Effects of demineralized bone matrix on tendon-bone healing: an in vivo, experimental study on rabbits.

OBJECTIVE: The aim of this study was to investigate the effects of demineralized bone matrix (DBM) on tendon-bone healing. METHODS: The extensor digitorum longus tendon was fixed with pegged suture technique in a tunnel at the proximal tibia in both legs of 12 New Zealand rabbits. Rabbit DBM was applied in the tunnel on the right limbs before fixation (study group), while the fixation was performed without DBM in the left legs (control group). Randomly, four rabbits were sacrificed at the 3rd, four rabbits at the 6th and the remaining four rabbits at the 9th week with an intravenous high dose (200 mg/kg) pentothal and both legs were collected for histological analysis. Each specimen was blindly and independently examined to assess fibrocartilage formation, new bone formation, tendon graft bonding to adjacent tissue and Sharpey's fiber formation. A scoring system was used for quantification of histopathological analysis. RESULTS: The DBM group showed higher number of Sharpey's fibers, slightly increased fibrocartilage formation and new bone formation scores than the control group in the 3rd week. All histological scores were similar in both groups in the 6th and 9th weeks (p>0.05). CONCLUSION: DBM increased new bone formation and the number of Sharpey's fibers in a bone tunnel animal model within the first three weeks of tendon-bone healing process.