What Causes a Flexor Tendon Tear? 3 Things to Know

Flexor tendons allow you to bend your wrist and fingers, and also help with grip. If your flexor tendon is torn, your hand function can be significantly impacted.

What do flexor tendons do?

Flexor tendons are cord-like structures that connect the muscles in the forearm to the bones in the fingers and palm. They allow your wrist, fingers and thumb to bend, enabling gripping and grasping actions. There are two main groups of flexor tendons in the fingers and one in the thumb.

Flexor tendon tears, also sometimes called flexor tendon lacerations, typically are caused by sudden trauma or injury. These commonly incude:

• Cuts or slashes from accidents involving knives, glass or other sharp objects
• Sports injuries that involve contact or sudden and forceful grasping
• Workplace accidents, commonly in manual labor or construction
• Animal bites, especially from dogs

Repetitive stress on the flexor tendon can sometimes lead to injuries, though this more frequently leads to tendonitis rather than a tear.

What does a torn flexor tendon feel like?

If you have a torn flexor tendon, you will not be able to bend your finger or thumb. You also likely will feel pain at the injury site, particularly when attempting to move the injured finger. You also might see swelling and bruising around the injury site.

If you suspect you have a flexor tendon tear, see a doctor to make sure you get the proper treatment.

A doctor will ask for a detailed account of how the injury occurred and whether you have had previous hand issues. They will also assess your range of motion and hand function. They may perform specific tests to evaluate tendon function.

A doctor also may order an MRI if there is concern about associated injuries to ligaments or nerves.

What is the treatment for a flexor tendon tear?

Most flexor tendon tears require surgery to restore function in the finger. It is recommended to have surgery within seven to 10 days of the injury for the best recovery and outcome.

After surgery, you likely will need to wear a splint or cast on your hand while the tendon heals. Your surgeon will recommend you see a hand therapist who will come up with a rehabilitation program for you to help regain strength and mobility in the affected fingers.

Tendons typically take several weeks to heal. Full recovery may take three to six months depending on the extent of the injury and a patient’s progress with rehab. It is important to take it easy after surgery. A flexor tendon repair can rupture if exposed to excessive force too soon.

Some people experience stiffness after a flexor tendon tear has healed. Due to scar tissue, it might be difficult to regain a full range of motion.

While flexor tendon tears are serious injuries that require surgery, most people can regain full functionality in their hands.