Intra- and Interobserver Reliability of Size Measurement of Morton Neuromas on Sonography

Sonography is often used for analysis of Morton neuromas, but the measurement reliability is unknown. The aim of this study was to determine the intra- and interobserver reliability and precision of sonographic measurement of Morton neuromas.

Three observers with different levels of sonography experience (observer A, expert; observer B, intermediate; observer C, beginner) performed repeated measurements of the size of Morton's neuroma in 20 patients. Intraclass correlation coefficient and limit of agreement were used to evaluate reliability and measurement precision.

The intraclass correlation coefficient for intraobserver reliability was 0.80, 0.71, and 0.43 (limit of agreement, 20%, 18%, and 47%) in observers A, B, and C, respectively. The intraclass correlation coefficient for interobserver reliability was 0.72, 0.38, and 0.38 (limit of agreement, 25%, 36%, and 35%) between observers A/B, A/C, and B/C, respectively.

The intra- and interobserver reliability values for sonographic measurement of Morton neuroma size were dependent on observer experience. Experienced observers had higher reliability, while observers who were less familiar with sonography showed moderate to low reliability.