Ankle Replacement Implants With Curved Surfaces for Stability
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Solution Overview
Problem
Current ankle replacement implants face issues such as loosening of the tibial component, stress concentrations in the medial malleolus, inadequate bone coverage of the talus component, and lack of vertical stabilization features.
Innovation Solution
The development of implants with specific articulating surfaces and insert designs that include medial and lateral curvatures, pegs and protrusions for stabilization, and dovetail engagement features to ensure proper fit and alignment, along with a method for implantation that includes coupling members to bones and inserting an insert to stabilize the joint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If currently available implants for total ankle replacement are used, then the basic joint replacement function is provided, but loosening of the tibial component occurs
Solution Approach 1:
The tibial articulating surface incorporates specific curvature radii (anterior-medial sagittal radius, posterior-medial sagittal radius, anterior-lateral sagittal radius, posterior-lateral sagittal radius) to match the natural talus bone geometry. This curved surface design improves contact area and stress distribution, preventing tibial component loosening while maintaining joint function
Solution Approach 2:
The implant uses a composite structure with a tibial component, talus component, and insert (likely different materials such as metal and polyethylene). This composite design provides both structural strength and appropriate articulating surface properties, ensuring long-term stability and preventing loosening
2Reliability
If currently available implants for total ankle replacement are used, then joint replacement is achieved, but stress concentrations occur in the medial malleolus
Solution Approach 1:
The implant design incorporates specific local geometric features including asymmetric curvature radii (anterior-lateral sagittal radius larger than anterior-medial sagittal radius; posterior-medial sagittal radius larger than posterior-lateral sagittal radius). This local variation in surface properties distributes stress more evenly across the medial and lateral malleolus, preventing stress concentrations that would lead to bone failure
3Reliability
If currently available implants for total ankle replacement are used, then basic joint replacement is provided, but proper bone coverage of the talus component is lacking
Solution Approach 1:
The talus component articulating surface is designed with specific curvature radii that conform to the natural geometry of the talus bone. This curved surface design increases the contact area between the implant and talus bone, providing proper bone coverage and preventing edge loading that would compromise implant stability
4Reliability
If currently available implants for total ankle replacement are used, then joint replacement is achieved, but vertical stabilization features on the tibia are absent
Solution Approach 1:
The tibial articulating surface incorporates specific sagittal radius curvatures (anterior-medial, posterior-medial, anterior-lateral, posterior-lateral) that provide vertical stabilization by matching the natural roll-back and pivot motions of the ankle joint. This curvature design prevents excessive vertical movement and stabilizes the joint during weight-bearing activities
Data Source
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AI summary
Implants, devices, and methods for maintaining, correcting and/or fusing joint deformities are disclosed. The implant a first member, a second member, and an insert with a top surface and a bottom surface. The top surface couples to the first member and the bottom surface engages the second member. Kits and methods of using the implants for maintaining, correcting and/or fusing joint deformities are also disclosed.