抄録
The course of the repair of the rotator cuff rupture has not been fully clarified experimentally in comparison with that of other tendons such as flexor tendon and Achilles tendon. The purpose of this study is to deliniate the repair of the canine rotator cuff rupture histologically in two instances; 1) only resection of the rotator cuff tendon and 2) tendon to bone repair after cuff resection.
24 adult mongrel dogs (12-17kg) were used. The study was divided into two groups: group I. Only resection of the rotator cuff; rotator cuff was resected 15 mm in width and 10 mm in length. Group II. Tendon to bone repair after cuff resection; the stump of the cuff was anchored into the trough cut at the greater tuberosity. After operation, a plaster cast was applied for 3 weeks. Dogs were killed at regular intervals and specimens including the cuff and the greater tuberosity were obtained. These were fixed, decalcified, embedded in paraffin, sectioned and stained with hematoxylin and eosin and with Azan-Mallory.
The gross and micro s copic changes were investigated. Group I. after 1 week, scar tissue formation was present, but not completely, at the gap between the proximal stump and the greater tuberosity. After 6 weeks, the gap was completely filled with scar tissue. However, microscopically, orientation of fibers was at random with many proliferating blood vessels and invasion of inflammatory cells. Group II. After 2 weeks, orientation of the fibers were at random with proliferations of blood vessels and fibroblasts. At the tendo-osseous junction, proliferation of cartilage tissue was noted. After 24 weeks, orientation of collagen fibers and appearance of tendo-osseous junction were similar to those seen in normal rotator cuff.
