How long does it take for nerve injuries to heal from pins through the elbow? Our son has a fracture of the upper arm bone just above the elbow. Pins were placed through the bone to hold it all together while it healed. The cast is off and the pins are out but there are some nerve problems.

Nerve injuries called neuropraxia associated with elbow fractures occur for one of two reasons. The first is from damage done to the nerve by the jagged edges of the displaced (separated) broken bones. The second is from pins used to hold the bone together while it heals.

Studies show that about 11 per cent of all children who have this type of elbow fracture also develop traumatic neuropraxia affecting one or more of the nerves (median, anterior interosseous, posterior interosseous, radial, ulnar). About four per cent develop nerve damage from the pins touching, compressing, or puncturing the nerve.

A little bit of information about neuropraxia here might help explain what happens to the patients with this type of fracture-induced (traumatic) or pin-induced (iatrogenic) injury. Iatrogenic means the problem developed as a result of the treatment. Neuropraxia describes nerve damage without disruption of the nerve or its sheath (covering). There is enough damage done that the messages sent along the nerve are interrupted. This causes a temporary loss of sensation and motor function that can last hours to weeks to months. Recovery does occur but can take six to eight weeks or longer.

Pin placement determines which nerve(s) is/are affected. For example, placing the pin through the lateral side of the bone (side away from the body) is more likely to cause median nerve injury. Pin placement through the medial side (inside of the elbow) increases the risk of ulnar nerve damage. Both of these nerves have sensory and motor functions so the patient experiences loss of sensation and muscle weakness or even paralysis.

Surgeons are aware that these kinds of complications can occur and make every effort to avoid causing iatrogenic neuropraxia. With a little time and patience, recovery is reported in 100 per cent of cases.