The bone-tendon interface of an infraspinatus tendon reattached to the fibrocartilageneous layer

The present study demonstrated histologic Features of the bone-tendon interface after infraspinatus tendon reattachment to a remaining short tendon end. The left infraspinatus muscles of eight mongrel clogs were transected and repaired between the uncalcified fibrocartilage layer and the tendon proper. Specimens were harvested at 3, 6, 12, and 16 postoperative weeks. Samples stained by HE were viewed with a polarized light. Until 6 postoperative weeks, the bone-tendon interface was filled with oriented fibrous tissue and immature collagen fibers that interdigitated with the uncalcified fibrocartilage layer. From 6 to 12 postoperative weeks, the bone-tendon interface was occupied by mature Fibroblasts and aligned collagen fibers that connected smoothly into the uncalcified fibrocartilage layer, forming a clear tide mark. This study demonstrated that reattachment of a free tendon to the remaining short tendon end on the greater tuberosity has potential to produce direct enthesis.