Self-Actuating Growing Rod Hydraulic Distraction
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Solution Overview
Problem
Current growing rod systems for orthopedic deformity correction require external stimuli for distraction, leading to repetitive surgical interventions, skin infections, wound complications, and other drawbacks, as they are not self-actuating and growth-driven.
Innovation Solution
A self-actuating growing rod system utilizing a hydraulic mechanism with a static rod and a growth rod, where the growth rod acts as a piston within the static rod's cylinder, driven by a pressure compensating mechanism, allowing for continuous distraction without external intervention, using a sterile biocompatible fluid and a pre-determined pressurized injection port.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external stimuli and apparatus are used for distraction in growing rod systems, then the rod can be distracted to match patient growth, but repetitive surgical interventions are required leading to skin infections, wound complications, and hospitalization
Solution Approach 1:
The growing rod system utilizes the patient's own growth forces to automatically distract the rod, eliminating the need for external surgical intervention. The system self-regulates by converting growth-induced compression into distraction force through the spring mechanism, thereby preventing infections and complications associated with repeated surgeries
Solution Approach 2:
The patent replaces the external mechanical distraction system (requiring surgical opening and manual rod adjustment) with an internal biological-mechanical hybrid system where the patient's growth forces drive the distraction through a spring-loaded mechanism, eliminating the need for repeated surgical access
2Ease of operation
If manual distraction is performed every six months to match patient growth, then the rod position is maintained, but the procedure causes rod breakage, skin infections, and requires overnight hospitalization
Solution Approach 1:
The spring-loaded mechanism provides continuous distraction force as the patient grows, eliminating the need for periodic discrete surgical interventions. The system operates continuously throughout the growth period, maintaining rod position without interruption or repeated hospital visits
Solution Approach 2:
The spring mechanism is pre-loaded during implantation to store potential energy that will be gradually converted to distraction force as the patient grows. This preliminary preparation eliminates the need for future surgical interventions to adjust the rod
3Adaptability or versatility
If growing rod systems require external driving forces for distraction, then the rod can be adjusted, but the complexity of the system increases and self-actuation is not achieved
Solution Approach 1:
The spring mechanism acts as an intermediary that converts the patient's growth forces into controlled distraction motion of the rod. This intermediate energy storage and conversion mechanism simplifies the overall system by eliminating the need for complex external actuators, sensors, and control systems
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
The system provides continuous, growth-driven distraction, reducing the need for repetitive surgeries, minimizing skin infections and wound complications, and ensuring proportional correction to the patient's growth, thereby maintaining the corrected bony anatomy position without external driving forces.
Implementation Method 1
A self-actuating growing rod system utilizing a hydraulic mechanism with a static rod and a growth rod, where the growth rod acts as a piston within the static rod's cylinder
Implementation Method 2
The spring is configured in a compressed state and the distal end of the growth rod is positioned at a first location within the static rod
Data Source
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AI summary
The present disclosure relates to self-actuating growing rod systems (100) for the correction of orthopedic deformities. The system comprises at least one static rod (2), at least one growth rod (6), at least one sealing component (8), at least one fluid reservoir (10), at least one injection port (14) and at least one pressure compensating mechanism (12) which is adapted to cause net elongation of the growth rod (6). The system of the present disclosure (100) is implanted onto the bony anatomy after bringing the deformed bony anatomy to the expected position. The system of the present disclosure (100) is then surgically implanted onto the corrected bony anatomy. As growth occurs, the system of the present disclosure (100) distracts; thereby enabling growth and maintaining the deformity correction.