2011 Volume 35 Issue 3 Pages 841-844
Many articles have reported that fatty infiltration of rotator cuff muscles was one of the important factors to affect the outcomes of rotator cuff repairs and did not improve even after successful rotator cuff repairs. However, these studies were based on qualitative evaluation of fatty infiltration such as Goutallier's staging. We reported that T2 mapping technique of MRI had potential to evaluate fatty infiltration quantitatively. The purpose of this study was to assess the changes in fatty infiltration of rotator cuff muscles after arthroscopic rotator cuff repairs (ARCR) using T2 mapping. Twelve shoulders from 12 patients were enrolled in this study. Subjects consisted of 7 males and 5 females with a mean age of 61 years old (range, 44-76). There were 2 partial, 4 small, 1 medium, 3 large and 2 massive tears. They underwent MRI at 3, 6 and 12 months after ARCR. T2 mapping was performed at Y-shaped view and the average T2 of the supraspinatus (SSP) and infraspinatus (ISP) muscles were measured. The cross-sectional areas of SSP and ISP were also measured. One-way repeated-measure ANOVA was used for statistical analysis and the level of significance was set at p<0.05. Re-tears were found in 1 large and 2 massive tears. Average T2 of SSP at 3, 6 and 12 months were 43.8 ± 7.2, 40.4 ± 4.7 and 38.6 ± 3.7 msec, respectively, and the change was significant (p=0.01). Average T2 of ISP were 39.1 ± 5.9, 37.4 ± 5.9 and 36.6 ± 2.9 msec, respectively (p=0.24). There were no significant changes in the cross-sectional areas of SSP and ISP. T2 of SSP significantly decreased in the successful repairs (p=0.04); however, there were no significant changes in the shoulders with re-tears. The results of this study indicated that fatty infiltration of rotator cuff muscles could be reversed after successful repairs.
