Open Traumatic Avulsion of the Flexor Pollicis Longus Tendon From the Musculotendinous Area: A Case Report

A traumatic avulsion of the flexor tendon at the musculotendinous junction in nonamputated digits is a very rare injury. We present a 14-year-old girl who sustained a longitudinal, tensile, injurious force directly to the flexor pollicis longus tendon after an open thenar injury resulting in its avulsion at the musculotendinous junction. In an effort to minimize soft-tissue damage and preserve the transverse ligament of the carpus the tendon was retrieved through a separate forearm incision. Direct repair was made by encapsulation of the tendon into the muscle belly. The functional result 30 months after surgery was satisfactory.