Knee Prosthesis Tibial Insert Snap-Fixing Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing knee prostheses with tibial components have complex structures requiring a vertical insert and corresponding hole for snap-fitting, which complicates the fixing mechanism.
Innovation Solution
A tibial component with a tibial plate and insert that uses a simpler snap-fitting mechanism, where the insert features a flexible tab and posterior cut-outs that match the shape of a promontory on the plate, eliminating the need for a vertical insert and hole, ensuring secure locking without additional structural complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vertical insert and corresponding hole are used for snap-fitting, then the fixing mechanism is achieved, but the structure becomes complex
Solution Approach 1:
The invention extracts and eliminates the vertical insert and corresponding hole from the snap-fitting mechanism. Instead, it uses a tab projecting from the anterior face of the insert that fits into a cut-out in the anterior abutment, combined with posterior tabs fitting into grooves in the posterior abutment. This removes the complex vertical insertion requirement while maintaining secure fixing.
Solution Approach 2:
The invention inverts the traditional snap-fitting approach by having the insert's anterior tab fit into a cut-out in the abutment rather than requiring a vertical insert to pass through a hole in the plate. The fixation is achieved through the tab engaging with the cut-out geometry and the flexible tab's elastic deformation, rather than through a vertical insertion mechanism.
2Device complexity
If a simpler snap-fitting mechanism is used without vertical insert and hole, then the structure is simplified, but fixing reliability may be compromised
Solution Approach 1:
The invention changes the physical state and geometric parameters of the tab and cut-out interface. The flexible tab is designed with specific dimensions and material properties that allow it to deform elastically during insertion and then lock into the cut-out. The cut-out geometry in the anterior abutment is specifically shaped to receive and retain the tab, creating a reliable fixation without complex structures.
Solution Approach 2:
The invention employs curved and contoured surfaces in the tab and cut-out design. The flexible tab has a curved profile that matches the cut-out geometry, allowing for smooth insertion and secure locking. The posterior tabs also feature curved surfaces that engage with the grooves in the posterior abutment, ensuring reliable fixation through geometric interlocking rather than simple flat surfaces.
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 provides improved fixing of the tibial insert to the tibial plate with a simpler structure, ensuring secure snap-fitting without the need for a vertical insert and hole, enhancing the stability and ease of assembly of the knee prosthesis.
Implementation Method 1
at least one flexible tab, in particular in the shape of a hook, projects from the insert on the anterior side, in particular centrally, so that it is able to lock, in particular by snapping fitting, into an anterior cut-out (11) in the form of a window in the tibial component
Data Source
AI summary
A tibial component of a knee prosthesis includes a tibial plate and a tibial insert, and anterior and posterior abutments projecting from an upper face of the tibial plate. The anterior abutment extends along at least part of the tibial plate and the posterior abutment extends for at least part of the tibial plate and comprises a part forming a promontory and an anterior cut-out, in particular central, in the form of a window formed in the anterior abutment opening onto the posterior face of the latter opposite the part forming the promontory. The tibial insert has a face upper, a face lower and a lateral face, which has a shape matching the part forming the promontory, characterised in that at least one flexible tab in the form of a hook projects centrally from an anterior face of the insert and locks by snap-fitting, into the anterior cut-out.