Open Injuries Conditions Open Hand Injuries Tendon Injuries

What are flexor tendon injuries?

Flexor tendons refer to the tendons that bend the fingers and the thumb. Flexor tendons run on the palm side of the hand. Each finger has two tendons (flexor) digitorumsuperficialis (FDS) and flexor digitorumprofundus (FDP)) and the thumb has one tendon called flexor pollicuslongus (FPL).

Injuries to these structures are devastating, and there is no quick fix. There are different types of flexor tendon injuries, such as:

  • Closed injuries - these injuries could be closed, as in a jersey finger where the attachment of the tendon is pulled off the bone. This injury is commonly found in rugby players hooking their fingers in the opponent's rugby jersey. This usually involves the ring finger.
  • Open injuries – these are usually caused by lacerations of the forearm, palm or fingers. Tendon injuries are complex injuries and should be managed by a dedicated hand surgeon and dedicated hand rehabilitation team. It must be dealt with as soon as possible as the tendons retract towards the arm and make surgery later more complex.

Flexor Tendon Injuries

What are the signs and symptoms of flexor tendon injuries?

Signs and symptoms of flexor tendon injuries may include the inability to bend your finger normally, pain when bending, minor swelling in the injured area and tenderness on the underside of the finger. There might also be an open wound or cut on the palm of the hand or finger.

How are flexor tendon injuries treated?

Dr Dirk van der Spuy will recommend finger surgery to repair the fingers. This involves the hand surgeon cutting into tendons in the fingers, which is even more complex, as this area has a very intricate fibrous tunnel with multiple pulleys keeping the tendons close to the bone to increase the flexion arc of the finger. Repairing tendons in this zone (called the no-mans-land) is very complex due to this pulley system, as well as the complex anatomy of the deep and superficial tendons attachment.

The hand surgeon will protect the operated site with the use of a forearm-based splint on the back of the hand. This helps prevent the fingers from straightening, which could potentially undo or rupture the repair. These injuries require a minimum of six weeks of full-time splinting and approximately a further six weeks of hand therapy to ensure optimal results.

It takes a lot of hard work to ensure the hand reaches its optimal strength, function and range of movement of the fingers.

Flexor Tendon Rehabilitation

Following a flexor tendon repair, it is important to start early protected mobilisation of the affected fingers around 3-5 days post-finger surgery. This is to ensure that the repaired tendon starts gliding, thereby preventing scar adhesions that stick or trap the tendons and prevent the fingers from moving. The movement, however, needs to be done in a careful, protected way so that the repaired tendon does not snap or rupture.

Five days post-finger surgery, Dr van der Spuy will remove the cast as well as the bulky dressing. The base layer of dressings should remain in place.

The hand surgeon will fabricate the thermoplastic splint and fit it at the back of the forearm, preventing the wrist and fingers from straightening. This splint is worn full-time for four weeks post-surgery. Thereafter, it will be worn when sleeping and for protection for a further two weeks.

The hand therapist will teach you specific active and passive exercises to promote the movement of the fingers without jeopardising the repaired tendon/s. The hand therapist will also assist with scarring and swelling management, and strengthening and give advice around the safe use of your hand.

Compliance with rehabilitation and home exercises is strongly recommended to achieve the best possible outcome.


1What is one common sign of a flexor tendon injury?
Pain when attempting to bend your finger and an inability to bend or straighten the tip of your finger
2How do you know you’ve damaged a finger tendon?
A sign you have damaged the extensor tendons is when you cannot straighten a single or multiple digits.
3Can I still bend my finger with a torn tendon?
No, you will not be able to bend the affected finger if the flexor tendon has been torn or lacerated

Please read the above text for more in-depth information to help answer these questions. It's important to consult with our qualified healthcare professionals to ensure the appropriate diagnosis and treatment plan for your specific situation.