Design and biomechanical study of polyaxial self-locking anatomical plate of distal tibia / 中华创伤杂志

ABSTRACT

Objective To evaluate biomechanical properties of self-designed polyaxial self-locking anatomical plate so as to offer scientific evidence for clinical application.Methods According to anatomic characteristics of distal tibiae of domestic people,a polyaxial self-locking anatomical plate for distal tibia was designed.Six paired ( left,right) fresh cadaver tibial specimens were used to make fracture fixation models and were divided into groups A and B,six specimens per group.Common anatomical locking plates were assembled in group A and polyaxial self-locking anatomical plates were assembled in group B.The biomechanical tests were performed by using 858 Mini Bionix testing machine.Non-destructive tests were performed in both groups,including axial loading,4-point bending and torsional loading and the stiffness of the two fixation instruments was compared.SPSS 13.0 software was used for statistical analysis.Results Polyaxial self-locking anatomical plate was fit for the morphology of distal tibiae.The self-designed pelyaxial plate could increase angular regulation amplitude for the locking screw up to 30°.Compression stiffness was (557.53 ± 20.72) N/mm in group A and (562.80 ± 28.26 ) N/mm in group B.Four-point bending stiffness was ( 268.02 ± 36.77) N/mm in group A and ( 265.76 ± 27.21 ) N/mm in group B.Torsional stiffness was (0.28 ±0.01) Nm/deg in group A and (0.29 ±0.02) Nm/deg in group B.The three tests in two groups showed no statistical significance ( P ＞ 0.05 ).Conclusions The self-designed polyaxial self-locking anatomical plate of distal tibia is fit for the tibial morphology of domestic people.Its biomechanical properties are equivalent to those of common anatomical locking plate,which can meet the needs for clinical application.