Spinal Implant Variable Angulation Convexity Fit

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Solution Overview

Problem

Current spinal implants for vertebral body replacement or fusion fail to adequately address the variation in anatomy along the spine, leading to instability and limited success in alleviating chronic back pain due to insufficient strength, material compatibility for bony growth, and improper fit.

Innovation Solution

A spinal implant with superior and inferior surfaces featuring surface teeth and a side wall with specific angulation, vertical through-channels, and undercuts, designed to match the lordosis and convexity of vertebral bodies, promoting bony ingrowth and stability through a customizable fit and fixation with anchor plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a standard spinal implant is used, then the implant can be easily manufactured and inserted, but it fails to accommodate anatomical variations in vertebral bodies leading to poor fit and stability

Engineering Contradiction:
Improveanatomical fitVSAvoidimplant design
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The implant incorporates variable angulation (2-30 degrees) and variable convexity (different radius of curvature values) in different regions of the implant body to match the local anatomical variations of vertebral bodies at different spinal levels, while maintaining a generally uniform cylindrical structure for manufacturing simplicity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies parameter changes by varying the angulation and convexity parameters of the implant to create a family of implants with different geometric characteristics that can be selected to match specific anatomical requirements, allowing standard manufacturing processes to produce multiple customized variants

Inventive Principle:
Principle #35Parameter changes

2Strength

If a simple spacer is used to fill the void, then the insertion is easy, but the spacer is not strong enough to support the spine and may not remain in position

Engineering Contradiction:
Improvestructural supportVSAvoidinsertion
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The implant features convex superior and inferior surfaces with radius of curvature values between 5-20mm that match the natural curvature of vertebral endplates, improving fit and stability while maintaining a simple cylindrical body that allows straightforward insertion through the prepared intervertebral space

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The implant incorporates asymmetric angulation (2-30 degrees) between superior and inferior surfaces to match the natural lordotic curvature of the spine, providing improved anatomical fit and load distribution while maintaining a relatively simple cylindrical structure for ease of insertion

Inventive Principle:
Principle #4Asymmetry

3Reliability

If a spacer with uniform surfaces is used, then the manufacturing is simple, but it does not promote bony growth around the spacer

Engineering Contradiction:
Improvebony fusionVSAvoidsurface fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The implant incorporates a porous coating on its surface that promotes bony ingrowth and fusion with the adjacent vertebral bodies, providing reliable biological fixation while the underlying cylindrical structure can be manufactured using standard processes before applying the porous surface treatment

Inventive Principle:
Principle #31Porous materials

Data Source

PatentEP2991590B1Vertebral body replacement or fusion device
Publication Date: 2019.11.13 DEPUY SYNTHES PROD INC
  • EP2991590B1 patent drawingFigure 1A~1F
  • EP2991590B1 patent drawingFigure 1E
  • EP2991590B1 patent drawingFigure 1G~1L

AI summary

The present disclosure relates to a spinal implant or spacer that addresses the variation in anatomy of vertebrae along the spine by having inferior and superior surface angle and convexity variations that are adapted to address the differences in lordosis and endplate surface convexity of the spine. The difference between the convexity of the superior and inferior surface of the spacer increases as the lordotic angle of the spacer increases. The spacers described herein thus provide overall improved fit into vertebral disc space and in some embodiments are even used in the absence of fusion for a prolonged period. The vertebral spacers described herein in some embodiments are used with supplemental internal fixation systems, such as an anchor plate. The interior of the spacer has channels and undercuts to increase graft volume and retention, support bony ingrowth, and bony stability for better secondary and tertiary stabilization.