Study On The Difference Of Bone Structure And Osteogenesis Between Patients With Tuberculosis And Pyogenic Spondylitis

Objective:To study the bone mineral density of femoral neck in patients with spinal tuberculosis and pyogenic spondylitis,and to explore the microstructure of focal sclerosing bone and the osteogenic differentiation ability of bone marrow mesenchymal stem cells(BMSCs)in patients with focal sclerosing spinal tuberculosis and pyogenic spondylitis.Methods:Thirty-six patients with spinal bone destruction diagnosed in the Department of Spinal surgery of Xiangya Hospital of Central South University were collected and divided into tuberculosis group(TB)and pyogenic group(PS)according to the diagnosis.The patients in both groups were matched according to sex and age and then included in the group.The disease courses,age,body mass index(BMI),bone mineral density(BMD)of femoral neck and preoperative CT gray value of diseased vertebrae and normal vertebrae were compared between the two groups.The sclerotic bone tissue around the focus of the two groups was scanned by micro-CT,and the microstructure of the sclerotic bone tissue of the two groups was compared.During the operation,the blood of spinal nail tract with obvious sclerosing bone formation was taken from patients with spinal tuberculosis and pyogenic spondylitis,and BMSCs was extracted for osteogenic differentiation test for 7 days,and their osteogenic differentiation ability was compared.Results:There was no significant difference in BMI,age,disease courses and BMD of femoral neck between tuberculosis group and pyogenic group.The gray value of CT of diseased vertebrae in tuberculosis group was higher than that of normal upper and lower adjacent vertebrae(t=8.688,p= 0.000)(t=9.069,p= 0.000),and the gray value of CT of diseased vertebrae in tuberculosis group was also higher than that of pyogenic group(t=3.838,p=0.001).The gray value of CT of diseased vertebrae in pyogenic group was higher than that of normal superior and inferior adjacent vertebrae(t= 3.254,p=0.003)、(t=3.137,p=0.004).The thickness and volume fraction of trabecular bone in tuberculosis group were larger than those in pyogenic group(t= 3.155,p=0.01)、(t= 3.945,p=0.003),and the separation degree of trabecular bone was lower than that in pyogenic group(t=-2.493,p=0.032).After 7 days of osteogenic induction and differentiation of BMSCs,the degree of mineralization in tuberculosis group was higher than that in pyogenic group(t=3.162,p=0.034).Conclusion:The phenomenon of osteosclerosis around the diseased vertebrae in patients with focal sclerosing spinal tuberculosis is more significant than that in patients with pyogenic spondylitis,which may be related to the stronger osteogenic differentiation ability of BMSCs of diseased vertebra in patients with focal sclerosing spinal tuberculosis.