Objectives To study the construction of tissue engineering sheath in vivo and its effects in preventing tendon adhesion. Methods Total 48 Leghorn chickens were randomly divided into three groups. Experimental group (n=16): repairing the removed sheath with the synoviocytes-polyglycolic acid (PGA) complex; Control group 1 (n=16): repairing the removed sheath using the PGA scaffold without cells. Control group 2 (n=16): removing the nature tendon sheath without repaired. The chickens were sacrificed at the ti...