# Inter- and Intra-Observer Variability of the AMADEUS Tool for Osteochondral Lesions of the Talus

## TL;DR

This study evaluates the reliability of the AMADEUS tool for measuring cartilage damage in the talus and finds it to be reliable with moderate observer agreement.

## Contribution

The study demonstrates the AMADEUS tool's reliability for small talar osteochondral defects and its potential clinical utility.

## Key findings

- AMADEUS showed good intra-observer reliability with an ICC of 0.82.
- Inter-observer variability was moderate with a κ statistic of 0.42.
- AMADEUS scores correlated strongly with pre-operative clinical scores (r = −0.618).

## Abstract

Background: Managing osteochondral cartilage defects (OCDs) of the talus is a common daily challenge in orthopaedics as they predispose patients to further cartilage damage and progression to osteoarthritis. Therefore, the implementation of a reliable tool to quantify the amount of cartilage damage that is present is of the essence. Methods: We retrospectively identified 15 adult patients diagnosed with uncontained OCDs of the talus measuring <150 mm2, which were treated arthroscopically with bone marrow stimulation. Five independent assessors evaluated the pre-operative MRI scans with the AMADEUS scoring system (i.e., MR-based pre-operative assessment system) and the intra-/inter-observer variability was then calculated by means of the intraclass correlation coefficients (ICC) and Kappa (κ) statistics, respectively. In addition, the correlation between the mean AMADEUS scores and pre-operative self-reported outcomes as measured by the Manchester–Oxford foot questionnaire (MOxFQ) was assessed. Results: The mean ICC and the κ statistic were 0.82 (95% CI [0.71, 0.94]) and 0.42 (95% CI [0.25, 0.59]). The Pearson correlation coefficient was found to be r = −0.618 (p = 0.014). Conclusions: The AMADEUS tool, which was originally designed to quantify knee osteochondral defect severity prior to cartilage repair surgery, demonstrated good reliability and moderate inter-observer variability for small OCDs of the talar shoulder. Given the strong negative correlation between the AMADEUS tool and pre-operative clinical scores, this tool could be implemented in clinical practise to reliably quantify the extent of the osteochondral defects of the talus.