In the Closed Ring Classification System of the ankle, a single disruption in the ring allows stability to be preserved while two disruptions will likely cause the joint to shift. Which single disruption is an exception to this rule and can still cause instability?

Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.