Comparison of 2 Methods of Immobilization of Fifth Metacarpal Neck Fractures: A Prospective Randomized Study

Purpose: The objective of this study was to prospectively compare the effectiveness of 2 methods of cast immobilization for fifth metacarpal neck fractures with respect to the time required for cast application, durability and tolerability of the cast, efficacy of maintaining reduction, and postimmobilization range of motion. Methods: After closed reduction, 81 predominately young, active-duty patients were prospectively randomized to a short-arm cast with volar outriggers (SAC-VOR) or to a short-arm cast extended to the proximal interphalangeal joint with a 3-point mold (MCP-ext). Radiographs were obtained before reduction and after reduction at 1 and 4 weeks. Outcome measures (Disabilities of the Arm, Shoulder, and Hand questionnaire), cast durability, radiographic parameters, and complications were evaluated at each visit. Final range of motion and grip strengths were obtained at the 3-month follow-up. Results: The average time for cast application was less for the MCP-ext group compared with that of the SAC-VOR group. An equal number of casts in each group (7) required replacement during treatment. There were no statistically significant differences in range of motion or final grip strength between the 2 techniques. Radiographic callus was seen in all patients at 4 weeks, and there was no difference in the 4-week postreduction angulation in the lateral or posteroanterior planes. In comparing the maintenance of the reduction, there was no difference in alignment in either the posteroanterior or lateral planes based on cast type. Conclusions: There was no difference between the 2 groups on maintaining the reduction on final lateral radiographs. Stiffness was not a complication of either group. Advantages of the MCP-ext cast include quicker application and, to a much lesser degree, better tolerability, range of motion, and final grip strength. Type of study/level of evidence: Therapeutic I.