New Bone Formation in Tuberculous-Infected Vertebral Body Defect after Administration of Bone Marrow Stromal Cells in Rabbit Model

STUDY DESIGN: Preliminary experimental study using a rabbit spondylitis model. PURPOSE: To observe the ossification in a micro-environment containing live Mycobacterium tuberculosis transplanted with bone marrow stromal cells (BMSCs) in rabbits. OVERVIEW OF LITERATURE: BMSCs differentiate to osteoblasts and then osteocytes during ossification. Mycobacterium tuberculosis does not affect BMSC growth in vitro. METHODS: Six rabbits were divided into two groups of three rabbits. One group was positive for spondylitis tuberculosis by culture, polymerase chain reaction (PCR), and histopathologically. The other group was positive by PCR and histopathologically. Both groups were treated using BMSC transplantation and anti-tuberculosis drugs. After 6 weeks, ossification was evaluated by enumerating the number of osteoblasts, osteocytes, and lesion level of calcium. RESULTS: Mean number of osteoblasts was 207.00±31.00 in the first group and 220.33±73.46 in the second group. Mean number of intra-lesions osteocytes was in the first and second group was 18.33±30.04 and 31.00±26.87, respectively. Mean calcium level in the first group and second group was 2.94%±0.89% and 2.51%±0.13%, respectively. Total ossification score in the first and second group was 31.00 and 25.67, respectively. CONCLUSIONS: Mycobacterium tuberculosis provides support for new bone formation by stimulating intra-lesion calcium metabolism. The microscopic environment containing live Mycobacterium tuberculosis enhances ossification.