Expandable Bone Filler Material for Vertebral Height Restoration

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Solution Overview

Problem

Existing bone cements used in procedures like vertebroplasty and kyphoplasty often leak out of the vertebrae due to high injection pressure, causing harm to adjacent tissues and inadequate height restoration in vertebral compression fractures.

Innovation Solution

An expandable bone filler material that expands upon heating or energy application, reducing the need for high injection pressure by incorporating air pockets or biodegradable materials that release gas, allowing for controlled expansion within the bone structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If liquid cement is injected at high pressure to treat vertebral fractures, then the fracture can be stabilized, but the cement may leak outside the vertebra or into blood vessels causing harm to adjacent tissues

Engineering Contradiction:
Improvefracture stabilizationVSAvoidcement leakage to adjacent tissues
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the physical parameters of the bone filler material by incorporating expandable agents (gas-generating compounds, foam-forming agents) that transform the material from a liquid state during injection to an expanded solid state after injection. This parameter change allows the material to be injected at lower pressures while still achieving adequate fracture stabilization, thereby reducing leakage risk to adjacent tissues

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention utilizes phase transitions of the bone filler material - transitioning from liquid phase during injection to solid/expanded phase after injection. The expandable agents cause gas generation or foam formation that increases the material's volume and viscosity, effectively preventing leakage while maintaining fracture stabilization capability

Inventive Principle:
Principle #36Phase transitions

2Productivity

If high injection pressure is used to deliver bone cement, then the cement can be delivered to the treatment site, but the risk of undesirable leakage increases

Engineering Contradiction:
Improvecement delivery efficiencyVSAvoidleakage into blood vessels
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention modifies the rheological parameters of the bone filler material by incorporating expandable agents that increase viscosity and induce expansion after injection. This allows efficient cement delivery at reduced pressures, preventing leakage into blood vessels while maintaining productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The expandable agents act as intermediaries that facilitate cement delivery by generating gas or foam that propels the material through the injection needle and into the vertebral body, reducing the need for high external injection pressures and thereby preventing leakage into blood vessels

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional bone cement is used, then the injection process is simple, but height restoration in vertebral compression fractures is inadequate

Engineering Contradiction:
Improveinjection process simplicityVSAvoidvertebral height restoration
Core Design Contradiction:
Ease of manufactureVSLength of stationary object

Solution Approach 1:

The invention changes the volumetric parameters of the bone filler material through expandable agents that generate gas or form foam, increasing the material's final volume by 2-10 times. This volume expansion enables effective vertebral height restoration while maintaining relatively simple injection procedures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention utilizes phase transitions from liquid to expanded gas-filled structure, where the expandable agents transform the cement into a high-volume foam or gas-expanded material that effectively restores vertebral height while keeping the injection process simple

Inventive Principle:
Principle #36Phase transitions

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 expandable bone filler material effectively reduces leakage risk and enhances vertebral height restoration with lower injection pressures, providing safer and more effective treatment for vertebral compression fractures.

Implementation Method 1

air pockets within the filler material expand when heated, thereby causing the filler material as a whole to expand

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

air pockets are temporarily encased in a degradable material, such as polyglycolic acid (PGA) which, when the degradable material breaks down, the air is released resulting in an expansion of the bone filler material matrix

Methodology Applied
Scientific EffectBiodegradation: Decomposition (biological)

Implementation Method 3

RF energy is emitted to enlarge the first volume filler viscosity

Methodology Applied
Scientific EffectRadiofrequency heating: Dielectric Heating

Implementation Method 4

at least a portion of the applied heat energy is from the exothermic reaction of the curing process of the bone filler material

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP2180850B1Expandable bone filler materials and methods of using same
Publication Date: 2018.11.21 DEPUY SPINE INC
  • EP2180850B1 patent drawingFigure 1
  • EP2180850B1 patent drawingFigure 2
  • EP2180850B1 patent drawingFigure 3a~3b

AI summary

A bone filler material, comprising: at least one component adapted to expand at least a portion of the bone filler material thereby increasing the overall volume of the bone filler material.