Reliability of a New Standardized Measurement Technique for Reverse Hill-Sachs Lesions in Posterior Shoulder Dislocations

Abstract

The purpose of this study was to determine whether standardized measurements are more reliable than mere estimation in determining the extent of the defect in reverse Hill-Sachs lesions. Twelve patients with 13 reverse Hill-Sachs lesions and available computed tomographic scans were included in this study. Based on the computed tomographic scans, estimation and measurement of the defect size in reverse Hill-Sachs lesions using a novel standardized method were carried out twice by 6 observers (3 experts and 3 residents), with an interval of 3 months between observations. To assess and compare the reliability of the estimation of the defect size and the measurement of the defect size, intraclass correlation coefficients were computed. Estimation of the defect size showed a low interobserver reliability of 0.61 (95% confidence interval [CI], 0.38 to 0.83) and 0.47 (95% CI, 0.24 to 0.74) and a moderate intraobserver reliability of 0.71 (95% CI, 0.51 to 0.89). The estimations of the different observers showed statistically significant differences (P < .001). The standardized measurements reached high interobserver reliability (at least ≥0.81) and excellent intraobserver reliability (at least ≥0.88). Residents provided less reliable estimations compared with experts; however, they obtained similarly high reliability when applying the standardized measurements. The mere estimation of the size of reverse Hill-Sachs lesions showed poor reliability, raising the concern for potential overestimation or underestimation in clinical practice. Standardized measurements, which showed good reliability, should be used whenever analyzing the size of a reverse Hill-Sachs defect. Level IV, diagnostic case series.