What are tendons?
Tendons are the thickened parts of muscle that attach to bone. When a muscle contracts, it pulls on the rope-like tendon, moving the bone. Muscles in the forearm have thin tendons that attach to the fingers, and are responsible for finger movement.
The tendons that run along the palm side of the finger are called 'flexors', as they cause the finger to flex (curl up). Tendons on the back of the finger are called extensors, as they cause finger extension (as in when pointing).
How are tendons injured?
Usually, a cut to the hand is the cause of tendon injury. This may be from a knife, broken glass or sharp lid of a tin can.
A common example is when trying to pry apart frozen burgers with a sharp blade - the point of the knife slips, stabbing into the palm of the hand holding the burgers! People who punch windows will also commonly be injured, and can sustain significant tendon and nerve damage to their hand and forearm.
What happens if a tendon is cut?
It is best to think of tendons like a rope - if the rope is part cut, then it can still work, but will be weakened and could snap at a later date. If the rope is completely cut through, it no longer works. Tendons that are partially cut through will still work, but may be painful and can snap some time later. Tendons that are completely severed will no longer work - for example, if the tendon is responsible for curling the index finger, then this action is no longer possible despite best efforts.
How are tendons repaired?
If the tendon is not repaired, then the affected movement will not return. Most tendons are repaired by surgery, although occasionally may be treated by splints alone (eg mallet finger).
The surgeon may well need to make the cut larger, in order to access the cut ends of the tendon. Occasionally, the cut end of a tendon can 'jump backwards' towards the wrist, and so the surgeon may need to make a cut over the wrist area to find it. The tendon ends are then stitched together with permanent sutures.
Is a splint or physiotherapy needed after tendon repair?
If the tendon was only 'nicked', then a splint is often not needed, or only needed for a couple of weeks. If the tendon was completely divided, though, then a splint is required. Extensor tendons usually need splintage for about 6 weeks, and flexor tendons need about 8 weeks of splintage. You will need to avoid any heavy lifting etc during this time.
Physiotherapy helps to get the hand moving again after surgery and is used in most cases of tendon injury. It is very important to adhere closely to the physiotherapy instructions - following them carefully will lead to maximal hand movement and function, whilst failing to follow instructions can lead to permanent hand stiffness or even rupture of the repaired tendon.
What are the risks of tendon injury?
Stiffness - it is very common to have a stiff hand joint after the splinting or procedure. This is due to the long period of splinting required and the nature of the injury itself. Physiotherapy helps to reduce the effects of this stiffness
Tendon rupture - after the tendon has been stitched, the repaired ends can break again. This can happen anytime from almost immediately to a few weeks after the repair. Another procedure will probably be needed, either to repair the tendon again or, occasionally, to perform a tendon graft or other complex operation.
Adhesions - once the tendon is stitched, the body continues to heal it by scarring. At the same time the overlying skin is also healing by scarring. The scar tissue may become mixed with each other, effectively healing the tendon to the non-mobile skin. The tendon is now 'tethered' and will not move effectively. A further simple procedure may be needed to free up the scar tissue, and allow the tendon to move again.
Any procedure involving skin incision can also result in unfavourable scarring, wound infection, or bleeding. This list of risks is not exhaustive, and you should discuss possible complications with your specialist. Whilst these risks will seem very worrysome, and indeed can be serious, it should also be borne in mind that many people have no postoperative problems whatsoever.
The information provided is as a guide only and you should discuss matters fully with your specialist before deciding if this is the right procedure for you. Please also read our disclaimer