Extensor Tendon Injury

Extensor tendons are the cord-like structures that run from the forearm to the thumb and fingers on the dorsal or "back side" of the forearm and hand. These tendons play a crucial role in our daily activities as they allow for the extension or straightening of the thumb and fingers, enabling us to open our hand.

Extensor tendon injuries are commonly caused by sharp lacerations that sever the tendon. However, they can also occur from forceful impacts on the hand and fingers, including injuries known as a mallet finger. Extensor tendon injuries typically require surgical intervention and should ideally be treated within 7-10 days of the injury to optimize recovery and results.

The diagnosis of an extensor tendon injury is primarily based on a thorough examination by a hand surgeon. Complete tendon injuries often result in an inability to extend one or more joints on the affected finger. In cases of partial injuries, you may still be able to extend your finger, but there could be associated pain or a catching sensation as you try to bend the finger.

In some cases, additional imaging with ultrasound or MRI may be used to confirm the diagnosis. If a mallet finger injury is suspected, then x-rays may be necessary.

It is also important to note that nerve injuries may accompany tendon injuries and will be assessed and treated if present.

Complete tendon injuries typically will not heal unless surgery is performed to repair the two ends of the tendon to one another. Additional incisions often are required in order to retrieve the two ends of the tendon. Delicate dissection and a strong repair are necessary to reduce scarring and optimize recovery.

After surgery, hand therapy is of critical importance. You will be placed into a splint immediately after your surgery. This typically will be removed by your hand therapist after surgery for them to make a custom splint for you, which in some situations may include a “relative motion splint”. You will then work with your hand therapist to begin a “range of motion protocol” in which you carefully begin moving your fingers. The purpose of beginning motion is to reduce scar tissue formation and associated stiffness in order to optimize the final hand function and outcome. However, hand therapy and the motion protocol must be balanced with the delicate tendon repair due to the risk of rupture of the repair in the early phases of healing. It is very important to follow instructions and limitations provided by your surgeon and hand therapist. Even with optimal healing, final recovery often can take several months.

Be sure to see an experienced surgeon to treat this condition. Our fellowship-trained specialists at The Buncke Clinic in San Francisco treat patients with extensor tendon injuries from across the Bay Area and Northern California. Contact us to schedule a consultation.

Below are links for third party resources

American Society for Surgery of the Hand