A runner develops progressive flatfoot after an ankle sprain. MRI shows disruption of the ligament stretching from the sustentaculum tali of the calcaneus to the navicular, supporting the head of the talus. Which ligament is torn?

• A Long plantar ligament
• B Plantar calcaneonavicular (spring) ligament ✓
• C Short plantar (plantar calcaneocuboid) ligament
• D Tibiocalcanean band of the deltoid ligament

Explanation

The spring (plantar calcaneonavicular) ligament spans from the sustentaculum tali to the navicular and forms a hammock supporting the head of the talus; it is the key static support of the medial longitudinal arch. Its rupture produces acquired adult flatfoot with lowering of the arch. The long and short plantar ligaments support the lateral column and cuboid joints respectively, while the tibiocalcanean band stabilizes the ankle mortise rather than the talar head.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.