Nerve injury is one of the leading causes for settled cases of litigation. Medical Protection Services data have shown that of all the cases that are recorded, 75% proceed to a claim for medical negligence. The incidence of nerve damage has been described as between 1:1,000 or as frequent as 1:350 cases.

The nerves most often affected are ulnar (30–43%), brachial plexus (25%), lumbosacral roots (16%) and common peroneal (11%). It has historically been considered that stretch and pressure effects on nerves are the predominant cause for nerve injury. Many retrospective studies looking at closed claims analysis have called this in to question, yet it remains the most often blamed cause for injury. Analysis of cases in studies has shown that many factors play a contributing role in the development of nerve injury. Some patients (the elderly, frail, diabetic, hypertensive, anaemic patient) can be identified as at greater risk, and extra care and attention can be placed on reducing the additive problems of pressure and stretch.

It is also interesting to note that cases of peripheral nerve injury may have a delayed presentation and are not often apparent in the recovery room. Most present within the first 24 hours, and over 90% present within seven days post-operatively. About 60% of patients with a nerve injury will recover within a year, but a quarter will suffer persistent pain.

Nerve injury can be caused by excessive stretch of nerves or plexi; pressure injury because of poor positioning; direct injury by needles or sharp surgical instruments; chemical injury because of local anaesthetics or antiseptic solutions.