Isolated Rupture of the Superior Rectus Muscle following Blunt Trauma – A Case Report

We report the rare case of a left isolated superior rectus muscle (SRM) rupture due to a bizarre mechanism of injury, where a universal serial bus (USB) flash drive entered the orbit during a motor vehicle accident leading to rupture of the SRM 7mm from the limbus. The proximal stump was relocated and reattached using a non-absorbable hangback suture. Post-operatively the patient had a residual 5 prism diopter left hypotropia (LHoT), which allowed for fusion in primary, with a slight chin up position, as well as downgaze. The globe, eyelids and orbit were spared of injury and orbital fractures were absent. We discuss our experience and surgical management of the case, which included locating the lost muscle and repairing it primarily in preference to a transposition.