Jae-Young Hong1, Sun-Woong Kang2, Jung-Wook Kim1, Seung-Woo Suh3, You-Jin Ko1, Jung-Ho Park4. 1. Department of Orthopedics, Korea University Ansan Hospital, Ansan, South Korea. 2. Next-Generation Pharmaceutical Research Center, Korea Institute of Toxicology, Daejeon, Republic of Korea. 3. Scoliosis Research Institute, Department of Orthopedics, Korea University Guro Hospital, Seoul, South Korea. 4. Department of Orthopedics, Korea University Ansan Hospital, Ansan, South Korea. Electronic address: canall@korea.ac.kr.
Abstract
BACKGROUND AIMS: Heparin-conjugated fibrin (HCF) is a carrier for long-term release of bone morphogenetic protein-2 (BMP-2) and has been shown to promote bone formation in animal models. We performed an experimental study to determine the optimal dose of BMP-2 with an HCF carrier that promotes bone formation comparable to that of autograft while minimizing complications in spinal fusion. METHODS: Twenty-four rabbits underwent posterolateral fusion of the L5-6 spinal segments. Different concentrations of HCF BMP-2 (1/10, 1/20, 1/30 or 1/40) were implanted in the spines of experimental rabbits, and autograft or INFUSE was implanted in the spines of control animals. Eight weeks after treatment, spinal fusion efficacy was evaluated by plain radiography, micro-computed tomography (micro-CT), mechanical testing and histomorphometry. RESULTS: Similar to autograft, the 1/40 HCF BMP-2 showed significant bone formation on micro-CT and histomorphometry with mechanical stability. However, the other HCF BMP-2 concentrations did not show significant bone formation compared with autograft. Although conventional BMP-2 (INFUSE) led to higher bone formation and stability, it also led to excessive ectopic bone and fibrous tissue formation. CONCLUSIONS: This study suggests the optimal concentration of BMP-2 using HCF for spinal fusion, which may decrease the complications of high-dose conventional BMP-2.
BACKGROUND AIMS: Heparin-conjugated fibrin (HCF) is a carrier for long-term release of bone morphogenetic protein-2 (BMP-2) and has been shown to promote bone formation in animal models. We performed an experimental study to determine the optimal dose of BMP-2 with an HCF carrier that promotes bone formation comparable to that of autograft while minimizing complications in spinal fusion. METHODS: Twenty-four rabbits underwent posterolateral fusion of the L5-6 spinal segments. Different concentrations of HCF BMP-2 (1/10, 1/20, 1/30 or 1/40) were implanted in the spines of experimental rabbits, and autograft or INFUSE was implanted in the spines of control animals. Eight weeks after treatment, spinal fusion efficacy was evaluated by plain radiography, micro-computed tomography (micro-CT), mechanical testing and histomorphometry. RESULTS: Similar to autograft, the 1/40 HCF BMP-2 showed significant bone formation on micro-CT and histomorphometry with mechanical stability. However, the other HCF BMP-2 concentrations did not show significant bone formation compared with autograft. Although conventional BMP-2 (INFUSE) led to higher bone formation and stability, it also led to excessive ectopic bone and fibrous tissue formation. CONCLUSIONS: This study suggests the optimal concentration of BMP-2 using HCF for spinal fusion, which may decrease the complications of high-dose conventional BMP-2.