Abstract
BackgroundSpinal fusion is a common orthopaedic procedure that has been previously modeled using canine, lapine, and rodent subjects. Despite the increasing availability of genetically modified mouse strains, murine models have only been infrequently described.PurposeTo present an efficient and minimally traumatic procedure for achieving spinal fusion in a mouse model and determine the optimal rhBMP-2 dose to achieve sufficient fusion mass.MethodMicroCT reconstructions of the unfused mouse spine and human spine were compared to design a surgical approach. In phase 1, posterolateral lumbar spine fusion in the mouse was evaluated using 18 animals allocated to three experimental groups. Group 1 received decortication only (n = 3), Group 2 received 10 μg rhBMP-2 in a collagen sponge bilaterally (n = 6), and Group 3 received 10 μg rhBMP-2 + decortication (n = 9). The surgical technique was assessed for intra-operative safety, efficacy, access and reproducibility. Spines were harvested for analysis at 3 weeks (Groups 1, 2) and 1, 2, and 3 weeks (Group 3). In phase 2, a dose response study was carried out in an additional 18 animals with C57BL6 mice receiving sponges containing 0, 0.5, 1, 2.5, 5 μg of rhBMP-2 per sponge bilaterally.ResultsThe operative procedure via midline access was rapid and reproducible, and fusion of the murine articular processes was found to be analogous to the human procedure. Unlike reports from other species, decortication alone (Group 1) yielded no new bone formation. Addition of rhBMP-2 (Groups 2 and 3) yielded a significant bone mass that bridged the L4-L6 vertebrae. The subsequent dose response experiment revealed that 0.5 μg rhBMP-2 per sponge was sufficient to create a fusion mass.ConclusionWe describe a new approach for mouse lumbar spine fusion that is safe, efficient, and highly reproducible. The technique we employed is analogous to the human midline procedure and may be highly suitable for genetically modified mouse models.
Highlights
Spinal fusion surgery has been performed since the pioneering work of Hibbs [1], Albee [2] and DeQuervain in the early 20th century
The operative procedure via midline access was rapid and reproducible, and fusion of the murine articular processes was found to be analogous to the human procedure
We describe a new approach for mouse lumbar spine fusion that is safe, efficient, and highly reproducible
Summary
Spinal fusion surgery has been performed since the pioneering work of Hibbs [1], Albee [2] and DeQuervain in the early 20th century. Animal surgical models have been utilized extensively to improve surgical technique and gain insight into the mechanisms of spinal fusion failure. Larger animals such as canine [4,5,6,7,8] and ovine subjects [9,10] have traditionally been employed due to their close approximation of the size and anatomy of human patients. Mouse models have rarely been studied, likely owing to the technical difficulty associated with surgical access and technique demanded by their small size. Purpose: To present an efficient and minimally traumatic procedure for achieving spinal fusion in a mouse model and determine the optimal rhBMP-2 dose to achieve sufficient fusion mass
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
