Scaphoid waist fractures in the presence of carpal coalitions: a consistent biomechanical weak point?

Carpal coalitions may alter intercarpal kinematics and load transfer. Reported coalition-associated scaphoid fractures show an exclusive predilection for the scaphoid waist, raising the possibility of a non-random biomechanical mechanism with focal stress concentration. These injuries have been associated with delayed union and nonunion. This pattern may justify CT-based assessment and consideration of a lower threshold for early surgical stabilization, including percutaneous screw fixation even in selected nondisplaced waist fractures. However, the currently available evidence is limited to case reports and does not allow firm treatment recommendations. Awareness of coalition anatomy and careful follow-up may be reasonable.