Dynamic Fracture Fixation Plates: A Systematic Review of Evolving Design Approaches.

Fracture fixation with standard locked plates can suppress interfragmentary motion beneficial for secondary bone healing. To address this limitation, dynamic fracture fixation plates have been developed which seek to maintain bending and torsional rigidity while providing controlled axial micromotion. This article provides a comprehensive systematic review of the history and current state of proposed dynamic plating technologies to better inform future development. 59 records (51 articles, 8 patents) describing 26 unique dynamic plating devices were identified across three literature and patent databases using PRISMA review guidelines. Concepts were grouped into one of 9 engineering approach categories, including plates that incorporate sliding mechanisms, elastic inserts, lattice structures, and mechanically compliant flexures, among others. Devices are compared in their technological characteristics, ranges of axial motion, stiffnesses, and levels of development. Despite many dynamic technologies demonstrating good healing results experimentally and clinically, widespread clinical adoption has not occurred. Some explanations for this are provided, including production costs for complex designs and the current co-existence of both rigid and flexible fixation approaches. Overall, dynamic plating offers a promising area of innovation to address the ongoing concerns of non-union rates associated with standard locked plating of long bone fractures.