doesn't involve the surrounding tissue, bones, joints or ligaments is simpler to treat. And if the treatment occurs in a timely manner and all therapy is adhered to, the odds of regaining full functionality are very high. When the injury goes beyond the extensor tendons and is considered a complex injury, regaining full functionality becomes more challenging.