Hybrid-Fixation Glenoid Implant for Stable Bone In-Growth

Solution Overview

Problem

Improving the stability of glenoid implants in shoulder arthroplasty remains a challenge in shoulder implant design.

Innovation Solution

The development of anatomic glenoid implants with a hybrid fixation post comprising a polymer base portion and a metallic distal portion, where the metallic portion includes a porous metallic layer to promote bone in-growth and is joined to the polymer base through an interdigitated lattice structure for a robust mechanical interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional single-material fixation post is used, then the manufacturing process is simple, but the stability and bone integration are insufficient

Engineering Contradiction:

ImprovestabilityVSAvoidstructure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fixation post is constructed as a composite structure with a metallic distal portion and a polymer proximal portion, combining the advantages of both materials: metal provides structural strength and bone ingrowth capability through porous coating, while polymer provides flexibility and reduces stress shielding. This composite approach directly resolves the contradiction by achieving superior stability without requiring entirely new manufacturing processes, as each material can be fabricated separately and then joined.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The fixation post is divided into two distinct segments: a distal metallic portion for bone engagement and a proximal polymer portion for structural support. This segmentation allows each portion to be optimized for its specific function - the metal portion with porous coating for bone ingrowth, and the polymer portion for flexibility - while being manufactured separately and then joined through interference fit or bonding, thus improving reliability without excessive complexity.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a porous metallic layer is added to promote bone in-growth, then bone integration improves, but the manufacturing complexity increases

Engineering Contradiction:

Improvebone integrationVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

A porous metallic layer or coating is applied to the distal portion of the fixation post to create an interconnected pore structure that facilitates bone ingrowth. The porosity allows osteoblasts to migrate into the structure and form new bone tissue, directly improving bone integration. The porous structure can be created through various established techniques such as plasma spray, electron beam physical vapor deposition, or sintering of metal particles, which are proven manufacturing processes that balance bone integration benefits with manufacturing feasibility.

Inventive Principle:

Principle #31Porous materials

3Strength

If an interdigitated lattice structure is used to join polymer and metal, then the mechanical interface strength increases, but the manufacturing precision requirements increase

Engineering Contradiction:

Improvemechanical interfaceVSAvoidinterface fit

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The fixation post is divided into two distinct segments: a distal metallic portion for bone engagement and a proximal polymer portion for structural support. This segmentation allows each portion to be optimized for its specific function - the metal portion with porous coating for bone ingrowth, and the polymer portion for flexibility - while being manufactured separately and then joined through interference fit or bonding, thus improving reliability without excessive complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixation post is constructed as a composite structure with a metallic distal portion and a polymer proximal portion, combining the advantages of both materials: metal provides structural strength and bone ingrowth capability through porous coating, while polymer provides flexibility and reduces stress shielding. This composite approach directly resolves the contradiction by achieving superior stability without requiring entirely new manufacturing processes, as each material can be fabricated separately and then joined.

Inventive Principle:

Principle #40Composite materials

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

Enhances the stability and integration of the glenoid implant by providing a strong hybrid structure that reduces slip-out and toggle movement, while promoting bone in-growth and ensuring a secure fixation.

Implementation Method 1

the metallic portion includes a porous metallic layer to promote bone in-growth

Methodology Applied

Scientific EffectOsteoconduction:

Implementation Method 2

joined to the polymer base through an interdigitated lattice structure for a robust mechanical interface

Methodology Applied

Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentUS20260033955A1Glenoid implants with hybrid fixation

Publication Date: 2026.02.05 HOWMEDICA OSTEONICS CORP

AI summary

Disclosed are embodiments of anatomic glenoid implants that incorporate hybrid fixation.