Adjustable External Fixation Struts for Wide-Range Length Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hexapod bone fixation systems face challenges with limited length adjustment ranges, requiring multiple strut lengths and a time-consuming selection process, which complicates clinical procedures and increases inventory costs.
Innovation Solution
The development of adjustable strut assemblies for external fixation systems, featuring an elongate tubular structure with a threaded rod and adjustment mechanisms, allowing for quick and easy length adjustment over a large range while remaining coupled to platforms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple struts of differing lengths are used to meet various clinical needs, then the adaptability to different clinical situations is improved, but the device complexity and inventory requirements increase
Solution Approach 1:
The strut incorporates an adjustable length mechanism with a telescopic design, allowing the strut length to be dynamically changed during clinical procedures. This eliminates the need for multiple fixed-length struts while maintaining adaptability to different clinical situations.
Solution Approach 2:
A single strut design with adjustable length capabilities performs multiple functions that previously required different strut lengths. The universal design allows one strut to replace multiple specialized struts, reducing inventory complexity while maintaining versatility.
2Reliability
If struts are progressively swapped during bone correction procedures to achieve acute corrections, then the correction effectiveness is improved, but the loss of time and increase in procedural complexity worsen
Solution Approach 1:
The adjustable strut allows for dynamic length modification during the procedure through a telescopic mechanism, eliminating the need to stop and swap struts. The continuous adjustability maintains correction effectiveness while significantly reducing procedural time.
Solution Approach 2:
The strut is pre-configured with an adjustable mechanism that allows all necessary length changes to be made during the procedure rather than requiring pre-selection and swapping of multiple struts. This preliminary preparation of the adjustment mechanism saves time during acute corrections.
3Measurement precision
If shorter struts are used to minimize distance between platforms, then the positioning precision is improved, but the adjustable range (maximum length) of the struts is reduced
Solution Approach 1:
The strut employs a telescopic design with nested tubular structures that allow the length to be dynamically adjusted. This provides both the precision of shorter struts and the extended range of longer struts within a single device, maintaining positioning precision across the full adjustable range.
Solution Approach 2:
The adjustable strut uses a nested tubular structure where one tube is inserted within another, allowing compact storage of the extended length while maintaining precision control. The inner tube can be precisely positioned relative to the outer tube, providing both range and precision.
4Ease of manufacture
If loose fasteners requiring instruments are used to connect struts to platforms, then the ease of manufacture is improved, but the ease of operation and tracking of parts worsen
Solution Approach 1:
The connection mechanism is designed to be self-contained and self-explanatory, with integrated features that guide the connection process without requiring external instruments or complex tracking procedures. The design makes the connection process intuitive and self-sufficient.
Solution Approach 2:
The fastening mechanism merges the connection and adjustment functions into a single integrated system. The adjustment mechanism itself serves as the connection interface, eliminating the need for separate loose fasteners and reducing the number of parts to track.
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 adjustable strut assemblies provide a significant increase in length adjustment range, allowing for quick and efficient adjustments during clinical procedures, reducing the need for multiple strut lengths and minimizing inventory and time costs.
Implementation Method 1
The second end member is threadably coupled to the intermediate member and extends from the intermediate member
Data Source
AI summary
Length-adjustable strut assemblies for external fixation systems, and corresponding external fixation systems, are disclosed. The strut assemblies include an elongate first and second end members, an elongate intermediate member, and first and second adjustment mechanisms. The intermediate member comprises a threaded rod fixedly coupled within an axial cavity thereof, and is rotatably fixed and axially translatably within an axial cavity of the first end member. An end portion of the second end member is received within the axial cavity of the intermediate member, and the second end member comprises an axial cavity threadably coupled with the threaded rod. The first adjustment mechanism is configured to selectively axially fix the intermediate member relative to the first end member. The second adjustment mechanism is configured to selectively rotate the second end member with respect to the threaded rod to axially translate the second end member relative to the intermediate member.