A hand splint maintains the wrist in extension, MCP joints flexed at 75 degrees, and IP joints flexed. Which area is most susceptible to contracture?

• A. Wrist
• B. Metacarpophalangeal joints
• C. Proximal and distal interphalangeal joints
• D. Thumb

Answer: (C)

When joints are held in a shortened position, the tissues crossing those joints tend to adapt by shortening, increasing the risk of contracture. In this scenario, the IP joints are kept flexed, which places the finger flexor tendons and the palmar soft tissues in a shortened state across the proximal and distal interphalangeal joints. Over time, this leads to a flexion contracture at the PIP and DIP joints because the structures crossing them (the flexor tendons, pulley system, and volar plates) shorten and lose extensibility. The wrist being in extension and the MCP joints flexed does not counteract this as directly for the IP joints; the PIP and DIP are the most vulnerable in a position where they are consistently flexed. The thumb and MCP joints are less at risk in this specific posture, making the IP joints the areas most susceptible to contracture.