Observation Of Tendon-bone Healing In Rabbits With Acute Infraspinatus Tendon Injury Repaired By Autogenous Periosteum Filling

Objective The growth of the junction of infraspinatus tendon and bone in rabbits was observed by biomechanical test and histomorphological study.The effect of autogenous periosteum on tendon healing on the surface of bone after acute rotator cuff injury in rabbits was further explored.It provides a way and method for improving tendon healing rate after rotator cuff injury in clinic,and provides an experimental carrier for further study of rotator cuff tendon healing using repair materials.Methods Forty-two New Zealand white rabbits,male and female,randomly numbered 1-42,were divided into three groups:control group with direct suture,experimental group with autogenous periosteum filling tendon-bone interface and suture,blank group without operation.Tendon-bone healing specimens were taken from experimental group and control group for biomechanical test and histological observation at 4,8 and 12 weeks after operation.The blank group was raised to 12 weeks of body weight and experimental group.Samples were directly executed for biomechanical test and histological observation.Results 1.Histological observation: granulation tissue filling was observed at the tendon-bone interface of the experimental group and the control group at 4 weeks after operation,and tendon-bone gap was large,and there was no obvious healing tendency.At 8 weeks,fibroblasts were found at the insertion point,a small amount of collagen fibers were connected,some uncalcified fibrocartilage grew into the tendon,tendon-bone gap was close,but still there were gaps.Chondrocytes in the experimental group were solid.At 12 weeks,the experimental group and the control group showed dense tendon-bone gap,collagen fiber junction,a large number of chondrocytes,and some osteoblasts,a large number of chondrocytes growing into the tendon,but in the control group,the arrangement of the fibers and chondrocytes was disordered,the tendon cells formed between collagen fibers bundles,and the chondrocytes and muscle fibers arranged in a regular column.In the blank group,normal terminal structures were observed:tendons,fibrocartilage,calcified fibrocartilage and bone.2.Biomechanical test results: The maximum tensile strength of tendon insertion rupture in the experimental group and the control group increased with time.At 12 weeks,the maximum tensile strength of the experimental group was close to that of the blank group.There was no significant difference in the maximum tensile strength between the experimental group and the control group at 4 weeks(P > 0.05);there was significant difference in the maximum tensile strength at 8weeks(P < 0.05);the maximum tensile strength at 12 weeks in the experimental group was higher than that in the control group(P < 0.05).There was no significant difference between the experimental group and the blank group at 12 weeks(P > 0.05),but the control group at 12 weeks was significantly lower than the blank group(P < 0.05).Conclusion Autogenous periosteum filling can promote the recovery of tendon-bone interface structure and improve the biomechanical properties of tendon insertion after rotator cuff injury in rabbits.