[Motor paralysis of the ulnar nerve in an ice-stab injury].

The isolated cut of the motor branch of a peripheral nerve is very rare. A case is reported of a motor paralysis of the ulnar nerve following an uncommon "ice-stab-injury". Operative revision showed soft hypothenar muscles without scars. Taking the muscles off the flexor retinaculum, one could see the cut of the deep branch of the ulnar nerve. The secondary suture of the nerve by microsurgical technique was very successful, even after 2 1/2 months.