Force-Sensor Gap Assessment for Consistent Knee Implant Sizing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing gap assessment in total knee arthroplasty relies heavily on qualitative 'feel-based' intuition, lacking standardized methods to quantify forces and torques applied during abduction-adduction examinations, leading to inconsistent surgical decisions.

Innovation Solution

A system and method utilizing force sensors placed at specific ankle and foot positions to measure applied forces, coupled with a computing device for data processing and analysis, providing real-time feedback and recommendations for optimal implant selection and soft tissue tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If force sensors and computing devices are introduced to quantify forces during gap assessment, then measurement precision and standardization are improved, but device complexity increases

Engineering Contradiction:

Improvequantification of applied forcesVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the traditional mechanical/visual assessment method with force sensors that electronically measure applied forces. The sensors convert mechanical force into electrical signals that are processed by a computing device, substituting the surgeon's subjective feel-based judgment with objective quantitative data.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The force sensors act as intermediaries between the surgeon's manual manipulation and the gap assessment measurement. The sensors are placed between the surgeon's hands and the patient's foot/ankle, translating the applied forces into quantifiable data that bridges the gap between physical examination and objective measurement.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If multiple force sensors are placed at various ankle and foot positions, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:

Improveforce measurement accuracyVSAvoidsurgical procedure simplicity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The measurement system is divided into multiple independent force sensors placed at specific locations (lateral ankle, medial ankle, lateral foot, medial foot). Each sensor independently measures forces at its location, and the computing device integrates these segmented measurements to provide comprehensive gap assessment data.

Inventive Principle:

Principle #1Segmentation

3Reliability

If real-time force data processing and feedback are implemented, then reliability of surgical decisions is improved, but loss of time increases

Engineering Contradiction:

Improvesurgical decision accuracyVSAvoidexamination time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The computing device provides real-time feedback to the surgeon by displaying quantified force data during the gap assessment examination. This immediate feedback allows the surgeon to adjust their manipulation and interpret gap balance with greater confidence, improving the reliability of surgical decisions without requiring separate post-examination analysis.

Inventive Principle:

Principle #23Feedback

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

Standardizes gap assessment by quantifying forces, reducing inconsistencies in surgical decisions, and improving knee stability by ensuring accurate implant sizing and bone cut modifications.

Implementation Method 1

a plurality of force sensors respectively placed at i) a lateral ankle position and a medial ankle position, ii) a lateral foot position and a medial foot position

Methodology Applied

Scientific EffectForce sensing: Force

Data Source

PatentUS12376973B2System and method for quantifying gap assessment examination

Publication Date: 2025.08.05 NEW YORK SOC FOR THE RUPTURED & CRIPPLED MAINTAINING THE HOSPITAL FOR SPECIAL SURGERY

AI summary

Measured forces applied by a medical professional during a gap assessment can be measured. A plurality of force sensors is placed at a lateral ankle position, a medial ankle position, a lateral foot position, and/or a medial foot position, and each detects an applied force during an abduction-adduction examination. Further, a computing device receives, from each of the plurality of sensors during the abduction-adduction examination, data representing an applied force occurring during the abduction-adduction examination at respective ones of the lateral ankle position, the medial ankle position, the lateral foot position, and the medial foot position. The computing device calculates, using the received data, respective peak applied forces during the abduction-adduction examination in extension and flexion, and provides information representing a correlation of the respective peak applied forces with other information.