Autogenous Bone Grafting Device with Rotatable Saw
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Solution Overview
Problem
Current bone grafting devices lack control over cutting depth and longitudinal position, and are unable to simultaneously cut bone sections both longitudinally and transversely, leading to inefficiencies and complications in autogenous bone harvesting, such as donor site morbidity and prolonged surgery times.
Innovation Solution
A device that allows for hand-controlled, simultaneous longitudinal and transverse cutting of bones during a drilling procedure, using a rotatable saw that can extend inwardly to support and carry the bone block, and outwardly to release it, with a mechanism that enables precise cutting and harvesting of bone blocks for grafting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a spring-loaded saw mechanism is used to automatically cut bone upon disc dislocation, then cutting action is achieved, but control over cutting depth and longitudinal position is lost
Solution Approach 1:
A rod acts as an intermediary component between the disc and the saw mechanism. The rod transmits the dislocation motion from the disc to the saw while allowing controlled movement, enabling both automatic activation and precise depth control through the rod's positioning and movement constraints.
Solution Approach 2:
The saw mechanism transitions from a static spring-loaded design to a dynamic system where the rod can be positioned at different depths and controlled during movement. This allows the cutting depth and longitudinal position to be adjusted dynamically during the procedure while maintaining automatic activation through disc dislocation.
2Productivity
If the saw swings uncontrollably inwards after disc dislocation, then bone cutting is achieved, but precision and control over the cutting plane are lost
Solution Approach 1:
The rod serves as a controlled intermediary between the disc dislocation and the saw movement. It transmits the activating force while constraining the saw's movement path and depth, ensuring precise cutting plane accuracy while maintaining the speed benefit of automatic activation.
Solution Approach 2:
The rod is pre-positioned at the desired cutting depth before disc dislocation occurs. This preliminary positioning ensures that when the saw is activated, it cuts at the predetermined precise plane rather than swinging uncontrollably, combining speed with accuracy.
3Quantity of substance
If bone harvesting is performed using traditional methods, then bone graft material is obtained, but donor site morbidity and blood loss increase
Solution Approach 1:
The bone block is divided into two separate blocks by the saw cutting through the center. This segmentation allows for precise harvesting of the required bone quantity while minimizing the donor site trauma, as the cuts are controlled and the bone block is removed as clean sections rather than through traumatic extraction.
Solution Approach 2:
The traditional traumatic mechanical extraction of bone is replaced with a controlled cutting system using the longitudinal cutting member and saw. This substitution reduces donor site morbidity and blood loss by using precise cutting rather than forceful removal, while still obtaining the required bone graft material.
4Device complexity
If the device structure is simplified with a single cutting mechanism, then device complexity is reduced, but the ability to perform both longitudinal and transverse cutting is lost
Solution Approach 1:
The same saw mechanism is used for both longitudinal and transverse cutting operations. The saw can be oriented and positioned to cut in different directions, providing multi-functionality without requiring separate cutting mechanisms, thus maintaining simplicity while achieving versatility.
Solution Approach 2:
The cutting mechanism is designed to be dynamic and reconfigurable, allowing the same components to perform different cutting directions based on their positioning and orientation during the procedure. This dynamic adaptability enables both longitudinal and transverse cutting with a single mechanism rather than requiring fixed, separate mechanisms.
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
A device (100) and method (1200) for autogenous bone grafting simultaneously cuts a cross-section of a bone (212), both longitudinally with a longitudinal cutting member (104), and transversely with a saw (140) during a bone drilling procedure to obtain a bone block (214) for repairing and rebuilding diseased bones. The device (100) is hand-controllable to selectively cut internally to the device (100), so as to cut captured bone (212) for internal bone harvesting. The device (100) also selectively cuts surrounding bone (212) outside the device (100) for external bone harvesting. The saw (140) is biased to stow in a wall space (120) when not in use, and rorate along a perpendicular plane (202) inwardly or outwardly for internal or external cutting of the bone (212), respectively. The saw (140) rotatably extends inwardly to support and carry the bone block (214) after a longitudinal section has been cut. The saw (140) rotatably extends outwardly from the device (100) to release the bone block (214) after the bone grafting procedure.