Modular Knee Arthroplasty Trial Assembly for In Vivo Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing orthopedic procedures for revision knee arthroplasty are costly and time-consuming due to the complexity of aligning and documenting the positions of multiple provisional components during surgery.

Innovation Solution

A provisional orthopedic system comprising a stem provisional assembly with interchangeable adaptors and extensions that can be assembled in vivo and maintained in relative positions, allowing for easy reference and efficient creation of permanent implants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple provisional components are used in revision knee arthroplasty, then the alignment and positioning of implants can be achieved, but the surgical process becomes complex and time-consuming

Engineering Contradiction:
Improvealignment precisionVSAvoidnumber of components
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple provisional components (adaptor, stem extension, and trial prosthesis) into a single integrated provisional assembly that functions as one unit. This merging reduces the number of separate components the surgeon must handle and document, while maintaining the ability to achieve precise alignment and positioning through the integrated design of the assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The provisional assembly is designed to perform multiple functions simultaneously: it provides alignment guidance, serves as a trial prosthesis, and establishes positioning references. The adaptor portion can accommodate different stem extensions, and the entire assembly can be used for both alignment and final positioning, reducing the need for multiple separate instruments.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple provisional components are used in revision knee arthroplasty, then the alignment and positioning of implants can be achieved, but the surgical time and cost increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsurgical time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

By combining multiple components into one integrated provisional assembly, the surgeon reduces the time required for assembly, documentation, and manipulation of multiple separate parts. The integrated design allows the assembly to be inserted and positioned as a single unit, significantly reducing surgical time while maintaining positioning accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The provisional assembly is pre-configured with the adaptor and stem extension connected before insertion. This preliminary assembly reduces the time required during surgery to combine multiple components and document their positions, as the relative positioning is already established in the pre-assembled unit.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If detailed positioning documentation of each provisional component is performed, then accurate implant placement can be achieved, but the surgical process becomes more complex

Engineering Contradiction:
Improveimplant placement accuracyVSAvoiddocumentation complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the positioning reference function into the integrated provisional assembly itself. The assembly's design incorporates inherent positioning features and relationships between components that maintain accuracy without requiring separate documentation of each component's position. The relative positions are preserved by the mechanical connection within the assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The provisional assembly serves as a physical template or copy of the final implant configuration. By maintaining the same geometric relationships and positions in the provisional assembly as will be used in the final implant, the system eliminates the need for detailed documentation - the assembly itself becomes the reference for accurate implant placement.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4248886B1Revision knee arthroplasty instruments
Publication Date: 2026.03.11 ZIMMER INC
  • EP4248886B1 patent drawingFigure 1
  • EP4248886B1 patent drawingFigure 2
  • EP4248886B1 patent drawingFigure 3

AI summary

According to one example, a provisional system for a knee arthroplasty is disclosed. The system can include any one or combination of a first provisional component, a second provisional component, a stem provisional assembly and a fastener. The first provisional component can be configured to be disposed on a resected bone surface. The second provisional component can be configured to be disposed in a first recess beneath the resected surface of the bone. The stem provisional assembly can be configured to be disposed in a second recess, the stem provisional assembly configured to be engageable in vivo to position the first provisional component on the resected surface of the bone. The fastener can be configured to couple the first provisional component, the second provisional component and the stem provisional assembly together as an assembly.