Tensile Force-Adjustable Fixing Tool for Ligament Reconstruction
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Solution Overview
Problem
Current fixing methods for tendon grafts with bone plugs in ligament reconstruction operations struggle to achieve the desired tensile force, making it difficult for operators to securely fix the grafts.
Innovation Solution
A tensile force-adjustable fixing tool comprising a fixing member with spike parts and a fixing screw with a self-tap portion and male screw portion, allowing for precise adjustment of the tensile force by screwing into the bone plug, ensuring the graft is securely fixed within the bone tunnel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fixing appliances (screws, spikes, ligaturing holes) are used to fix the tendon graft, then the graft can be fixed to the bone tunnel, but the tensile force cannot be adjusted to the intended value
Solution Approach 1:
The fixing screw is designed with a threaded structure that allows dynamic adjustment of the compression force applied to the bone plug. By rotating the screw, the operator can precisely control the amount of compression, thereby adjusting the tensile force on the tendon graft to the intended value. This transforms a static fixing device into a dynamic one capable of force modulation.
Solution Approach 2:
The invention changes the physical parameter of compression force through the threaded mechanism of the fixing screw. As the screw is rotated into the bone plug, the gradual reduction in thread pitch and increase in compression allow precise control over the force applied, directly enabling tensile force adjustment on the graft.
2Manufacturing precision
If the tendon graft is fixed using existing methods, then the graft is secured in the bone tunnel, but the tensile force deviation from intended value is large
Solution Approach 1:
The fixing device is segmented into distinct functional components: the fixing member with spikes for bone anchoring, the bone plug for graft attachment, and the fixing screw with threaded structure for force adjustment. This segmentation allows each component to perform its specific function while collectively achieving precise tensile force control.
Solution Approach 2:
The fixing screw acts as an intermediary mechanism between the operator's manual input and the bone plug compression. The threaded structure of the screw translates rotational motion into precise linear compression, serving as a mechanical intermediary that enables fine-tuned force application to achieve the intended tensile force on the graft.
3Ease of operation
If simple fixing appliances are used, then the device structure remains simple, but the ability to fix the graft at the intended tensile force is lost
Solution Approach 1:
The invention merges multiple functions into a single integrated fixing system: the fixing member provides mechanical anchoring to the bone, the bone plug provides a secure attachment point for the graft, and the fixing screw provides adjustable compression. This combination of functions in one system enables tensile force control without requiring multiple separate devices.
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 tool enables secure fixation of tendon grafts with bone plugs at the intended tensile force, reducing deviation and improving the stability of the graft within the bone tunnel, thus enhancing the effectiveness of ligament reconstruction operations.
Implementation Method 1
two spike parts which extend almost parallelly from both side edges of said main body part with said spike parts spaced at a predetermined interval longer than a diameter of said bone tunnel and can be stricken into said bone
Implementation Method 2
said fixing screw includes a shaft part having a self-tap portion and a male screw portion both of which can be penetrated through said through-hole of said fixing member and screwed into said bone plug
Implementation Method 3
a pulling member mounted on said tendon graft is extendable from a gap between said main body part of said fixing member and said opening of said bone tunnel, said fixing screw can be screwed into said bone plug in a state where a guide pin pierced into said bone plug is penetrated through said lumen of said fixing screw and said pulling member extended from said gap is being pulled
Data Source
AI summary
A fixing tool used in a ligament reconstruction operation includes a fixing member having a main body part provided with a through-hole and two spike parts which can be stricken into the bone and a fixing screw. The fixing screw includes a shaft part having a self-tap portion and a male screw portion, a head part, and a lumen. The fixing screw can be screwed into the bone plug in a state where a guide pin pierced into the bone plug penetrates the lumen of the fixing screw and a pulling member mounted to the bone plug and extended from the bone tunnel is being pulled. The fixing screw can adjust a tensile force of the tendon graft by adjusting the amount of screwing of the fixing screw into the bone plug after the head part of the fixing screw contacts the fixing member.