Digital nerve injuries of the upper limb – surgical repair

What is the aim of this leaflet?

To provide patients and their families and/or carers with information about therapy management after surgical repair of digital nerve injuries in your hands.

What is a peripheral nerve?

A nerve delivers information to and from the brain to all parts of your body. A digital nerve is known as a sensory nerve. Sensory nerves send signals to your brain about what you are touching or feeling. They tell you when something is hot, cold, sharp, blunt, hard or soft. They also help you recognise objects by touch, without seeing them, for example feeling for keys in your pocket.

Nerves are made of fibers called axons that are insulated by surrounding tissues in a tube.

Some damaged nerves may need surgery.

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

There are two digital nerves in each finger of the hand. They are positioned one on each side of every finger and thumb. We refer to these as ulnar or radial digital nerves

The ulnar side is the side nearest to your little finger.

The radial side is the side nearest to your thumb.

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 3-4 weeks to heal. You may need to wear a splint during that time to protect the surgical repair, but not necessarily. Your Doctor / therapist will advise you if you need a splint.

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 2-3 weeks, it starts to regrow at approximately 1mm a day. You will not regain sensation (feeling) until the nerve grows back to its destination. Usually after three months you will notice feeling starting to come back, but, you need to be aware, that feeling may never come back completely.

What will happen whilst the nerve is recovering?

Following your surgery, you may have tingling or pins and needles, or a burning feeling in the affected part 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.

Your hand may be more sensitive to temperature changes. You may feel the cold more so you should wear warm gloves when you are in the cold.

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. If CUH is not your most local hospital, 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 with the hand therapy team

After surgery it is normal to have a swollen hand. 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 you see your hand therapist. The cast must be kept dry.

What to expect at your first appointment?

Your first appointment will last an hour. We will remove your cast if you have one.. We may replace this with a lighter weight thermoplastic splint to protect the repaired nerve as the repaired outer layer of the nerve heals, but not all digital nerve repairs need a thermoplastic splint.

If you do need a splint, it 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 (if 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 redness and pressure areas.When you remove the splint to do this, ensure you keep the hand in the 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). Check the plastic bag for any holes or splits before using.

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

Wound care

|It is important to look after the wound whilst it is healing to prevent infection. Keep it clean and dry until the stitches have been removed and it is healed,which takes approximately 10 to 14 days following surgery. If they are dissolvable stitches then they need to stay clean and dry for at least 12-14 days. Your dressings clinic,your local GP practice nurse or hand therapist will advise you.

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 scarring.

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 longer.

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? What do I do?

If the wound is healed and dry, you can start scar care 24 to 48 hours after your stitches have been removed.

If you have dissolvable stitches you can start massaging your scar at approximately 12- 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 are 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 alcohol.

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 5-10 repetitions, every two hours initially.

Some movements may not be allowed in the first 3-6 weeks post-op if they risk putting tension on the nerve repair. Your therapist will show you exactly which exercises you should be doing for your particular nerve injury and tell you when and how to increase them.

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, call 01223 348507 (Monday to Friday 08:30 to 16:30), your local GP practice, NHS 111 or visit 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 the skin of your injured hand.
• 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 the first phase of sensory re-training. There is another phase, phase two, which your therapist will go through with you when the feeling is starting to return. It is very important to continue to do these exercises, even if you have no feeling.

Safety

You need to be very aware that you may not be able to feel hot or cold or sharp objects. Therefore, 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:

• Anything hot (coffee, radiators,etc.)
• Steam from kettles/ cooking
• Hot radiators, hobs or ovens
• Sharp objects, (open tins, knives)
• Anything cold (ice, dry 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 if you were given one. Your therapist will assess if these are necessary.

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

My Chart

If you have not already done so, we would encourage you to sign up for MyChart. This is the electronic patient portal at Cambridge University Hospitals which allows patients to securely access parts of their health record held within the hospitals’ electronic patient record system (Epic). It is available via your home computer or smart phone.

If you are interested in this please let us know and we can provide information, or look on our website: CUH website - My Chart

Contacts/ Further Information

The Occupational Therapy department is located in clinic 30 at 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.