81 patients from a naval medical center presenting with an acute isolated fracture of the fifth metacarpal neck were randomized to receive immobilization with either a short-arm cast with volar outriggers (SAC-VOR) with the metacarpophalangeal (MCP) joint in flexion, or immobilization with the MCP joint in extension using a cast with a 3-point mold about the fracture following closed reduction. The results indicated that both the MCP-flexion and MCP-extension casts were effective in maintaining fracture reduction, and no significant differences were observed between these two groups in terms of fracture healing, range of motion, grip strength and durability.