Combination Spinal Instrument for Rod Reduction and Derotation

Solution Overview

Problem

Conventional surgical instruments require multiple separate tools for performing tasks like vertebral derotation, rod reduction, and setscrew insertion during spinal surgery, leading to surgeon fatigue, prolonged operating time, and increased costs.

Innovation Solution

A combination surgical instrument featuring an inner sleeve with a threaded proximal portion and a distal rotating portion, an intermediate sleeve with extensions and movable arms, and an outer sleeve that locks the instrument to the bone anchor, allowing for rod reduction, derotation, and setscrew insertion in a single instrument.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple separate instruments are used for rod reduction, derotation, and setscrew insertion, then each function can be performed with specialized instrumentation, but the number of instruments increases, surgeon fatigue increases, and operating time is prolonged

Engineering Contradiction:

Improvefunctional capabilityVSAvoidnumber of instruments

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate surgical instruments (rod reduction instrument, derotation instrument, and setscrew insertion instrument) into a single integrated combination instrument. This instrument includes an inner sleeve with threaded portion for rod reduction, an intermediate sleeve with extensions for derotation, and an outer sleeve with locking mechanism for setscrew insertion, all integrated into one tool that can perform all three functions sequentially during spinal surgery.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The combination instrument is designed as a universal tool that can perform multiple functions: rod reduction through the inner sleeve's threaded portion, vertebral derotation through the intermediate sleeve's extensions, and setscrew insertion through the outer sleeve's locking mechanism. This multi-functional design eliminates the need for multiple specialized instruments while maintaining all required capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If multiple separate instruments are used, then each task can be performed with dedicated tooling, but instrument switching frequency increases and operating time is prolonged

Engineering Contradiction:

Improvetask performanceVSAvoidoperating time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent combines multiple separate surgical instruments (rod reduction instrument, derotation instrument, and setscrew insertion instrument) into a single integrated combination instrument. This instrument includes an inner sleeve with threaded portion for rod reduction, an intermediate sleeve with extensions for derotation, and an outer sleeve with locking mechanism for setscrew insertion, all integrated into one tool that can perform all three functions sequentially during spinal surgery.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The combination instrument enables continuous performance of surgical tasks without interruption for instrument switching. The inner, intermediate, and outer sleeves can be used sequentially in a continuous workflow, maintaining uninterrupted surgical action and eliminating the time losses associated with removing and reinserting multiple separate instruments.

Inventive Principle:

Principle #20Continuity of useful action

3Adaptability or versatility

If multiple separate instruments are used, then each function has specialized instrumentation, but the number of preparation steps and instrument availability requirements increase

Engineering Contradiction:

Improvefunctional specializationVSAvoidinstrument preparation

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent combines multiple separate surgical instruments (rod reduction instrument, derotation instrument, and setscrew insertion instrument) into a single integrated combination instrument. This instrument includes an inner sleeve with threaded portion for rod reduction, an intermediate sleeve with extensions for derotation, and an outer sleeve with locking mechanism for setscrew insertion, all integrated into one tool that can perform all three functions sequentially during spinal surgery.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The combination instrument is designed as a universal tool that can perform multiple functions: rod reduction through the inner sleeve's threaded portion, vertebral derotation through the intermediate sleeve's extensions, and setscrew insertion through the outer sleeve's locking mechanism. This multi-functional design eliminates the need for multiple specialized instruments while maintaining all required capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

The instrument streamlines spinal surgery by reducing the number of instruments needed, minimizing surgeon fatigue, and reducing operating time while maintaining the precision and effectiveness required for complex spinal procedures.

Implementation Method 1

an inner sleeve with a proximal threaded portion, a distal portion configured to rotate relative to the proximal threaded portion

Methodology Applied

Scientific EffectThread engagement: Screw

Implementation Method 2

when the outer sleeve is advanced distally relative to the intermediate sleeve, the pair of extensions of the outer sleeve cover the pair of extensions of the intermediate sleeve and prevent the movable arms of the intermediate sleeve from moving radially outward

Methodology Applied

Scientific EffectMechanical interference: Physical Containment

Implementation Method 3

the pair of extensions of the intermediate sleeve can each include a movable arm configured to extend into the inner channel of the intermediate sleeve and facilitate coupling to an implant disposed between the pair of extensions of the intermediate sleeve

Methodology Applied

Scientific EffectGeometric interlocking: Geometry

Data Source

PatentUS20250120754A1Combination derotation and reducer instruments and methods

Publication Date: 2025.04.17 MEDOS INT SARL

AI summary

Surgical instruments and related methods are disclosed for performing rod reduction, derotation, and/or setscrew insertion during spinal surgery. One example instrument that can accommodate performing all of these functions can include an inner sleeve having a proximal threaded portion, a distal portion configured to rotate relative to the proximal threaded portion, an inner channel, and a modular drive interface disposed at a proximal end of the threaded portion. The instrument can further include an intermediate sleeve having an inner channel with a threaded proximal portion configured to receive the inner sleeve, the intermediate sleeve terminating in a pair of extensions at a distal end thereof. The instrument can further include an outer sleeve having an inner channel configured to receive the intermediate sleeve, the outer sleeve terminating in a pair of extensions at a distal end thereof.