Dual Mobility Acetabular Insert with Segmented Chamfers

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Solution Overview

Problem

Current dual mobility acetabular implants suffer from increased contact stress and potential damage due to a single chamfer design that is not optimized for the variety of femoral neck and head combinations, leading to impingement conditions and risk of dislocation.

Innovation Solution

The insert for a dual mobility acetabular implant is designed with multiple chamfers to define multiple contact surfaces, accommodating various femoral neck and head configurations, reducing contact stress and preventing dislocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single chamfer design is used in the insert, then the structure is simple and easy to manufacture, but it cannot accommodate various femoral neck and head configurations, leading to increased contact stress and impingement

Engineering Contradiction:
Improveaccommodation of various femoral neck and head configurationsVSAvoidinsert structure with multiple chamfers
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The insert rim is segmented into multiple chamfers (first chamfer, second chamfer, third chamfer) instead of a single continuous chamfer. Each chamfer is positioned at different angles and locations to accommodate different femoral neck and head configurations. This segmentation allows the insert to adapt to various impingement conditions while distributing contact stress across multiple surfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the insert rim are given different geometric properties through the multiple chamfers. Each chamfer has specific angular orientations (e.g., first chamfer at 45 degrees, second chamfer at 30 degrees, third chamfer at 60 degrees) optimized for specific femoral component combinations. This local differentiation of geometric quality enables the insert to handle diverse impingement scenarios effectively.

Inventive Principle:
Principle #3Local quality

2Stress or pressure

If a single chamfer is used at the insert rim, then the manufacturing process is simple, but contact stress is concentrated leading to potential damage and dislocation

Engineering Contradiction:
Improvecontact stress distributionVSAvoidinsert manufacturing complexity
Core Design Contradiction:
Stress or pressureVSEase of manufacture

Solution Approach 1:

The contact surface at the insert rim is divided into multiple segmented chamfers instead of one large continuous chamfer. This segmentation distributes the contact stress from femoral neck impingement across multiple smaller surfaces, reducing peak stress concentrations that would lead to material damage or dislocation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a single-dimensional chamfer (one contact surface) to a multi-dimensional arrangement of multiple chamfers at different angular positions around the insert rim. This dimensional expansion in the angular domain allows stress distribution across multiple planes and orientations.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4281015B1Dual mobility acetabular implant for hip revision surgery
Publication Date: 2025.04.02 SMITH & NEPHEW INC
  • EP4281015B1 patent drawingFigure 1
  • EP4281015B1 patent drawingFigure 2A
  • EP4281015B1 patent drawingFigure 2B

AI summary

An insert (240) arranged and configured for use in a dual mobility acetabular implant (100) is disclosed. The insert includes a plurality of chamfers (260, 262, 264) arranged and configured to contact the femoral neck (172) and/or head (170) of a femoral implant (175). The insert includes a plurality of chamfers such as, for example, two or three chamfers to define a plurality of differently arranged contact surfaces for contacting the femoral component to accommodate a variety of different femoral component configurations and/or impingement conditions in order to reduce contact stress between the insert and the femoral component.