Reliability of the 8 Week Time Point for Single Assessment of Midcarpal Fusion by CT Scan

High rates of nonunion have recently been reported for midcarpal fusions. Due to curvature and overlap of carpal interfaces, two dimensional films are not reliable in determining union of a midcarpal fusion. Computed tomography is the most reliable radiographic method of evaluating osseous union. Initiating motion as soon as fusion has occurred is a priority with the goal of maximizing final range. Cost control in healthcare makes obtaining serial scans unreasonable. The single optimal time point for a computed tomography scan to determine union of a midcarpal fusion remains to be determined. A prospective protocol selected 8 weeks post operative as the point in time to obtain the single determining scan. Forty-six consecutive midcarpal fusions with scaphoidectomy were retrospectively analyzed for the reliability of this time point. All fusions had achieved union by 8 weeks and only this one scan was clinically necessary to advance the patients on to full range of motion without a splint at that time