The ulnar nerve is a large nerve that runs behind the elbow, along the inner side, just behind the prominent bone known as the medial humeral epicondyle. It is the “funny bone” nerve, and when struck it causes the familiar painful burning in the hand and ring/little finger. In throwers, this nerve may become irritated by the repetitive strain placed on the nerve during the flexion, extension, and torque on the elbow. The nerve is adjacent to the ulnar collateral ligament and is subject to similar stresses. In fact, if the UCL is stretched out or torn, the ulnar nerve is subject to more stress and often becomes irritated because of the looseness of the ligament. So, any thrower with ulnar nerve symptoms must have a careful evaluation of his UCL. It is possible that the nerve problem is coming from a ligament problem, and both may need to be treated.
The surgery is simple in concept: the nerve is re-routed from its normal position behind the elbow to a new position in front of the epicondyle. The idea is that the nerve get stretched during elbow flexion and perhaps kinked. By bringing it in front of the elbow, the nerve no longer needs to turn a corner, and the kink is eliminated. It is the same principle as cutting a dogleg in golf — the shortest distance between two points is a straight line.
The recovery from this surgery is much shorter than from a Tommy John surgery. Usually within a few months the athlete is ready to begin throwing. Dr. Dan Keefe and I wrote a chapter about this injury and other nerve problems in throwers’ elbows. It is published in Clinics in Sports Medicine:
Nerve Injuries in the Throwing Elbow. Keefe, DT and Lintner DM. In Clinics in Sports Medicine, Marc Saffron Ed. Volume 23, 723-742