Rod Contouring Alignment Linkage for Minimally Invasive Spine Surgery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current orthopedic implant configuration methods require large incisions for accurate bone measurement, which contradicts the minimally invasive surgical approach by necessitating exposure of a significant area for implant selection and configuration.
Innovation Solution
A system utilizing pedicle screws with polyaxial coupling and extenders, along with an alignment linkage, allows for the projection of anatomic points outside the body, enabling precise rod contouring and implant selection through small incisions by ensuring extenders are parallel, thus mimicking the spatial relationship of internal anatomic points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If large incisions are made to permit bone measurement and implant selection, then measurement precision is improved, but surgical trauma and procedure complexity increase
Solution Approach 1:
The patent introduces extenders as intermediary devices that attach to pedicle screws and project anatomic points outside the body. These extenders act as mediators between the internal bone structures and the external measurement tools, allowing accurate measurement through small incisions without requiring large exposure areas. The extenders transmit the spatial relationships of internal anatomic landmarks to an externally accessible location.
2Measurement precision
If large incisions are made to permit bone measurement, then measurement precision is improved, but device complexity and surgical procedure complexity increase
Solution Approach 1:
The alignment linkage serves as an intermediary device that connects to the extenders and provides a mechanical framework for accurate measurement. This linkage system simplifies the overall procedure by providing a structured method to establish spatial relationships and guide implant selection, reducing the need for complex surgical techniques while maintaining measurement precision through small incisions.
3Adaptability or versatility
If extenders are not parallel to each other, then adaptability to varying bone trajectories is improved, but measurement accuracy and rod configuration precision deteriorate
Solution Approach 1:
The extenders are designed with dynamic adjustment capabilities, allowing them to be positioned at various angles to accommodate different bone trajectories and anatomical variations. The alignment linkage provides a dynamic framework that can adapt to varying spatial relationships while maintaining the parallel configuration necessary for accurate measurement. This dynamic system enables the surgeon to adjust extender positions to match patient-specific anatomy while ensuring proper alignment for precise rod contouring.
Data Source
AI summary
Pedicle screws are designed to provide polyaxial coupling to pedicles of a vertebra. Intermediate pieces are attached to the pedicles screws and receive extender shafts. Extenders are inserted in the intermediate piece. The extenders project the anatomic points located in the cage outside the patient's body to facilitate proper contouring of a rod. An alignment linkage is used to ensure that the extenders are parallel to each other. The alignment linkage includes a linkage frame, an articulating linkage and a locking member. The articulating linkage has all rotational degrees of freedom and thereby adapts to any varying trajectories of the extenders and distance between the extenders. The alignment linkage includes a locking member with a pop-up indicator. The pop-up indicator notifies the users when the locking member is tightened with two of the extenders in non-parallel configuration.