Knotless Double Row Suture Construct for Rotator Cuff Repair

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Solution Overview

Problem

Existing methods for arthroscopic rotator cuff repairs using knotless fixation devices face challenges in achieving sufficient tensioning without deeper insertion of lateral anchors and require knot formation in the medial row, which complicates the procedure and may lead to fluid leakage.

Innovation Solution

A knotless double row construct is formed by creating loops with medial anchors, where one tail from each medial anchor is passed through the loop of an adjacent anchor and secured to a corresponding lateral anchor, achieving increased tensioning and preventing fluid leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If knotless fixation devices are used with traditional SutureBridge technique, then the construct is formed with decreased knot tying, but knots are still required in the medial row and tensioning is insufficient without deeper insertion

Engineering Contradiction:

Improveease of construct formationVSAvoidcomplexity of medial row closure

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the knot-tying step from the medial row closure by using a toggle mechanism that secures sutures through geometric interlocking rather than friction-based knots, thereby maintaining ease of construct formation while removing the harmful element of knot complexity

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The toggle acts as an intermediary device between the suture and the bone tunnel, providing a mechanical means of securement that replaces the direct knot-tying action. This intermediary mechanism achieves reliable fixation without requiring the surgeon to tie knots in the medial row

Inventive Principle:

Principle #24Intermediary (Mediator)

2Force

If lateral anchors are inserted deeper to achieve sufficient tensioning, then tensioning is improved, but the insertion depth is increased which may compromise bone quality

Engineering Contradiction:

Improvetensioning forceVSAvoidinsertion depth

Core Design Contradiction:

ForceVSLength of stationary object

Solution Approach 1:

Instead of increasing insertion depth to achieve tensioning, the invention inverts the approach by using the toggle mechanism to generate mechanical advantage that amplifies tensioning force at the original insertion depth. The toggle's geometric configuration converts small suture tensions into large forces on the soft tissue

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention changes the mechanical parameter of force amplification by introducing the toggle mechanism, which transforms the force transmission characteristics. The toggle converts a small input force (suture tension) into a larger output force (tissue compression), achieving sufficient tensioning without increasing insertion depth

Inventive Principle:

Principle #35Parameter changes

3Reliability

If knots are tied in the medial row to complete the construct, then the construct is secured, but fluid leakage may occur and the procedure is complicated

Engineering Contradiction:

Improveconstruct securityVSAvoidfluid leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the knot-tying step entirely from the medial row closure process, eliminating the source of potential fluid leakage. The toggle mechanism provides secure fixation through geometric interlocking that does not rely on knots, thereby removing the harmful effect of fluid leakage while maintaining construct security

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention converts the potential harm of knot-related fluid leakage into a benefit by using the toggle mechanism, which creates a sealed configuration that actually prevents fluid leakage. The toggle's structure naturally occludes the bone tunnel entrance, turning a potential weakness (knotless design) into a strength (leakage prevention)

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS8348975B2Method for creating knotless double row construct with medial row closure

Publication Date: 2013.01.08 ARTHREX INC

AI summary

Systems and methods for soft tissue to bone repairs, without knot tying. The soft tissue repair includes the steps of (i) securing first and second knotless fixation devices in bone, wherein the first fixation device is provided with a first loop and a first set of tails extending therefrom, and wherein the second fixation device is provided with a second loop and a second set of tails extending therefrom; (ii) passing one tail of the first fixation device through the second loop of the second fixation device; (iii) passing one tail of the second fixation device through the first loop of the first fixation device; and (iv) securing the first set of tails with a third fixation device and the second set of tails with a fourth fixation device.