What Are Flexor Tendon Lacerations?

A flexor tendon laceration is a deep cut on inside of the fingers, hand, wrist, or forearm.

A tendon is a tissue that connects the muscles to bone. Flexor tendons on the palm side of the fingers help in bending the fingers.

Tendons and muscles of the forearm, wrist, and hand control the movement in the hand and fingers. When muscles tighten, tendons pull on the bones, resulting in the movement of fingers. The tendons on the top of the fingers (extensor tendons) straighten the fingers.

Surrounding the flexor tendon is the tendon sheath, a membranous layer that helps to keep the tendon in place.

A flexor tendon laceration is a deep cut on the palm side of the fingers, hand, wrist, or forearm that can injure the flexor tendon.

Flexor tendon lacerations make it impossible to bend joints in a finger. Because the flexor tendons are close to the surface of the skin, a deep cut on the skin can affect the flexor tendon. 

If the tendon is torn, the ends of the tendon will rip, leading to insufficient healing of the tendon. Sometimes, a nerve close to the tendon may be damaged, causing numbness on one or both sides of the fingers.

A flexor tendon laceration causes sudden pain and immobility of the fingers. Other common signs include

• open wound on the hand,
• inability to bend or straighten a joint or finger,
• pain while bending the finger,
• numbness of the finger and
• tenderness of the finger.

Flexor tendon lacerations can occur to anyone who sustains a deep cut to the hand, wrist, or arm. Diseases such as rheumatoid arthritis weakens the tendon, making it vulnerable to a sudden rupture. Additionally, athletes are at a high risk of flexor tendon injury.

The physician physically examines for any cuts, swelling, bruising, and flexibility of fingers. An X-ray can be useful to identify any damage to the bone.

A flexor tendon laceration can be managed by surgical and non-surgical therapy.

Partially torn tendons can be treated with nonsurgical treatments. Non-surgical management can only be done if less than 60% tendon is involved. Non-surgical treatment options include

• using a splint,
• applying ice packs on the affected area and
• anti-inflammatory and pain relievers, such as ibuprofen.

These are not definitive treatments. Physicians might order surgical therapy if the injury is restricting the blood flow to the hand or finger.

Surgical treatment

As tendons tear in different ways—such as straight across, at an angle, or pulled right off of the bone—there are various methods to repair the flexor tendon injury. These surgical methods involve special stitches or sutures.

Healing after the surgery

Tendon injuries can lead to scarring and stiffness after the surgery. It can take up to two months for the hand to heal completely after the repair. It may take another month or so before the hands can be used in full force.

Specific exercises and physical therapy will restore the function and movement of the hands.