Adjustable Spacer Device for Limb Prosthesis Infection Treatment

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Solution Overview

Problem

Current spacer devices for arthroprosthesis infections lack efficient, safe, and cost-effective mutual locking mechanisms between the stem and head, and do not adequately adapt to varying patient anatomy, which can lead to suboptimal articular functionality and prolonged recovery times.

Innovation Solution

A biologically compatible spacer device with adjustable connecting means featuring a screw/nut screw connection with rounded threading and a visual indicator for secure locking, allowing for customizable fit and pharmaceutical/therapeutic ingredient delivery, made from materials like polymethylmethacrylate, which can be adapted to different sizes and loaded with antibiotics or other active ingredients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If adjustable connecting means with screw/nut screw connection are used to adapt spacer device to different patient sizes, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improveadaptability to different patient sizesVSAvoidcomplexity of locking mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The spacer device employs adjustable connecting means with rounded threading that allows dynamic adaptation to different patient anatomies. The adjustable nature enables the device to be customized for various sizes while maintaining a relatively simple overall structure, resolving the contradiction between adaptability and complexity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If secure locking mechanism is implemented between stem and head, then reliability is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvesecurity of mutual lockingVSAvoidease of locking operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces traditional complex screw/threaded locking systems with a rounded threading mechanism that provides secure locking through simplified mechanical interaction. This substitution maintains reliability while significantly improving ease of operation during implantation and adjustment procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If biologically compatible porous material is used for pharmaceutical delivery, then therapeutic effectiveness is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvetherapeutic effectivenessVSAvoidprecision of porous structure
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The spacer device is constructed from biologically compatible porous material that enables pharmaceutical product delivery to the infection site. The porous structure allows for drug loading and controlled release while maintaining manufacturability through established porous material fabrication techniques, balancing therapeutic effectiveness with manufacturing feasibility.

Inventive Principle:
Principle #31Porous materials

Data Source

PatentEP2758003B1Modular spacer device for the treatment of infections of the prosthesis of the human limbs
Publication Date: 2020.11.11 TECRES SPA
  • EP2758003B1 patent drawingFigure 1~15
  • EP2758003B1 patent drawingFigure 2~7
  • EP2758003B1 patent drawingFigure 8~13

AI summary

A spacer device (1) for the two-stage treatment of infections of the prosthesis of the human limbs, made of biologically compatible material adapted to be added and/or which can be added with pharmaceutical products, active and/or therapeutic ingredients, comprising a first portion (2) adapted to be fixed to a corresponding bone bed, a second portion (3) adapted to be inserted in a corresponding articular area of the patient, said first portion (2) and said second portion (3) being connected through adjustable joining means (4). The device comprises mutual coupling surfaces (10,11) respectively provided in said first portion (2) and said second portion (3) coated with said biologically compatible material. A method for locking the first portion (2) to the second portion (3) is also provided.