This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
The stability of the ankle joint is maintained by all of the following, except - 
Select and explain. 
A. Plantar calcaneonavicular (spring) ligament, B. Deltoid ligament, C. Lateral ligament, D. Shape of the superior talar articular surface
A: Plantar calcaneonavicular (spring) ligament
Answer: A: Plantar calcaneonavicular (spring) ligament 
Explanation: Calcaneonavicular ligament or spring ligament is a powerful ligament attahced posteriorly to the calcaneum and anteriorly to the navicular bone. So it is obvious that it will not participate in the formation of ankle joint.