Introduction Isolated distal ulnar shaft fracture Mechanism is direct blow: commonly seen in hockey, lacrosse, martial arts when forearm is used to block assault to head and neck ("night stick fracture") Displacement <50% displaced - stable >50% displaced - unstable Ulnar styloid fracture occurs together with distal radius fracture that has high degree of initial displacement associated with distal radioulnar joint (DRUJ) instability Presentation Wrist pain and deformity Evaluation X-ray DRUJ is unstable if lateral xray - ulnar head is subluxed dorsally out of sigmoid notch of radius AP xray - DRUJ is widened Treatment Closed reduction followed by long arm cast immobilization for 2-4 weeks: followed by bracing