Surgical Thread Tensioner With Knot Groove for Bone Cerclage

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Solution Overview

Problem

Existing surgical thread cerclage techniques require a large wound or maneuvering space to effectively tension a surgical thread, leading to potential tissue damage and the need for a metal snag to prevent untying, which causes pain and injury.

Innovation Solution

A device for tensioning a surgical thread with an elongated body and maneuvering member, utilizing a screw and nut-screw mechanism to space apart or approach the body and member, allowing for effective knot tightening in a minimally invasive manner using a biocompatible fabric thread.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a metal surgical thread is used for cerclage, then the thread can be twisted and stabilized, but a metal snag protrudes from the bone causing pain and injury to surrounding soft tissues

Engineering Contradiction:
Improvethread stabilityVSAvoidtissue injury
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter of the surgical thread from metal to biocompatible fabric, which fundamentally alters the interaction with surrounding tissues. The fabric material eliminates the harmful metal snag effect while maintaining cerclage functionality through knotting mechanisms

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If a softer biocompatible fabric thread is used instead of metal, then tissue injury is reduced, but the thread cannot be twisted and must be knotted requiring a larger wound for maneuvering

Engineering Contradiction:
Improvetissue injuryVSAvoidwound size
Core Design Contradiction:
Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The device nests the thread tensioning mechanism within a compact structure that fits through minimal wounds. The elongated body with coupling portions and maneuvering member creates a nested configuration where the thread loop is contained and manipulated within a small spatial footprint, eliminating the need for large wound openings

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If a large wound is made to allow thread tensioning and knotting, then the surgical thread can be properly tensioned, but the invasiveness of the procedure increases and tissue damage worsens

Engineering Contradiction:
Improvethread tensioningVSAvoidtissue damage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The device transitions the tensioning operation from a two-dimensional surface maneuver (requiring large wound opening) to a three-dimensional internal operation. The elongated body is inserted through the wound and performs tensioning within the internal space, utilizing the third dimension (depth) to resolve the spatial conflict between maneuverability and minimal invasion

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

4Ease of operation

If a passer instrument is used to pass the thread about the fractured bone, then the thread can be positioned, but the instrument must be removed and complex tensioning instruments inserted requiring significant maneuvering space

Engineering Contradiction:
Improvethread positioningVSAvoidinstrument complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the positioning and tensioning functions into a single integrated device. The elongated body with coupling portions both positions the thread loop about the bone and tensions it simultaneously, eliminating the need for separate passer instruments and complex tensioning devices that require significant maneuvering space

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables efficient cerclage with a knot that reduces tissue damage and eliminates the need for a metal snag, ensuring a stable and safe cerclage without requiring a large wound.

Implementation Method 1

The elongated body is connected to the maneuvering member by means of a screw and nut-screw mechanism configured to mutually space apart or approach the elongated body and the maneuvering member

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP4135610B1Device for tensioning a surgical thread and bone cerclage kit
Publication Date: 2025.08.20 MEDACTA INT SA
  • EP4135610B1 patent drawingFigure 1
  • EP4135610B1 patent drawingFigure 2
  • EP4135610B1 patent drawingFigure 3

AI summary

A device (1) for tensioning a surgical thread comprising: - an elongated body (10) having a tip portion (11) adapted to be arranged in contact with a knot (101) of a surgical thread (100) wound about a patient's bone (B), and - a maneuvering member (20) connected to the elongated body (10) by means of a screw and nut-screw mechanism (30) configured to mutually space apart or approach said elongated body (10) and said maneuvering member (20), said maneuvering member (20) having respective coupling portions (21) for coupling opposite ends (102) of the surgical thread (100) wound and knotted about the bone (B). The opposite ends (102) of the surgical thread (100) can be reversibly constrained to the respective coupling portions (21) in a use configuration of the device (1). The elongated body (10) and the maneuvering member (20) can be mutually spaced apart along a movement axis (X) in order to tension the opposite ends (102) so as to tighten the surgical thread (100) about the bone (B). The tip portion (11) has a groove (12) shaped to receive at least partially the knot (101) in the use configuration of the device (1). The groove (12) extends perpendicularly to the movement axis (X) to open onto opposite sides of the elongated body (10) at respective return portions (14) along which the opposite ends (102) can be returned toward the coupling portions (21), so that the opposite ends (102) of the surgical thread (100) can be arranged tangentially to the bone (B) over a first stretch between the return portions (14) inside the groove (12), and transversely to the bone (B) along respective second stretches, having a greater length than the first stretch, between the return portions (14) and the coupling portions (21).