Bone Anchor Receiver Tooling for Percutaneous Rod Reduction

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Solution Overview

Problem

Existing implant deployment and insertion tools for spinal surgery are bulky and invasive, causing tissue trauma and complicating percutaneous procedures due to insufficient clearance and tool manipulation requirements.

Innovation Solution

A rotate-on and rotate-off tool assembly with a partially tubular structure that engages both inner and outer surfaces of a bone anchor receiver, allowing for easy rotation and fixation of a longitudinal connecting member, even when a rod is present, using a cap and helical threads to secure the tool to the bone anchor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional open surgery tools are used for percutaneous surgery, then the implantation process is simplified, but tissue trauma increases due to bulky tools and insufficient clearance

Engineering Contradiction:

Improveimplantation processVSAvoidtissue trauma

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The tool is divided into distinct functional segments: a slender shaft for percutaneous insertion, a receiver engagement structure at the distal end, and a rod reduction mechanism. This segmentation allows each component to be optimized for its specific function while maintaining overall tool compactness suitable for minimally invasive surgery.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The tool transitions from a bulky three-dimensional structure to a slender, elongated form factor that can be inserted through small incisions. The rod reduction mechanism uses a cam-like structure that converts rotational motion into linear displacement, enabling rod compression within the constrained space of the receiver.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Force

If bulky tools are used for rod reduction, then the reduction force is sufficient, but the tool cannot fit within the limited space of percutaneous surgery

Engineering Contradiction:

Improvereduction forceVSAvoidtool size

Core Design Contradiction:

ForceVSVolume of moving object

Solution Approach 1:

The tool replaces manual compression force with a mechanical cam mechanism that converts rotational motion into linear rod compression. The cam profile is designed to provide progressive reduction force as the tool is rotated, enabling sufficient reduction force within a compact tool geometry suitable for percutaneous insertion.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If irregular surfaces or protrusions are added to tools for better engagement, then the holding capability improves, but the tool causes additional tissue trauma

Engineering Contradiction:

Improveholding capabilityVSAvoidtissue trauma

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The tool features smooth, polished surfaces along the shaft and engagement surfaces to minimize tissue trauma during insertion and manipulation. The receiver engagement structure includes localized protrusions and cam surfaces that provide reliable mechanical engagement with the rod and receiver, concentrating the irregular surfaces only where needed for function rather than along the entire tool length.

Inventive Principle:

Principle #3Local quality

4Power

If a projecting actuator arm is used for rod reduction, then the mechanical advantage is improved, but there is insufficient clearance in percutaneous surgery

Engineering Contradiction:

Improvemechanical advantageVSAvoidactuator arm length

Core Design Contradiction:

PowerVSLength of moving object

Solution Approach 1:

The cam mechanism for rod reduction is nested within the receiver engagement structure, with the cam surface formed as an integral part of the tool body rather than as a separate projecting arm. This nested configuration provides the necessary mechanical advantage for rod reduction while maintaining a compact overall tool size that can be inserted through small percutaneous incisions.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS12629180B2Method of attaching tooling to the receiver of a bone anchor assembly for minimally invasive surgery

Publication Date: 2026.05.19 JACKSON CORP

AI summary

A method of assembling a bone anchor system for securing an elongate rod to a head of a shank includes positioning a lower attachment portion of tooling onto an upper end of a receiver having a pair of integral upright arms extending upward from a base portion. The lower attachment portion includes a discontinuous inner convex cylindrical surface of a downwardly-opening discontinuous recess that is closely received by inner concave cylindrical surfaces extending downward from arcuate top inner edges of the upright arms, simultaneous with a pair of opposing inwardly-directed protrusions of the lower attachment portion below the recess being closely received within horizontally-extending tool engagement grooves formed below upper outer surfaces the upright arms.