Subtalar Joint Prosthesis Minimizing Bone Resection
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Solution Overview
Problem
Current treatments for subtalar joint arthritis and disease, such as fusion and existing ankle joint prostheses, result in significant bone resection and compromise the stability of the prosthesis, leading to potential failure and increased load on adjacent joints, with no suitable subtalar joint prosthesis available.
Innovation Solution
A subtalar joint prosthesis with talar and calcaneal components designed to minimize bone resection, featuring inner and outer surfaces that mimic the natural joint contours, allowing for functional motion, and a surgical method using a measurement and cutting device to precisely prepare the joint for implantation, reducing bone loss and preserving strong bone structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ankle joint prostheses are used for subtalar joint replacement, then joint replacement function is achieved, but significant bone resection is required and prosthesis stability is compromised
Solution Approach 1:
Instead of adapting ankle joint prostheses (designed for tibial-talar articulation) to the subtalar joint, the invention inverts the approach by designing a prosthesis specifically tailored to the subtalar joint's unique anatomy and motion characteristics, with components sized and shaped to match the talus and calcaneus bones rather than requiring significant bone resection
Solution Approach 2:
The prosthesis components are designed with local quality by creating talus and calcaneus components with specific geometries that match the unique articular surfaces of the subtalar joint, allowing for stable implantation without compromising surrounding bone structures
2Ease of manufacture
If significant bone resection is performed to accommodate the prosthesis, then the prosthesis can be implanted, but the stability and orientation of the prosthesis diminish over time
Solution Approach 1:
The invention applies preliminary action by pre-sizing the prosthesis components to match the patient's specific bone anatomy before implantation, using measurement tools to determine the exact dimensions of the talus and calcaneus bones, thereby minimizing the need for bone resection and ensuring stable implantation from the outset
3Stability of the object's composition
If fusion is performed to treat subtalar joint arthritis, then joint stability is improved, but motion is limited and load distribution to adjacent joints increases
Solution Approach 1:
The invention applies dynamics by designing a mobile bearing prosthesis that preserves physiological motion at the subtalar joint, allowing the talus and calcaneus components to move relative to each other during weight-bearing activities, thereby maintaining natural load distribution patterns to adjacent joints while providing joint stability
Data Source
AI summary
A subtalar joint prosthesis that is adapted to replace the natural subtalar joint that exists between a patient's talus and calcaneus bones includes talar and calcaneal components. Each of these is configured to have a shape that is herein defined as being a portion of the boundary surface of a frustum. Meanwhile, these components' inner surfaces are configured to: (a) generally follow the anatomic contour of the original joint surface to which each component is to be attached, and (b) minimize each components's average thickness, consistent with providing sufficient strength and rigidity for the components, so as to require minimum bone resection for the implantation of these components.