Ulnar Nerve Injuries – A Tricky Bifurcation

We present two cases of ulnar nerve injury exemplifying the myriad of penetrating injuries possibly affecting the ulnar nerve. The first case is an isolated injury to the motor branch of the ulnar nerve. This rare injury was initially missed when assessed in the Emergency Department. The diagnosis was performed when the patient failed to perform the motor tests associated with ulnar nerve injury when assessed by a hand surgeon. The finding of isolated severance of the motor branch of the ulnar nerve was corroborated when surgery was performed and the severed motor branch repaired. The second case we present is of a 26 year old dairy worker who sustained a degloving injury to the ulnar aspect of his right hand. The degloved flap originated at the distal wrist crease and included both skin and underlying tissues, within them was buried the severed volar ulnar sensory nerve branch which was primarily repaired followed by flap suture. These two cases represent the possible complexity of ulnar nerve injuries and emphasize the importance of a complete and thorough physical diagnosis when assessing even minor injuries to the hand. Incorporating this is a key to orthopedic resident education as we demonstrate here.