Orthopedic Implant Surface Texture for Bone Ingrowth
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Solution Overview
Problem
Current orthopaedic prosthetic components face challenges in achieving stable bone ingrowth and preventing debris formation during implantation due to the design of existing surface features, which can lead to inadequate fixation and increased risk of breakage.
Innovation Solution
A porous three-dimensional structure with engagement studs extending from its surface, featuring a cone or pyramid shape, is designed to promote bone ingrowth and minimize debris formation, where the studs are integrated with the structure and have a specific height and orientation to enhance static friction and structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional sintered porous coatings or additive manufacturing structures with protruding particles or cylindrical spikes are used, then initial friction with bone is increased, but the structures are prone to breaking during impaction and generate significant debris
Solution Approach 1:
The surface features are segmented into multiple engagement studs with varying heights rather than uniform protrusions. This segmentation creates a progressive engagement mechanism where shorter studs engage first, followed by taller ones, distributing the impact force across multiple elements and reducing the likelihood of any single feature breaking.
Solution Approach 2:
Different regions of the implant surface have engagement studs with different heights (first height and second height greater than first). This local quality variation allows the implant to provide different levels of engagement and friction at different locations, optimizing both initial fixation and resistance to breakage during impaction.
2Strength
If engagement structures with greater height are used to increase friction and mechanical interlock, then bone ingrowth is promoted, but the risk of debris formation during impaction increases
Solution Approach 1:
The engagement structures are divided into multiple studs of varying heights rather than using a single uniform height. This segmentation allows the implant to engage bone progressively, with shorter studs making initial contact and taller studs providing additional mechanical interlock, thereby achieving strong bone ingrowth promotion without requiring any single feature to be excessively tall and debris-prone.
Solution Approach 2:
The height parameter of engagement studs is varied across different locations on the implant surface. By changing this geometric parameter, the design optimizes the balance between mechanical interlock strength and debris generation, ensuring that no single stud is so tall as to be fragile yet the collective structure provides sufficient engagement.
3Ease of manufacture
If random particles or uniform cylindrical spikes are used as surface features, then manufacturing is simplified, but the implant lacks stable mechanical interlock and is prone to breakage
Solution Approach 1:
The implant surface features are designed with local quality variations, specifically engagement studs of different heights at different locations. This provides stable mechanical interlock through progressive engagement while remaining compatible with additive manufacturing processes that can easily vary geometric parameters during construction.
Solution Approach 2:
The design adds height as a varying dimension to the engagement studs, transitioning from uniform two-dimensional surface patterns to three-dimensional structures with varying prominence. This dimensional variation enhances mechanical interlock stability while still being manufacturable through modern additive processes.
Data Source
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AI summary
An orthopaedic prosthetic component is provided. The prosthetic component comprises a base, a porous three-dimensional structure and at least one engagement stud extending past a surface boundary of the porous three-dimensional structure to engage a patient's bone.