Use of bisphosphonates in experimental bone tuberculous osteitis: CT imaging

Introduction The complex treatment of osteoarticular tuberculosis is based on combination of anti-tuberculosis therapy, complete (radical) removal of involved bone and restoration of the supporting and motor function of the affected musculoskeletal segment. Inhibited activity of osteoclasts involved in osteoresorption as one of the mechanisms of reparative osteoregeneration can be involved in regulation of bone formation after radical reconstructive surgery. The objective was to explore CT signs of osteoregeneration due to multimodal treatment of experimental tuberculous osteitis with use of bisphosphonates as targeted inhibitors of osteoclasts. Material and methods An experimental study was carried out on 21 mature male Chinchilla rabbits. The first stage included bone tuberculosis simulated in the medial condyle of the right femur using invasive local infection with M. tuberculosis strains H37Rv, a virulent reference laboratory strain. Pathological focus was resected and bone graft used at the second stage. Animals receiving anti-tuberculosis therapy (ATT), ATT and bisphosphonates (BP) and BP only were divided into three groups at the third stage. Animals were sacrificed at 3 and 6 months of surgical treatment at the fourth stage. Autopsy implantation zone, bone of the contralateral condyle and intact femur were quantitatively and qualitatively assessed using micro-CT imaging. Results Positive dynamics in bone restoration was seen in the groups. ATT group showed complete lysis of the implant with bone cavities identified and no bone restoration in half of the cases seen at 6 months. Rabbits treated with BP demonstrated absence of complete lysis of the implant and CT signs of ingrowth of bone trabeculae. CT signs of maximum osteoregeneration were noted in the group of isolated BP therapy. Discussion The use of bisphosphonates can prevent lysis of grafts preserving the osteoconductive properties and facilitating formation of new bone. Conclusion Targeted osteoclast inhibitors can be safety and efficaciously used in the complex treatment of focal infectious skeletal lesions and be recommended as a potential component of pathogenetic therapy in the postoperative treatment of infectious (tuberculous) skeletal lesions.