A 27-year-old gentleman was presented with an inability to extend the ulnar three fingers of his left hand after sustaining closed fractures of the left ulna and radius after a motorbicycle accident. The patient recovered partially over the course of 3 months but continues to be functionally compromised by the persistent radial deviation of his left wrist and incomplete mobility of the ulnar 3 fingers upon extension. On second exploration, we found the denervated muscles supplied by the recurrent branch of posterior interosseous nerve. Tendon transfer was performed with good clinical outcome at 12 months.

This is a rare case of isolated injury to branch of posterior interosseous nerve. This generates the suspicion of possibility of PIN or its branch injury even in closed fractures of the forearm. In addition, this highlights the importance of interval generation during the fracture fixation to prevent the possibility of iatrogenic injury to branches of PIN. Keywords : Posterior interosseous nerve, Peripheral nerve palsy, Ulna fracture, Radius fracture