Background: To analyze the feasibility and clinical results of the modified Brostr & ouml;m operation (MBO) combined with suture tape augmentation under arthroscopy for chronic lateral ankle instability (CLAI) in patients with generalized joint laxity (GJL). Methods: From October 2019 to October 2021, a total of 111 patients (111 ankles) treated with MBO combined with suture tape augmentation under arthroscope were retrospectively divided into a GJL group (29 patients) and a control group (82 patients). Mechanical stability of the affected ankle joint was evaluated radiographically preoperatively, at 6 months postoperatively, and the last follow-up. Complications and surgical failures, as well as visual analog scale (VAS) score, the Foot and Ankle Ability Measure (FAAM), and the Karlsson score were also recorded. All statistical analyses were completed using SPSS 20.0. Results: The average follow-up time was 21.7 +/- 5.2 months for the GJL group, and 20.9 +/- 5.3 months for the control group. Pain and symptoms in both groups were effectively relieved by the procedure reflected by decreased VAS scores, improved FAAM and Karlsson scores at 6 months postoperatively, and the final follow-up (P < .05). Preoperative talar tilt angle and anterior talar translation were significantly greater in the GJL group than those in the control group (P < .05). Postoperatively, both talar tilt angle and anterior talar translation were reduced in both groups at 6 months postoperatively and the last follow-up (P < .05), and we found no significant difference between the two groups (P > .05). Furthermore, we found no significant difference in VAS, FAAM, and Karlsson scores between the 2 groups 6 months postoperatively and at the last follow-up. Conclusion: Arthroscopic MBO combined with suture tape augmentation is a reliable procedure for treating CLAI with GJL. At short-term follow-up, we found that the GJL group achieved an equivalent level of stability compared with the control group.