Segmented Joint Implant Surface for Bone Ingrowth and Bacterial Resistance

Solution Overview

Problem

Current joint implants face challenges in achieving long-term stability through bone ingrowth while minimizing the risk of bacterial colonization, which can lead to implant failure due to the trade-off between osseointegration and antimicrobial properties.

Innovation Solution

The implant features a stem with a porous portion and a ridge, where the porous portion promotes bone ingrowth for secondary stability and the ridge provides primary stability with lower surface roughness to reduce bacterial adhesion, made from titanium alloys using additive manufacturing techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If porous structures are used to increase surface area for bone ingrowth, then osseointegration is improved, but the risk of bacterial colonization increases

Engineering Contradiction:

ImproveosseointegrationVSAvoidbacterial colonization

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The implant surface is segmented into distinct zones with different roughness characteristics. The proximal portion features high surface roughness (Ra ≥ 1.0 μm) to promote bone ingrowth and osseointegration, while the distal portion features low surface roughness (Ra < 0.5 μm) to minimize bacterial adhesion. This spatial segmentation allows each region to optimize for its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the implant surface are赋予 different local properties. The proximal section has high roughness specifically where bone contact is needed, while the distal section has low roughness where fluid flow and bacterial resistance are prioritized. This local differentiation of surface quality enables simultaneous optimization of osseointegration and antimicrobial properties in different locations.

Inventive Principle:

Principle #3Local quality

2Strength

If high surface roughness is applied to improve micromechanical retention, then primary and secondary implant stability are enhanced, but bacterial adhesion increases

Engineering Contradiction:

Improvemicromechanical retentionVSAvoidbacterial adhesion

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The implant surface is segmented into distinct zones with different roughness characteristics. The proximal portion features high surface roughness (Ra ≥ 1.0 μm) to promote bone ingrowth and osseointegration, while the distal portion features low surface roughness (Ra < 0.5 μm) to minimize bacterial adhesion. This spatial segmentation allows each region to optimize for its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the implant surface are赋予 different local properties. The proximal section has high roughness specifically where bone contact is needed, while the distal section has low roughness where fluid flow and bacterial resistance are prioritized. This local differentiation of surface quality enables simultaneous optimization of osseointegration and antimicrobial properties in different locations.

Inventive Principle:

Principle #3Local quality

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

This design enhances both primary and secondary stability of the implant by facilitating bone integration while minimizing bacterial colonization, thereby improving the long-term success of the implantation.

Implementation Method 1

insert an implant with at least a partial osteoconductive surface into a bone cavity. Such an osteoconductive surface promotes ingrowth of the surrounding bone tissue

Methodology Applied

Scientific EffectOsteoconduction:

Implementation Method 2

a press-fit is applied for primary stability to initiate bone ingrowth and to create a strong interface between the bone tissue and the implant

Methodology Applied

Scientific EffectPress-fit:

Implementation Method 3

titanium plays a vital role due to its biocompatibility and positive effect on osteoblasts in terms of creation of bone tissue on an implant's surface

Methodology Applied

Scientific EffectBiocompatibility:

Data Source

PatentUS20240268962A1Joint implant with a porous structure

Publication Date: 2024.08.15 WALDEMAR LINK GMBH & CO KG

AI summary

The disclosure includes an implant configured to contact a portion of a bone, the implant including a stem having a proximal section and a distal section and a porous portion extending a distance along the stem in a longitudinal direction of the stem.