Download Information leafletTendon injuries
What is it?
The fingers have no muscles but tendons, that either bend the fingers or thumb into a palm or straighten the fingers or thumb. Tendons attach the muscles that begin in the forearm to the hand.
The tendons that bend the fingers are on the front of the fingers and are called ‘flexor tendons’. Each finger has two flexor tendons while the thumb has one.
The tendons that straighten the fingers are called ‘extensor tendons’ and they are on the back of the hand.
What is its cause?
Tendons lie very near the skin and hence the most common cause of tendon injuries is a direct cut. Less commonly, tendons may be pulled off from their bony attachment by a sudden pull against a strong grip (Mallet finger, Jersey finger).
Tendons can also rupture because of attrition over a bony prominence or ‘synovitis’ (rheumatoid disease).
What are the symptoms and how is the condition diagnosed?
Depending on which tendon is injured, the patient will not be able to either bend or straighten the finger. If a flexor tendon has been damaged the finger will lie straighter than the other fingers. If an extensor tendon is damaged, the finger(s) will drop.
Nerves that take sensations from the finger, lie very close to the flexor tendons and may be also be damaged. In such circumstances there will numbness further away from the injury.
Will further tests or investigations be needed?
Depending on the mechanism of injury x-rays, ultrasound or MR scan may be advised.
What is the treatment?
- Surgery is always required for acute injuries, as tendons do not heal. Because of the pull of the muscles, the tendons will frequently move away from one another. The wound needs to be cleaned, explored and the tendons need to be approximated and repaired by special techniques. Any other nerve or bony injuries need to be dealt with at the same operation. The procedure is usually carried out under general anaesthesia. After the operation, the hand will be immobilised in a special splint. Hand therapy is essential after the operations to produce a successful outcome.
- Certain injuries in which the tendon has pulled off from the bone are initially treated with a splint (mallet finger need link here), central slip extensor tendon injury)
- If tendons rupture due to attrition, they are usually not amenable for direct repair. These injuries are treated by transferring another tendon from elsewhere to the injured tendon.
What happens if it is not treated?
Active movement of the finger will be lost. Secondary deformities may develop in that digit due to action of other muscles or ligaments in that digit ('Boutonnière deformity' as in picture below)
What is the success of surgical treatment?
A functional range of movement can be expected after most repairs of tendons. The outcome can be compromised if the tendon injury occurred after a crush injury with associated skin or bone damage.
What are the complications of surgical treatment?
- Infection of the wound is possible but usually can be successfully treated with antibiotics. Very rarely infection may spread into the joint replacement.
- The tendon repair may not hold and the tendon may re-rupture.
- Finger stiffness: The tendon may not glide as smoothly as before due to scar tissue (adhesions) that may form in response to the injury or repair.
- Severe complex regional pain syndrome (CRPS) is a rare but serious complication after hand surgery. Unfortunately it is not possible to predict this problem but it needs to be monitored and treated (usually with just physiotherapy), if it develops.
- Any surgical intervention has the risk of developing complications / setbacks which are unpredicted. These complications may have the potential to leave the patient worse than before surgery.
Is there anything I can do to improve the outcome?
Keep the wounds dry and clean until they have healed.
After the operation the therapist will see you and make a lightweight splint to protect the repaired tendon. At the same time the therapist will prescribe the way by which you can move the finger to avoid stiffness. It is important that these instructions are followed to achieve most successful outcome.
When can I do various activities?
Return to work depends on many factors including the nature of the job and hand dominance. Return to work will vary and depend on which tendon and the tendon area (zone) was damaged. Generally tendons repaired need to be protected for 6-8 weeks and return to full functional activity may take three months.
