Parallel external fixator for correcting ankle biplane angle deformity

Abstract

The invention relates to a parallel external fixator for correcting ankle biplane angle deformity. The parallel external fixator comprises a fixing ring assembly, a tail end ring assembly and an active traction rod assembly. In order to meet the correction requirements of different body segments of the ankle part, the fixing ring assembly comprises a hexagonal fixing ring, a horizontal U-shaped fixing ring and a vertical U-shaped fixing ring, and the tail end ring assembly comprises a large hexagonal tail end ring and a small hexagonal tail end ring. In addition, the active traction rod assembly comprises two six-degree-of-freedom active traction rods, one five-degree-of-freedom constraint force traction rod and one five-degree-of-freedom constraint force couple traction rod. According to the external fixator, only aiming at the situation that angle deformity exists in two planes of an ankle part, the universal joint pin pointing of a five-degree-of-freedom constraint couple traction rod hooke pair can be adjusted to adapt to the combination of different deformity planes, and the number of drivers just meets the deformity correction freedom degree requirement; and the defect that the correction freedom degree is redundant when an existing parallel external fixator is used for correcting the type of deformity is overcome.

Description

technical field [0001] The invention relates to a parallel external fixator for feet and ankles, in particular to a parallel mechanism for assisting the correction of complex deformities at the feet and ankles. 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: distal tibial sagittal anterior arch / posterior arch-transverse internal / external rotation deformity, distal tibial frontal varus / valgus-transverse internal / external rotation Deformity, sagittal horseshoe / high arch-transverse internal / external rotation deformity before ankle fusion, sagittal high arch / rocker foot-frontal plane pronation / supination deformity, anterior midfoot sagittal deformity High arch / rocker foot-transverse plane adduction / abduction deformity, anterior mid...

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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