Understanding Flexor Tendon Injuries in the Hand

Flexor tendon injuries have an incident rate of about 14 per 100,000 person years in the United States. These injuries are more common in younger populations with a steadily decreasing risk as people get older. Males show a higher incidence rate than females.

Understanding the Importance of Flexor Tendons

Flexor tendons are essential connectors that facilitate movement in the hand. These tendons allow you to flex your fingers and form a fist. When the forearm muscle contracts, it activates the flexor tendons to manipulate your hand appropriately.

Brief Overview of Flexor Tendon Anatomy and Function

The flexor tendons are smooth cord-like structures that run from the bones in the fingers and thumb through a tunnel at the wrist to the forearm muscle. The hand includes two flexor tendons for each finger and one flexor tendon for the thumb.

Flexor tendon injuries can result from a deep cut to the inside of the finger, which nicks or severs the tendon. Climbers may suffer flexor tendon injuries from keeping their hands in a strained and flexed position. This strain can rupture the tendon sheath and injure the tendon beneath. Flexor tendon injuries may also result from certain athletic activities such as football, rugby, or wrestling, where the finger may get pulled backward sharply. With enough force, this motion can pull the tendon off the bone.

Rheumatoid arthritis increases your risk of experiencing a flexor tendon injury because it weakens the muscles and tendons, making them more likely to tear.

A cut on the palm side of the wrist, hand, forearm, or finger is the most obvious sign of a flexor tendon injury. These types of injuries typically bleed profusely and result in an immediate trip to the hospital. In cases where the skin isn’t broken, you may notice symptoms such as the following:

• Pain when bending the finger
• Numbness and tingling in the fingers
• Tenderness along the palm
• Inability to bend the finger at one or more joints
• One finger sitting straighter than the others

You should see a healthcare professional immediately for treatment if you have any signs or symptoms of a flexor tendon injury.

Surgical vs. Non-Surgical Options

A complete tear of the flexor tendon will require surgery. Until recently, nearly all flexor tendon injuries were treated with surgery. Recent evidence suggests that a non-surgical approach using only splinting and hand exercises may be adequate for partial tears.

There are many ways to approach surgery for a flexor tendon injury. This procedure can take place under a regional or general anesthetic. The surgeon typically enlarges the wound or cuts into the area above the injured tendon. They will then locate both ends of the tendon and rejoin them with stitches. If the tendons are too damaged to reattach properly, the surgeon may perform a tendon transfer. This involves detaching one of the two flexor tendons from another finger and reattaching it to the injured finger. When the procedure is complete, the incision is closed with stitches.

The hand and forearm are immobilized in a rigid plaster splint after surgery to facilitate proper healing. Flexor tendon surgery typically takes 45 to 60 minutes to complete, but the procedure may take longer for more complicated injuries.

Innovative Surgical Techniques for Tendon Repair

There have been several recent advancements in flexor tendon repair. Innovations that are gaining traction in the surgical community include the following:

• Strand-by-strand repair technique
• Core suture techniques
• Biological augmentation
• Tendon repair implants

It takes three to four months for a flexor tendon to heal completely. You’ll typically need to wear the plaster splint for six to eight weeks to immobilize your hand. Your physical therapist may begin a light exercise regimen within days of your surgery to help retain and restore your range of motion. It’s crucial to follow the therapist’s instructions exactly. Gentle yet regular movement is necessary to keep the tendon from sticking in the sheath while carefully avoiding any reinjury.

Once the splint has been removed, you’ll advance to more strenuous physical therapy exercises. Continue to follow the prescribed program exactly to support your hand’s healing and rehabilitation. It typically takes three to six months to regain full strength in your hand.

The most common complication with flexor tendon injury is a recurring break. This usually happens shortly after the initial surgery. The tendon can snap easily at this stage of recovery, particularly if you strain your finger. You may feel the tendon snap in your finger. Lack of movement is another key sign that the tendon has broken. You may have only days to repair the tendon again at this point, so it’s important to contact your surgeon immediately.

If physical therapy isn’t sufficient to relieve the stiffness after your flexor tendon repair, you may need follow-up surgery, known as tenolysis. When necessary, this surgery is performed about four to six months after the initial tendon repair. Tenolysis removes the adhesions that may form between the tendon and flexor sheath, inhibiting their movement.

If you sustain an injury to your arm, wrist, or hand that compromises your movement or causes pain, you should contact a healthcare professional as soon as possible. Our experts at The Hand and Wrist Institute can promptly diagnose your injury and create a plan of action to help retain your range of motion and restore the full use of your hand.