Orthopaedic Knee Prosthesis Cam-Post Anterior Stabilization
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Solution Overview
Problem
Total knee arthroplasty procedures often require sacrificing the anterior cruciate ligament (ACL), which can lead to negative clinical impacts, particularly in patients engaging in contact sports or activities involving fast changes in direction and twisting movements, as the ACL plays a crucial role in balance and stability of the knee joint.
Innovation Solution
An orthopaedic prosthetic system comprising femoral and tibial components with adjustable configurations, including tibial insert components with asymmetrical and symmetrical concave surfaces, and a cam-post mechanism, designed to provide anterior stabilization without the need for an intact ACL, allowing for various implant configurations to accommodate different patient anatomies and activity levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the anterior cruciate ligament (ACL) is sacrificed during total knee arthroplasty, then the surgical procedure can be completed with standard implant configurations, but the knee joint loses anterior stability and balance, particularly affecting patients engaged in contact sports or activities involving fast changes in direction
Solution Approach 1:
The patent introduces a cam-post mechanism as an intermediary structure that mediates the function previously provided by the ACL. The cam portion on the femoral component interacts with the post on the tibial insert to provide anterior stability, replacing the ligament's function through a mechanical intermediary rather than relying on the biological tissue
Solution Approach 2:
The patent changes the mechanical parameters of the knee joint by introducing adjustable cam-post configurations. The cam and post can be positioned at different locations and orientations to replicate the ACL's functional parameters, providing anterior stability through modified geometric relationships rather than relying on the original ligamentous constraints
2Ease of operation
If standard symmetrical tibial inserts are used, then the implantation process is simplified, but the prosthesis cannot adequately accommodate varying patient anatomies and activity levels, particularly those requiring enhanced anterior stability
Solution Approach 1:
The patent segments the tibial insert into distinct functional zones with asymmetrical concave surfaces that can be selectively engaged by the femoral condyles. This segmentation allows different portions of the insert to serve different purposes - providing anterior stability in certain configurations while maintaining posterior stability in others, accommodating varying patient needs through selective engagement patterns
Solution Approach 2:
The patent employs asymmetrical concave surfaces on the tibial insert that are specifically designed to work with the cam-post mechanism. The asymmetry allows the insert to provide enhanced anterior stability for patients who need it while still accommodating standard anatomies, offering versatility without requiring completely different implant designs for different patient populations
Data Source
AI summary
An orthopaedic prosthesis system and associated instrumentation is disclosed. The system includes femoral and tibial components configured to be used in a number of different implanted configurations. The instrumentation is configured to facilitate preparation of the bones and selection of the implant configuration. A method of using the system is also disclosed.