Implantable Tensioning Cable Locking Device for Orthopedic Fixation
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Solution Overview
Problem
Existing cable loop systems for bone fixation are cumbersome to install, require specialized tools, and lack the ability to retighten or measure tension, leading to potential loss of fixation due to bone movement or shifting.
Innovation Solution
A tension device with a rotating spool and elastic components that applies and maintains tension on a cable looped around a bone, allowing for easy installation and measurement of tension, and the option to leave the device implanted to prevent loosening over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional cable loop systems are used, then cable fixation can be achieved, but installation requires bulky and heavy specialized tools that are hard to work with
Solution Approach 1:
The patent extracts the tensioning function from a separate bulky tool and integrates it directly into the cable loop system itself. The tension device is incorporated as part of the cable assembly, allowing tensioning to be performed during installation without requiring external specialized tools. This integration eliminates the need for separate tensioning devices while maintaining the ability to apply and maintain cable tension.
2Reliability
If traditional cable loop systems are used, then cable fixation can be achieved, but there is no way to retighten the cable intraoperatively or postoperatively
Solution Approach 1:
The patent implements a dynamic tensioning mechanism where the cable can be tensioned during installation and then locked in place. The system allows for initial adjustment during surgery and provides a mechanism to maintain tension over time. The cable loop system includes features that enable the cable to be tightened to the desired tension and then secured, providing both initial and long-term tension maintenance capability.
3Ease of manufacture
If the cable is cut after tensioning in traditional systems, then excess cable is removed, but frayed ends may be left exposed at the surgical site
Solution Approach 1:
The patent performs the cable end finishing action during the tensioning process itself rather than as a separate subsequent step. As the cable is tensioned and secured, the excess cable is simultaneously trimmed or secured in a manner that prevents fraying. This preliminary action ensures that when the cable is cut or excess portions are removed, the ends are already prepared or protected, eliminating the need for separate end-finishing operations and preventing frayed ends at the surgical site.
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 tension device simplifies the installation process, eliminates the need for bulky tools, allows for controlled tension application, and maintains cable tension indefinitely, reducing the risk of bone fixation failure due to bone movement.
Implementation Method 1
The spool may include an inner ring and an outer ring with an elastic layer bonded therebetween. Desirably, the elastic layer in accordance with those aspects is adapted to bias the spool in the first direction.
Implementation Method 2
A spring component may be positioned between the pin and the spool. Desirably, such spring component may be adapted to bias the spool in the first direction.
Data Source
AI summary
A tension device for applying tension to an orthopedic cable loop system is designed to remain implanted in vivo after completion of the surgical procedure in which the device is used. The tension device may include a spool rotatable in one direction, such as by having outer flanges engageable with ratcheting protrusions along a cavity within the body of the device. The tension device may maintain a biasing force on the cable, which force may be applied by an elastic material. For example, the elastic may be provided in an opening of the body of the device. In another example, the elastic may be provided in the spool, such as by constructing the flanges of the spool from elastic material or by providing elastic material between an inner and an outer ring of the spool. Other biasing components as well as measuring components may be provided in the tension device.