A comparative biomechanical evaluation of a noncontacting plate and currently used devices for tibial fixation.

The appearance of porous bone under fixation plates during fracture healing, attributed to disturbance of blood supply by the plate, has led to new plate designs with reduced plate to bone contact. The fixation stability afforded by these devices, in comparison to implants commonly used for fixation, is not well known. Therefore, the construct stiffnesses of osteotomized synthetic tibiae fixed with dynamic compression plates, external fixators, or two configurations of noncontact plates were compared in axial compression, bending, and torsion with and without cortical contact at the osteotomy site. The results of this study show that (1) the noncontact plated constructs achieve comparable fixation rigidity to constructs using dynamic compression plates or external fixators, if applied at a distance no greater than 5 mm from the surface of the tibia, and (2) the fixation rigidity of the noncontact plate decreases as the distance between plate and bone surface increases.