PURE ANKLE DISLOCATION: A RARE INJURY

Introduction: Pure dislocation of the ankle is an extremely rare injury accounting for only 0.065% of all ankle injuries and 0.46% of all ankle dislocations. The mechanism of the injury generally consists of high- energy trauma which is associated with a combination of plantar flexion and inversion or eversion of the foot.

Purpose: We present a case of a 22- year- old male patient who sustained a closed pure ankle dislocation after a fall from a small height. He was treated conservatively with closed reduction and circumferential cast immobilization for six weeks, followed by a functional rehabilitation program.

Material and methods: The patient presented to the emergency department with an acutely painful and deformed right ankle after falling from a height of 1 m (stairs). Dorsalis Pedis and posterior tibial arteries were intact. Radiographs showed a posteromedial ankle dislocation without fracture. Urgent closed reduction of the dislocation was performed and a posterior below knee back slab was applied to immobilize the ankle. Check x- rays confirmed proper reduction of the ankle joint. Post reduction computed tomography (CT) scan was did not show any associated fractures. Magnetic resonance imaging (MRI) revealed a multiligamentous ankle injury.

Results: The back slab was changed for below knee circular cast two weeks later, when the soft tissue swelling subsided. The cast was removed at the 6 weeks follow up and physiotherapy was started in order to gain functional rehabilitation and improve the range of motion. At the final follow up (12 months), the patient achieved full range of motion of the ankle, and he was able to return to his work as laborer to the preinjury level.

Conclusion: Even though pure ankle dislocation is a rare injury, the appropriate conservative treatment and rehabilitation protocol lead to a satisfactory outcome in most cases.