Objective:To compare the post-operative outcomes between extended lateral approach and L-shaped lateral approach in surgical treatment of Sanders type III intra-articular calcaneal fractures.Methods:A retrospective case-control study was made on clinical data of 34 patients with fresh Sanders type III intra-articular calcaneal fractures hospitalized in Langfang Hospital of Traditional Chinese Medicine from October 2014 to October 2017. There were 33 males and 1 female, with the age of 18-56 years [(42.5±9.4)years]. All fractures were fresh. Seventeen patients were fixed by the extended lateral approach (extended approach group) and seventeen patients by L-shaped lateral approach (L-shaped approach group). Operation duration, intraoperative bleeding volume, length of hospital stay, one-stage wound healing rate and complication rate were observed. B?hler and Gissane angle were measured before operation, one week after operation and 12 months after operation. American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale was applied to evaluate function recovery.Results:There were no significant differences between groups in operative time and intraoperative bleeding volume ( P>0.05). There were significant differences between extended approach group and L-shaped approach group in length of hospital stay [(15.7±4.0)days vs.(22.4±9.6)days], one-stage wound healing rate [88%(15/17) vs. 47%(8/12)] and postoperative complication rate [12%(2/17) vs. 47%(8/17)] ( P<0.05). The B?hler and Gissane angles did not differ significantly between groups before operation and one week and 12 months after operation ( P>0.05). At postoperative 12 months, the B?hler and Gissane angles were improved from preoperative (8.2±6.0)°, (85.3±10.5)° to (23.9±6.1)° and (119.3±6.2)° respectively in extended approach group, and those from preoperative (9.4±3.9)°, (85.5±7.1)° to (25.8±3.7)° and (122.2±5.6)° respectively in L-shaped approach group (all P>0.05). At 12 months after operation, the AOFAS score was (86.9±7.5)points in extended approach group, with the excellent and good rate of 88%; and was (83.3±12.5)points in L-shaped approach group, with the excellent and good rate of 76% ( P>0.05). While the score of hindfoot joint activity in extended approach group was (5.8±0.7)points, significantly higher than (3.4±1.0)points in L-shaped approach group ( P<0.05). Conclusion:For Sanders III intraarticular calcaneal fractures, compared with L-shaped approach group, plate fixation via extended approach can promote fracture healing, shorten hospital stay, reduce incidence of complications and facilitate function recovery of subtalar joint.