Review Question - QID 219910

A 23-year-old male presents to the orthopedic clinic for follow-up. 12 weeks ago, he suffered an accidental laceration to the left volar wrist while using a box-cutting knife. The emergency room consult documented an intact median and ulnar nerve exam. The patient underwent a primary repair of the FDS and FDP to the ring finger. In the clinic today, he cannot fully extend the wrist and simultaneously extend all fingers. He has full passive flexion of the wrist and fingers. However, when actively closing his fingers into a fist the small and long fingers do not contact the palm. Which of the events listed below is most likely to explain the current function of his left hand?