Boutonniere splint is used for arthritis if passively correctable. Which of the following best describes it?

Boutonniere splint is used for arthritis if passively correctable. Which of the following best describes it?

• A. Used for extensor tendon injuries at the DIP
• B. Arthritis (if passively correctable)
• C. Used to fix swan neck deformity by immobilizing MCP
• D. Indicated only in rheumatoid arthritis of the thumb

Answer: (B)

The key idea is that the boutonniere splint keeps the PIP joint in extension to protect the central slip of the extensor mechanism. When a boutonniere-type deformity develops in arthritis, particularly rheumatoid arthritis, and the PIP deformity is still passively correctable (flexible, not fixed), immobilizing the PIP in extension helps restore and maintain proper extensor function and prevents progression of the deformity. The DIP is left free to flex, which is important for normal finger motion. This isn’t used for extensor tendon injuries at the DIP (that’s a different management), it doesn’t address swan neck by immobilizing the MCP, and it isn’t limited to the thumb.

The key idea is that the boutonniere splint keeps the PIP joint in extension to protect the central slip of the extensor mechanism. When a boutonniere-type deformity develops in arthritis, particularly rheumatoid arthritis, and the PIP deformity is still passively correctable (flexible, not fixed), immobilizing the PIP in extension helps restore and maintain proper extensor function and prevents progression of the deformity. The DIP is left free to flex, which is important for normal finger motion.

This isn’t used for extensor tendon injuries at the DIP (that’s a different management), it doesn’t address swan neck by immobilizing the MCP, and it isn’t limited to the thumb.