Damage in a Distal Radius Fracture Model Treated With Locked Volar Plating After Simulated Postoperative Loading.

Autor:	Salas C; Department of Orthopaedics and Rehabilitation, University of New Mexico, Albuquerque, NM; Department of Mechanical Engineering, University of New Mexico, Albuquerque, NM; Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM. Electronic address: chrsalas@salud.unm.edu., Brantley JA; Department of Orthopaedics and Rehabilitation, University of New Mexico, Albuquerque, NM; Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM., Clark J; Department of Orthopaedics and Rehabilitation, University of New Mexico, Albuquerque, NM., Reda Taha M; Department of Civil Engineering, University of New Mexico, Albuquerque, NM., Myers OB; Department of Internal Medicine, University of New Mexico, Albuquerque, NM., Mercer D; Department of Orthopaedics and Rehabilitation, University of New Mexico, Albuquerque, NM.
Jazyk:	angličtina
Zdroj:	The Journal of hand surgery [J Hand Surg Am] 2018 Jul; Vol. 43 (7), pp. 679.e1-679.e6. Date of Electronic Publication: 2018 Feb 06.
DOI:	10.1016/j.jhsa.2017.12.019
Abstrakt:	Purpose: "Damage" is an engineering term defining a period between a state of material perfection and the onset of crack initiation. Clinically, it is a loss of fixation due to microstructural breakdown, indirectly measured as a reduction of stiffness of the bone-implant construct, normalized by the cross-sectional area and length of the bone. The purpose of this study was to characterize damage in a cadaver model of extra-articular distal radius fracture with dorsal comminution treated using 2-column volar distal radius plates. Methods: Ten matched distal radii were randomly divided into 2 groups: group I specimens were treated with a volar distal radius plate with an independent, 2-tiered scaffold design; group II specimens (contralateral limbs) were treated with a volar plate with a single-head design for enhanced ulnar buttressing. Specimens were cyclically loaded to simulate a 6-month postoperative load-bearing period. We report damage after a defined protocol of cyclical loading and load to failure simulating a fall on an outstretched hand. Results: Group II specimens experienced more damage under cyclic loading conditions than group I specimens. Group I specimens were stiffer than group II specimens under load-to-failure conditions. Ultimate force at failure in group I and group II specimens was not different. Specimens failed by plate bending (group I, n = 6/10; group II, n = 2/10) and fracture of the lunate facet (group I, n = 4/10; group II, n = 8/10). Conclusions: Group I specimens had less screw cutout at the lunate facet than group II specimens under cyclic loading as indicated by lower damage measures and fewer facet fractures during load-to-failure testing. The overall strength of the construct is not affected by plate design. Clinical Relevance: Microstructural damage or a loss of fixation due to an overly rigid volar plate design may cause malunion or nonunion of fracture fragments and lead to bone-implant instability. (Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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