A Parallel External Fixator for Correcting Biplane Angle Deformity of Foot and Ankle

Abstract

The invention relates to a parallel external fixator for correcting biplane angle deformity of the foot and ankle, which comprises a fixation ring assembly, an end ring assembly and an active traction rod assembly. In order to meet the correction needs of different body segments of the ankle, the fixing ring assembly includes a hexagonal fixing ring, a horizontal U-shaped fixing ring and a vertical U-shaped fixing ring, and the end ring assembly includes a large hexagonal end ring and a small hexagonal ring. end ring. In addition, the active drawbar assembly includes two active drawbars with six degrees of freedom, one drawbar with restraint force with five degrees of freedom and one drawbar with restraint force couple with five degrees of freedom. The external fixator in the present invention is only aimed at the angle deformity in the two planes of the foot and ankle, and can adapt to the combination of different deformed planes by adjusting the cross axis pointing of the five-degree-of-freedom restraining force couple traction rod Hooke pair, and the number of drivers is just right It satisfies the requirement of degrees of freedom for deformity correction, and solves the shortcomings of redundant correction degrees of freedom existing in the correction of this type of deformity with the existing parallel external fixator.

Description

technical field [0001] The invention relates to a foot and ankle parallel external fixator, in particular to a parallel mechanism for assisting the foot and ankle to complete the correction of complex deformities. Background technique [0002] The biomechanical mechanism of the foot and ankle is complex, and the corresponding deformity types and shapes are diverse. In many clinical cases, it is not uncommon for angular deformities to exist in two basic planes. Specifically, this type of deformity involves: sagittal anterior arch / posterior arch-transverse internal rotation / external rotation deformity of the distal tibia, frontal varus / valgus-transverse internal rotation / external rotation of the distal tibia Deformity, sagittal horseshoe / high arch-transverse internal rotation / external rotation deformity before ankle fusion, front midfoot sagittal high arch / rocker foot-frontal pronation / supination deformity, anterior midfoot sagittal High arch / rocker foot-transverse adduction...

AI Technical Summary

Problems solved by technology

When there is an angular deformity of the ankle in two planes, as mentioned above, the degree of freedom required for correction is 4, and the corresponding number of drivers is also 4. In clinical applications, the external fixation based on parallel mechanism The device configuration is mostly 6 degrees of freedom. In the process of correcting this type of deformity, there is a problem of redundant correction degrees of freedom, which leads to more drives and increases the cost.

In the follow-up manual adjustment process for a long period of time, it will increase the difficulty of memory and operation of the patient's family members

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