1. Every type of recent elbow fracture may be accompanied by a peripheral nerve lesion, but such complications are almost unknown except in fractures of the lower end of the humerus.

(a) The ulnar lesions occur most often in internal epicondylar fractures, and occasionally in supracondylar fractures, or dislocations of the elbow joint. The lesions are always incomplete, and may be due to a primary contusion, or a secondary friction neuritis developing in the first few weeks. A mild transitory neuritis is sometimes seen in fractures treated efficiently, but the severe lesions are almost always due to ineffective or injudicious treatment—e.g., imperfect reduction, clumsy manipulation, or forced movements of the elbow. In severe neuritis, early operation is always advisable.

(b) The median and musculospiral lesions are less common. They are usually associated with supracondylar fractures, where there is considerable displacement of the lower fragment. The nerve trunks are contused, torn, or frayed out by a sharp bony projection. The median lesions are often grave, and generally demand operation.

2. The prevention of peripheral nerve involvement in fractures of the lower end of the humerus lies in the due observance of the three canons of treatment:—

(a) Early and accurate reduction of the fracture (The importance of lateral displacement of the lower fragment in supracondylar fractures should not be overlooked).

(b) A period of complete rest for the elbow, lasting from ten to fourteen days.

(c) Cautious and gradual mobilization of the elbow by the patient's own unassisted efforts.

Forced movements at any stage are always disastrous.