抄録
Although MRI has been proved effective in diagnosing a re-rupture of repaired rotator cuff tendon, there are only a few studies about the signal changes of the repaired tendon over time. The objective of this study was to follow the changes of the MRI findings of the repaired cuff tendon over 1 year. Twenty-two shoulders, which received open tendon-to-bone repair by a pull-out method and acromioplasty, were evaluated with MRI postoperatively at least twice within 1 year and over 1 year. There were 10 males and 12 females; their age at the operation was 50-80 years old (average: 63.8). There were 6 incomplete, 3 small, 6 medium, 3 large, and 4 massive tears. MRI was performed on an 0.5-T system and T2-weightened images were obtained. Intensity of the tendon or the bone-tendon interface was defined as ‘high’ when it was as high as joint fluid, as ‘low’ when it was the same as the normal tendon, and as ‘medium’ when it was between ‘high’ and ‘low’. The follow-up period was 12-106 months (average: 21.8). The re-rupture rate was 18% in the whole and 27% in the large and massive tears. In 6 shoulders which showed ‘low’ within 1 year, 5 remained ‘low’ and 1 changed to ‘high’ at the final follow-up. In 10 shoulders which showed ‘medium’ first, 2 remained ‘medium’, 7 changed to ‘low’, and 1 changed to ‘high’ finally. In 6 shoulders which showed ‘high’ first, 3 remained ‘high’, 1 changed to ‘low’, and 2 changed to ‘medium’ finally. The JOA scores significantly improved from 43.5-88 points (average: 63.1) preoperatively to 75-100 points (average: 93.1) postoperatively. There was no correlation between the size of the tear and the intensity. In 50% of the cases, high intensity changed to low over 1 year. Therefore, it is suggested that high intensity of the tendon within 1 year after repair does not necessarily mean a re-rupture.
