Spatiotemporal responses of trabecular and cortical bone to complete spinal cord injury in skeletally mature rats
Jonathan A. Williams,
Carmen Huesa,
James F.C. Windmill,
Mariel Purcell,
Stuart Reid,
Sylvie Coupaud,
John S. Riddell
Affiliations
Jonathan A. Williams
Department of Biomedical Engineering, Wolfson Building, University of Strathclyde, Glasgow G4 0NW, UK; School of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, UK; Scottish Centre for Innovation in Spinal Cord Injury, Queen Elizabeth National Spinal Injuries Unit, Glasgow, UK; Corresponding author at: Department of Biomedical Engineering, Wolfson Building, University of Strathclyde, 106 Rottenrow East, Glasgow G4 0NW, UK.
Carmen Huesa
Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, UK
James F.C. Windmill
Department of Electronic and Electrical Engineering, Royal College Building, University of Strathclyde, Glasgow G1 1XW, UK
Mariel Purcell
Scottish Centre for Innovation in Spinal Cord Injury, Queen Elizabeth National Spinal Injuries Unit, Glasgow, UK
Stuart Reid
Department of Biomedical Engineering, Wolfson Building, University of Strathclyde, Glasgow G4 0NW, UK
Sylvie Coupaud
Department of Biomedical Engineering, Wolfson Building, University of Strathclyde, Glasgow G4 0NW, UK; Scottish Centre for Innovation in Spinal Cord Injury, Queen Elizabeth National Spinal Injuries Unit, Glasgow, UK
John S. Riddell
School of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, UK; Scottish Centre for Innovation in Spinal Cord Injury, Queen Elizabeth National Spinal Injuries Unit, Glasgow, UK
Objective: Characterise the spatiotemporal responses of trabecular and cortical bone to complete spinal cord injury (SCI) in the skeletally mature rat in the acute (4-week) period following injury. Methods: The spinal cord of 5-month old male rats was transected at the T9 level. Outcome measures were assessed using micro-computed tomography, three-point bending and serum markers at 1-, 2-, and 4-weeks post-transection. Comparison was made with time-0 and sham animals. Results: Lower levels of circulating serum bone formation markers and higher bone resorption markers suggested uncoupled bone turnover as early at 1-week post-transection. Micro-computed tomography showed metaphyseal and epiphyseal trabecular bone loss was observed only at 4-weeks post-transection. The bone loss was site-specific with a more severe reduction in trabecular BV/TV observed in the metaphyseal (50%) relative to epiphyseal (19%) region. Metaphyseal trabecular bone exhibited a 54% reduction in connectivity density while the epiphyseal trabecular bone was unaffected. Cortical bone deficits were not seen over the time periods examined. Conclusions: The study demonstrates that the skeletally mature spinal cord transected rat model replicates the biphasic pattern of osteoporotic changes observed in the human SCI population, providing a relevant model for testing the efficacy of interventions against SCI-induced osteoporosis.
