Nested Counter-Torque Wrench for Minimally Invasive Bone Screw Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current counter-torque wrench systems for bone screw systems are not minimally invasive, leading to larger incisions during surgery due to the size and complexity of the tools required for securing set screws within tulip heads.
Innovation Solution
A counter-torque wrench system with a proximal end, distal end, body, and hollow channel, featuring at least one wing and an annular protrusion, designed to fit within the tulip head, allowing for smaller incisions by stabilizing the mounting rod and enabling secure fastening of set screws through a set screw driver within the hollow channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a traditional counter-torque wrench system is used to secure set screws within tulip heads, then the fastening function is achieved, but the incision size must be larger due to the tool width
Solution Approach 1:
The counter-torque wrench is designed with a hollow channel that receives the set screw driver, creating a nested configuration where one tool is inserted within another. This nesting reduces the overall tool width required for insertion while maintaining both the counter-torque function and set screw fastening capability, thereby enabling smaller incisions
2Length of moving object
If the counter-torque wrench width is reduced for minimally invasive surgery, then incision size is reduced, but tool stability may be compromised
Solution Approach 1:
The hollow channel structure provides internal support and confinement for the set screw driver, enhancing tool stability despite the reduced overall width. The nested configuration creates a more rigid assembly that maintains stability during the fastening operation while enabling smaller incision access
3Device complexity
If a compact counter-torque wrench design is used, then device complexity is reduced, but the ability to perform both counter-torque and set screw fastening functions may be compromised
Solution Approach 1:
The counter-torque wrench integrates multiple functions into a single device: the hollow channel serves both as a structural element for the counter-torque mechanism and as a receptacle for the set screw driver. This merging of functions allows the tool to perform both counter-torque application and set screw fastening without requiring separate devices, maintaining versatility while simplifying the overall system
Solution Approach 2:
The set screw driver is received within the hollow channel of the counter-torque wrench, creating a nested multi-functional assembly. This nested configuration allows both tools to be integrated into a single operational unit that maintains the functionality of both the counter-torque wrench and the set screw driver while reducing the number of separate components
Data Source
AI summary
A minimally invasive counter-torque system may comprise a bone screw system, a counter-torque wrench, a set screw driver, a counter-torque wrench handle, and a removable set screw driver handle. A body of the counter-torque wrench may be positioned entirely within a space as defined by or between removable arms of a tulip head of the bone screw system, such that only the wings of the counter-torque wrench extend beyond a width of the bone screw system. In operation, the counter-torque wrench handle may be received on a proximal end of the counter-torque wrench and may be used to stabilize and prevent rotation of the counter-torque wrench and the bone screw system. Then, the removable set screw drive handle may be engaged to a proximal end of the set screw driver and may be used to fasten a set screw into the saddle of the bone screw system.