Multi-Axial Cervical Retraction System for Spinal Fusion Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current retractor systems used in anterior cervical spinal fusion procedures cause significant retraction injuries, including swallowing difficulties and potential damage to the esophagus, trachea, and carotid artery, due to the need for extensive retraction and misalignment of distractor posts, leading to complications in plate placement and bone fusion.
Innovation Solution
A retractor device with multi-axial post and rod assemblies that allow for pivoted orientation, combined with retractor blades to minimize anatomical structure displacement, facilitating safer exposure and proper alignment for anterior cervical plate placement, reducing retraction-related injuries and improving surgical precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If extensive retraction is performed to expose the anterior cervical spine, then surgical exposure is improved, but retraction injuries to the esophagus, trachea, and carotid artery increase
Solution Approach 1:
The retractor system is divided into multiple independent post assemblies (first post assembly, second post assembly, etc.), each with its own rod and retractor blade. This segmentation allows each component to be independently positioned and adjusted, enabling precise control over retraction forces and distribution, thereby improving surgical exposure while minimizing concentrated retraction injuries to anatomical structures.
Solution Approach 2:
The rod is coupled to the post in a multi-axial manner allowing the rod to pivot relative to the post. This dynamic coupling enables the retractor blades to be positioned at optimal angles for exposure while distributing retraction forces more evenly across multiple attachment points, reducing the risk of injury to the esophagus, trachea, and carotid artery compared to fixed single-point retraction.
2Ease of operation
If distractor posts are inserted into adjacent vertebral bodies to distract open the disc space, then discectomy and graft placement are facilitated, but midline alignment is lost leading to crooked plate placement
Solution Approach 1:
The post assembly serves multiple functions: it acts as both a distractor to open the disc space and as a reference marker for midline alignment. The same post that distracts the vertebrae maintains its position to guide accurate plate placement, eliminating the need to remove distractors before plate insertion and ensuring consistent midline alignment throughout the procedure.
Solution Approach 2:
The post is inserted into the vertebral body at the correct midline position before distraction is applied. This preliminary correct positioning ensures that even after distraction forces are applied, the post remains in the proper midline location to serve as an alignment reference for subsequent plate placement, preventing crooked positioning.
3Reliability
If distractor posts are removed after distraction, then graft compression is achieved, but the ability to expose the anterior cervical spine and guide plate placement is lost
Solution Approach 1:
The coupling between the post and rod is designed to allow the rod to pivot and be positioned independently while maintaining the post's fixed position in the vertebral body. This dynamic design enables the rod and attached retractor blades to be removed for graft compression while the post remains in place to guide plate placement, achieving both graft compression and alignment guidance.
4Productivity
If current retractor systems are used, then disc space distraction is achieved, but the posts may slip out of place or rotate causing injury or perforation
Solution Approach 1:
The retractor system uses multiple separate post assemblies rather than a single centralized distractor. This segmentation distributes the distraction forces across multiple stable attachment points in the vertebral bodies, reducing the likelihood of any single post slipping or rotating, thereby improving overall system reliability and patient safety.
Data Source
AI summary
A retractor device for cervical spinal fusion surgery. The retractor device includes a first post assembly having a first pin for mounting the first post assembly to a first vertebral body and a first rod coupled thereto in a multi-axial manner so that the first rod can be pivoted relative to the first pin. The retractor device also includes a second post assembly having a second pin for mounting the second post assembly to a second vertebral body and a second rod coupled thereto in a multi-axial manner so that the second rod can be pivoted relative to the second pin. The retractor device also includes a first retractor blade having a first retractor blade arm slideably engageable to the first rod, and a second retractor blade having a second retractor blade arm slideably engageable to the second rod. The first retractor blade is slid down the first rod and the second retractor blade is slid down the second rod to be positioned and separate the anatomical structures.