Objective: To investigate the surgical technology and clinical efficacy of using the all-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ. Methods: The clinical data of 33 patients (33 feet) with intra-articular displaced calcaneal fractures treated by modified all-inside arthroscopic from March 2017 to March 2019 at Department of Orthopedics,Xuzhou Central Hospital were retrospectively analyzed.There were 19 male patients,and 14 female patients,aged (32.6±11.3) years(range:20 to 55 years). According to the Sanders classification,there were 12 cases of type Ⅱ and 21 cases of type Ⅲ. The duration from injury to surgery was (101.2±32.1) hours(range:6 to 140 hours).The preoperative visual analogue scale (VAS) was 6.4±2.9 (range: 4 to 8); The preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale and the SF-36 score was 63.3±11.8 (range:50 to 75) and 94.8±9.1 (range:70 to 105) respectively.All the patients were managed with the all-side subtalar arthroscopy through three portals combined with rafting screws technique.The incision healing,reduction of fracture,and fracture healing were recorded.The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were used to assess the pain and functional outcomes.Repeated-measurement was used to compare the scores before and after surgery. Results: The time of operation was (69.7±10.4) minutes (range:40 to 110 minutes). All patients did not undergo bone grafting.The incision healed in one stage without complications of skin sensory and peroneal tendon injury.All patients were followed up for 24 months.At the last follow-up,all the patients were satisfied with the hindfoot alignment,function,and hindfoot appearance.Postoperative calcaneal imaging indicators (calcaneal length,calcaneal width,calcaneal height,Bohler angle and Gissane angle) were significantly improved compared with those before surgery (P<0.01).There was no statistically significant difference in the imaging indexes of calcaneus at 1 day,1 year and 2 years after surgery,indicating no loss of fracture reduction (all P>0.05).The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were 1.5±0.4 (range: 0 to 2),94.0±6.5 (range:90 to 100),and 119.1±7.2 (range:105 to 130),respectively,which were better than those before surgery (all P>0.05).According to the AOFAS scoring system,27 cases were excellent,4 cases were good, 2 cases were fair,and the excellent and good rate was 94.0%. Conclusion: All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ provides precise reduction,reliable fixation,satisfactory function and limited complications,which is an alternative method.