Bosworth-type fibular entrapment injuries of the ankle: the Bosworth lesion. A report of 6 cases and literature review.

Objectives: To evaluate patients with Bosworth-type fibular entrapment injuries of the ankle.

Design: Retrospective clinical study and analysis of the literature.

Setting: University hospital.

Patients: Six cases treated for Bosworth-type fibular entrapment injuries (the Bosworth lesion) in the period 2001 to 2004.

Intervention: Five patients were treated with open reduction and internal fixation (ORIF), and 1 patient was treated with closed reduction and cast.

Results: All patients treated by ORIF healed without complications with a good subjective outcome. In 1 case treated nonoperatively, an ankle fusion had to be performed 2 years after injury for severe osteoarthritis. Additionally, we have recorded 3 cases, 2 not previously described in the literature, in which the fracture of the fibula was located at the middle or proximal third of its shaft.In the literature we found another 54 cases with dislocation of the fibula behind the posterior tubercle of the distal tibia. The analysis showed that morphology of the Bosworth lesion, as we prefer to refer to this complex fracture-dislocation, changes with age and may be divided into 3 basic types. In children and adolescents the dislocation of the distal fibula is associated with epiphyseolysis of the distal tibia; in young adults the fibula dislocates without fracture; in middle-aged and older adults, the dislocated fibula fractures, probably because of the decreased elasticity.

Conclusions: The Bosworth lesion is a severe injury of the ankle, and its successful treatment requires a correct diagnosis based on careful initial clinical and radiographic evaluation and early surgical treatment.