What is Nerve Transfer (Neurotisation)?
Nerve transfer, also known as neurotisation, is a surgical procedure used to restore movement and function in muscles that have lost their nerve supply due to injury. In this procedure, a healthy nerve fascicle or nerve branch from a nearby area (called an expendable donor nerve) is transferred to replace the function of a damaged nerve that can no longer send signals to a muscle. This helps to reinnervate the affected muscle, allowing it to regain strength and movement over time.
How Does Nerve Transfer Work?
When a nerve is damaged beyond repair and cannot regenerate on its own, the muscles it controls may lose their function. This can result in weakness or paralysis of the affected muscle. Nerve transfer aims to bypass the damaged nerve by taking a small portion of a nearby functioning nerve that serves a different muscle, and rerouting it to the muscle that has lost function.
For example, if a nerve that controls your elbow flexion (the ability to bend your elbow) is damaged, a surgeon may take part of a functioning nerve that controls wrist movement and transfer it to the elbow muscle, allowing you to regain some movement over time.
Key Principles of Nerve Transfer
Successful nerve transfer surgery is guided by several key principles to achieve the best results:
-
Proximity to the target muscle: The donor nerve should be close to the muscle that needs reinnervation to speed up recovery.
-
Expendable donor nerve: The nerve being transferred should be one that can be spared without causing significant loss of function in its original area.
-
Motor nerve selection: It is important to choose a donor nerve that controls movement (a motor nerve) rather than one that controls sensation (a sensory nerve).
-
Size match: The size of the donor nerve should match the recipient nerve to ensure proper signal transmission.
-
Functional similarity: The function of the donor nerve should be similar to the function you want to restore (e.g., transferring a nerve that controls bending for a muscle that also bends).
-
Motor re-education: After the surgery, patients undergo rehabilitation to retrain the brain to use the new nerve connection, improving the muscle’s function over time.
How is the Donor Nerve Chosen?
Choosing the right donor nerve involves a careful evaluation of several factors:
-
Which nerve is not working? This helps identify the affected area and the lost function.
-
What function needs to be restored? The goal is to identify which movements or actions need to be recovered.
-
Which donor nerves are available nearby? The surgeon looks for nearby nerves that can take over the function of the damaged nerve.
-
Which donor nerve is most appropriate? The surgeon selects the nerve that will provide the best chance of restoring the lost function without causing significant impairment elsewhere.
Examples of Common Nerve Transfers
Here are some examples of commonly performed nerve transfers:
-
Restoring Elbow Flexion (Bending the Elbow):
-
A fascicle from the ulnar nerve (which controls wrist flexion via the flexor carpi ulnaris muscle) can be transferred to the musculocutaneous nerve to reinnervate the biceps muscle, helping restore elbow flexion.
-
Similarly, a fascicle from the median nerve (which controls wrist flexion via the flexor carpi radialis muscle) can be transferred to the musculocutaneous nerve to reinnervate the brachialis muscle, also contributing to elbow flexion.
-
Restoring Shoulder Function and Stability:
-
The spinal accessory nerve, which controls the trapezius muscle (important for shoulder movement), can be transferred to the suprascapular nerve, which controls the supraspinatus and infraspinatus muscles responsible for stabilising and lifting the shoulder.
-
A branch of the radial nerve (which controls the triceps muscle) can be transferred to the axillary nerve, which controls the deltoid muscle, helping restore shoulder function and stability.
What Happens After Surgery?
Nerve transfer surgery is just the first step in recovery. After the procedure, rehabilitation is a crucial part of the process. Patients typically undergo physical therapy to help retrain their muscles and re-educate their brain to use the new nerve connections effectively. It may take months or even years for full function to return, but with proper care and effort, many patients see significant improvements.
Key Message
-
Nerve transfer is a procedure used to restore lost muscle function by transferring a healthy nerve to the affected area.
-
Rehabilitation after surgery is essential to retrain the muscles and improve recovery.