In a triple arthrodesis, which joint fusion most directly reduces hindfoot motion?

In a triple arthrodesis, which joint fusion most directly reduces hindfoot motion?

• A. Tibiotalar joint
• B. Subtalar joint
• C. Calcaneocuboid joint
• D. Talonavicular joint

Answer: (B)

The key idea is that hindfoot motion primarily comes from the subtalar (talocalcaneal) joint, which governs inversion and eversion of the hindfoot. Fusing this joint directly eliminates the main source of hindfoot movement. While fusing the ankle (tibiotalar) stops ankle motion, it doesn’t abolish hindfoot motion on its own. Fusion of the midfoot joints (talonavicular and calcaneocuboid) contributes to overall hindfoot and midfoot stability, but the subtalar joint is the primary driver of hindfoot motion. Therefore, fusing the subtalar joint most directly reduces hindfoot motion.

The key idea is that hindfoot motion primarily comes from the subtalar (talocalcaneal) joint, which governs inversion and eversion of the hindfoot. Fusing this joint directly eliminates the main source of hindfoot movement. While fusing the ankle (tibiotalar) stops ankle motion, it doesn’t abolish hindfoot motion on its own. Fusion of the midfoot joints (talonavicular and calcaneocuboid) contributes to overall hindfoot and midfoot stability, but the subtalar joint is the primary driver of hindfoot motion. Therefore, fusing the subtalar joint most directly reduces hindfoot motion.