MRI Assessment of Torn Tendons in Small Rotator Cuff Tears.

Abstract

The supraspinatus (SSP ) tendon attaches to the superior facet and the superior half of the middle facet, whereas the infraspinatus ( ISP) tendon attaches to the entire middle facet, making an overlap between these tendons. Therefore, it seems possible to identify the tendons involved in a tear judging from the facets. The purpose of this study was to assess torn tendons in small tears of the rotator cuff on MRIs. Among forty-two symptomatic shoulders of 40 consecutive patients with a rotator cuff tear on MRI,18 shoulders with small tears (area<4cm²) were enrolled in this study. T2 weighted images in sagittal oblique and coronal oblique planes were obtained using a 0.5-T MR imager (Toshiba FLEXART ) The patients were divided into two groups: high signal intensity on the superior facet only (Group 1 ) and high signal area extending to the middle facet (Group 2 ). Group 1 corresponds to the isolatedSSP tears and Group 2 corresponds to the SSP-ISP tears. The statistical significance between the tear size in Group 1 and Group 2 was assessed using the Student t test. Eight shoulders were isolated SSP tears (Group 1 ), and 10 shoulders were SSP-ISP tears (Group 2 ). The size of the isolated SSP tears and the SSP-ISP tears were 1,55 ±0.72cm²and 1.52 ±0.96cm², respectively. There was no significant difference between the tear size in either group. Small tears of the rotator cuff involved ISP tendon rupture in more than 50 %.