A Bosworth fracture is a posterior fracture–dislocation of the distal fibula where an incarcerated fragment remains locked behind the osseous posterolateral ridge of the tibia, which is often irreducible by closed means. Variations of this fracture pattern have been described—including an interposition of the posterior tibial tendon and/or neurovascular bundle that prevented anatomic reduction.

While early diagnosis and treatment of this rare injury may prevent devastating complications such as compartment syndrome, vascular injury, or need for future ankle arthrodesis, there is a paucity of published literature on the diagnosis. A high degree of suspicion must be exercised to avoid a poor outcome. We report the first closed, nonreducible Bosworth fracture–dislocation involving anterior compartment musculature interposition affecting both closed and open reduction. The purpose of this report is to suggest an algorithm for the diagnosis and management of this rare, irreducible fracture–dislocation.