Abstract:[Objective] To investigate the clinical outcomes of oblique T-shaped buttress plate for posterolateral tibial plateau frac-tures through a posterior midline small incision. [Methods] A retrospective research was done on 21 patients who received open reductionand internal fixation for tibial plateau fractures complicated with posterolateral plateau collapse from June 2018 to June 2022. All the pa-tients had the posterolateral bone fragments fixed with an oblique T-shaped buttress plate through a posterior midline small incision. Clini-cal and imaging documents were evaluated. [Results] All the 21 patients successfully completed the operation, without vascular, nerve inju-ry and other complications occurred during the operation, while with operation time of (119.1±11.5) min, and incision length was (6.1±1.1)cm. All patients were followed up for an average of (16.3±1.4) months. As time went from 1 month, 3 months postoperatively to the last fol-low-up, the VAS score [(1.2±1.3), (0.5±0.8), (0.0±0.0), P＜0.001], HSS score [(48.6±11.5), (69.6±12.6), (91.3±5.5), P＜0.001], knee ROM[(91.1±20.2)°, (114.4±11.5)°, (123.4±8.7)°, P＜0.001] significantly improved. In term of imaging, compared with those 1 month after sur-gery, the medial proximal tibial angle (MPTA), posterior tibial slope (PTS) and Rasmussen image scores remained unchanged 3 months aftersurgery and at the last follow-up (P＞0.05). [Conclusion] This oblique T-shaped buttress plate for posterolateral tibial plateau fracturesthrough a posterior midline small incision has good clinical consequences in this study.