Peripheral nerve injuries of the upper limb – surgical repair

What is the aim of this leaflet?

To provide information about therapy management following surgical repair of peripheral nerve injuries in the upper limb.

What is a peripheral nerve?

A nerve is a structure within your body that delivers information to and from the brain. A peripheral nerve is a network of nerves that connect the brain and spinal cord (the central nervous system) to the entire human body. Motor nerves send signals to your muscles to allow movement. Sensory nerves send signals to your brain about what you are touching or feeling.

Peripheral nerves are made of fibres called axons that are insulated by surrounding tissues.

Nerves can be damaged in different ways and sometimes need to be repaired with surgery.

Think of them like an electricity cable. The outer layer / tube is the part that gets repaired in surgery, and it is the fibres within the tube that have to regrow from the point where they have been damaged.

There are three main nerves that affect the hand: the median nerve, the ulnar nerve and the radial nerve.

You have had the . . . . . . . . . . . . . . . . . . . nerve repaired.

How long will it take to heal?

The outer part of the nerve that has been repaired (the epineurium) takes 3 to 6 weeks to heal. You will need to wear a splint during that time to protect the surgical repair.

The inner part of the nerve (the axon) needs to grow back within its tube, from the point of where it was damaged. It can take time for it to carry signals again. After the first 2 to 3 weeks, it starts to regrow at approximately 1mm a day. You will not regain sensation (feeling) or muscle power (movement) until the nerve axon grows back and reconnects to its destination. Usually after three months you will notice movement and feeling start to come back, but it can take up to two to five years and may never recover completely.

What will happen when the nerve is recovering?

You may have some loss of active movement as some of your muscles won’t work immediately after surgery and when they do start to work again they may be weak. Your hand may rest in a certain position because some of the muscles are not working. You may start to notice some areas of muscle wasting after a few weeks. The exact muscles where you may have problems will depend on which nerve has been repaired and position along the nerve where the damage is.

Below shows some of the common postures and functional difficulties that can occur with damage to each of the three nerves affecting the hand:

Common postures and functional difficulties

Radial nerve

Median nerve

Ulnar nerve

You may have tingling or pins and needles, or a burning feeling in the affected parts of your hand. You may have no feeling at all in the affected part of your hand initially, but then start to get tingling or pins and needles as feeling starts to come back. It can also be normal to get electric shock type sensations and involuntary muscle twitches.

• You may not be able to feel with your hand properly so you must take care with hot, cold or sharp objects. You may cut or burn your hand without realizing and, if you do damage your hand, it will take longer to heal.
• Your hand may be more sensitive to temperature changes. You may feel the cold more easily so you should wear warm gloves when you are in the cold.
• Your hand may not sweat properly after nerve injury. This can lead to dry skin therefore you will need to wash and moisturise it regularly.

Below is a chart that shows the normal areas of sensation (feeling) for each of the three nerves affecting the hand.

What can you expect immediately following surgery?

You will be contacted by the hand therapy team to arrange an appointment within a week of your surgery. It may be possible to transfer your hand therapy care closer to home after the first few appointments, depending on what specialist services are available in your local area.

You might experience some discomfort or pain following surgery and it is important to take regular pain relief as required.

What to do in the few days before your first appointment

Following the surgery it is normal for the hand to be swollen. To reduce this swelling keeping the hand elevated (resting on your shoulder) or in a sling can be beneficial.

Until you are seen, do not remove your post-surgery cast or attempt to use your hand at all. Don’t attempt any of the exercises until seen by your hand therapist. The cast must be kept dry.

What to expect at your first appointment?

Your first appointment will last an hour. Your dressings and cast will be removed and replaced with a lighter weight thermoplastic splint to protect the repaired nerve as the repaired outer layer of the nerve heals. This splint needs to be worn 24 hours a day for up to six weeks as directed by your therapist. In most cases you will start your exercises at your first appointment. We would recommend you eat something and take pain relief before attending your first appointment to make your experience more comfortable.

Splint care (once you have been fitted with a thermoplastic splint)

Do not place the splint in hot water or near a heater or it will change shape.

Check your skin regularly for red / pressure areas and when you remove the splint to do this, ensure you keep the hand in the same position it would be in if you still had the splint on. Contact your therapist if any problem occurs.

If your splint becomes too loose or too tight please contact your hand therapist.

Use a plastic bag over the whole arm when in the bath or shower (do not take the splint off).

Why is it important to look after your wound and scar?

Wound care

To prevent infection it is important to look after the wound whilst it is healing. It should be kept clean and dry until the stitches have been removed and the wound is healed and dry which is approximately 10 to 14 days following surgery. If they are dissolvable stitches then they need to stay clean and dry for at least 12 to 14 days. You will be guided on this by the dressings clinic or your local GP practice nurse or hand therapist.

Scar care

Scars are collagen fibres produced as a result of the body’s normal healing process. The amount of scar tissue produced by the body varies depending on the individual and type of surgery / injury. As the wound heals there will be little scar tissue produced but over time the body may develop more.

Initially scars can be firm, thick and red in colour (active phase) but over time they soften and become pale in colour (matured). This whole process may take 12 to 18 months or more.

During the “active phase” you can use treatments to influence your scar. Initially as scar tissue forms it is thick and lumpy and can stick to structures around it; scar care helps to flatten the scar and make it softer as well as reducing the chance of scar tissue sticking (adhesions).

When can I start my scar care?

If the wound is healed and dry, 24 to 48 hours after your stitches have been removed.

If you have dissolvable stitches you can start massaging your scar at approximately 12 to 14 days after your surgery, providing the wound is healed and dry.

You will need a basic, un-perfumed moisturising cream, such as aqueous cream or ‘E45 cream’, which is ideal for massaging scars.

The scar massage needs to be in circular movements, on and around the scar line, to keep the skin moving freely. In the first few days you may only tolerate gentle massage, but you should then aim to increase it to a deep and firm massage to reduce the risk of adhesions (see picture below).

Please keep your splint on when doing scar massage. If this is not possible due to the location of the scar, ensure you keep the hand in the position it would be in if the splint was on.

Start date: . . . . . . . . . . . . . . . . . . . . . . . . . . .

Repeat . . . . . . . . times per day for approximately . . . . . . . . minutes, ideally before your exercises.

How can you help your recovery?

To help your recovery you should cut down or stop smoking and drinking.

Keep your hand elevated as much as practically possible to prevent swelling in your hand.

Do not use your hand for anything other than your exercises until advised by your hand therapist. This includes driving.

Exercise (including uninvolved joints) – why it is important

Exercise is important to help your recovery. It will reduce stiffness and swelling in the hand and thumb and help to prevent complications. Your therapist will teach you specific exercises which you must complete throughout the day – normally 5 to 10 repetitions, every two hours initially.

Although some of the muscles may not be working due to the nerve damage, it is important to keep the joints supple ready for when the motor nerves do start to conduct messages again. Some movements may not be allowed in the first 3 to 6 weeks post op if they put tension on the nerve repair. Your therapist will show you exactly which exercises you should be doing for your particular nerve injury.

Potential signs of infection or possible rupture and what to do

If you notice that your hand feels hot to the touch, is red, has an unpleasant smell or you have increased pain, this may be a sign of an infection.

If you feel a popping or snapping sensation and notice any sudden pain or swelling, this may suggest the nerve repair has ruptured.

In these instances, you should contact the plastic surgery unit on 01223 348507 (Monday to Friday 08:30 to 16:30), your local GP practice, 111 or your local emergency department if out of hours.

Sensory re-training

If you cannot feel a part of your hand, your brain may begin to forget that part is there.

Straight after your operation, some simple brain exercises can help stop you forgetting what your hand should feel like, and keep that area of your brain ready to receive sensory messages (feelings) from the hand again in the future.

Examples are:

• Look at different objects and textures and imagine what they should feel like on your skin.
• Ask someone to touch an area of your hand that you cannot feel at the same time as the same area on your other hand. Notice how it feels and how it should feel on your injured hand. You can even gently touch the numb area over the top of the dressings whilst looking at it as you touch it.

Exercises done while you have no feeling are phase one of sensory re-training. There is also a second phase which your therapist will go through with you when the feeling is starting to return.

Safety

Be aware that you may not be able to feel hot or cold or sharp objects – so you will need to be extra careful with your hand. Check your skin condition regularly whilst wearing splints as you may not feel areas that are rubbing. If your splint is rubbing, please let your therapist know.

Please take care with:

• Hot drinks
• Steam from kettles / cooking
• Hot radiators
• Sharp objects, such as tins / knives
• Ice
• Activities that cause friction / pressure, such as holding a tool / object for a long time, rubbing your hand dry.

What happens later on?

Your therapist will advise when you can stop wearing the protective splint, and after that may fabricate different splints that aim to assist you to use your hand whilst waiting for the muscle function to return. Your therapist will assess if these are necessary.

Your therapist will monitor your sensory recovery and muscle recovery and will provide additional exercises to help strengthen muscles as they start to work again, and start phase two of sensory re-education once the sensation is starting to return.

Contacts / Further information

The Occupational Therapy department is located in clinic 30 in the Addenbrooke’s Treatment Centre (ATC). This is approximately 10 minutes walk from the main bus stop at the front of the hospital. The occupational therapy reception telephone number is 01223 216769.

References / sources of evidence

NICE clinical guideline No 74: Surgical site infection (October 2008); Department of Health: High Impact Intervention No 4: Care bundle to preventing surgical site infection (August 2007)

Standards of Hand Therapy Practice in the management of nerve trauma’ published by BAHT in 2022.

Peripheral nerve injuries – patient information leaflet. St Georges Hospital NHS trust.