ObjectiveTo compare the effectiveness of all-arthroscopic technique and modified open Broström technique in repair of anterior talofibular ligament (ATFL) for lateral instability of the ankle (LIA).MethodsA retrospective analysis was made on 65 patients who underwent ATFL repair with anchors for LIA between January 2014 and January 2017. The ATFL was repaired by all-arthroscopic technique in 35 patients (arthroscopic group) and modified open Broström technique in 30 patients (open group). There was no significant difference in age, gender, the side of injured ankle, the time from injury to operation, and preoperative anterior displacement of talus, tilt angle of talus, the Karlsson Ankle Functional (KAF) score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and Japanese Society for Surgery of the foot ankle-hindfoot (JSSF) scale score between the two groups (P>0.05). The operation time, the intraoperative bleeding volume, and the length of time for surgery recovery were recorded. The anterior displacement of talus, the tilt angle of talus, KAF score, AOFAS score, and JSSF scale score were evaluated at 2 weeks, 3 months, and the last follow-up.ResultsAll patients were followed up 24-30 months, with an average of 26 months. The operation time, intraoperative bleeding volume, and the length of time for surgery recovery of arthroscopic group were superior to open group (P<0.05). There were 2 cases of temporary ankle and dorsum numbness and 1 case of thread reaction in arthroscopic group; and there were 2 cases of temporary ankle and dorsum numbness and 2 cases of thread reaction in open group. The AOFAS score, KAF score, and JSSF scale score in arthroscopic group were significantly higher than those in open group (P<0.05) at 2 weeks after operation; there was no significant difference between the two groups at 3 months and the last follow-up (P>0.05). There was no significant difference in the anterior displacement of talus and the tilt angle of talus between the two groups at 2 weeks, 3 months, and last follow-up (P>0.05).ConclusionCompared with the modified open Broström technique, the all-arthroscopic technique, as a minimally invasive technique, can achieve the same effectiveness, and has the advantages of shorter operation time, less intraoperative bleeding, and less pain in the early stage.