A parallel external fixator system for ankle deformity requiring five-degree-of-freedom correction

Abstract

The invention relates to a parallel external fixator system for ankle deformity requiring five-degree-of-freedom correction, comprising a reference ring assembly, a traction ring assembly and a driving 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. The traction ring assembly includes a large hexagonal traction ring, a small hexagonal Towing rings and U-shaped towing rings. By choosing a five-degree-of-freedom restraint drive rod or a five-degree-of-freedom restraint force couple drive rod to match four six-degree-of-freedom drive rods, three-rotation-two-transfer and two-rotation-three-transfer parallel external fixators can be obtained to adapt to all five-degree-of-freedom Deformities that require high-degree correction. In this case, the number of drivers just satisfies the requirement of degrees of freedom for deformity correction, which solves the shortcomings of redundant correction degrees of freedom in the existing parallel external fixator when correcting this type of deformity.

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 complex deformity correction of the feet and ankles. Background technique [0002] The ankle region has complex biomechanical mechanisms and a wide variety of deformities and shapes. For complex ankle deformities, the number of degrees of freedom required for correction may be 5, including a combination of 3 degrees of freedom of rotation and 2 degrees of freedom of movement or a combination of 2 degrees of freedom of rotation and 3 degrees of freedom of movement. In many clinical cases, the deformities that require such correction degrees of freedom involve: distal tibial sagittal anterior arch / posterior arch-frontal varus / valgus deformity, sagittal horseshoe / high deformity before ankle fusion Arch-frontal varus / valgus deformity, Frontal varus / valgus-frontal varus / valgus-transverse plane internal / external rotatio...

AI Technical Summary

Problems solved by technology

When the correction degree of freedom required for the correction of ankle deformity is 5, the corresponding number of drivers is also 5. In clinical applications, the configuration of external fixator based on parallel mechanism is mostly 6 degrees of freedom. In the process of type 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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