Cannulated Reamer Guide for Bone Cavity Shaping

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Solution Overview

Problem

Current surgical methods for preparing bone cavities for joint prosthesis revision procedures are inefficient, often requiring manual and time-consuming techniques that can lead to inaccurate cavity shapes and increased risk of infection, especially in cases of sclerotic bone or large bone voids.

Innovation Solution

A fully guided surgical system comprising a reaming guide assembly with a trial stem, guide tube, and cannulated reamer assembly, which allows for precise bone cavity preparation with optional manual or powered operation, minimizing the need for freehand bone removal and ensuring accurate fit for prosthetic components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual broaching or freehand bone removal is used to prepare bone voids, then the surgeon can access irregularly shaped bone cavities, but the procedure becomes time-consuming and increases the risk of infection

Engineering Contradiction:

Improveability to prepare irregular bone voidsVSAvoidsurgical procedure time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical broaching with a powered reaming system that can be driven by a drill or other power source. The reamer is guided through the bone void by a guide tube, allowing automated bone removal while maintaining adaptability to irregular shapes through the guiding mechanism rather than manual manipulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The guide tube assembly acts as an intermediary between the surgeon's control and the reaming action. It provides a guided path for the reamer, enabling precise bone cavity preparation without requiring direct manual manipulation of the cutting tool, thus reducing surgical time while maintaining accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If multiple-step broaching is performed for large bone voids, then sufficient bone removal can be achieved, but the procedure requires high impact forces and extended time

Engineering Contradiction:

Improvevolume of bone removedVSAvoidimpact force required

Core Design Contradiction:

Quantity of substanceVSForce

Solution Approach 1:

The powered reaming system replaces manual impact-based broaching with continuous rotational cutting. The reamer can be driven by a drill or power source to efficiently remove large volumes of bone through sustained cutting action rather than repeated impact blows, reducing both the force required and the number of steps needed.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If freehand bone removal is used to create accurate cavity shapes, then the surgeon has flexibility in shaping, but the process is time-consuming and may result in inaccurate fits

Engineering Contradiction:

Improveaccuracy of cavity shapeVSAvoidbone preparation time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The guide tube assembly serves as a guiding intermediary that directs the reamer along a predetermined path through the bone void. This ensures accurate cavity shaping without requiring time-consuming freehand manipulation, as the guide tube constrains the reaming action to the desired trajectory and geometry.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The guide tube is positioned and secured in the bone void before reaming begins. This preliminary placement establishes the correct path and orientation for cavity preparation, ensuring accurate shaping from the start of the reaming process rather than requiring iterative adjustments during bone removal.

Inventive Principle:

Principle #10Preliminary action

4Manufacturing precision

If iterative bone removal with multiple checks against the MRD is performed, then an accurate fit can be achieved, but the procedure becomes excessively time-consuming

Engineering Contradiction:

Improvefit accuracy between cavity and MRDVSAvoidbone preparation efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The guide tube assembly acts as a permanent guiding structure that ensures the reamer creates a cavity matching the intended MRD geometry. This eliminates the need for iterative checking and adjustment, as the guide tube itself encodes the correct cavity shape and orientation, allowing single-pass accurate preparation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUSRE48163E1Surgical reaming instrument for shaping a bone cavity

Publication Date: 2020.08.18 HOWMEDICA OSTEONICS CORP

AI summary

Disclosed herein are systems and methods for shaping bone voids during revision procedures of total knee replacements. The systems disclosed herein generally include a cannulated reamer assembly, a reaming guide assembly, a guide tube assembly, a trial stem assembly, and an optional insertion/removal tool. Metaphyseal reconstruction devices can be used to fill the bone voids in conjunction with the systems and methods disclosed herein.