Ultrasound assessment of the rotator cuff cable: comparison between young and elderly asymptomatic volunteers and interobserver reproducibility

Our aim was to characterize rotator cable ultrasound appearance in shoulders of different-aged asymptomatic volunteers, also estimating interobserver reproducibility. We studied 83 shoulders in 42 young volunteers (mean age 26 ± 7.0 years, range 21-35 years) and 66 shoulders in 36 elderly volunteers (65-81 years, 73 ± 4.9 years), noting rotator cable visibility and its minimum thickness and width. Interobserver reproducibility was tested in elderly volunteers by two blinded observers. χ(2), U Mann-Whitney, t-test, Bland-Altman, and κ statistics were used. Rotator cable was less frequently detected in younger than elderly volunteers (25/83 vs. 36/66 shoulders; p = 0.002). Young subjects had thicker (1.5 ± 0.2 mm, range 1.3-1.8 mm vs. 1.1 ± 0.1 mm, 0.9-1.3 mm; p < 0.001) and wider rotator cable (5.8 ± 0.7 mm, 4.5-7.1 mm vs. 4.0 ± 1.2 mm, 2.5-7.1 mm; p < 0.001) than elderly volunteers. Thickness and width reproducibility index were 89% and 94%, respectively; κ = 0.87. Ultrasound demonstrated different rotator cable consistency in younger and elderly asymptomatic patients, with high interobserver reproducibility.