This paper is on the character of the torn rotator cuff especially patients in a younger age group. Biopsy speciments of the torn cuffs of 15 patients aged between from 20 and 40 were examined. There were 2 complete and 13 incomplete tears (3 articular sides,7 bursal sides and 3 intratendinous tears). Histological sections were investigated using H-E, Elastica-Masson stainings as well as immunostaining them with antibodies against the C-terminal of procollagen type I.
Tears with a depth of more than one-half of the tendon thickness were observed i n 6 of the 13 incomplete tears. The disappearance of the wavy pattern of the tendon fibers were seen in all the specimens. Vessels were distributed within the tendon proper close to the torn stumps in complete tears, while they were found in the bursal side and were sparse in the articular side. Positive immunostaining was found. at the vessel walls and fibroblasts adjacent to them. They were also found at the margin of the torn stumps in the complete tears. In the incomplete tears, in contact, it was only found in the vicinity of vessels close to the bursal side.
These findings suggest the healing potential of incomplete tears are limited compared with complete ones in patients of the younger age group.
