1. In a survey of 2,000 supposedly normal elbows, recurrent dislocation of the ulnar nerve was found in 16.2 percent of the subjects. It occurs slightly more often in females than in males.
2. The probable cause of recurrent dislocation is congenital laxity of supporting ligaments.
3. Such nerves usually remain asymptomatic unless they are subjected to trauma; friction neuritis may develop as a result of trauma.
4. Hypermobility is classified into Type A (incomplete dislocation of the ulnar nerve) and Type B (complete dislocation of the ulnar nerve).
5. Observation of thirty-four cases of ulnar neuritis due to dislocation indicates that Type A ulnar nerves are subject to direct trauma, whereas Type B ulnar nerves are more vulnerable to friction irritation.
6. Industrial workers are more often affected than other people and their complaints are usually at the hand and not at the elbow.
7. Unnecessary and prolonged treatment could be avoided by a correct early diagnosis and by informing the patient of his anomaly.
8. In anterior transplantation, deep intramuscular placement of the nerve is superior to the subcutaneous method.