Cable Fixation Device Collinear Axis Torsion Prevention
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Solution Overview
Problem
Current surgical cable fixation systems require multiple instruments, lead to torsional forces on cables, and are not suitable for repeated adjustments, causing potential damage and complications during procedures.
Innovation Solution
A multi-part tapered collet system with a cannulated lock cap that encircles the cable, allowing for repeated locking and unlocking without damage, and a clamp housing with a collinear central axis to prevent torsion, along with a cerclage insertion instrument featuring a clasp activator mechanism for easy assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional cable fixation system with separate tensioner and locking screw is used, then the cable can be tensioned and locked, but two spaced instruments must be operated simultaneously in a small surgical space, increasing procedural complexity
Solution Approach 1:
The patent combines the tensioning and locking functions into a single integrated cable fixation device. The device includes a body with a cable passage, a tensioning mechanism, and a locking mechanism that all work together in one unit, eliminating the need to operate separate tensioner and locking screw instruments simultaneously in the surgical field.
Solution Approach 2:
The cable fixation device is designed to perform multiple functions: it can tension the cable, lock the cable in place, and be easily removed or adjusted. The single device serves as both a tensioning instrument and a locking mechanism, reducing the number of instruments needed during the surgical procedure.
2Reliability
If conventional cable tensioning and locking methods are used, then cable stabilization is achieved, but the cable and crimp may be damaged during provisional tensioning and retensioning operations
Solution Approach 1:
The locking mechanism includes a movable locking element that can be easily engaged and disengaged, allowing the cable to be provisionally tensioned, adjusted, and retensioned without permanent deformation of the crimp or cable. The dynamic locking system enables repeated adjustments while maintaining cable integrity.
Solution Approach 2:
The device allows for changes in cable tension parameters through its adjustable locking mechanism. The locking element can be positioned at different locations along the cable passage, enabling provisional tensioning at one tension level and subsequent adjustment to a different tension level without damaging the cable or crimp structure.
3Reliability
If internal crimp locking mechanisms are used, then cable locking is achieved, but the system cannot be used for multiple locking and unlocking cycles when cable re-adjustments are needed
Solution Approach 1:
The locking mechanism features a movable locking element that can be easily engaged and disengaged multiple times. This dynamic system allows the cable to be locked securely and then unlocked for adjustments, and re-locked again, enabling multiple locking and unlocking cycles without compromising the integrity of the cable or locking mechanism.
4Stability of the object's composition
If cable ends are spaced along the long axis of the bone, then the cable loop can be formed, but the cable fails to lay in the same plane causing torsional force on the locking mechanism and improper seating on the bone
Solution Approach 1:
The device includes a cable guide structure that ensures both cable ends are positioned in the same plane, eliminating torsional forces. The guide structure creates an equipotential configuration where the cable lays flat against the bone surface without twisting or bending out of plane, ensuring proper seating and stable fixation.
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 solution reduces the number of instruments needed, minimizes torsional forces, enables easy cable adjustments, and prevents cable damage, providing stable fixation with reduced surgical complexity and tissue damage.
Implementation Method 1
The device includes a body with an internal tapered void. A wedge shaped plug with recessed edges for containment of a cable is slidable into the void therein locking the cable between the body and plug.
Implementation Method 2
A wedge shaped plug with recessed edges for containment of a cable is slidable into the void therein locking the cable between the body and plug.
Implementation Method 3
The cable within the loop fails to lay in the same plane therein causing a torsional force on the locking mechanism and improper seating on the bone.
Implementation Method 4
a cerclage insertion instrument featuring a clasp activator mechanism for easy assembly and disassembly
Data Source
AI summary
Various forms of a cable fixation device, instrumentation, kit, and methods useful for repairing the skeletal system are introduced. The system utilizes a clamp housing fixing a head end of a surgical cable therein. In an operative configuration the cable is looped around a damaged bone segment and reentered through a lock aperture in the clamp housing then through a multi-part collet and lock cap residing within a lock aperture. The cable loop and each aforementioned component comprise a central axis aligned within a single plane. A sliding interface situated between the lock cap and collet prevent twisting of the surgical cable. The locking mechanism is non-destructive to the cable despite repeated unlocking and relocking of the fixation device. The axis for tensioning of the cable is coincident with the locking axis. A cerclage inserter instrument is disclosed.