Abstract: Objective  To compare the efficacy of intramedullary nail and plate internal fixation in the treatment of chronic infectious tibial plateau fractures, and their effects on knee joint function and inflammation. 
Methods  Ninety patients with chronic infectious tibial plateau fractures were selected and divided into study group and control group according to different surgical methods, with 45 cases in each group. The study group received intramedullary nail treatment, and the control group received steel plate internal fixation. The operation time, intraoperative blood loss, wound healing time, hospitalization time, fracture healing time, full weight bearing time and complication rate were compared between two groups. The callus growth score, knee joint function score, maximum knee extension angle and maximum knee flexion angle were compared between two groups at 1 day and 3 months after surgery. Serum high-sensitivity C-reactive protein(hs-CRP) was compared between two groups at 1 day and 2 weeks after surgery interleukin-6(IL-6), interleukin-8(IL-8) and tumor necrosis factor-α(TNF-α) levels. 
Results  The operation time, intraoperative blood loss, wound healing time, hospitalization time, fracture healing time and full weight bearing time in the study group were significantly less than those in the control group(P＜0.01). At 3 months after surgery, the callus growth score, knee joint function score, maximum knee extension angle, and maximum knee flexion angle in two groups were significantly higher than those at the first day after surgery. The callus growth score, knee joint function score, and knee extension maximum in the study group, the angle and the maximum angle of knee bending were higher than those of the control group(P＜0.01). Two weeks after surgery, the serum levels of hs-CRP, IL-6, IL-8 and TNF-α in two groups were significantly reduced on the first day after surgery. The serum hs-CRP, IL-6, IL-8 and TNF-α in the study group were lower than those in the control group(P＜0.01). The incidence of complications in the study group was lower than that in the control group(P＜0.05). 
Conclusion  Intramedullary nails are more effective in treating chronic infectious tibial plateau fractures, with less trauma and less blood supply damage, which is beneficial to promote postoperative knee function recovery and control inflammation. 

Key words: tibial fractures, fractures, ununited, intramedullary nail, infection