Intraoperative Image Analysis for Hip Arthroplasty Leg Length Prediction

Solution Overview

Problem

Existing intraoperative systems for hip arthroplasty lack the ability to predict changes in leg length and offset when modifying modular prosthetic options, leading to repetitive and time-consuming trial processes, increasing the risk of femoral fractures during surgery.

Innovation Solution

A system that acquires preoperative and intraoperative images of a patient's skeletal and articulating bones, identifies centers of rotation, and aligns digital implant representations to estimate offset and length differentials, allowing for the prediction of changes in leg length and offset without the need for progressive trialing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If progressive trialing is used to determine optimal prosthetic options, then accurate leg length and offset data can be obtained, but surgical time increases and the risk of femoral fractures increases

Engineering Contradiction:

Improveleg length and offset data accuracyVSAvoidsurgical time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs image acquisition, processing, and predictive analysis preoperatively or before final implant selection. By calculating leg length and offset for all modular options in advance using intraoperative images and digital modeling, the surgeon has all necessary data before making the final implant choice, eliminating the need for repetitive intraoperative trialing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system creates digital copies and representations of the patient's anatomy and prosthetic components. Digital models of the bone and modular prosthetic options are generated from images, allowing virtual trial of different configurations without physical manipulation. The system copies the intraoperative image and overlays digital representations to predict outcomes.

Inventive Principle:

Principle #26Copying

2Measurement precision

If progressive trialing is used to determine optimal prosthetic options, then accurate leg length and offset data can be obtained, but the risk of femoral fractures increases

Engineering Contradiction:

Improveleg length and offset data accuracyVSAvoidsurgical safety

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system creates digital copies and representations of the patient's anatomy and prosthetic components. Digital models of the bone and modular prosthetic options are generated from images, allowing virtual trial of different configurations without physical manipulation. The system copies the intraoperative image and overlays digital representations to predict outcomes.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The system replaces the mechanical process of physical trialing (inserting, removing, and reinserting trial prosthetics) with a computational image analysis system. Software algorithms automatically calculate leg length and offset for different modular options based on digital models, eliminating the mechanical manipulation that causes bone trauma and fracture risk.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If multiple modular options are evaluated through physical trialing, then the optimal implant can be selected, but the complexity of the surgical process increases

Engineering Contradiction:

Improveprosthetic option selectionVSAvoidsurgical process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system provides a universal platform that handles all modular prosthetic options through a single integrated process. The image analysis software can evaluate any modular configuration (different stems, heads, offsets) using the same digital modeling and calculation methods, eliminating the need for separate physical trialing procedures for each option.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system replaces the mechanical process of physical trialing (inserting, removing, and reinserting trial prosthetics) with a computational image analysis system. Software algorithms automatically calculate leg length and offset for different modular options based on digital models, eliminating the mechanical manipulation that causes bone trauma and fracture risk.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4170591A1Systems and methods for intra-operative image analysis

Publication Date: 2023.04.26 DEPUY SYNTHES PROD INC

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AI summary

A system and method that acquire (i) at least a reference image including one of a preoperative image of a surgical site with skeletal and articulating bones and a contralateral image on an opposite side of the patient from the surgical site, and (ii) at least an intraoperative image of the site after an implant has been affixed to the articulating bone. The system preferably generates at least one reference stationary point on at least the skeletal bone in the reference image and at least one intraoperative stationary point on at least the skeletal bone in the intraoperative image. The location of the implant is identified in the intraoperative image, preferably including the position of first and second centers of rotation, which are digitally represented and copied into the reference image to analyze at least one of offset and length differential.