Pliable Acetabular Cup Snap-Fit Cartilage Recess

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Solution Overview

Problem

Existing prosthetic hip joint components require significant bone removal during implantation, leading to invasive and irreversible procedures that can be painful and compromise the natural bone structure.

Innovation Solution

A method of implanting a prosthetic acetabular socket made of a pliable structural material with a non-linear stress-strain relationship, which is snap-fitted into the natural acetabulum without removing or damaging any bone, using a tool to create a recess in the articular cartilage and forming a liquid adhesion bond for secure engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional prosthetic hip joint components are implanted using conventional methods, then the prosthetic device can be securely fixed in place, but significant bone removal is required which is invasive and irreversible

Engineering Contradiction:

Improvesecure fixationVSAvoidbone removal damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts only the necessary articular cartilage layer (without bone) to create a recess for the prosthetic device. The cutting tool is designed to stop at the bone-cartilage interface, removing only the cartilage layer while preserving the underlying bone structure, thus achieving secure fixation without invasive bone removal

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention applies local quality by creating a recess with specific depth control that targets only the articular cartilage layer. The recess depth is precisely controlled to penetrate the cartilage layer and reach the bone surface without removing bone, providing localized preparation where needed while preserving the overall bone structure

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If a pliable structural material is used for the prosthetic device, then bone stress can be dissipated and bone strength preserved, but the device may have reduced structural stability

Engineering Contradiction:

Improvebone stressVSAvoiddevice structural stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The invention changes the material parameter from rigid to pliable by using elastomeric material with specific durometer values (40-80 Shore A). This parameter change allows the device to conform to the prepared recess and dissipate bone stress while maintaining sufficient structural stability through the material's elastic properties and the mechanical interlock provided by the snap-fit engagement

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the prosthetic device is made to conform to the prepared recess, then secure engagement is achieved, but the device requires custom shaping which increases manufacturing complexity

Engineering Contradiction:

Improveengagement securityVSAvoiddevice fabrication

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention applies dynamics by using a pliable, elastomeric material that can dynamically conform to the prepared recess shape during implantation. The material's elasticity allows it to be compressed during insertion and then expand to engage the recess walls, achieving secure engagement without requiring complex custom fabrication for each patient's anatomy

Inventive Principle:

Principle #15Dynamics

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 approach allows for the preservation of natural bone structure, reduces pain and invasiveness, and enables the prosthetic device to dissipate bone stress and potentially regenerate bone strength, while providing a secure and durable hip joint replacement.

Implementation Method 1

having mechanical properties characterized by a non-linear stress-strain relationship defined by a polynomial mathematical curve having more than two coefficients

Methodology Applied

Scientific EffectNon-linear stress-strain relationship: Viscoelasticity

Implementation Method 2

securely engaging the prosthetic acetabular cup with the acetabulum by snap-fitting the snap-fit structure of the prosthetic acetabular cup with the recess in the articular cartilage

Methodology Applied

Scientific EffectLiquid adhesion bond: Adhesive

Implementation Method 3

an outer surface of the prosthetic acetabular cup is wetted in some instances

Methodology Applied

Scientific EffectWetting: Wetting

Data Source

PatentUS7780740B2Methods, systems, and apparatus for implanting prosthetic devices into cartilage

Publication Date: 2010.08.24 ACTIVE IMPLANTS LLC

AI summary

A method of implanting a prosthetic acetabular cup into a patient is disclosed. The method comprises gaining access to an acetabulum of the patient, where the acetabulum includes an inner portion formed of bone and an outer portion formed of articular cartilage. The method also comprises creating a recess within the articular cartilage of the outer portion of the acetabulum without removing any portion of bone from the inner portion of the acetabulum. The recess is shaped to mate with a snap-fit structure of the prosthetic acetabular cup. Finally, the method comprises securely engaging the prosthetic acetabular cup with the acetabulum by snap-fitting the snap-fit structure of the prosthetic acetabular cup with the recess in the articular cartilage of the outer portion of the acetabulum.