Objective To evaluate the effectiveness of arthroscopic anterior talofibular ligament (ATFL) repair with retaining of avulsion fragments at the fibular insertion site in treatment of ATFL injury. Methods A retrospective case series was conducted on 135 patients who underwent arthroscopic ATFL repair with retaining of avulsion fragments at the fibular insertion site between September 2019 and December 2024. The analysis included 72 males and 63 females, with a mean age of 29 years (range, 12-61 years). Concomitant pathologies included osteochondral lesions of the talus in 21 cases, calcaneofibular ligament injury in 41 cases, and tarsal sinus syndrome in 43 cases. The mean duration of symptoms was 10 months (range, 8-60 months). The talus tilt test was positive or suspected positive in 41 patients before operation. Pre- and post-operative evaluations of pain relief and functional recovery of ankle joint were performed using pain visual analogue scale (VAS) score, American Orthopedic Foot & Ankle Society (AOFAS) score, and Foot & Ankle Outcome Score (FAOS) (including 5 subscales: symptoms, pain, activities of daily living, sport, and quality of life). Ankle stability was evaluated using anterior drawer test [measuring anterior talar translation (ATT)] and talus tilt test. Additionally, time to return to sports, recurrent ankle sprain, and complications were recorded as well. ResultsThe mean operation time was 40 minutes (range, 30-50 minutes), and the mean intraoperative blood loss was 2 mL (range, 1-3 mL). All patients were followed up 12-75 months (mean, 44 months). All incisions achieved primary healing, and no complication such as infection, neurovascular or tendon injury, or thrombosis was observed. At last follow-up, VAS score significantly decreased when compared with preoperative value, AOFAS score and all FAOS subscale scores significantly increased, ATT measured on anterior drawer test significantly reduced (all graded as 0). All differences were significant (P<0.05). Patients who tested positive or suspected positive in preoperative talus tilt test were all negative at last follow-up. Patients returned to sports at a mean of 9 months (range, 3-18 months) postoperatively. Twelve patients (8.9%) experienced recurrent ankle sprain due to sports-related injury after returning to sports and all recovered with conservative management without revision surgery. Conclusion Arthroscopic ATFL repair with retaining of avulsion fragments at the fibular insertion site can restore ankle stability, significantly relieve pain, restore motor ability, have an enhanced recovery and achieve satisfactory activity recovery.