Lockable Polyaxial Ball and Socket Fastener for Spinal Implants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spinal implant systems require a large inventory of variously sized implants and often necessitate angular insertion due to muscle and nerve structures, leading to increased surgical difficulty and trauma, as the bone structure cannot be determined until exposure, and existing polyaxial screws lack flexibility in accommodating different bone conditions.
Innovation Solution
A lockable polyaxial ball and socket joint system that allows snap-together assembly and polyaxial movement, featuring a U-shaped connector with dual retainer rings for secure attachment of anchoring screws without tools, enabling flexible positioning and adjustment during surgery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a large inventory of various sized implants is maintained to accommodate different bone conditions, then the ability to address diverse spinal pathologies is improved, but the device complexity and inventory management burden increase
Solution Approach 1:
The ball and socket fastener is designed with a universal socket interface that can accommodate multiple ball sizes and configurations. The socket member features a polyaxial reception cavity that can securely hold balls of varying diameters, allowing a single socket design to serve multiple anchoring screw sizes and types, thereby reducing the need for multiple specialized components
Solution Approach 2:
The fastener incorporates polyaxial movement capability, allowing the ball to move freely within the socket during insertion and positioning. This dynamic feature enables the system to adapt to different insertion angles and bone orientations without requiring precise pre-planning, accommodating various spinal pathologies with a standardized component set
2Reliability
If angular insertion is required to accommodate muscle and nerve structures, then the ability to secure anchoring is improved, but the surgical difficulty and patient trauma increase
Solution Approach 1:
The polyaxial ball and socket mechanism allows the ball to move dynamically within the socket during insertion, accommodating various angles of approach. This dynamic positioning capability enables surgeons to insert anchoring screws at optimal angles relative to muscle and nerve structures while maintaining secure connection to the stabilizing rod, reducing surgical difficulty and patient trauma
Solution Approach 2:
The system allows change in the orientation parameter of the ball relative to the socket during insertion. The polyaxial design permits the ball to be inserted at multiple angles and then locked into position, enabling adaptation to different anatomical conditions without requiring complex surgical maneuvers or causing excessive tissue trauma
3Reliability
If oversize threads are used to achieve suitable bone purchase, then the anchoring reliability is improved, but the device complexity and inventory requirements increase
Solution Approach 1:
The socket member is designed with a universal reception cavity that can accommodate balls of different sizes, including those with oversize threads. The polyaxial design and adjustable retention mechanism allow the same socket to securely hold various ball configurations, enabling a single socket design to work with multiple anchoring screw variants, thereby reducing device complexity while maintaining anchoring reliability
Data Source
AI summary
A polyaxial ball and socket joint that can be locked into a fixed position. The fastening system consists of the polyaxial ball and socket joint used in conjunction with a bone screw having threads on one end for use in anchoring to the spine and a spherical connector on the other end operating as a pivot point about which a connecting assembly moves in a polyaxial fashion. A substantially U-shaped connecting assembly has a lower receptacle that operates as a socket for housing an upper retainer ring and a lower split retaining ring. The socket is receptive to the spherical connector which is inserted through the lower split retainer ring causing a momentary displacement thereof which allows for the positioning of the spherical connector between the upper and lower retainer rings.