SPL
Publications
Locking Screws With a Threaded Degradable Polymer Collar Reduce
Schultz BJ, MD; Amin NH, MD; Mattison BJ, BS; Mir HR., MD, MBA; Shah AR, MD;
Cerynik, DL, MD, MBA
Journal of Orthopaedic Trauma: March 2020 - Volume 34 - Issue 3 - p 151-157
Objectives:
The stiffness of locking plates provide increased stability for early fracture healing but may limit late interfragmentary motion (IFM) necessary for secondary bone healing. An ideal plating construct would provide early rigidity and late flexibility to optimize bone healing. A novel screw plate construct utilizing locking screws with a degradable polymer locking mechanism is a dynamic option.
Conclusions:
Use of locking plates with a degradable polymer collar show potential for in vitro construct dynamization. Future in vivo studies are warranted to assess performance under combined loading and the effects of decreasing construct stiffness during the course of bony healing.
Controversies in Fracture Healing: Early Versus Late Dynamization
Schultz BJ, MD; Koval K, MD; Salehi PP, MD; Gardner MJ, MD; Cerynik DL, MD, MBA
Orthopedics. 2020;43(3):e125-e133
Abstract:
Dynamization of fracture fixation constructs provides early rigidity for primary bone healing and late motion for secondary healing. A review of laboratory, animal, and clinical studies investigating the impact, and optimal timing, of dynamization is limited by lack of standardization across studies. However, in animal models, dynamization improves histologic and biomechanical properties compared with statically rigid or flexible controls. In animals, dynamization at 3 to 4 weeks showed improved histologic results. In clinical studies, it showed faster, stronger, and stiffer bone healing. Clinical success dynamizing external fixators and intramedullary nails suggests a role for late dynamization in other fixation types, such as bridge plating.