The radial nerve innervates the extensors of the elbow, wrist, and fingers and gives the back of the hand its sensitivity.
Lesions at axillary exit level (rare) result in complete failure of active extension for the elbow, wrist and fingers as well as insensitivity of the back of the hand.
Lesions at arm level are mainly encountered as the result of humeral diaphysis fractures and result in failure of extension for the wrist and fingers.
Lesions at elbow level are encountered in elbow fractures/dislocations but also spontaneously in posterior interosseous nerve compression syndromes.This lesion at elbow level causes wrist extension weakness and failure of extension for fingers and the thumb.
Wherever the lesion is sited, emergency surgery will be necessary for bone stabilization in case of fracture, or exploration if there is a wound.
In closed injuries, if recovery doesn’t begin 5 months from injury, nerve exploration repair surgery will be necessary.
For paralysis diagnosed late (over one year from injury), forearm tendon transfer procedures will restore wrist and finger extension.