Abstract: Objective To explore the therapeutic effect of patients with chronic lateral lateral ankle instability after modified Brostrom surgery and arthroscopic ligament enhancement. Methods Fifty-six patients with chronic lateral lateral ankle instability and surgical treatment were enrolled in our hospital from January 2016 to August 2018.They were divided into modified Brostrom group and arthroscopy group according to random number table，28 cases in each group.Patients in the modified Brostrom group were treated with modified Brostrom，and the arthroscopy group underwent arthroscopic fixation of the ligament with anchors and sutures.After treatment，the two groups of patients were followed up for 1 year.The operation time，intraoperative blood loss，postoperative activity time，wound healing and ankle instability were compared between the two groups.The FOAS scoring system，FAAM scoring system，talar inclination angle，and talar advance distance were evaluated at 6 months and one year after surgery to evaluate the ankle joint function status and the recurrence of 〖JP2〗lateral ankle instability. Result The arthroscopic operation time（50.91±8.07）min and postoperative ground movement time（4.67±1.36）d were shorter than the modified Brostrom operation group（56.76±7.93）min and postoperative ground movement time（6.35±2.04）d.The bleeding volume in the arthroscopy group（37.05±8.17）ml was less than that in the modified Brostrom operation group（42.43±6.98）ml，P<0.05.The pain score（54.23±5.28/44.63±4.45）and symptoms（52.53±6.34/47.81±5.22）of the arthroscopic group at 6 months and 1 year after surgery were significantly lower than the pain score（66.12±5.29/62.19）and symptoms（62.25±6.23/52.88±4.67）of the modified Brostrom group（P<0.05）.The differences in living ability，sports ability，quality of life，daily activities，activity ability and total scores were statistically significant 6 months and 1 year after surgery（P<0.05）.The talar tilt angle（4.43±1.03）° 〖JP3〗and talar advance distance [（4.65±1.41）mm] in the arthroscopic group after 1 year were lower than those of the modified Brostrom operation group [（5.73±1.45）°/（5.68±1.69）mm，P<0.05] .There was no significant difference in wound healing between the two groups during follow-up，but the incidence of ankle instability（14.28%）in the modified Brostrom group was higher than that in the arthroscopy group（P<0.05）. Conlusion For the treatment of patients with chronic lateral ankle instability，arthroscopic ligament augmentation and fixation can not only reduce surgical trauma，but also improve ankle motion capacity and obtain better ankle stability compared with modified Brostrom，and help patients to go to the ground as early as possible.

Key words: ankle joint function instability, improved brostrom, arthroscopy, ligament enhancement, ankle function, stability