Multi-Axial Spinal Anchor With Removable Extension Post
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Solution Overview
Problem
Current orthopedic spinal surgery techniques lack systems and methods that provide multi-axial capabilities for anchor assemblies to securely attach elongated implants like plates or rods to vertebrae, limiting the flexibility and stability in correcting bone misalignment disorders and spinal fusion.
Innovation Solution
A multi-axial anchor assembly is introduced, featuring a coupling member with a post and receiver portion, a locking mechanism, and a crown that securely engages an elongate plate member to a vertebra, allowing for pivotal movement and secure fixation, enabling dynamic or rigid stabilization of the spinal column.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional anchor assemblies are used to secure plates to vertebrae, then the plate can be attached to the bone, but the system lacks multi-axial capabilities and flexibility in positioning
Solution Approach 1:
The anchor assembly is divided into separate functional components: a coupling member with receiver portion, a crown element, a locking member, and an extension portion. This segmentation allows each component to perform its specific function while enabling multi-axial adjustment capabilities without requiring a completely complex monolithic structure.
Solution Approach 2:
The coupling member is designed to allow dynamic adjustment between locked and unlocked states, enabling multi-axial positioning of the crown relative to the plate. The locking member can be engaged or disengaged to fix the crown in desired orientations, providing both flexibility during positioning and stability after fixation.
2Ease of operation
If the anchor assembly allows pivotal movement for multi-axial adjustment, then flexibility in positioning is improved, but the stability and secure fixation may be compromised
Solution Approach 1:
The system transitions from a static fixed-position anchor to a dynamic system that can be adjusted in multiple axes during positioning, then locked into place. The coupling member enables pivotal movement when unlocked, allowing the surgeon to position the crown optimally, and provides secure fixation when the locking member is engaged.
Solution Approach 2:
The locking member is designed to maintain the crown in its positioned orientation without requiring additional active components or continuous adjustment. Once the desired multi-axial position is achieved, the locking mechanism secures the position passively, providing reliable fixation that maintains positioning flexibility while ensuring secure attachment.
3Strength
If the post extends proximally for plate engagement, then the plate can be securely attached, but the profile and space requirements increase
Solution Approach 1:
The post is segmented into an extension portion and a main body portion separated by a breakable junction. The extension portion can be removed after plate attachment, leaving only the essential coupling member and crown in place. This reduces the overall profile of the implanted device while maintaining the strength needed for secure plate attachment during the attachment process.
Solution Approach 2:
The extension portion of the post is designed as a temporary component that is extracted (removed) after serving its purpose of facilitating plate attachment. This extraction reduces the volume and profile of the permanent implant while having already provided the necessary structural support for secure plate fixation.
4Stability of the object's composition
If the locking member secures the plate to the coupling member, then rigid fixation is achieved, but the multi-axial adjustment capability is lost
Solution Approach 1:
The system is designed with dynamic characteristics that allow it to transition between two states: an unlocked state where the crown can pivot multi-axially relative to the coupling member for positioning, and a locked state where the locking member secures the crown in the desired position, providing rigid fixation. The ability to switch between these states resolves the contradiction between adjustability and rigidity.
Data Source
AI summary
Systems and methods are provided that include a plate member engageable to the spinal column with an anchor assembly. The anchor assembly includes a coupling member having a post extending through at least one opening of the plate member and an anchor member pivotally captured in a receiver member of the coupling member below a lower surface of the plate member. A locking member secures the plate member to the coupling member. The coupling member includes an extended post with a proximal removable portion. The extended post facilitates placement of the plate member in position relative to the anchor assembly when engaged to the patient and be employed to reduce the plate member toward the anchor assembly when engaged to a vertebra.