The efficacy of dynamic external fixation for treatment of distalradius fractures using 3D kinematic analysis

摘要

The purpose of this study was to investigate the kinematics ofexternal fixation devices used for distal radius fractures. Dynamicexternal fixator devices that are placed across the wrist jointfacilitate fracture healing by allowing force transmission across thefracture site and articular cartilage repair by allowing wrist motion.If external fixation devices are to be used dynamically, then theiractual effect on wrist kinematics should be determined. Unfortunately,there has been no agreement among authors regarding normal carpalkinematics. This study investigated several parameters, global wristflexion/extension, angles between carpal bones, and the instantaneousscrew axis (ISA), in an attempt to quantify normal kinematics and thekinematics of wrists with external fixators attached. The results ofthis study show that the center of rotation of the wrist is not limitedto the proximal head of the capitate as previously suggested. It alsoshows that the global range of motion of the wrist is limited with theapplication of any of the dynamic external fixators tested. Finally, theintercarpal bone joint angles are altered with the application of anexternal fixator. The radial-lunate joint has an increased range ofmotion with an external fixator attached in order to compensate for theconstraints imposed by the external fixator