Nerve injuries of the upper extremity and hand

Abstract

A nerve injury has a profound impact on the patient's daily life due to the impaired sensory and motor function, impaired dexterity, sensitivity to cold as well as eventual pain problems.To perform an appropriate treatment of nerve injuries, a correct diagnosis must be made, where the injury is properly classified, leading to an optimal surgical approach and technique, where timing of surgery is also important for the outcome.Knowledge about the nerve regeneration process, where delicate processes occur in neurons, non-neuronal cells (i.e. Schwann cells) and other cells in the peripheral as well as the central nervous systems, is crucial for the treating surgeon.The surgical decision to perform nerve repair and/or reconstruction depends on the type of injury, the condition of the wound as well as the vascularity of the wound.To reconnect injured nerve ends, various techniques can be used, which include both epineurial and fascicular nerve repair, and if a nerve defect is caused by the injury, a nerve reconstruction procedure has to be performed, including bridging the defect using nerve-grafts or nerve transfer techniques.The patients must be evaluated properly and regularly after the surgical procedure and appropriate rehabilitation programmes are useful to improve the final outcome. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160071. Originally published online at www.efortopenreviews.org.

Keywords: nerve injury; nerve reconstruction; nerve regeneration; nerve repair; nerve transfer; neuroma.

Fig. 1

Schematic drawings showing a nerve transection injury (A), after cutting necrotic parts away from the nerve ends, which is repaired after co-aptation and secured using 9-0 nylon sutures (B). Illustrations performed by Peregrin Frost.

Fig. 2

Schematic drawings showing a nerve injury with a defect (A), after resection of the lacerated parts of the bundles of fascicles (sometimes done in steps as indicated). The nerve defect is reconstructed using nerve grafts (here four cables attached), which are secured with single 9-0 nylon sutures (B). After application of the sutures fibrin glue is usually applied (shown in Fig. 3). Illustrations performed by Peregrin Frost.

Fig. 3

Intra-operative photographs showing the steps in reconstruction of a tibial nerve trunk in the lower leg using the sural nerve as cables in the nerve graft procedure. The proximal and distal nerve ends (arrows) are carefully resected (A) visualising healthy nerve fascicles (shown in the insert in the upper corner in A; arrowhead). Sural nerve cables are individually attached between the nerve ends (arrows indicating the proximal (right) and distal (left) nerve ends) and secured with single 9-0 nylon sutures (hardly seen; B). Finally, fibrin glue is applied around the proximal and distal site of attachment, respectively (grey substance around the sites; C).

Fig. 4

Intra-operative photographs showing a nerve transfer procedure, where the ulnar nerve (A; arrow) is used to reconstruct an injured musculocutaneous nerve (distal nerve end indicated by arrowhead). A few nerve fascicles, innervating the flexor carpi ulnaris muscle, from an intact ulnar nerve (B) are identified with electrical stimulation (C; arrow), transected and transferred (D; arrow) to the distal end of the initially injured musculocutaneous nerve (D; arrowhead). The axons from the ulnar nerve are in this way allowed to regenerate through the site of repair (E; arrow) through the musculocutaneous nerve down to the target, i.e. biceps and brachialis muscles. The nerve repair is finally secured with fibrin glue (F; grey substance). During the rehabilitation period, the patient learns how to use the ulnar nerve fibres in elbow flexion by using cerebral plasticity.