Cervical Spinal Plate with Tulip Assembly for Secure Fixation
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Solution Overview
Problem
Existing spinal fixation techniques, such as lateral mass screws, often result in poor bone purchase and a high risk of screw pullout or loosening, especially in patients with osteoporosis or kyphotic deformities, due to inadequate bone strength and push-in torque.
Innovation Solution
A spinal plate and screw system that includes a plate with multiple locking screws and a tulip assembly, allowing for secure attachment to the spine without engaging the full length of pedicles and vertebral bodies, thereby providing a stronger and safer fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lateral mass screws are used for cervical fixation, then the surgery is safe and easy to perform with minimal fluoroscopic guidance, but the bone purchase is poor and there is a high risk of screw pullout or loosening
Solution Approach 1:
The invention divides the fixation system into separate components: a cervical plate that spans multiple vertebrae and individual screws that attach to the plate. This segmentation allows the plate to distribute fixation forces across multiple attachment points, improving overall bone purchase while maintaining the ease of screw placement characteristic of lateral mass screws.
Solution Approach 2:
The invention combines multiple lateral mass screw attachments into a single plate construct. By merging several individual screw fixations into one integrated plate system, the overall fixation strength is enhanced while preserving the advantages of lateral mass screw placement (ease of insertion, minimal fluoroscopic guidance required).
2Reliability
If cervical pedicle screws are used for stronger fixation, then the bone purchase is improved, but the surgical complexity increases and there is a higher risk of vertebral artery or spinal cord injury
Solution Approach 1:
The cervical plate serves as an intermediary structure between the vertebrae. Instead of placing screws directly into the pedicles (which risks vertebral artery or spinal cord injury), the plate attaches to the lateral masses or other safe locations on adjacent vertebrae, providing strong fixation without the need for dangerous pedicle screw placement.
Solution Approach 2:
The invention shifts the fixation approach from a vertical orientation (pedicle screws going through the pedicle) to a more horizontal or lateral orientation (plate attaching to lateral masses). This dimensional change allows achieving strong bone purchase while avoiding the critical structures located within the pedicle pathway.
3Strength
If longer screws are used to engage the full length of pedicles and vertebral bodies, then the fixation strength is improved, but the risk of nerve and vascular damage increases
Solution Approach 1:
The cervical plate performs multiple functions: it provides fixation strength across multiple vertebrae, distributes mechanical loads, and avoids the need for long pedicle screws. This multi-functionality allows achieving strong fixation without the harmful effects of long screw insertion into critical anatomical structures.
Data Source
AI summary
Disclosed herein is a device that comprises include a plate; a plurality of locking screws attached to the plate; a locking polyaxial and/or a monoaxial screw; a tulip assembly, having inner threads and a bottom hole, attached to the plate with the plurality of the locking polyaxial and/or monoaxial screw; a set screw having threads; and a rod connected to the tulip assembly by the set screw.