Experimental Study of Osseointegration Properties of Porous Implants for the Reconstruction of Long Bone Defects

Background : Restoration of the load-bearing function of long bones in the treatment of post-resection defects remains a significant challenge in modern surgery. Objective : To evaluate early osseointegration of porous titanium and carbon-based implants in a model of long bone defects in immunodeficient mice. Materials and methods : The study was conducted on 21 male Balb/c Nude mice. The animals were divided into three groups: Group 1 (n=7) control group, in which a femoral bone defect was created; Group 2 (n=7), in which a titanium implant was placed into the defect, Group 3 (n=7), in which a carbon nanostructured implant was placed into the defect. Fourteen days after injury introduction and implant placement, radiographic examination of the femur was performed, and serum levels of alkaline phosphatase, total calcium, and procollagen type 1 N-terminal propeptide (P1NP) in animals were assessed. Results : Alkaline phosphatase levels in Groups 2 and 3 were higher than those in Group 1 by 1.3-fold ( p=0.002 ) and 1.4-fold ( p=0.0002 ), respectively. Total calcium levels were comparable across all groups, with no statistically significant differences observed. P1NP levels increased in Groups 2 and 3 compared with Group 1 by 5.1% ( p=0.002 ) and 7.8% ( p=0.0002 ), respectively; moreover, P1NP values in Group 3 were 3.4% higher than those in Group 2 ( p=0.0035 ). Conclusion : The carbon nanostructured material demonstrated superior osseointegration compared with the titanium implant, which was associated with higher circulating P1NP levels.