Slotted Augmentation Sleeve for Bone Screw Fixation
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Solution Overview
Problem
The distribution of fixation cement within bone tissue is neither reliable nor controllable, leading to potential shifting of implants in osteoporotic bone tissue under applied forces.
Innovation Solution
A sleeve system for augmenting implants, such as bone screws, with a leading end portion and a trailing end portion featuring an axial bore and lateral bores, allowing for the insertion of augmentation material through an augmentation tool, which is then pressed into the bone to stabilize the screw beneath hard bone tissue, using a fluidizable polymer material that hardens in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If fixation cement is injected through a screw into bone tissue under pressure, then the cement is adequately fluidized to pass through the screw, but the distribution of fixation cement within the bone is neither reliable nor sufficiently controllable
Solution Approach 1:
The invention divides the cement delivery system into multiple channels: an axial through-bore for main cement flow and multiple lateral bores for distributed cement release. This segmentation allows controlled distribution of fixation cement at different locations along the screw, improving both quantity control and placement precision in osteoporotic bone tissue.
Solution Approach 2:
The augmentation sleeve provides different delivery mechanisms at different locations: the axial bore delivers cement to the trailing end, while lateral bores deliver cement to specific circumferential positions. This local differentiation enables precise control of cement distribution patterns matching the specific needs of osteoporotic bone augmentation.
2Strength
If fixation cement is injected under pressure to fluidize and pass through the screw, then the screw can be augmented in the bone, but the implant together with the fixation cement may shift within osteoporotic bone tissue as forces apply
Solution Approach 1:
The invention performs preliminary augmentation of the trailing end of the screw with bone cement before the implant is subjected to load forces. The augmentation sleeve delivers cement that hardens in place, creating a stable anchor point that prevents subsequent shifting of the implant within osteoporotic bone tissue under applied forces.
Solution Approach 2:
The augmentation sleeve acts as an intermediary device that facilitates controlled cement delivery and then can be removed. It mediates between the cement source and the screw, enabling precise cement placement in the trailing end and lateral regions, which then serves as a stable intermediary structure preventing implant-shaft shifting under load.
3Strength
If a sleeve is used to guide augmentation material through lateral bores, then the screw can be supported beneath hard bone tissue, but the sleeve must be removed after augmentation
Solution Approach 1:
The augmentation sleeve is designed as a disposable, single-use component that is removed after serving its purpose of guiding augmentation material. It is a temporary tool that facilitates precise cement delivery through lateral bores to provide screw support beneath hard bone tissue, then is discarded rather than reused or permanently retained.
Solution Approach 2:
The invention extracts the augmentation sleeve from the final implant configuration. The sleeve is used temporarily during the augmentation process to guide material delivery, then is removed (taken out) after the augmentation material has hardened and provided the necessary support. This separates the temporary delivery mechanism from the permanent implant structure.
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 system provides a reliable and controlled augmentation of the implant, enhancing its fixation within the bone by distributing augmentation material effectively around the screw, thereby stabilizing it with respect to hard bone structures and preventing shifting.
Implementation Method 1
using a fluidizable polymer material that hardens in place
Data Source
AI summary
A combination of an implant (100) like a bone screw together with an augmentation sleeve (200) is suggested. The bone screw may comprise a trailing end portion with a plurality of lateral bores (120). The augmentation sleeve may comprise a leading end portion which is adapted to be coupled to the trailing end portion of the bone screw, and a lateral opening (220) at the leading end. The augmentation sleeve may be adapted to guide an augmentation tool to the trailing end portion of the bone screw and to the leading end portion of the augmentation sleeve so that the trailing end portion of the bone screw may be augmented by pressing augmentation material through the plurality of lateral bores at the trailing end portion of the bone screw and further through the lateral opening of the augmentation sleeve into the bone at the trailing end of the bone screw, or other implant. After the augmentation of the trailing end portion of the bone screw, the augmentation sleeve may be removed.