Objective To compare the clinical effects of arthroscopically-assisted reduction and internal fixation(ARIF)combined with enhanced recovery after surgery(ERAS)and open reduction and internal fixation surgery(ORIF)in the treatment of posterior lateral tibial plateau fractures.Methods Seventy patients with posterior lateral tibial plateau fractures in the Department of Orthopaedics,Xuzhou Central Hospital,from January 2020 to November 2022 were retrospectively selected and divided into ARIF group(with ERAS,n=32)and ORIF group(without ERAS,n=38)according to the treatment methods.All patients were evaluated for fracture type by imaging examination after admission.The operation time,length of hospital stay,early postoperative pain score(evaluated by visual analogue scale[VAS]),knee joint function(evaluated by hospital for special surgery[HSS]scale)at 3 months and thigh circumference difference at 6 months postoperatively were compared between the two groups.Results The operation time in the ARIF group was significantly shorter than that in the ORIF group([67.84±9.89]min vs[85.16±9.18]min,P＜0.001),and the length of hospital stay was significantly shorter in the ARIF group([7.13±1.41]d vs[8.74±1.84]d,P＜0.001).On the third day after operation,the VAS score in the ARIF group was significantly lower than that in the ORIF group([4.00±1.44]vs[5.39±1.24],P＜0.001).ARIF group had better joint function than ORIF group 3 months after operation,and the difference of 10 cm thigh circumference on patella in ARIF group was smaller than that in ORIF group 6 months after operation.Conclusions Compared to ORIF,patients with posterior lateral tibial plateau fractures treated with ARIF combined with ERAS showed faster postoperative recovery,shorter hospital stay,and more precise clinical efficacy.