Objective:To explore the effects of different fixation methods on the short-and long-term lower limb function in pa-tients with trimalleolar fractures.Methods:A retrospective analysis was conducted on clinical data from 84 patients with trimalleolar fractures patients were divided into two groups based on their posterior malleolus fracture fixation method:a plate fixation group(n=45)and a cannulated screw fixation group(n=39).Surgical indicators(operation time,intraoperative blood loss,postoperative hospital stay),preoperative and early postoperative ankle plantarflexion and dorsiflexion angles,Visual Analogue Scale(VAS)pain scores,and American Orthopaedic Foot & Ankle Society(AOFAS)Ankle-Hindfoot Scores were compared between the two groups.All patients un-derwent follow-up for 12 months after surgery to compare the time to posterior malleolus union and AOFAS Ankle-Hindfoot Scores at 6 and 12 months postoperatively.Results:The operation time was longer in the plate fixation group compared to the cannulated screw fixa-tion group(P＜0.05).There were no significant differences between the two groups in terms of intraoperative blood loss and postopera-tive hospital stay(P＞0.05).1 month postoperatively,both groups showed increased ankle plantarflexion and dorsiflexion angles,with the plate fixation group having larger angles than the cannulated screw fixation group(P＜0.05).At 1 month postoperatively,both groups had reduced pain Visual Analogue Scale(VAS)scores and increased American Orthopaedic Foot & Ankle Society(AOFAS)Ankle-Hindfoot Scores(P＜0.05),with the plate fixation group showing greater changes in both VAS scores and AOFAS Ankle-Hind-foot Scores compared to the cannulated screw fixation group(P＜0.05).There was no significant difference in the short-term treatment success rate between the two groups(P＞0.05).The time to posterior malleolus union and AOFAS Ankle-Hindfoot Scores at 6 and 12 months postoperatively did not differ significantly between the plate fixation group and the cannulated screw fixation group(P＞0.05).Conclusion:Compared to cannulated screw fixation,plate fixation is more beneficial for early postoperative recovery of ankle function in patients with trimalleolar fractures.However,there are no significant differences between the two fixation methods in terms of long-term lower limb function.