Double-Ended Fixation Implant for Skeletal Joint Repair
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Solution Overview
Problem
Current fixation methods for skeletal joints are inadequate in securely reconstructing and stabilizing soft tissues and grafts, particularly in metapodial phalangeal joints, as they lack effective solutions for threaded engagement and secure attachment of grafts and sutures without causing damage.
Innovation Solution
A double-ended fixation implant with a separable elongated shaft and threaded end portions, made of a polymer, is used to create interference fits in bone tunnels, allowing secure attachment and reconstruction of soft tissues and grafts by threading and cutting the implant to optimize engagement and minimize length for efficient fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixation implant is used to secure grafts and sutures in bone tunnels, then secure attachment and stabilization of soft tissues is achieved, but the implant may cause damage to the bone or soft tissues during insertion and fixation
Solution Approach 1:
The fixation implant is divided into separable components: a reusable shaft and disposable threaded end portions. The end portions are inserted into bone tunnels to secure grafts and sutures, then severed from the shaft. This segmentation allows the implant to provide secure fixation while minimizing damage through controlled insertion and removal of specific components.
Solution Approach 2:
The threaded end portions are extracted as separate, disposable components from the reusable shaft. After performing the fixation function of securing grafts and sutures in bone tunnels, the end portions are severed and removed, taking with them any associated damage or contamination, while the shaft remains for future use.
2Reliability
If the implant shaft is made long to provide sufficient threading engagement in bone tunnels, then secure fixation is achieved, but the implant length increases requiring larger incisions and causing more tissue disruption
Solution Approach 1:
The implant is segmented into a reusable shaft and disposable end portions. The shaft can be optimized for minimal length necessary for handling and insertion, while the threaded end portions provide the necessary engagement length in bone tunnels. This separation allows the shaft to be short without compromising fixation capability.
Solution Approach 2:
The threaded engagement function is extracted from the shaft and placed in separate end portions. This allows the shaft to maintain minimal necessary length for surgical manipulation while the end portions provide extended threaded engagement with bone tunnels, reducing the overall implant length requirement.
3Ease of manufacture
If the implant is designed as a single piece for simplicity of manufacture, then manufacturing is easier, but the implant cannot be optimized for different bone tunnel lengths and configurations
Solution Approach 1:
The implant is segmented into a reusable shaft and disposable end portions that can be manufactured separately and then assembled. This allows each component to be optimized independently: the shaft for manufacturing simplicity and the end portions for specific bone tunnel configurations, achieving both ease of manufacture and adaptability.
Solution Approach 2:
The implant design transitions from a static single-piece structure to a dynamic modular system where the shaft and end portions can be separated and reconfigured. This allows the implant to adapt to different bone tunnel lengths and configurations by selecting appropriate end portions while maintaining manufacturing simplicity through modular production.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides secure and stable fixation of soft tissues and grafts in skeletal joints, minimizing damage and ensuring effective reconstruction by optimizing the length and threading of the implant for secure engagement with bone tunnels, thus enhancing joint function and reconstruction outcomes.
Implementation Method 1
threading a first end of a double ended fixation implant into one of the metapodial bone tunnel and phalangeal bone tunnel in interference fashion to secure the graft relative to the bone tunnel
Data Source
AI summary
A fixation implant and associated methods are presented. The fixation implant includes a shaft extending from a first end portion to a second end portion and having an intermediate portion therebetween. The intermediate portion is generally smooth and the end portions are threaded. The method includes use of the fixation implant for repair of a metapodial phalangeal joint of a human extremity. The method includes: forming a bone tunnel in a bone; approximating material near the bone tunnel; and threading the fixation implant into the bone tunnel in interference fashion to secure the material relative to the bone tunnel. The fixation implant may be cut such that the end portion is flush with the bone.