Generating Differential Ligamentotaxis Across the Radiocarpal Joint

This study sought to determine if traction through the index or long finger metacarpal provided a selective distraction force through either the distal radius’ radial or ulnar column. In eight specimens, the radius was cut transversely 1 cm proximal to the Lister tubercle. Index and long finger metacarpals were cut and two-hole plates were fixed to metacarpals. Traction forces were alternately applied to index, then long finger metacarpals, sequentially through each metacarpal from 4.5N to 89N. Traction loading through the index finger metacarpal resulted in significantly more distraction force transmitted through the distal radius fragment’s radial column at all force intervals. Traction loading through long finger metacarpal resulted in significantly higher force transmission through distal radius’ ulnar column. In both cohorts, force transmission increased linearly in response to higher loads. Selective traction force of either the index or long finger metacarpal resulted in differential tensioning of the distal radius’ ulnar and radial columns. (Journal of Surgical Orthopaedic Advances 28(2):104–107, 2019) Key words: biomechanics, distal radius fracture, dorsal spanning plate, internal fixation, wrist