Dynamic Bone Fixation Cable With Pivoting Anchor
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Solution Overview
Problem
Existing devices and surgical techniques for treating type IV supination external rotation injuries and fractures in bones like the femur, tibia, and fibula are not entirely satisfactory in reducing and fixing fractures while effectively limiting syndesmotic motion between the fibula and tibia.
Innovation Solution
A device comprising an intramedullary rod with transverse holes for screws, a flexible cobalt-chrome cable, and a cobalt-chrome anchor with a curved bone-engaging surface, which allows for the reduction and fixation of fractures and limited syndesmotic motion by aligning and stabilizing bone fragments and allowing some pivotal movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rigid fixation device is used to completely prevent syndesmotic motion, then fracture fixation stability is improved, but natural pivotal movement between bones is completely restricted
Solution Approach 1:
The device transitions from a completely rigid fixation system to a dynamic system where the cable can pivot relative to the intramedullary rod. The cable is capable of limited pivotal movement around the rod while maintaining tension, allowing the system to adapt between stable fixation and natural motion as needed during healing.
Solution Approach 2:
The system changes the parameter of motion restriction from complete prevention to limited controlled movement. The cable's pivotal movement is constrained within specific parameters (limited angle and tension) to allow natural syndesmotic motion while maintaining overall fracture stability.
2Adaptability or versatility
If a flexible cable system is used to allow pivotal motion, then natural movement is accommodated, but fracture fixation stability is reduced
Solution Approach 1:
The device is segmented into two functional components: the intramedullary rod providing rigid fracture fixation and the cable providing controlled pivotal motion. This segmentation allows each component to perform its specific function optimally without compromising the other.
Solution Approach 2:
The cable is designed with dynamic properties that allow it to pivot relative to the rod while maintaining tension. This dynamic capability enables the system to accommodate natural pivotal motion during healing while the rod maintains overall fracture stability.
3Stability of the object's composition
If existing intramedullary rods with transverse holes are used, then fracture fixation is achieved, but syndesmotic motion cannot be effectively limited
Solution Approach 1:
The cable acts as an intermediary element between the intramedullary rod and the bone fragments. It transmits controlled forces and allows limited pivotal motion while preventing uncontrolled syndesmotic motion, serving as a mediator that refines the interaction between the rod and bone.
Solution Approach 2:
The system adds a new parameter of controlled pivotal motion to the traditional intramedullary rod fixation. The cable introduces angular and tensile parameters that limit syndesmotic motion while allowing natural movement, changing the motion control parameter from none to limited controlled movement.
Data Source
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AI summary
An apparatus includes: a member configured to be received within an intramedullary canal, the member having an opening therethrough; a flexible elongate element sized to extend through the opening; a section having a first bone-engaging surface and a coupling structure for fixedly securing the section to the elongate element; and a further section having a bone-engaging surface and a coupling structure for fixedly securing the further section to the elongate element. In another form, an apparatus includes a first section having spaced first and second surface portions to engage a bone and a second section configured to extend into a bone. The first surface portion exerts a first force in a direction that is at an angle with respect to a force exerted by the second surface portion. Yet another form involves methods of using each apparatus.