Bundle Graft Construct for Ligament Reconstruction Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current ligament reconstruction methods face challenges in achieving optimal graft tunnel alignment and tensioning, leading to inadequate stability and elongation of the graft, particularly during the reattachment of ligaments or tendons to bones.

Innovation Solution

A method and construct involving a triple bundle anterior cruciate ligament graft formed by suturing single tendon strands of varying lengths, creating regions of tied and loose segments, which increases pull-out strength by approximately 30% with interference device fixation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the graft is tensioned prior to fixation, then stability is improved, but the risk of excessive tension capturing the joint increases

Engineering Contradiction:
ImprovestabilityVSAvoidexcessive tension capturing joint
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The graft is divided into multiple tendon strands (e.g., four strands) that are bundled together. This segmentation allows the tension to be distributed across multiple individual strands rather than concentrated on a single graft, enabling more controlled and uniform tensioning that achieves stability without excessive force that could capture the joint.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different properties to different parts of the graft system. Specifically, the graft strands are arranged with varying lengths and tensioning characteristics, allowing localized adjustment of tension distribution. This enables optimal tensioning at the fixation points while preventing excessive tension in other regions that could lead to joint capture.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the graft tunnel is drilled at a particular angle and location, then optimal graft placement is achieved, but the complexity of the surgical procedure increases

Engineering Contradiction:
Improvegraft tunnel alignmentVSAvoidsurgical procedure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The graft is constructed as multiple separate tendon strands that are bundled together. This segmentation provides inherent flexibility and adaptability, allowing the graft to be more easily directed through the bone tunnel at the required angle and location. The individual strands can be independently positioned and tensioned, simplifying the alignment process compared to a single rigid graft.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multi-strand graft construction provides dynamic adaptability during insertion. The individual strands can move and adjust relative to each other, allowing the graft bundle to conform to the tunnel geometry and achieve proper angulation more easily than a fixed single-graft construction, thereby reducing surgical complexity.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If tensioning is performed after the graft is partially in place, then adjustment is possible, but the tensioning process becomes cumbersome

Engineering Contradiction:
Improvetension adjustment capabilityVSAvoidtensioning ease
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The graft consists of multiple independent tendon strands that can be individually tensioned and adjusted. This segmentation allows surgeons to apply tension to each strand separately, making the tensioning process more manageable and less cumbersome compared to tensioning a single large graft. The individual strands can be manipulated independently to achieve the desired tension distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent allows for partial tensioning of individual graft strands rather than requiring full tensioning of the entire graft at once. This partial action approach makes the tensioning process more manageable and less cumbersome, enabling step-by-step adjustment while achieving the necessary overall tension for stability.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP1832246B1Bundle graft and method of making same
Publication Date: 2019.06.12 ARTHREX INC
  • EP1832246B1 patent drawingFigure 1~1(a)
  • EP1832246B1 patent drawingFigure 2
  • EP1832246B1 patent drawingFigure 3

AI summary

A graft construct (100) formed of a plurality of single tendon strands (10,20) or soft tissue grafts placed together so that at least a portion of one of the single tendon strands (10) is wrapped around a portion of another of the single tendon strands (20) by employing suturing, for example. The graft construct is provided with at least two regions (50,60), one region (50) formed of at least a plurality of tendon strands tied together, and the other region (60) formed of loose segments of the plurality of tendon strands.