Effect of Time Lag from Injury to Surgery on the Temporal Expression of Growth Factors After Intramedullary Nailing of Isolated Fracture of Femur Shaft

Background Growth factors are considered to play an important role in the process of bone healing. This study assessed serum levels of transforming growth factor-beta 1 (TGF-beta 1) and vascular endothelial growth factor (VEGF) in patients undergoing intramedullary nailing for isolated fracture of femur shaft operated at various time lag from injury. Patients and methods All patients between 18 and 60 years of age group operated for isolated femoral shaft fractures (AO/OTA32 A, B, C) were included. The serum levels of VEGF and TGF-beta 1 were compared at various intervals amongst the study group divided into two groups based on the time lag between injury and surgery along with a health control cohort. Results 31 patients were operated within the first 48 h while 28 patients were operated within 2-12 days after injury. Highest VEGF levels were observed on postop day 3, followed by a subsequent decline thereafter. TGF-beta 1 level also showed increasing trend after surgery, but the levels reached dual peaks after 2 weeks and 12 weeks after surgery. Both groups revealed similar trends of temporal expression of serum VEGF and TGF-beta 1. There was no statistical difference between the two groups at any point of time during the observation period. There was also no statistical difference in clinico-radiological healing of fractures among the groups. Conclusion There is a definite and specific trend of serum levels of growth factors in the fracture healing process. There is no effect of time lag from injury to surgery on the healing outcome of isolated femoral shaft fractures both at the molecular level and also at the clinical level.