Background <p>This study evaluated the efficacy of tibial condylar valgus osteotomy (TCVO) for correcting varus deformity following malunited tibial plateau fractures.</p> Methods <p>A retrospective cohort analysis was performed on patients undergoing TCVO (January 2019 – June 2023). Radiographic parameters comprised Mechanical Axis position (%MA), Medial Proximal Tibial Angle (MPTA), Femorotibial Angle (FTA), Joint Line Convergence Angle (JLCA), Medial Tibial Plateau Depression (MTPD), and Posterior Proximal Tibial Angle (PPTA). Functional outcomes were evaluated using Knee Society Score (KSS), Lysholm Knee Score (LKS), and Visual Analog Scale (VAS).</p> Results <p>A total of 29 patients with posttraumatic knee varus deformity secondary to malunited tibial plateau fractures were included in this study (mean postoperative follow-up 21.3 ± 7.6 months) and demonstrated osseous union at 15.3 ± 1.6 weeks. The %MA improved from 1.4 ± 14.8% preoperatively to 60.0 ± 8.1%, while the FTA decreased from 186.7 ± 2.9 to 172.1 ± 2.1°. MPTA improved from 82.6 ± 1.3° before surgery to 87.1 ± 1.6° afterwards. JLCA decreased from 5.5 ± 1.5° preoperatively to 1.1 ± 0.9° postoperatively. The MTPD decreased from 6.4 ± 1.8° to 1.1 ± 1.0°. Postoperative assessments indicated significant improvements in knee function with Knee Society Scale (KSS) improved from 48.4 ± 14.1 to 88.6 ± 4.7 and Lysholm Knee Score (LKS) improved from 51.6 ± 9.8 to 90.1 ± 3.6.</p> Conclusion <p>TCVO effectively restores limb alignment and functional capacity in patients with malunion-induced varus deformity, providing a viable solution for this complex posttraumatic condition.</p>