Orthopedic Knee Insert With Non-Continuous Contact Regions
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Solution Overview
Problem
Current orthopedic inserts in knee implant systems face issues with jamming due to high manufacturing tolerances and continuous contact regions, leading to unwanted binding and potential detachment from the tibial component during insertion.
Innovation Solution
The design incorporates a lip on the orthopedic insert with non-continuous contact regions, such as recesses or splines on the tibial component, allowing for reduced contact surface area and improved alignment options during insertion, including offset and angled placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous contact regions are used between the lip and mating member, then the locking feature provides continuous support, but binding and jamming occur during insertion due to high manufacturing tolerances
Solution Approach 1:
The continuous contact region is divided into non-continuous contact regions by introducing recesses in the lip or splines on the mating member. This segmentation eliminates binding during insertion while maintaining locking stability, as the discrete contact points reduce interference from manufacturing tolerances during the insertion process.
Solution Approach 2:
Different regions of the lip-mating member interface are given different properties: the contact regions provide stable locking, while the recesses or gaps between contact regions allow for tolerance compensation during insertion. This local differentiation resolves the contradiction between locking reliability and insertion ease.
2Ease of operation
If high manufacturing tolerances (less than 0.003 inches) are required to reduce insertion forces to 10-20 pounds, then binding is reduced, but manufacturing complexity and cost increase
Solution Approach 1:
By segmenting the contact region into discrete contact points separated by recesses or splines, the system becomes less sensitive to cumulative tolerance errors. This allows higher tolerances to be used while maintaining acceptable insertion forces, as each discrete contact point can vary independently without causing binding.
Solution Approach 2:
The contact geometry is changed from continuous to non-continuous, fundamentally altering how tolerances affect insertion forces. This parameter change allows the system to operate with higher tolerances while maintaining low insertion forces, eliminating the need for ultra-precise manufacturing.
3Adaptability or versatility
If the orthopedic insert is inserted from an anterior-to-posterior direction, then the current system provides a fixed insertion path, but flexibility in alignment and placement is limited
Solution Approach 1:
The segmented contact regions with recesses or splines allow the insert to be inserted from multiple directions (anterior-to-posterior, lateral-to-medial, or at angles) without causing binding. The discrete contact points accommodate various insertion paths, providing surgical flexibility without requiring complex alignment procedures.
Data Source
AI summary
Systems, devices, and methods are described for providing orthopedic knee inserts. The orthopedic knee inserts include a surface portion having a lip configured to couple with a mating member of a tibial component, where the lip has recesses that define non-continuous contact regions between the lip and the mating member of the tibial component. Alternatively, or additionally, in certain embodiments the mating member includes a shelf for mating with an insert, the mating member having a plurality of splines disposed along the shelf that form non-continuous contact regions between the mating member and the insert.