Conservative management of an acute ‘mallet finger’ (a closed disruption of the terminal extensor tendon) involves rigid splinting of the distal interphalangeal (DIP) joint. To ensure successful tendon healing, what is the absolute minimum duration the DIP joint must be maintained in continuous, uninterrupted extension?

Explanation:
The correct option is d. The extensor mechanism at zone I is incredibly thin and relies on forming robust scar tissue to bridge the gap. For non-operative management of a mallet finger, the DIP joint must be splinted in neutral to slight hyperextension 24 hours a day for a strict minimum of 6 to 8 weeks. Patient compliance is critical; if the patient removes the splint even once during this period and allows the fingertip to flex, the healing scar tissue stretches or tears, resetting the clock to day zero. Following the 8 weeks, night splinting is often continued for an additional 2 to 4 weeks. Reference: Green's Operative Hand Surgery.