What splint corrects boutonniere deformity?

• A. DIP extension splint
• B. Dorsal blocking splint
• C. Thumb spica
• D. PIP extension splint

Answer: (D)

Boutonniere deformity comes from injury to the central slip of the extensor mechanism at the proximal interphalangeal joint, so the goal is to stop the PIP joint from flexing and let the central slip heal. Holding the PIP in extension directly prevents further flexion at that joint, stabilizes the corrected position, and allows the damaged central slip to recover while the DIP can glide normally. This makes a PIP extension splint the most targeted and effective choice for restoring alignment and function.

An immobilization at the DIP would not address the primary issue at the PIP. A thumb spica targets the thumb, not the finger joints involved here. A dorsal blocking splint can also protect the extensor mechanism by limiting PIP flexion, but the direct, simplest method to keep the PIP extended for healing is a PIP extension splint.