Anatomic relationships in distal radius bridge plating: a cadaveric study.

Abstract

Two separate approaches have been described for radiocarpal spanning internal fixation for high-energy distal radius fractures with metaphyseal extension. To our knowledge, relevant anatomic relationships and structures at risk for iatrogenic injury have not been identified in the literature. Twelve fresh frozen cadaver arms were randomized to fixation with a dorsal radiocarpal spanning plate using one of two techniques: (1) index finger metacarpal fixation (index group) or (2) middle finger metacarpal fixation (middle group). Cadaveric dissection and relevant anatomic relationships were assessed in relation to the plate. Superficial branches of the radial sensory nerve were in contact with the index group plate in all specimens, while no contact occurred in the middle group specimens. No extensor digitorum comminus (EDC) middle extensor tendons contacted the plate in the index group; an average of 10cm of plate contact was seen in the middle group. The extensor pollicis longus (EPL) tendon contacted the plate in both the index and middle groups for an average distance of 12.4 and 25.5mm, respectively. One complication [EPL and extensor indicis proprius (EIP) entrapment] was observed in the middle finger metacarpal group. Mounting the dorsal bridge plate to the index finger metacarpal places the superficial branches of the radial sensory nerve at risk during dissection, while mounting the plate to the middle finger metacarpal leads to a greater degree of tendon-plate contact.