Constrained Intervertebral Disc Prosthesis Insertion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for inserting intervertebral disc prostheses require excessive vertebral distraction, leading to tissue trauma and increased pain, as they necessitate wide spreading of vertebrae to accommodate the prosthesis, which is invasive and causes unnecessary strain on surrounding muscles, ligaments, and nerves.
Innovation Solution
The method involves inserting the prosthesis partway under constraint to prevent endplate articulation, then releasing the constraint to allow endplates to articulate, reducing the need for excessive distraction and enabling the prosthesis to be positioned closer to the posterior vertebrae edges, thus minimizing tissue trauma and invasiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wide spreading of vertebrae is used to accommodate the prosthesis, then the prosthesis can be inserted into the intervertebral space, but tissue trauma and pain increase
Solution Approach 1:
The method performs preliminary preparation by removing the damaged disc and creating the intervertebral space before prosthesis insertion, allowing the prosthesis to be inserted with minimal additional distraction. The constrained insertion method also preliminarily positions the prosthesis before final articulation, reducing the need for excessive spreading during the actual insertion process.
Solution Approach 2:
The prosthesis transitions from a constrained state during initial insertion to an unconstrained state where endplates can articulate. This dynamic approach allows the prosthesis to adapt to the intervertebral space after insertion, eliminating the need for permanent wide spreading of vertebrae and reducing tissue trauma.
2Ease of operation
If vertebrae are spread wide to insert the prosthesis, then insertion is achieved, but strain on surrounding muscles, ligaments, and nerves increases
Solution Approach 1:
The intervertebral space is preliminarily prepared by removing the damaged disc and creating adequate space before prosthesis insertion. This preliminary action reduces the force needed during actual prosthesis insertion, minimizing strain on surrounding tissues.
Solution Approach 2:
The constrained insertion method acts as an intermediary approach, allowing the prosthesis to be inserted in a controlled manner without requiring the vertebrae to be spread wide. The constraint mechanism mediates between the need for insertion and the need to minimize tissue strain.
3Adaptability or versatility
If the prosthesis is inserted without constraint allowing immediate articulation, then endplates can move freely, but positioning control and precision are reduced
Solution Approach 1:
The prosthesis is preliminarily positioned in the intervertebral space under constraint before articulation is allowed. This preliminary positioning ensures accurate placement, and only after correct positioning is the constraint released to allow natural endplate movement.
Solution Approach 2:
The prosthesis transitions from a constrained state during positioning to an unconstrained state for articulation. This dynamic approach ensures that positioning precision is maintained during insertion, while adaptability is preserved once the prosthesis is correctly positioned.
4Ease of operation
If excessive distraction is applied to insert the prosthesis, then insertion is facilitated, but post-surgical pain and invasiveness increase
Solution Approach 1:
The damaged disc is preliminarily removed and the intervertebral space is prepared before prosthesis insertion, creating adequate space without requiring excessive distraction during the actual insertion process.
Solution Approach 2:
The constrained insertion method serves as an intermediary technique that facilitates prosthesis insertion without requiring excessive distraction. The constraint mechanism allows controlled insertion while minimizing the harmful effects of over-distraction on surrounding tissues.
Data Source
AI summary
A method for inserting an intervertebral disc prosthesis into a space between two vertebrae involves inserting the prosthesis partway into the space under constraint to prevent endplates of the prosthesis from articulating, releasing the prosthesis from constraint, and inserting the unconstrained prosthesis farther into the space. In some embodiments, the method involves grasping the prosthesis with a grasping device to insert the prosthesis partway under constraint, loosing the grasping device to release the prosthesis from constraint, and pushing the prosthesis farther into the disc space using the grasping device and/or one or more separate pusher devices. A system includes a grasping device, at least one separate pushing device, and optionally a vertebral spreading device and/or a vertebral midline indicator device.