Composite Porous Spinal Interbody for Osseointegration and Anchor Locking
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Solution Overview
Problem
Current spinal interbody implants face challenges with long-term stability and osseointegration, as well as issues with bone anchors loosening and causing tissue damage due to micro motion between vertebrae.
Innovation Solution
A composite interbody design is developed, featuring a metal alloy body with porous metal bonding on both surfaces, and a locking mechanism to prevent bone anchor back-out, utilizing titanium alloys and porous titanium for enhanced osseointegration and stability, along with a rotatable blocker to secure bone anchors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If porous titanium is used for interbody construction to improve osseointegration, then bone on-growth and in-growth are enhanced, but strength and durability decrease compared to solid titanium
Solution Approach 1:
The patent applies composite materials by combining solid titanium alloy (for structural strength) with porous titanium (for osseointegration) in a single interbody implant. The solid titanium alloy provides the mechanical framework and strength, while the porous titanium sections enable bone ingrowth and osseointegration, resolving the contradiction between strength and bone integration.
2Force
If bone anchors are used to fix the interbody in place, then initial stability is achieved, but micro motion causes the anchors to loosen and back-out over time
Solution Approach 1:
The patent applies dynamics by incorporating a rotatable blocker mechanism that transitions from an unlocked state (allowing bone anchor insertion) to a locked state (preventing back-out). The blocker rotates to engage with the bone anchors, dynamically adapting to the insertion process and then providing long-term stability by preventing reverse motion caused by micro-motion.
3Force
If bone anchors are used to secure the implant, then initial fixation is achieved, but the anchors may protrude and cause damage to sensitive tissue and organs
Solution Approach 1:
The patent applies beforehand cushioning by using the solid titanium alloy body as a protective barrier between the bone anchors and surrounding tissues. The solid material absorbs and distributes forces, preventing anchor protrusion and potential tissue damage while maintaining effective fixation.
4Strength
If solid metal alloy is used for the entire interbody, then strength and durability are maximized, but osseointegration and bone on-growth are insufficient
Solution Approach 1:
The patent applies local quality by creating regions of different material properties within the same implant - solid titanium alloy in areas requiring strength and structural support, and porous titanium in areas requiring bone contact and osseointegration. This localized differentiation optimizes both mechanical performance and biological integration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composite interbody design improves short and long-term stability, enhances osseointegration, and prevents bone anchor loosening, thereby reducing the risk of implant failure and tissue damage.
Implementation Method 1
bonding porous metal to the top surface; bonding porous metal to the bottom surface to form a composite metal alloy block
Data Source
AI summary
A method of forming a composite titanium body for use in forming spinal implant interbodies includes selecting a metal alloy body, carving out a top portion and a bottom portion from the metal alloy body, and bonding a porous material to the carved-out top and bottom portions. Multiple pieces may be cut from the composite titanium body, each having a front face formed of the metal alloy, top and bottom portions formed of the porous material, and with a medial portion of the metal alloy extending from the front face to the back. Methods and devices for spinal interbodies having locking mechanisms to prevent bone screw back-out are also described.