What is Extensor Tendon Injury?
An extensor tendon injury is a partial or complete injury to the tendon. Tendons are bands of tissue that connect muscles to bones. The extensor tendon is a strong, smooth cord that connects the finger bones to the muscles in the hand.
Tendons are bands of tissue that connect muscles to bones. The extensor tendon is a strong, smooth cord that connects the finger bones to the muscles in the hand. The extensor tendons are located just under the skin, directly on the bone, on the back of the hand and fingers. It helps you open your hands and move or straighten your wrist, fingers and thumb.
An extensor tendon injury is a partial or complete injury to the tendon. This may be due to:
- Finger jamming
- Crushing injury on the back of the fingers
- Hand trauma or overuse
- Tear or broken bone in the fingers
- Nerve entrapment
Injury to the extensor tendon is a condition that can result in a tendon tear or tendon rupture. It can greatly affect the fine motor function of the hand and the stability of the wrist.
Some of the extensor tendon injuries include:
Hammer Toe:
It is characterized by sagging of the end joint of the finger due to cut or tear of the extensor tendon in the last joint.
Boutonniere Deformity:
Characterized by a bent (bent) position of the middle joint of the finger caused by a cut or tear of the extensor tendon in the middle joint.
What Are the Symptoms of Extensor Tendon Injuries?
The most common symptoms of extensor tendon injury are pain and swelling at the fingertip.
Other important symptoms include:
- Redness and warmth near the injury
- Stiffness in the finger joint
- Inability to straighten the finger or thumb
- Finger or thumb drooping
- Discomfort that increases with activity
- Crepitus (feeling of brittleness in the affected tendon)
- Finger deformity or loss of function
What If Extensor Tendon Injury Is Untreated?
If left untreated, extensor tendon injuries can result in:
- Permanent damage to the extensor tendon
- Inability to straighten the finger or thumb
- Serious functional impairment
- Permanent deformity or disability
How Are Extensor Tendon Injuries Diagnosed?
To diagnose extensor tendon injuries, your doctor may ask questions about your pain and other symptoms and perform a physical examination of the affected hand. The doctor may also order an X-ray to make sure no bones are broken. In severe cases, ultrasound or MRI may be ordered to determine the extent of the damage and to obtain a detailed view of all the bones, muscles and tendons around the injury.
How Are Extensor Tendon Injuries Treated?
Conservative Treatment
Usually, if the injury is mild, the symptoms will improve with adequate rest and icing. However, the specific treatment of an extensor tendon injury varies according to the level of its severity.
Non-surgical treatments are the first choice and usually include:
- Splinting the affected part to heal in proper alignment
- Anti-inflammatory drugs
- Special exercises and hand therapy
Extensor Tendon Surgical Treatment
- Extensor tendon repair surgery can be performed under local, regional or general anesthesia.
- The ends of the injured tendon are sutured and a pin (as an internal splint) may be placed.
- After surgery, the treated area will be immobilized in a splint to allow the tendon to heal.
- In cases of loss of motion, surgery may involve release of scar tissue followed by hand treatment.
- For severe injuries involving a major tear or complete tendon rupture, surgical options such as tendon repair, tendon reconstruction, extensor indisis proprius/extensor pollicis longus (EIP/EPL) tendon transfer or bone avulsion fixation may be considered.
Extensor Tendon Injury: Frequently Asked Questions
What is an extensor tendon injury and how does it happen?
Extensor tendons are the tissues that connect your forearm muscles to the bones in your fingers and thumb, allowing you to straighten your fingers and wrist. Because these tendons are located just under the skin on the back of the hand and fingers, they are highly vulnerable to injury.
Common causes of injury include:
- Cuts or Lacerations: A sharp object cutting through the skin and tendon.
- Trauma: A direct blow to the hand or jamming a finger (often seen in sports).
- Overuse: Repetitive strain leading to inflammation or minor tears.
- Arthritis: In some cases, rheumatoid arthritis can cause tendons to weaken and eventually rupture.
What are the symptoms of a torn extensor tendon?
The most obvious sign of an extensor tendon injury is the inability to fully straighten one or more fingers or the thumb. Other symptoms include:
- Pain on the back of the hand or fingers.
- Swelling and bruising around the site of the injury.
- Weakness when trying to open the hand.
- A “drooping” finger (Mallet Finger) or a deformity where the middle joint bends toward the palm (Boutonniere Deformity).
Does an extensor tendon injury require surgery?
Whether or not surgery is required depends on the severity and type of the injury. If the tendon is only partially torn or involves a specific type of “closed” injury (where the skin isn’t cut), it can often be treated with specialized splinting and hand therapy.
However, if the tendon is completely severed by a cut, surgery is usually necessary to sew the ends back together. Without surgical repair, the muscle will pull the tendon ends further apart, making it impossible for the tendon to heal and restore function on its own.
How long is the recovery time after extensor tendon repair?
Recovery for an extensor tendon is a slow process because tendons have a limited blood supply. Generally, the timeline is as follows:
- 0–4 Weeks: The hand is kept in a splint or cast to protect the repair. Movement is strictly limited.
- 4–8 Weeks: Gentle, guided exercises begin with a hand therapist to prevent stiffness.
- 8–12 Weeks: Gradual strengthening and returning to daily activities.
- 3–6 Months: Full return to heavy lifting or high-impact sports.
What is the role of hand therapy in recovery?
Hand therapy is critical to a successful outcome. Because tendons slide through narrow tunnels (sheaths), they are prone to developing scar tissue (adhesions) that can “glue” the tendon to surrounding tissue, causing permanent stiffness.
A hand therapist will design a specific program of “gliding exercises” that allow the tendon to move just enough to stay flexible without putting enough tension on it to break the repair.
Can I use my hand normally while the tendon heals?
Absolutely not. During the early stages of healing, the repair is held together only by thin sutures. Any forceful attempt to straighten the finger or grip an object can rupture the repair, requiring a second surgery. It is vital to follow your surgeon’s and therapist’s instructions regarding splint use and activity restrictions.
