Experimental fascial autografting for the supraspinatus tendon defect: remodeling process of the grafted fascia and the insertion into bone.

To elucidate the postoperative histologic changes of fascial autografting, tendinous defects (1.5 x 1.5 cm) were created close to the supraspinatus insertion and were covered by fascial autografts in 21 rabbits. Shoulders harvested on the fourth day and 1, 2, 3, 4, 6, and 8 weeks after surgery were examined histologically and immunohistochemically. At the fascia-bone junction, chondrocytes started to appear at 2 weeks after surgery and increased rapidly thereafter. Although a tidemark was not seen, remodeling of direct insertion with fibrocartilage was almost complete by 8 weeks. The distribution of collagen types II and III represented a pattern similar to that of a normal supraspinatus tendon insertion. In the grafted fascia, the cellular density showed a marked increase over time (r2 = 0.74, P <.0001). Our study revealed that both the tendinous tissue and its insertion were reformed after this procedure. Fascial autografting might be useful for repairing a supraspinatus tendon defect.