Objective: There are very few studies about total knee arthroplasty biomechanical and biochemical effects in the early postoperative period. The aim of this study was to investigate the effect of total knee arthroplasty on pain intensity, knee joint valgus angle, malalignment, functional status, knee joint position sense, and cytokine levels., Methods: A total of 29 patients (female/male: 24/5) who underwent total knee arthroplasty were included in the late-stage knee osteoarthritis group, and 22 patients (female/male: 13/9) with grade 4 osteoarthritis were included in the early-stage knee osteoarthritis group. The visual analog scale and the Western Ontario and McMaster Universities Osteoarthritis Index were used to evaluate the pain intensity and functional status. Alignment and knee position sense measurements were also calculated. Systemic venous blood samples were taken to evaluate the interleukin-6, tumor necrosis factor-alpha, and interleukin-1 beta cytokine levels., Results: In the study group, there were positive improvements in pain intensity, functional status, valgus angle, malalignment, amount of joint position sense deviation at 70° knee flexion angle parameters, and interleukin-6 of patients at the postoperative 6th week compared to the preoperative period (p<0.05). The patients in the study group had similar or better results in pain intensity, functional status, valgus angle, malalignment, amount of joint position sense deviation at 35°, 55°, and 70° knee flexion angles parameters, and in interleukin-6, compared to the control group at postoperative 6th week., Conclusion: Total knee arthroplasty provides improvements in pain, function, valgus angle, joint position sense, and interleukin-6 in the early postoperative period.