Tendon transfers

Patients suffering from an SCI that has compromised their upper limbs may consider the option of tendon-transfer surgery

Living with spinal cord injury (SCI) is challenging at the best of times. Individuals with an SCI where upper limb function is normal and preserved (paraplegics) are usually functionally independent in all their activities of daily life (ADL).

However, for those patients who suffer a SCI where the function of the upper limbs is compromised (tetraplegia), total independence in ADL usually is impossible and assistance is required in some activities that require advanced upper limb function.

Take, for instance, someone who suffers an injury at the C5 level. This means that shoulder function and flexion at the elbows is possible, but all other movements are impaired or absent – so no wrist or finger function. The result is that the person will require assistance in ADLs that require intact hand function.

Besides the use of splinting devices to assist with functional activities, there are many surgical options available to improve function of the paralysed limb. These operations are known as tendon-transfer operations. They can improve function in the arm and hand by using working muscles and transferring them to act as “motors” for paralysed muscles.

A tendon is the part of the muscle that crosses a joint (elbow or wrist) and attaches to the bone. When the tendon crosses the joint, it helps to transmit muscle action into joint movement. By connecting a strong working muscle to the tendon of a paralysed muscle, movement across a joint can be restored.

So, let’s look at who could benefit from these procedures.

C5 and C6 injuries

Elbow extension

The ability to actively straighten the elbow from a bent position adds greatly to a person’s independence. This is one of the most important functions to restore in tetraplegia. The working deltoid muscle, or part of biceps-to-triceps tendon transfer, restores reasonable elbow extension (movement against gravity and light resistance).

Activities such as dressing, reaching overhead, driving a power wheelchair (or a car) and supporting oneself in sitting become easier, as the strong pull of the biceps muscle is balanced by the action of the triceps muscle.

Wrist extension

The ability to actively extend the wrist removes the need for a wrist orthosis (splint). Muscles that remain active in the forearm (brachioradialis) are used to augment function. At the same time a procedure to bring the thumb into contact with the index finger is performed to improve pincer grip with obvious advantages.

C6/7 and C8 injuries and hand function

Improvement in the overall functioning of the hand with improved grip can be achieved through various tendon transfers in the forearm. Activities such as eating, writing, and picking up heavier objects are improved with these transfers. In conjunction with the key grip procedure, a tendon transfer to enable grasping ability with the fingers is generally performed at the same time.

C6 and C7 injuries can result in the tightening of the fingers due to spasticity in the hand and/or contracture of the finger joints; this can make it difficult to open the hand to release objects. The problem may develop years after injury due to tightening of the natural tenodesis of the hand. A procedure can be carried out that improves the passive opening of the fingers when the wrist is relaxed.

These surgeries are extensive, however, and mean many months of post-operation hand rehabilitation in order to strengthen and learn the new functions. They should not be undertaken by those who are not committed to the post-operative rehabilitation programme or don’t have a full understanding of what is possible with tendon transfers.

 


Dr Ed Baalbergen is the medical officer at the Vincent Pallotti Rehabilitation Centre (Cape Town) and is a member of the International Spinal Cord Society and the Southern African Neurological Rehabilitation Association. email: ed.baalbergen@lifehealthcare.co.za

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