Carpal coalition, the union of at least two carpals, is a rare and often incidental finding.Although typically asymptomatic, symptoms may arise from altered biomechanics, degenerative arthritis, or increased fracture risk.Nearly all combinations of carpal coalitions have been reported, with lunate-triquetrum coalitions being the most common.We present the case of a 62-year-old woman with left radial wrist pain after a ground-level fall whose initial radiographs were negative for fracture; however, careful review of the radiographs revealed an unusual articulation between the capitate, trapezoid, and trapezium.Magnetic resonance imaging confirmed an incomplete capitate-trapezoid-trapezium coalition, and an isolated nondisplaced trapezoid fracture with edema.She was treated conservatively with splinting and fully recovered within 2 months.An incomplete capitate-trapezoid-trapezium coalition has not been previously documented and given the rarity of isolated trapezoid fractures, this case highlights a unique presentation in which abnormal carpal kinematics likely predisposed the trapezoid to fracture.
Dalal et al. (Thu,) studied this question.