Inclusion Criteria:  For the first time, the knee joint simply ruptures the anterior cruciate ligament (ACL) and requires surgical reconstruction; it can be combined with meniscus injury, and the Outerbridge injury score is ≤ Grade II; There is no history of trauma or fracture of the ipsilateral knee joint; Posterior Cruciate Ligament (PCL) has no damage; Medial Collateral Ligament (MCL) or Lateral collateral ligaments (LCL) has no damage or only slight damage (no more than I degree).  Exclusion Criteria:  BMI is less than 18.5 or greater than 35 kg/m2; Patients with moderate or severe knee degeneration; Those with limited flexion angle (<120 degrees); The cartilage defect area is greater than 2 cm2 or the Outerbridge damage score is> Grade II.