External Bone Fixation Struts With In Situ Range Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hexapod bone fixation systems require time-consuming and costly processes to swap struts of varying lengths, leading to inventory challenges and difficulties in achieving precise adjustments during bone or tissue corrections, especially in situations with extreme angulations or rotations.
Innovation Solution
The system includes length-adjustable strut assemblies with externally threaded rods and bodies, allowing for incremental length adjustments without detachment from platforms, and the use of add-on rods to extend the range, facilitating quick and efficient positioning of bone segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple struts of differing lengths are used to accommodate various platform distances, then the system can handle different clinical situations, but the device complexity and inventory requirements increase significantly
Solution Approach 1:
The patent implements a single strut design with dynamic length adjustability through threaded rod assemblies that allow the strut length to be changed continuously or in increments. This dynamic adjustment capability replaces the need for multiple fixed-length struts, reducing inventory complexity while maintaining adaptability to various platform distances
Solution Approach 2:
The single adjustable strut design serves multiple functions by accommodating various platform distances within a wide range (e.g., 3 to 15 inches or more). This universal strut can replace multiple specialized struts of different lengths, simplifying the overall system while maintaining versatility for different clinical scenarios
2Manufacturing precision
If struts are physically swapped during bone correction processes, then the correct strut length can be achieved, but the operational time and procedural complexity increase
Solution Approach 1:
The threaded rod assembly allows for continuous or incremental length adjustment of the strut during the surgical procedure without requiring detachment or swapping. The rod can be rotated to extend or retract, enabling real-time length modification to achieve precise positioning while eliminating the time-consuming swap process
Solution Approach 2:
The strut is pre-configured with an adjustable mechanism that allows length modification to be performed in advance or during the procedure as needed. This preliminary preparation of the adjustment mechanism enables quick length changes without requiring complete strut replacement, reducing operational time
3Length of moving object
If shorter struts are used to minimize distance between platforms, then the platforms can be positioned closely, but the adjustable range (maximum length) of the struts is limited
Solution Approach 1:
The threaded rod assembly provides dynamic length adjustment that enables the strut to achieve both short lengths (for minimizing platform distance) and long lengths (for maximum adjustable range). The continuous adjustment capability allows the strut to adapt to any distance within its extended range, simultaneously satisfying both requirements that would be conflicting with fixed-length struts
Solution Approach 2:
The strut is segmented into a body portion and a threaded rod portion that can extend or retract relative to each other. This segmentation allows the rod to be translated through the body, enabling the strut to achieve varying lengths from compact to extended positions, thus providing both short minimum distance capability and long maximum adjustable range
4Reliability
If multiple fasteners are used to connect struts to platforms, then secure connections are achieved, but the ease of operation and assembly time are reduced
Solution Approach 1:
The connection mechanism merges the fastening and adjustment functions into a single integrated system. The threaded rod assembly that provides length adjustment also serves as the connection interface, eliminating the need for separate fasteners. This integration maintains secure connections while simplifying the assembly and adjustment operations
Data Source
AI summary
The present application provides external bone fixation systems. The systems include one or more pairs of bone fixation platforms in the form of rings or partial rings. The platforms may be coupled to corresponding bone segments. The pair of platforms are configured to accept a plurality of struts extending therebetween. The struts are configured to attach to the platforms via joints that provide three degrees of rotation. The struts are also configured such that their longitudinal length extending between the joints/platforms can be incrementally adjusted while attached to the platforms. The struts are further configured such that their total range of length adjustment can be increased by coupling at least one add-on component to the struts in situ. The lengths of each of the plurality of struts may be adjusted to arrange the platforms, and thereby the bone segment coupled thereto, in particular relative positions and orientations.