抄録
We studied the relationship between fatty degeneration in the supraspinatus muscle following a rotator cuff tear and the degree of muscle atrophy, retracted tendon dissecting 22 supraspinatus muscles from 41 cadavers averaging 74.1 years of age. Eighteen shoulders had a supraspinatus tendon tear. The transverse sections of the supraspinatus muscle were made at the proximal end of the scapular notch. The tendon fiber areas were stained red, the muscle fiber areas were stained yellow by the van Gieson method, the fatty degenerative areas were stained orange red by the Sudan 3 method and then measured quantitatively using a computer color image analysis system. There were few fatty degenerative changes in the supraspinatus muscles associated with normal cuffs and they did not correlate with age. But there were many areas of fatty degenerative change, mainly around the tendon fibers and the vessels, in the supraspinatus muscles associated with cuff tears. The fatty degeneration in the supraspinatus muscle following a cuff tear was associated with the degree of retraction of the tendon fiber rather than muscle atrophy. Such fatty degeneration is considered to reduce the remaining function of the supraspinatus muscle with a cuff tear and cause a bad prognosis after repairing a torn cuff.
