Dome Toe Resurfacing System for Metatarsophalangeal Joint Replacement
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Solution Overview
Problem
Current metatarsophalangeal joint replacement technologies face issues such as implant wear, silicone synovitis, bone resection, bone loss, and metatarsalgia, leading to suboptimal patient satisfaction and complications like nonunion and reoperation.
Innovation Solution
The Dome Toe Resurfacing System employs cone extensions with ridges for a press fit, a cone and cup reaming system to mimic natural anatomy, and a silastic implant with potential multiple hinge options, reducing bone reactions and wear, and preserving bone length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional metatarsophalangeal joint replacement is performed, then joint replacement is achieved, but implant wear and silicone synovitis occur
Solution Approach 1:
The implant system is divided into separate components: a metatarsal head prosthesis and a phalangeal prosthesis with cone extension. This segmentation allows each component to be optimized independently for its specific function, reducing wear at interfaces and minimizing silicone synovitis by separating the articulating surfaces from bone-contact surfaces.
Solution Approach 2:
A cone extension with ridges acts as an intermediary structure between the phalangeal prosthesis and the bone. The ridges catch bone on insertion and provide a press fit, mediating the interface between implant and bone to reduce wear and prevent direct contact between silicone and bone that causes synovitis.
2Manufacturing precision
If aggressive bone resection is performed to accommodate implant, then implant fit is improved, but bone loss and metatarsalgia increase
Solution Approach 1:
The cone extension changes the geometric parameters of the implant-bone interface by creating a tapered configuration with ridges. This parameter change allows the implant to achieve precise fit and press fit engagement without requiring aggressive bone resection, thereby minimizing bone loss and preventing metatarsalgia.
3Ease of manufacture
If conventional reaming is used, then canal preparation is completed, but anatomical accuracy and stability are insufficient
Solution Approach 1:
The cone extension features a curved, tapered geometry with ridges that conform to the natural anatomy of the phalangeal canal. This curved design provides anatomical accuracy while the ridges engage with bone to enhance stability, overcoming the limitations of conventional straight reaming.
Data Source
AI summary
An innovative dome toe resurfacing system for performing metatarsophalangeal joint replacement is disclosed. The present invention comprises a prosthetic implant for metatarsophalangeal joint, and one or more cone extensions that covers portions of the prosthesis that extends into the metatarsal bone and phalanx bone. The cone extensions include a plurality of ridges that will catch bone on insertion and provide a press fit. The present invention also includes a cone and cup reaming system wherein one or more reamers will ream a cone/cup shape for the articular surfaces, and prepare the metatarsal and phalangeal canals for the insertion of the cone extensions. The cone extensions have ends that fit the reamed cone/cup shape wherein the cone/cup shape resembles the natural anatomy of articular surfaces of metatarsophalangeal joint.