Kinematic Implications of Altering the Design of the Wrist: A Cadaveric Study Examining Midcarpal Fusion and Scaphoid Excision

During surgical salvage procedures, surgeons permanently alter the kinematic design of the wrist by removing and fusing carpal bones. Although salvage procedures successfully relieve arthritic pain, they have the unintended consequence of long-term functional impairments [1]. One common surgical salvage procedure is scaphoid-excision, four-corner fusion (SE4CF). During SE4CF, the scaphoid is removed, and the lunate, triquetrum, capitate, and hamate are fused together. Surgical preference dictates the amount of scaphoid removed and the position in which the bones are fused. Importantly, fusion eliminates motion between the carpal rows, creating a wrist joint in which motion occurs between the radius and a single, rigid block of carpal bones.