Blunt-Tip Bone Screw with Extraction Rod for Sacrum Ilium Fusion
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Solution Overview
Problem
Conventional methods for fusing the sacrum and ilium bones, such as using screws with pointed tips, can cause discomfort and injury due to the sharp tips being near the sacral foramina, and do not efficiently facilitate bone growth and fusion.
Innovation Solution
A bone screw implant system comprising a rod and screw with a blunt distal end and a frustoconical tip, allowing for secure fixation of the sacrum and ilium without leaving a pointed tip, and featuring apertures for bone growth material delivery to promote fusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pointed-tip screw is used for implantation, then the screw can be easily inserted into the bone, but discomfort or injury can be caused by the sharp tip being near the sacral foramina
Solution Approach 1:
The pointed tip is extracted from the final implant screw and transferred to a separate rod that is removed after insertion. The screw itself has a blunt distal end, eliminating the harmful sharp tip while preserving the insertion capability through the temporary rod.
Solution Approach 2:
A rod with a pointed tip serves as an intermediary tool to facilitate insertion of the blunt-tipped screw. The rod is inserted first to create the pathway, then the screw is threaded onto the rod and advanced to the target location, and finally both the rod and any excess screw portion are removed.
2Stability of the object's composition
If conventional implants are used to fuse sacrum and ilium, then the bones can be stabilized, but the process involves multiple complex steps including drilling, tapping, and implant insertion
Solution Approach 1:
The drilling, tapping, and implant insertion steps are merged into a single integrated process. The rod serves multiple functions: it acts as a drill bit to create the pathway, as a tap to prepare the bone, and as an insertion tool for the screw, thereby simplifying the overall procedure.
Solution Approach 2:
The rod is designed with multi-functionality, serving as both an insertion tool and part of the final implant assembly. It can be used to drive the screw into place and then removed, leaving the screw securely positioned to maintain bone stability.
3Reliability
If bone grafting material is packed into conventional screws, then bone fusion can be promoted, but the screw passages require additional packing steps and may not deliver material efficiently
Solution Approach 1:
A syringe is used to deliver bone grafting material through the hollow interior of the screw in a controlled manner. The material is injected through the distal opening and can be distributed evenly along the screw length, eliminating the need for manual packing and ensuring reliable material delivery.
Solution Approach 2:
The screw features a hollow interior with porous or open structure that allows bone grafting material to be delivered and retained. The material can be injected through the syringe and will remain in the screw's interior, promoting bone fusion as the material is gradually released and integrated with surrounding bone tissue.
Data Source
AI summary
A system for implanting an implant screw into one or more bones of a patient, such as the sacrum and the ilium, can include a rod and a screw. The screw can be generally hollow and have a blunt distal end. The rod can include a threaded and pointed distal end that is inserted through the rod to drive the screw through the bones. Once the screw is at a desired position, the rod can be removed such that the sharp driving edge used to seat the screw does not remain in the bone. The system can further include an extraction tool having a generally hollow body sized to be inserted over the rod and a distally located screw engagement portion configured to engage the screw to adjust positioning of the screw after it is initially seated.