A parallel external fixator system for single-plane deformity correction of ankle

Abstract

The invention relates to a parallel external fixator system for correcting single-plane deformity of the foot and ankle, comprising a reference ring assembly, a motion ring assembly and a traction rod assembly. In order to meet the correction needs of different body segments of the ankle, the reference ring assembly includes a hexagonal reference ring, a horizontal U-shaped reference ring and a vertical U-shaped reference ring, and the exercise ring assembly includes a large hexagonal exercise ring, a small hexagonal Sport ring and U-shaped sport ring. In addition, the drawbar assembly includes 2 6DOF drawbars, 1 3DOF drawbar and 2 5DOF drawbars, by combining specific drawbar assemblies and connecting the reference ring assembly and motion in parallel The ring component can realize the switching between the three-degree-of-freedom configuration and the four-degree-of-freedom configuration. The external fixator system in the present invention is only aimed at single-plane ankle deformity, and the number of drivers just meets the requirement of degree of freedom for deformity correction, which solves the disadvantage of redundant correction degree of freedom existing in the correction of this type of deformity in the existing parallel external fixator.

Description

technical field [0001] The invention relates to a parallel external fixator system for feet and ankles, in particular to two parallel mechanisms for assisting the correction of single-plane deformities at the feet and ankles. Background technique [0002] Uniplanar deformity is a simple type of deformity of the foot and ankle, which means that the angular deformity exists in only one plane. In the ankle region, this type of deformity involves: anterior / posterior arch deformity in the sagittal plane of the distal tibia, varus / valgus deformity in the frontal plane of the distal tibia, High arch / equeshoe deformity, high arch / rocker foot deformity in the sagittal plane of the fore-midfoot, pronation / supination deformity in the frontal plane of the fore-midfoot, and adduction / abduction deformity in the transverse plane of the fore-midfoot. When correcting the above-mentioned deformities, in addition to the degree of freedom of rotational correction required for angular deformity...

AI Technical Summary

Problems solved by technology

The correction degrees of freedom required for single-plane deformity are 3 or 4, and the corresponding actuators are also 3 or 4. In clinical applications, the configuration of external fixators based on parallel mechanisms is mostly 6 degrees of freedom. In the process of planar 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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