Introduction: When an attempt to restore function by means of a tendon graft fails to give the desired results, the reason is practically always the formation of adhesions between the tendon and the surrounding tissue. Since this process is essential for the vascularisation of the graft, it must not be prevented but an attempt can be made to influence the nature of the adhesions in order to limit the functional restrictions caused by them. Basically, the formation of collagenous adhesions may be modified in two ways : by the administration of drugs or by the induction of a tendon sheath. Methods to control a natural healing process by administration of drugs are still in an experimental stage. The appropriate drugs (lathyrogens) are capable of changing the physical characteristics of collagen in a specific manner. Results of experiments with one of these drugs (beta-amino-proprio-nitril) are promising (Peacock, 1968). In this paper we are mainly concerned with the second approach. The capacity of cell-poor tissue to form collagen is rather limited. Since the tendon sheath has a small number of cells, the grafting of a tendon in an intact sheath would seem to offer advantages in the form of a collagen-poor adhesion formation with little limitation of function.