The Effect of Working Length, Fracture, and Screw Configuration on Plate Strain in a 3.5-mm LCP Bone Model of Comminuted Fractures

Introduction This study provides a comprehensive examination of plate strain under realistic fracture configurations. The effect of plate working length, plate contact, fracture length, and position on strain was evaluated using bone surrogates subjected to “load-controlled,” nondestructive conditions. Materials and Methods Five 3.5-mm locking compression plates (LCP) were instrumented with six strain gauges. The gauges were glued between holes in predetermined locations marked by laser engraving. Nine fracture models were created using bone surrogate, each representing a combination of the criteria under study: long versus short working length, degree of plate compression, fracture location, and fracture length. All five plates were tested under each of the nine configurations. The constructs were mounted in an Instron testing machine with a 5-kN load cell. Each specimen was cyclically loaded at a rate of 5 mm/min to 50, 100, and 200 N. Results Decreased plate strain was noted with a short plate working length in all fracture configurations (p