| Objective:1,To observe serum and callus leptin expression within the rat model of fracture and traumatic spinal cord injury(SCI).2,To investigated the effects of serum leptin and bone mineral density(BMD)on the healing of long bone fractures in men with spinal cord injury(SCI)Methods:1,72 male SD rats were randomized equally into 4 groups:control,SCI group,fracture group,and fracture/SCI group.Rats were sacrificed at 1,2,4,8,12 weeks post fracture/SCI.Serum leptin was detected using radioimmunoassayat 1,2,4,8 and12 weeks,and callus formation was measured radiologically at 2,4,8 and 12 weeks.Callus leptin was analyzed with immunohistochemistry.2,15 male SCI patients and 15 matched controls were included in our study.All patients sustained an isolated shaft fracture of the femur or tibia and were treated with a closed,antegrade,reamed intramedullary nailing technique.These patients were followed up in the same rehabilitation unit Blood samples were taken from all subjects between 7:00 AM and 8:00 AM after an overnight fast at 2,4,8 and 16 weeks after the operation.t he fracture healing process was assessed clinically and radiologically,and standard anteroposterior and lateral radiographs were taken for all patients during the usual follow-up examinations,which were planned at 2,4,8 and 16 weeks after the operation..BMD was assessed at 2,4,8 and 16 weeks after the operation by dual-energy X-ray absorptiometryResults:1,Serum leptin in the fracture group,SCI group and combined fracture/SCI group were all significantly increased compared to control group at the 1?2?4?8week time-point(p<0.05).Serum leptin in the combined fracture/SCI group was significantly higher than the fracture group at 2,4 and 8weeks(p<0.05),and higher than SCI groups at 2 and 4 weeks after operation(p<0.05).The percentage of leptin-positive cells in the fracture/SCI callus,and callus volume was significantly higher than the fracture-only group(p<0.001).2,The outcome showed that callus production in SCI patients was higher than in controls at 4 and 8 weeks(p<0.05)after bone fracture and that the BMD was significantly reduced at 2,4 and 8 weeks(p<0.05).Additionally,we found that patients with SCI had significantly higher serum leptin levels than controls at each time Point(p<0.05),and no association was found between serum leptin level and BMD of lumbar vertebrae in SCI patients.BMD was positively correlated with bone formation in both groupsConclusions:1,Overall,we demonstrated elevated leptin expression within healing bone especially in the 8 weeks of a rat model combining fracture and SCI.A close association exists between leptin levels and the degree of callus formation in fractures.2,These findings suggested that fracture healing was enhanced in SCI patients at the early phases(at 4,8 weeks)and that different factors,such as hormonal and mechanical factors,participated in the complex healing process. |
PDF Full Text Request