Expandable Flange Talar Dome Implant Anchoring

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Solution Overview

Problem

Current total ankle replacement methods require significant bone modification and larger holes for stem insertion, which can be invasive and may not adequately anchor the implants, leading to potential instability and pain in damaged ankle joints.

Innovation Solution

An expandable stem implant with multiple flanges that can be inserted into a smaller hole in the bone and expanded using an expansion device to securely anchor the implant, mimicking the natural ankle joint's articulation surfaces and providing stability without extensive bone resection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional total ankle replacement methods are used with fixed stems, then the implant can be anchored in the bone, but significant bone modification and larger holes are required, which is more invasive and may not provide adequate anchoring

Engineering Contradiction:
Improveanchoring stabilityVSAvoidbone modification invasiveness
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The stem is designed to transition from a compressed low-profile configuration for insertion through a small canal to an expanded configuration that engages the bone wall, providing dynamic adaptation rather than requiring a large pre-formed hole

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stem's physical parameters (diameter, cross-sectional area) are changed from a compressed state during insertion to an expanded state after insertion, allowing the same component to pass through a small canal and then occupy a larger space for anchoring

Inventive Principle:
Principle #35Parameter changes

2Reliability

If larger holes are drilled for stem insertion, then better anchoring may be achieved, but more bone is removed and the procedure becomes more invasive

Engineering Contradiction:
Improveimplant anchoringVSAvoidbone removal
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The expandable stem allows the anchoring structure to be created after insertion rather than requiring a large hole to be drilled beforehand, thus preserving bone while achieving secure anchoring

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The compressed stem is nested within the small bone canal during insertion, then the stem expands outward to engage the canal walls, similar to a nested doll that fits through a small opening then occupies more space

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of manufacture

If more bone is resected to make space for the talar stem, then the implant can be installed, but the procedure becomes more invasive with potential instability and pain

Engineering Contradiction:
Improveimplant installationVSAvoidbone resection invasiveness
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The dynamic expansion capability allows the stem to be inserted through a minimal canal and then expanded to provide stable anchoring, eliminating the need for extensive bone resection that would be required for a fixed large-diameter stem

Inventive Principle:
Principle #15Dynamics

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 stem implant offers improved anchoring and stability in the ankle joint, reducing the need for extensive bone modification and potentially providing better pain relief and joint function compared to traditional methods.

Implementation Method 1

The plurality of flanges are expandable from a first diameter to a second diameter by driving an expansion device between the plurality of flanges

Methodology Applied
Scientific EffectMechanical Expansion: Mechanical Force

Data Source

PatentEP3649990B1Inbone talar dome with expandable flanges
Publication Date: 2022.07.06 WRIGHT MEDICAL TECHNOLOGY INC
  • EP3649990B1 patent drawingFigure 1~2
  • EP3649990B1 patent drawingFigure 3
  • EP3649990B1 patent drawingFigure 4

AI summary

A joint replacement implant (202) is disclosed. The implant includes a body (203) having a bone contact surface (210) and an articulation surface (204). An expandable stem (208) extends longitudinally from the bone contact surface. The expandable stem includes a plurality of flanges (208a, 208b). The plurality of flanges are expandable from a first diameter to a second diameter to anchor the implant to a bone.