A Millimetre a Day, and a Sign You Can Track Yourself
A cut nerve in the hand or wrist has been stitched back together, or a gap has been bridged with a graft.
The operation took a couple of hours…but it’s not really healed or connected immediately in that sense.
Real recovery takes a year or two…sometimes longer.
That’s not slow surgery. It’s just that stitching a nerve doesn’t restore it. It builds a bridge, and then thousands of nerve fibres have to grow across that bridge and travel all the way down to the skin and muscle they used to supply.
They do that at roughly one millimetre a day. About an inch a month. Measure from your scar to your fingertip and you’ll have a rough idea of the timescale you’re dealing with.
Even then, it may not reconnect or function like before. This is the same reason why people who injured their spinal cord…doesn’t always regain back the ability to stand, walk or run. Our nerves are an entirely different cell compared to muscles and bones that heal so fast.
The sign you can track at home
This is the single most useful thing to know, because it turns an invisible process into something you can watch.
Tap gently along the path of the nerve, starting below the scar and working towards the fingertip. At the point the regrowing fibres have reached, tapping produces a distinct electric tingle into the finger.
Mark that spot.
Check again in a month.
If the tingling point has moved a couple of centimetres further down the finger, the nerve is growing. That’s Tinel’s sign, and following it monthly tells you more about your progress than anything else available to you.
A tingling point that’s advancing means it’s working. A tingling point that hasn’t moved in three months means someone should look again.
Feeling comes back in layers
Sensation doesn’t return as a single switch. It arrives in a sequence, and the early stages feel unpleasant and wrong, which is normal.
- Pain and temperature first. Often unpleasantly sharp and poorly located.
- Then moving touch and vibration. You’ll feel something being dragged across the skin before you can feel it resting there.
- Then constant touch.
- Last, discrimination: telling two points apart, judging textures, recognising an object by feel without looking.
Along the way, sensation is frequently misreported.
Touching one spot feels like a different spot, or feels electric, or feels far too intense. The fibres have grown back but not necessarily to their original addresses, and your brain has to relearn the new map.
Sensory re-education, which is the actual work
This is the part of nerve recovery that people don’t know exists, and it’s the difference between a hand that feels and a hand that has sensation but can’t use it.
- Early phase, once you can feel moving touch: stroke the area with a fingertip while watching, then repeat with your eyes closed, then look again to confirm. Short sessions, several times a day. You’re teaching your brain to match the new signal to the right place.
- Later phase, once you can feel constant touch: identify textures and everyday objects by feel with your eyes closed, then check. Coins, keys, fabric, rice, buttons.
It’s tedious and it works, and the people who do it end up using the hand normally rather than protecting it.
Protecting a hand that can’t feel
While the area is numb, it will burn and cut without warning you.
That’s not a small risk, it’s a routine one.
- Check the numb area visually, daily, for cuts, blisters and redness you didn’t feel happen.
- Test water temperature with the other hand. Always.
- Be deliberate around hot pans, kettles, cigarettes, radiators and engines.
- Watch for pressure marks from tools and grips.
Timeline and honest expectations
- Weeks 0 to 4: the repair is protected in a splint that stops the joints stretching the stitched nerve. Every joint that isn’t restricted is moved daily.
- Weeks 4 to 8: splint gradually weaned, full movement restored, scar work, nerve gliding.
- Months 2 to 12: the waiting period. Tinel’s sign tracked monthly, sensory re-education started the moment there’s anything to work with, muscles kept supple.
- Months 12 to 24: the final picture. Judge the result here.
Three things that genuinely change the outcome, none of which are effort-related:
- your age, because children recover far better than adults and results decline steadily with age;
- how clean the injury was, since a sharp cut repairs better than a crush; and
- whether a graft was needed, because a graft means two junctions to cross instead of one.
Realistic goal for most adults is protective sensation: enough to know when something is hot, sharp or pressing. Fine discrimination is a bonus rather than an expectation. And cold intolerance, an aching, unpleasant response to cold weather, is close to universal and is usually the complaint that lasts longest.
The short version
A millimetre a day. Track the tingling point monthly so you can see it moving.
Protect the numb skin, because it will not tell you when it’s being damaged. Do the sensory re-education as soon as there’s anything to feel.
And judge the result at a year or two, because this is the one recovery on this site where six months genuinely tells you very little.
Written by Nigel Chua, hand occupational therapist in practice since 2005. Tens of thousands of hands, wrists and elbows assessed and treated. My credentials are here. This article explains; it doesn’t examine. Follow your own surgeon’s protocol where it differs from anything here.