Repair of the Complete Radial Tear of the Anterior Horn of the Medial Meniscus in Rabbits: A Comparison between Simple Pullout Repair and Pullout Repair with Human Bone Marrow Stem Cell Implantation

PURPOSE: To evaluate the degree of biological healing response that occurs between the anterior horn of the medial meniscus (MM) and the tibial plateau and investigate the biological healing response after injection of human bone marrow stem cells (hBMSCs) in a rabbit model. MATERIALS AND METHODS: Twenty-five rabbits with a mean body weight of 2.5 kg were chosen for this study. On the left knee, a complete radial tear was made at the anterior tibial attachment site of MM and after removal of tibial cartilage, pullout repair of the torn MM was performed on the tibial plateau. On the right knee, the same procedure was performed, and a scaff old (matrix gel) that contained human bone marrow stem cell was implanted between MM and the tibial plateau. A biopsy was performed at 2 (group 1), 4 (group 2), and 8 (group 3) weeks postoperatively. The authors compared the differences in the degree of biological healing of each group and investigated the degree of biologic healing after hBMSC implantation by comparing the left knee with the right knee. RESULTS: On the biopsy of 40 knees of 20 rabbits that survived after operation, all groups did not show the healing response between the undersurface of MM and the tibial plateau. There was no significant difference in terms of the pathological criteria such as fibroblasts and fibrochondrocytes etc., with and without hBMSC implantation. CONCLUSIONS: There was no attachment between the repaired MM and the tibial plateau after complete radial tear on MM and the authors could not identify the effect of hBMSC.