This study mainly evaluated the clinical effect of total arthroscopic repair of the anterior talofibular ligament in the treatment of chronic instability of the lateral ankle. For patients with chronic instability of the lateral ankle, a randomized controlled trial was used to compare the curative effect, operation time, surgical complications, postoperative recurrence rate, postoperative recovery time and patients' satisfaction of the total arthroscopic repair of the anterior talofibular ligament surgery and the modified BrostrÖm surgery.

Inclusion Criteria:

1. A history of acute lateral ankle sprain.
2. The patient has chronic instability of the lateral ankle joint, including functional instability or mechanical instability; functional instability refers to the patient's subjective ankle joint looseness or instability; mechanical instability refers to the presence of the ankle joint History of repeated sprains, positive examination of the front drawer test or positive X-ray examination of the stress position (inversion stress, anterior axial stress).
3. The ankle MRI suggested the anterior talofibular ligament injury.
4. It is invalid after 3 months of formal conservative treatment.

Exclusion Criteria:

1. Co-infection.
2. There was a previous ankle fracture in the affected limb.
3. The affected limb has previously undergone foot and ankle surgery.
4. Ankle inverted arthritis or Charcot joint disease.
5. Suffer from mental illness.