flexor & extensor

Table of Contents

What is flexor and extensor tendon injuries?

The most common type of flexor/extensor injury is a laceration or cut. Flexor tendons are located on the palm-side of the fingers and attach the flexor muscles to the finger bones, enabling the finger to be flexed into the palm for grasping and gripping. Extensor tendons are on the top side of fingers and help the digits to straighten, grasp and let go of objects. Laceration to any of these tendons resulting from an injury caused by a knife or glass can cause pain, loss of function and damage to surrounding tissue.
The injury can partially sever the tendons, in which fingers can still move, or completely cut the flexor or extensor tendons, causing total loss of mobility in affected fingers for a given direction of motion (bending vs. straightening).

Why do I need a specialist for flexor or extensor injures?

Due to complications with finger lacerations, and urgency for rapid surgical repair in almost all cases, it is critical to have a careful evaluation by a physician specializing in conditions of the hand right away to receive the best possible treatment. The surgeons at Arizona Center for Hand to Shoulder Surgery are using cutting-edge surgical procedures to treat lacerations.

How does flexor/ extensor injures usually occur?

Most commonly, lacerations to any of these tendons are a result from an injury caused by a knife or glass. Another type of Flexor and Extensor Injury is a rupture. These may also occur during sports, such as football, wrestling, rugby, and rock climbing.  Rheumatoid arthritis can cause flexor tendons to rupture. The outward injury often appears simple but is usually complex when involving the tendons and possibly the nerves.

What are the symptoms of flexor and extensor tendon injuries?

Symptoms of flexor or extensor tendon laceration are usually easy to identify because it causes sudden immobility of a given finger.

The following are common signs:

  • Open injury on the hand, such as a cut
  • Inability to independently bend or straighten a joint or finger
  • Pain when bending finger
  • Numbness of a finger can suggest a combined tendon and nerve injury

What are the risk factors for flexor and extensor tendon injuries?

Flexor tendon and extensor tendon lacerations are usually caused by an injury to the finger, hand or arm. Cuts to these areas can cause simple-looking injuries that may have actually done extensive damage to the intricate groups of tendons, nerves and blood vessels that are critical to proper hand function. Careful evaluation is needed to avoid permanent damage, especially in deep finger cuts. Some athletic activities can cause lacerations, such as wrestling or playing football. Some conditions, such as rheumatoid arthritis, can weaken the tendons, making them prone to tears. Often when the tendon is partially torn, it will eventually completely tear. For complete tendon tears, surgery is almost inevitable as the torn tendon ends pull away from each other at the tear and cannot heal back together on their own.

How are flexor and extensor tendon injuries diagnosed?

Flexor and extensor tendon lacerations are diagnosed through a careful examination by an orthopedic surgeon specializing in the hand. He or she will check for visible cuts, swelling, bruising and flexibility of fingers. An X-ray may be ordered to ensure no damage was sustained to the bones.

What are the treatment options?

Non-surgical Treatment Options

Splinting can help, applying ice to the affected area and NSAIDS such as Ibuprofen or naproxen may all help with symptoms. The vast majority of tendon lacerations are surgical injuries require surgery, to allow repair of the cut tendon(s). Splints, ice, and anti-inflammatories are useful pre-operatively for comfort and soft tissue healing, but except for partial lacerations these are not definitive treatments.


There are many ways to surgically repair flexor tendons.  Certain types of injuries need specific types of surgery. Your hand surgeon will stitch the ends of the tendon together and repair damaged nerves, blood vessels, or bones.  A splint will immobilize your hand to allow the flexor tendon to heal after surgery.
If you suffer from any of the symptoms of flexor or extensor injury, please contact Arizona Center for Hand to Shoulder Surgery for a consultation. Our caring staff will be honored to take care of you.

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