ABSTRACT
Purpose: The author hypothesizes that exogenously injected BMP, which is mixed with fibrin glue, can accelerate the healing of a bone-tendon junction injury and increase its holding strength during the early regeneration period. Materials and Methods: A direct injury model of the bone-tendon junction was made using the Achilles tendon-calcaneus bone of 54 rabbits: and the transected Achilles tendon was repaired to its original insertion site using the Krackow method. In Group 1, no additional manipulation was performed. In Group 2, only fibrin glue was injected into the junction between the Achilles tendon and the calcaneus in order to exclude the effect of the fibrin glue. In Group 3, BMP-2 incorporated into the fibrin glue was injected into the junction. The results were evaluated by histological analysis and biomechanical tests at 2, 4, and 8 weeks after surgery. The Kruskal-Wallis test was used for a statistical evaluation. Results: Histological analysis revealed the early appearance of fibrocartilage at 2 weeks in Group 3: the area of the fibrocartilage expanded with time. The biomechanical tests showed significant differences in the maximum stress between Groups 1 and 3, and between Groups 2 and 3, at 2, 4, and 8 weeks. 74.4% of the normal maximum stress was recovered at 8 weeks in Group 3. Conclusion: The combined use of BMP-2 and the fibrin glue can accelerate the healing of an injury of the bone-tendon junction.