Sliding Ring Fixator for Angular Correction of Pediatric Lower Limbs
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Solution Overview
Problem
Current methods for angular correction of the lower limb in pediatric patients, such as intraoperative correction, osteotomy with external fixation, and internal devices guiding growth cartilage, face limitations like small correction angles, lengthy treatment times, pain, and risk of secondary deviations, especially when correcting congenital or early-age defects.
Innovation Solution
A device comprising two ring-shaped fixator bodies that can be slidably constrained along their annular extensions, allowing for rotational adjustment via micrometric screws, to indirectly guide growth cartilage into its correct anatomical configuration without the need for osteotomy or multiple surgeries, enabling gradual and controlled correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If intraoperative angular correction with internal fixation is performed, then angular correction can be achieved, but only for small angles and requires multiple operations for larger corrections
Solution Approach 1:
The device employs dynamic adjustment capabilities through telescopic arms that can be extended or retracted, allowing the correction angle to be modified during the growth period. This dynamic structure enables the device to adapt to different correction requirements without requiring multiple surgical interventions.
Solution Approach 2:
The device performs preliminary angular correction during the growth period before the bone fully matures. By initiating correction early and utilizing the growth cartilage's natural remodeling capability, the device can achieve larger total correction angles that would be impossible with conventional intraoperative methods.
2Manufacturing precision
If osteotomy with external fixation is performed, then angular correction can be achieved, but treatment time is prolonged and pain occurs
Solution Approach 1:
The device utilizes the body's own growth cartilage to perform the correction process. The growth cartilage naturally remodels and guides the bone segments into the correct position without requiring external manipulation or prolonged fixation, thereby reducing treatment time and avoiding the pain associated with osteotomy.
Solution Approach 2:
The growth cartilage acts as an intermediary element that mediates the correction process. Rather than directly manipulating the bone through osteotomy, the device guides the growth cartilage to naturally redirect bone growth, achieving correction more quickly and with less pain.
3Manufacturing precision
If internal devices for guiding growth cartilage are used, then angular correction can be achieved, but secondary angular deviations may occur and require two operations
Solution Approach 1:
The device incorporates multiple functional elements within a single integrated structure. The telescopic arms provide both guidance and stabilization functions, while the adjustable mechanisms allow for precise control of correction angles. This multi-functionality reduces the risk of secondary deviations and eliminates the need for multiple operations.
Solution Approach 2:
The device incorporates adjustable mechanisms that allow for real-time monitoring and correction of the growth cartilage's path. By enabling controlled adjustment of the telescopic arms, the device can feedback and correct any developing angular deviations, ensuring accurate correction without requiring additional surgical interventions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for precise angular correction of the lower limb without pain, reduces treatment time, and allows for out-patient removal, ensuring effective and controlled bone defect correction while respecting cartilage growth.
Implementation Method 1
adjusting means suitable for allowing relative sliding of said first fixator body with respect to said second fixator body
Implementation Method 2
constrained together slidably along their annular extension
Implementation Method 3
forcing the relative twisting of the bone portions above and below the growth cartilage
Implementation Method 4
First fixation means, for fixing the first fixator body to the first bone site, are provided directly at the first attachment basis
Data Source
AI summary
Device for the angular correction of a lower limb in pediatric patients, comprising: a first fixator body and a second fixator body which are both shaped like a ring or ring portion and can be placed around a lower limb and fixed to two bone sites of said lower limb straddling a growth cartilage, said first fixator body and said second fixator body being constrained together slidably along their annular extension; and adjusting means suitable for allowing relative sliding of said first fixator body with respect to said second fixator body.