Unstable Open Posterior Subtalar Dislocation Treated With a Ring External Fixator: A Case Report and Review of the Literature

Traumatic dislocation of the subtalar joint is an infrequently occurring injury, with open true posterior dislocation an even rarer injury. We describe our treatment of a young motorcyclist who was brought into hospital after a road traffic accident, having sustained an open posterior subtalar dislocation. After initial reduction and resuscitation in the emergency department, he was taken to the operating theater for emergent wound debridement and external fixation of his ankle using a unilateral external fixator device. After 2 subsequent repeat debridements, this was changed to a ring external fixator device, followed by split-thickness skin grafting of his wound. He was allowed full weightbearing and was discharged from hospital 10 days after his last operation. He continued to improve clinically at his outpatient appointments to the 1-year follow-up point, with his external fixator removed at 6 weeks postoperatively. At the last follow-up appointment, he had successfully returned to his previous employment. To the best of our knowledge, only 1 other description of an open posterior dislocation has been reported, which was managed nonoperatively after wound debridement. Ours is the first reported case of an open posterior dislocation managed surgically using a ring external fixator. We believe the ability to allow immediate weightbearing resulting from the additional stability provided by this type of fixation is advantageous, with a theoretical reduction in the risk of periarticular osteoporosis and calf muscle atrophy. The early mobilization afforded by this treatment is hoped to improve the typically poor long-term outcomes for these patients.