Cortical Button Rib and Adjustable Loop for Joint Repair

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Solution Overview

Problem

Existing tissue fixation systems for joint repair face challenges such as bending cortical buttons, loosening adjustable loop constructs due to loop slip or creep, and requiring extreme forces to reduce the loop construct and position the graft, along with complex assembly and high forces that can damage tissues.

Innovation Solution

The development of a cortical button with a rib extension to increase structural integrity, an adjustable loop construct with a knotlessly locked configuration, and a reduction handle system that manages the assembly and reduction of the loop construct to facilitate easier graft positioning and fixation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a thin cortical button is used to lie flat on bone surface and limit palpability, then patient comfort is improved, but the button bends under fixation loading

Engineering Contradiction:
Improvepatient comfortVSAvoidbutton rigidity
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The cortical button is segmented into a body portion and a separate rib portion. The rib portion is configured to engage the bone tunnel and provide structural support, while the body portion lies flat on the bone surface. This segmentation allows the button to maintain both thin profile for comfort and sufficient rigidity through the rib's engagement with the bone tunnel.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If adjustable loop construct is made flexible for easy adjustment, then ease of operation is improved, but loop slip or creep occurs under loading

Engineering Contradiction:
Improveloop adjustabilityVSAvoidloop stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The adjustable loop construct incorporates a dynamic locking mechanism that allows the loop to be adjusted during surgery and then locked in place. The loop can transition between an adjustable state during operation and a locked state during fixation, providing both ease of adjustment and stability under loading.

Inventive Principle:
Principle #15Dynamics

3Productivity

If extreme forces are applied to reduce the adjustable loop construct, then graft positioning is achieved, but tissue and graft damage occurs

Engineering Contradiction:
Improvegraft positioning efficiencyVSAvoidtissue damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A reduction tool is introduced as an intermediary device to assist in reducing the adjustable loop construct. The reduction tool engages with the loop construct and allows for controlled reduction forces to be applied, distributing the load and preventing direct damage to the tissue and graft while achieving proper graft positioning.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If complicated assembly steps are used for fixation system, then adaptability to different procedures is improved, but ease of manufacture and surgical workflow deteriorates

Engineering Contradiction:
Improveprocedure adaptabilityVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The fixation system is divided into separate modular components including a cortical button, adjustable loop construct, and reduction tool. Each component can be manufactured independently and assembled during surgery as needed, providing adaptability to different procedures while simplifying manufacturing and reducing assembly complexity through standardization.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4329635B1Devices for joint repair
Publication Date: 2025.06.11 SMITH & NEPHEW INC
  • EP4329635B1 patent drawingFigure 1A~1B
  • EP4329635B1 patent drawingFigure 1C~1E
  • EP4329635B1 patent drawingFigure 1F~1G

AI summary

Methods and devices for tissue fixation. A cortical button with a rib between two slotted openings. The rib increases the cortical button structural rigidity without increasing palpability. An adjustable loop construct with two discrete locking passages that provides manageable loop reduction and improved tissue coupling. The adjustable loop construct may be coupled to tissue via a passing construct. An assembly with a reduction bar, a button and an adjustable loop construct, the assembly provided assembled in a first configuration that disassembles to guide steps of tissue fixation. The reduction bar may be assembled to the reduction bar for reducing the adjustable loop construct.