Successful re-innervation of proximal limb peripheral nerve injuries is rare. Axons regenerate at ~1 mm/day, reaching hand muscles by 24 months, finding them atrophied and fibrosed. Peripheral nerve injury repair is often delayed waiting for spontaneous recovery. This waiting time should not be longer than 6 months as after 18 months reinnervation will not achieve effective muscular function. When spontaneous recovery is impossible, referral too late or damage too severe, other options like a transfer from a nearby healthy nerve to the injured one must be considered. They are very successful, and the deficit in the donor site is usually minimal. The most common nerve transfers are a branch of the spinal nerve to the trapezius muscle to the suprascapular nerve, a branch of the long head of the triceps to the axillary nerve, a fascicle of the ulnar nerve to the motor branch of the biceps muscle, two branches of the median nerve to the posterior interosseous nerve and the anterior interosseous nerve to the ulnar nerve. There are many more options that can suit particular cases. Introduced in brachial plexus injury repair, they are now also applied to lower limb, to stroke and to some spinal cord injuries.
Part of the book: Peripheral Nerve Regeneration