Review Question - QID 8201

Figures 63a and 63b are the radiographs of a 24-year-old left-hand dominant man who felt a "snap" in the left mid-arm while arm wrestling. Examination reveals an isolated closed injury. He has significant pain and gross instability about the upper arm. His compartments are soft and he has good pulses with a well-perfused hand. He is unable to actively extend his wrist and fingers. Following splinting of the arm, his examination findings remain unchanged. What is the next most appropriate step in management?