Expanding Hip Joint Fixation Without Cement or Screws

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Solution Overview

Problem

Current hip joint prosthetics face complications such as loosening and dislocation due to abnormal strain, often requiring bone cement or penetrating screws, which can lead to bodily reactions and instability.

Innovation Solution

A medical device with an expanding portion that inserts into the femoral bone to provide fixation without penetrating or using bone cement, featuring a plurality of expansion members that distribute force evenly and can adapt to the bone's anatomy, along with a stabilizing member for enhanced stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bone cement or penetrating screws are used for fixation, then the prosthesis can be secured to the femoral bone, but the prosthesis may loosen or dislocate due to abnormal strain and cause bodily reactions

Engineering Contradiction:

Improvefixation stabilityVSAvoidbodily reaction and loosening

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The fixation device is divided into multiple expansion members (at least three) that can independently expand and contact the bone wall at different locations. This segmentation distributes the fixation force and creates multiple contact points, enhancing stability while reducing stress concentration that could cause loosening or bodily reactions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The expansion members are designed to be deformable and expandable within the bone cavity. They can dynamically adjust their shape and position to accommodate anatomical variations and distribute forces evenly against the bone wall, creating a stable fixation without rigid penetrating screws that may cause loosening under abnormal strain.

Inventive Principle:

Principle #15Dynamics

2Strength

If penetrating screws or bone cement are used for fixation, then the prosthesis can be attached to the bone, but the fixation may cause instability under abnormal strain such as falling or rapid movement

Engineering Contradiction:

Improvefixation strengthVSAvoidfixation stability under strain

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

Different expansion members are positioned at different locations on the bone wall to create localized fixation points. Each expansion member contacts the bone wall at its specific location, distributing the fixation strength across multiple areas. This local quality approach ensures that abnormal strain at one location does not compromise the entire fixation, maintaining stability under falling or rapid movement.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The fixation device combines multiple expansion members made of appropriate materials that can deform and expand within the bone cavity. This composite structure of multiple expandable elements working together creates a fixation system that maintains strength while adapting to strain, preventing loosening and dislocation.

Inventive Principle:

Principle #40Composite materials

3Device complexity

If a simple expanding portion is used, then the device structure is simpler, but it may not accommodate anatomical variations of the femoral bone

Engineering Contradiction:

Improvedevice structureVSAvoidanatomical adaptation

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The expansion members are designed to be deformable and capable of expanding in different directions and degrees. This dynamic capability allows the fixation device to adapt to the specific anatomical shape and size of the femoral bone cavity, accommodating anatomical variations without requiring complex pre-shaped structures for each patient.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The fixation device consists of multiple independent expansion members that can be positioned and expanded to match the specific geometry of the bone cavity. This segmented approach provides adaptability to anatomical variations while keeping each individual expansion member relatively simple in structure.

Inventive Principle:

Principle #1Segmentation

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 solution achieves sturdy fixation without bone cement or penetrating screws, allowing for stable integration of the prosthetic hip joint while accommodating anatomical variations and withstanding movement-related stresses.

Implementation Method 1

the expanding portion comprises a plurality of expansion members (658a-d), adapted to expand radially away from the longitudinal axis (656)

Methodology Applied

Scientific EffectRadial expansion:

Data Source

PatentUS20230397994A1Hip Joint Device

Publication Date: 2023.12.14 FORSELL PETER

AI summary

A medical device for fixation in a femoral bone of a patient is provided, the medical device comprises: a connecting portion adapted to be connected to a prosthetic hip joint contacting portion, an expanding portion, and a bone contacting surface on the expanding portion. The expanding portion could be adapted to be at least partially inserted into the femoral bone of a patient and to expand within the femoral bone, such that the bone contacting surface is placed in contact with the inside of the femoral bone for fixating the medical device to the femoral bone. By the fixation using an expanding portion a sturdy fixation is achieved without the need to go into or penetrate bone, or the need for fixation using bone cement.