Biomechanical Evaluation of Disposable Digital External Fixators (DDEFs):A Comparative Study with New Design.

ABSTRACT

Background: There are many conditions of phalangeal fractures require digital external fixators  both  commercial  and disposable. The biomechanical comparative studies of these fixators have not been reported especially for disposable digital external fixators(DDEFs). The new design,  adjustable length digital external fixator (ALDiEs) was innovated Purpose: To compare the biomechanical properties of various DDEFs.Materials and Methods: Synbone ; Swiss made, Model 4060 900285 were used to be the phalangeal model for the biomechanical testing. Three types of DDEs and their applications were tested. Ten samples of each type were fixed into phalangeal models. Biomechanical analyses were performed by material testing machine, Loyed Instrument interfaced with Windap data analysis software. The structural stiffness (SS), Yield stress (YS) and ultimate stress (US) both in compression and distraction forces were recorded. Statistical analysis was performed using ANOVA and a post hoc LSD .Study  design   Experimental  studySetting   Orthopedics  department,  Faculty  of Medicine,  Khon  Kaen  UniversityResults: The SS of one frame Poorman DDEFs, Godwin DDEFs and ALDiEs were 14.54, 14.83 and 12.43 N/mm. in orderly. The Godwin DDEFs had the highest SS (P