Early reactions after reimplantation of the tendon of supraspinatus into bone - A study in rabbits

In 14 rabbits we determined the origin of the cells effecting healing of th e tendon of supraspinatus inserted into a bony trough, After two weeks both the cellularity of the underlying bone and the thickness of the subacromia l bursa were significantly increased in the operated compared with the cont rol shoulders. The cellularity of the stump of the tendon, however, was sig nificantly decreased in the operated shoulders. In this model, both the und erlying bone and the subacromial bursa but not the stump of the tendon cont ributed to the process of repair. We conclude that the medial stump should be debrided judiciously but that c utting back to bleeding tissue is not necessary during repair of the rotato r cuff. Moreover, great care should be taken to preserve the subacromial bu rsa since it seems to play an important role in the healing process.