Spinal Rod Reducer Assembly with Derotation Sleeve

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current spinal surgery techniques face challenges in efficiently and minimally invasively reducing spinal rods into pedicle screw housings, often requiring complex maneuvers that can stress or break frangible members, leading to inefficiencies and potential complications.

Innovation Solution

A rod reducer assembly with a pedicle screw housing and extension assembly coupled by a frangible member, featuring a knob and sleeve assembly that allows axial movement of the outer sleeve relative to the inner sleeve to reduce the spinal rod into the housing, along with a derotation sleeve to inhibit frangible member breakage during manipulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional spinal surgery techniques are used to reduce spinal rods into pedicle screw housings, then the procedure can be performed, but the complexity of maneuvers increases and frangible members are stressed or broken

Engineering Contradiction:

Improvefrangible member integrityVSAvoidsurgical maneuver complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The device is divided into distinct functional modules: a rod reducer component for reducing the rod, a derotation sleeve for preventing rotation, and a frangible member that can be controlled to break at a specific point. This segmentation allows each component to perform its specific function independently, reducing overall surgical complexity while maintaining reliability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The derotation sleeve is installed beforehand to prevent rotation of the pedicle screw housing during the rod reduction process. The frangible member is designed with a controlled break point that will fail at a predetermined moment. These preliminary actions prevent complications before they occur, reducing the need for complex corrective maneuvers

Inventive Principle:

Principle #10Preliminary action

2Productivity

If complex maneuvers are performed to reduce spinal rods, then rod reduction can be achieved, but frangible members are stressed or broken leading to inefficiencies

Engineering Contradiction:

Improvesurgical procedure efficiencyVSAvoidfrangible member integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The derotation sleeve acts as an intermediary component between the surgeon's manipulation and the frangible member. It absorbs and controls rotational forces, preventing them from being transmitted to the frangible member, thereby protecting the frangible member while enabling efficient rod reduction

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If manual manipulation is used to reduce spinal rods, then the procedure can be performed, but surgical precision and control are reduced

Engineering Contradiction:

Improverod reduction precisionVSAvoidsurgical operation ease

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The rod reducer features a dynamic mechanism with movable arms that can be adjusted to engage the spinal rod. The derotation sleeve provides rotational constraint while allowing controlled movement. This dynamic design enables precise rod reduction through simple rotational motion of the reducer, improving both precision and ease of operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The device replaces complex manual manipulation with a mechanical system consisting of the rod reducer and derotation sleeve. The mechanical advantage provided by the reducer's lever arms and the rotational constraint of the sleeve transform difficult manual operations into simple, precise rotational movements, enhancing both precision and ease of operation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 and minimally invasive reduction of spinal rods into pedicle screw housings, reducing the risk of frangible member breakage and enhancing surgical precision and control, thereby improving procedural efficiency and safety.

Implementation Method 1

an extension assembly that extends from the pedicle screw housing. The extension assembly is coupled to the pedicle screw housing by a frangible member

Methodology Applied

Scientific EffectFracture Mechanics: Fracture Mechanics

Implementation Method 2

The knob may be threadably coupled to the inner sleeve. The knob may be rotatable about the inner sleeve, which, in turn, causes axial translation of the knob and the outer sleeve relative to the inner sleeve

Methodology Applied

Scientific EffectScrew: Screw

Data Source

PatentUS12178479B2Rod reducer assembly

Publication Date: 2024.12.31 VB SPINE LLC

AI summary

A rod reducer assembly is provided and is selectively mountable to a pedicle screw assembly. The pedicle screw assembly includes a pedicle screw housing that defines a rod-receiving recess. The pedicle screw assembly includes an extension assembly that is coupled to the pedicle screw housing by a frangible member. The rod reducer is configured to reduce a spinal rod into the rod-receiving recess of the pedicle screw assembly. The rod reducer assembly may include a derotation sleeve configured to inhibit the frangible member from breaking while manipulating a spinal bone.