Evaluation of a nontoxic rigid polymer as connecting bar in external skeletal fixators.
OBJECTIVE
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.


METHODS
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.


CONCLUSIONS
RP connecting bars in an ESF are a reliable, versatile, nontoxic and inexpensive option for the veterinary surgeon.
Störk
Christoph K
CK
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. cks@vetspecialist.co.uk
Canivet
Philippe
P
Baidak
Alexandre A
AA
Balligand
Marc H
MH
D000818:Animals; D001696:Biomechanical Phenomena; D001843:Bone Cements; D001858:Bone Nails; D004867:Equipment Design; D016267:External Fixators / Q000592:standards / Q000662:veterinary*; D005592:Fracture Fixation / Q000295:instrumentation / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary; D019904:Polymethyl Methacrylate; D013193:Stainless Steel; D013314:Stress, Mechanical
D001843:Bone Cements; D013193:Stainless Steel; D019904:Polymethyl Methacrylate