Rotator cuff regeneration using chitin fabric as an acellular matrix

Twenty-one rabbits were used to investigate the feasibility of using nonwoven chitin fabric as an acellular matrix for rotator cuff regeneration. Infraspinatus tendons were cut bilaterally to create 10 × 10–mm defects. The defect in the right shoulder was covered with chitin fabric. The contralateral defect was left free as a control. The specimens were evaluated histologically and immunohistochemically at 2, 4, 8, and 12 weeks and biomechanically at 12 weeks after surgery. The acellular matrix increased cell numbers and improved collagen fiber alignment. The regenerated tissues were composed of type III collagen. The structural properties of the grafted shoulder were significantly greater than those of the control. This study revealed that using chitin fabric as an acellular matrix has advantages in enhancing both biologic and mechanical regeneration of rotator cuff tendons.