For sustentaculum tali fracture, the foot should be cast in which position?

For sustentaculum tali fracture, the foot should be cast in which position?

• A. Dorsiflexed and everted
• B. Plantarflexed and inverted
• C. Neutral
• D. Plantarflexed and everted

Answer: (B)

Immobilization after a sustentaculum tali fracture aims to minimize movement of the medial fragment by using the surrounding soft-tissue structures to hold it in place. Placing the foot in plantarflexion brings the talus into a position that reduces anterior–posterior shear at the fracture site, and it relaxes the posterior encounter with the calcaneus, helping to stabilize the medial structure. Inversion tightens the medial soft-tissue restraints, including the deltoid complex and the posterior tibial tendon, which wrap around the sustentaculum tali. This increased medial tension helps resist lateral or medial displacement of the sustentaculum fragment, keeping the fragment aligned during healing. Other positions don’t provide the same combination of mechanical and soft-tissue stability. Neutral or dorsiflexed positions lack the dynamic medial support, and eversion would increase lateral stress and potentially destabilize the fragment.

Immobilization after a sustentaculum tali fracture aims to minimize movement of the medial fragment by using the surrounding soft-tissue structures to hold it in place. Placing the foot in plantarflexion brings the talus into a position that reduces anterior–posterior shear at the fracture site, and it relaxes the posterior encounter with the calcaneus, helping to stabilize the medial structure.

Inversion tightens the medial soft-tissue restraints, including the deltoid complex and the posterior tibial tendon, which wrap around the sustentaculum tali. This increased medial tension helps resist lateral or medial displacement of the sustentaculum fragment, keeping the fragment aligned during healing.

Other positions don’t provide the same combination of mechanical and soft-tissue stability. Neutral or dorsiflexed positions lack the dynamic medial support, and eversion would increase lateral stress and potentially destabilize the fragment.