Patient-Specific Knee Alignment Guide with Modular Components

Solution Overview

Problem

Proper alignment of prosthetic components in knee arthroplasty is crucial for longevity and function, but existing methods often result in misalignment, leading to increased wear and patient discomfort, highlighting the need for patient-specific alignment techniques.

Innovation Solution

A patient-specific alignment guide system comprising multiple components with three-dimensional bone engagement surfaces and a coupling mechanism, allowing for precise anatomical matching and intra-operative adjustments, along with a positioner for accurate imaging and a method for soft tissue balancing that eliminates the need to determine the femoral head center.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional alignment methods are used, then the surgical procedure is simpler and faster, but the alignment precision deteriorates leading to misalignment

Engineering Contradiction:

Improvealignment precisionVSAvoidalignment guide complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The alignment guide is divided into multiple components including a femoral component, tibial component, and connection arm. Each component can be independently designed and manufactured to fit specific anatomical regions, allowing for high precision alignment while maintaining manageable complexity through modular construction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The alignment guide is designed and manufactured before the surgical procedure using preoperative planning and imaging data. This preliminary creation of a custom-fit guide ensures optimal alignment precision is achieved during surgery without requiring complex intraoperative adjustments or measurements.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If patient-specific alignment guides are used, then the alignment precision improves, but the preparation time and manufacturing complexity increase

Engineering Contradiction:

Improvealignment precisionVSAvoidpreparation time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The alignment guide is designed and manufactured before the surgical procedure using preoperative planning and imaging data. This preliminary creation of a custom-fit guide ensures optimal alignment precision is achieved during surgery without requiring complex intraoperative adjustments or measurements.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The alignment guide is created as a physical replica or mold of the patient's specific bone anatomy based on preoperative imaging. This copying process translates digital imaging data into a tangible guide that perfectly fits the patient's anatomy, achieving high precision without time-consuming intraoperative measurements.

Inventive Principle:

Principle #26Copying

3Adaptability or versatility

If the alignment guide is made customizable and adjustable, then the adaptability improves, but the device complexity increases

Engineering Contradiction:

Improvealignment guide adaptabilityVSAvoidcoupling mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The alignment guide is divided into multiple components including a femoral component, tibial component, and connection arm. Each component can be independently designed and manufactured to fit specific anatomical regions, allowing for high precision alignment while maintaining manageable complexity through modular construction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The connection arm incorporates a hinge mechanism that allows dynamic adjustment between different positions (e.g., 90 degrees and other angles). This dynamic element provides adaptability for various surgical scenarios while the hinge design keeps the complexity manageable by allowing simple rotational movement rather than complex mechanical systems.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8282646B2Patient specific knee alignment guide and associated method

Publication Date: 2012.10.09 BIOMET MFG LLC

AI summary

An orthopedic apparatus including a patient-specific alignment guide attachable to a surface of a bone being prepared for receiving a prosthetic implant. The guide includes at least first and second components and a coupling mechanism connecting the first and second components to one another. The first component has a first bone engagement surface and the second component has a second bone engagement surface, the first and second bone engagement surfaces anatomically matching corresponding first and second portions of the surface of the bone. At least one of the first and second components defines at least one alignment formation.