In short. Loss of sensation versus loss of movement after nerve injury, why nerve recovery is slow and often incomplete, and the options including grafting and tendon transfer.
Key points
- Nerves do regrow, and good repairs produce useful recovery — but the honest expectation is partial.
- Sensation may return over months and still feel different from the other hand.
- Protective sensation often returns before fine discrimination.
Nerves in the hand do two different jobs, and it helps enormously to keep them separate. Sensory nerves carry feeling from the skin. Motor nerves carry the signal that makes a muscle contract. A nerve injury may take away feeling, take away movement, or take away both, and the treatment and the prognosis differ in each case.
Two kinds of loss
The median nerve supplies sensation to the thumb, index, middle, and half of the ring finger, and supplies the muscles that let the thumb oppose — the movement that makes a pinch possible. The ulnar nerve supplies the little finger and most of the small muscles of the hand. The radial nerve is mostly motor in the hand, straightening the wrist and fingers. Loss of sensation is felt as numbness and as a hand that does not know what it is touching; loss of movement is felt as weakness, and as a hand that cannot grip or pinch reliably.
Why recovery is slow
When a nerve is divided, the fibres on the far side degenerate and must regrow from the repair site at roughly a millimetre a day. A nerve repaired at the wrist therefore takes months to reach the fingertips, and one repaired at the elbow takes considerably longer. During that time the target muscle and skin are changing, and a muscle may not recover at all if it is reinnervated too late.
Recovery is real but rarely complete
Nerves do regrow, and good repairs produce useful recovery — but the honest expectation is partial. Sensation may return over months and still feel different from the other hand. Protective sensation often returns before fine discrimination. Some movement may never come back, particularly after a high injury or a long delay before repair. Normal nerve does not come back; usable nerve sometimes does.
The reconstruction options
A clean cut is repaired directly. A gap too long to close without tension needs a nerve graft, usually a sensory nerve taken from the leg or forearm, which acts as a scaffold for regrowth. A nerve that cannot be repaired at all, or one whose muscle has already failed, is bypassed with a tendon transfer: a working tendon is rerouted to do the job of the paralysed one, and therapy teaches the brain to use it. Nerve transfers, in which a nearby functioning nerve is rerouted to a more important target, are used in selected injuries.
What cannot be restored
Perfect sensation, normal strength, and full dexterity are not realistic goals. Cold intolerance and altered sensation are common and often persistent, and a hand that has lost protective feeling needs care to avoid burns and cuts. Final assessment is at twelve months or longer, and often beyond two years after a high injury. No outcome is guaranteed.
Seek care if
- Numbness is new or spreading, or the hand cannot feel heat or cold safely.
- Weakness develops or worsens after an injury or an operation.
- The hand becomes pale, cold, or increasingly painful, or a wound becomes red and hot.
Frequently asked questions
What is the difference between losing feeling and losing movement?
Sensory nerves carry feeling from the skin; motor nerves make muscles contract. The median nerve supplies both sensation to the thumb side and the muscles that let the thumb oppose, so an injury can take away feeling, movement or both.
Will feeling come back after a nerve injury?
It may return over months, and it usually feels different from the other hand. Protective sensation often returns before fine discrimination. Some movement may never come back, particularly after a high injury or a long delay before repair.
What is a tendon transfer?
It is used when a nerve cannot be repaired or its muscle has already failed. A working tendon is rerouted to do the job of the paralysed one, and therapy then teaches the brain to use the new arrangement.
Risks & Limitations
- Incomplete return of sensation or movement. Nerve recovery is slow — roughly a millimetre a day — and some feeling or movement may never come back.
- Stiffness and contracture. A stiff hand is the commonest reason a technically good operation gives a disappointing result.
- Rupture of a tendon repair with forceful use too early in the protected period.
- Infection, which may require antibiotics and further surgery.
- Scarring and scar contracture. Scars are permanent, may stay sensitive or cold-intolerant, and can tether a joint or a web space.
- Growth disturbance in children, which may require later surgery as the hand grows.
- Prolonged hand therapy. Splinting and graded exercise are part of the treatment, not optional aftercare.
- No outcome is guaranteed. Final assessment is made at 12 months or longer, and longer still in growing children.
When to Seek Care
- A hand that becomes pale, cold, blue or numb, or fingers that change colour.
- A wound that becomes red, hot or discharging, or a fever above 38 °C.
- Sudden loss of movement after tendon repair, or a pop felt in the finger.
- Severe pain or swelling in a cast or splint, or a splint that has become too tight.
- Bleeding that does not stop with gentle pressure.
- New or worsening numbness or weakness at any stage after surgery.
References & Further Reading
- American Society for Surgery of the Hand (ASSH) — hand and upper limb condition guidance
- American Society of Plastic Surgeons (ASPS) — reconstructive and hand surgery guidance
- Cochrane Library — systematic reviews in hand surgery and hand therapy
- Chinese Medical Association, Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.