Evaluation of a Nontoxic Rigid Polymer as Connecting Bar in External Skeletal Fixators
To investigate the mechanical characteristics of a nontoxic, low-cost, rigid polymer (RP) and to compare the structural and mechanical properties of a full-frame external skeletal fixator (ESF) with either RP connecting bars, polymethylmethacrylate (PMMA) connecting bars, or stainless-steel (SS) clamps and connecting bars. Study Design
In vitro mechanical evaluation. Methods
Mechanical properties were assessed using an in vitro bone fracture model with a bilateral uniplanar ESF (type II). Identical ESF were built with connecting bars using RP ( n = 8 ), PMMA ( n = 8 ), and SS connecting bars and clamps (System Meynard; n = 3 ). Nondestructive mechanical tests were performed in uniaxial compression (AC) and craniocaudal (CC) 4-point bending, as well as fatigue AC. Composite stiffness for each specimen and for each loading mode was calculated from 6 replicate measures using the slope of the load displacement curve at small displacements. Results
RP, PMMA, and SS ESF constructs yielded mean ± SD composite stiffness values of 227 ± 15, 381 ± 30, and 394 ± 9 N/mm in AC and of 35 ± 2, 24 ± 2, and 15 ± 0 N/mm in CC, respectively. Conclusions
Structural and mechanical properties of RP are satisfactorily rigid and fatigue resistant for its use as a connecting bar in ESF. Clinical Relevance
RP connecting bars in an ESF are a reliable, versatile, nontoxic and inexpensive option for the veterinary surgeon.
©Copyright 2003 by The American College of Veterinary Surgeons
Document Type: Research Article
Affiliations: From the Department of Clinical Sciences, Faculty of Veterinary Medicine and the Department of Macromolecular Chemistry and Multi-Materials, Faculty of Applied Sciences, University of Liège, Liège, Belgium.
Publication date: 2003-05-01