Scapho-lunate Reconstruction Targeting Apparatus for Bone Alignment
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Solution Overview
Problem
Current surgical methods for treating scapho-lunate dissociation face challenges such as limited clearance and visibility for medical tools, accuracy issues in implant delivery, and difficulty in aligning and stabilizing bones due to the compact nature of the scaphoid and lunate bones, leading to suboptimal results like loss of motion and high failure rates.
Innovation Solution
A targeting apparatus and medical implant assembly that includes a reduction frame with modular engagement modules for precise alignment and implant placement, allowing for independent rotation of threaded ends and using guidewires to correct rotational deformities, along with a depth gauge for accurate implant positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If K-wires and guide wires are used simultaneously in the RASL procedure, then bone alignment can be achieved, but clearance and visibility between tools is insufficient making the procedure difficult and error-prone
Solution Approach 1:
The patent introduces a guide wire as an intermediary tool that facilitates the placement of the cannulated screw. The guide wire is inserted first to establish the correct trajectory and position, serving as a mediator that enables subsequent screw placement without requiring simultaneous manipulation of multiple tools in the confined space.
Solution Approach 2:
The procedure performs preliminary actions by first inserting K-wires to achieve bone alignment, then inserting a guide wire to establish the screw trajectory, and finally removing the K-wires before screw placement. This sequential preliminary action approach avoids the complexity of manipulating multiple tools simultaneously while ensuring proper alignment is achieved.
2Measurement precision
If surgeon experience and anatomical landmarks are used to position the guide wire, then implant placement accuracy can be achieved, but the procedure requires years of experience and is difficult to replicate
Solution Approach 1:
The guide wire and targeting apparatus are designed to self-align and self-position based on the anatomical landmarks and bone geometry. The system performs its own positioning function without requiring extensive surgeon interpretation or manual adjustment, making the procedure more reproducible and less dependent on surgeon experience.
Solution Approach 2:
The patent replaces the reliance on surgeon experience and manual anatomical landmark identification with a mechanical guide wire system and targeting apparatus that automatically establish the correct implant trajectory. This mechanical substitution transforms a skill-dependent procedure into a more standardized, reproducible technique.
3Reliability
If the screw is positioned along the instantaneous center of motion axis, then optimal biomechanical function is achieved, but identifying and drilling along this axis is difficult and requires very skilled surgeons
Solution Approach 1:
The guide wire serves as an intermediary tool that physically establishes the instantaneous center of motion axis. By inserting the guide wire along the desired trajectory before screw placement, the complex task of identifying and maintaining the correct axis during screw drilling is simplified into following the pre-established guide wire path.
Data Source
AI summary
A method for bone reconstruction includes aligning a first hone with a second bone using a plurality of guidewires to correct rotational deformity of the first and second bones. A first module of a targeting apparatus is positioned in proximity to the first bone. A tip of the first module is engaged with the first bone. A second module of the targeting apparatus is positioned in proximity to the second bone. A tip of the second module is engaged with the second bone. Alignment of the first module and the second module is secured. The alignment is verified using a guidewire, the guidewire wire is inserted through a passage extending through the second module. A length between the first bone and the second bone is determined using a depth gauge. An implant is selected based on the determined length for delivery along the passage extending through the second module.