Reliability of an Ultrasonographic Automated Length Measurement System in Assessing Medial Elbow Joint Space

Objective: The aim of this study was to clarify the reliability of measuring the medial elbow joint space (MEJS) using an automated length measurement system (ALMS), utilizing sonography. Materials and Methods: A series of sonographic videos were captured of the MEJS. These were recorded during the transition from a resting state to a valgus stress condition, in 44 young male asymptomatic baseball players (N = 88 elbows). Two evaluators conducted the measurements using both the ALMS and manual methods to assess interrater reliability of each approach. Results: The interrater reliability of the ALMS ranged from good to excellent (intraclass correlation coefficient [ICC] 2.1, 0.83–0.98), while that of manual measurements ranged from low to excellent (ICC 2.1, 0.47–0.95). There were no significant differences in the absolute values of maximum and minimum distances of MEJS and the gap between an ALMS and manual measurements. Conclusion: Measurement of the MEJS in this cohort of young baseball players, the ALMS, based on the sonogram, demonstrated superior interrater reliability compared with manual measurements.