Inclusion Criteria:  18-45 years old, with closed epiphyses; For the first time, the knee joint is simply ruptured with a cruciate ligament and requires surgical reconstruction; it can be combined with meniscus injury, and the Outerbridge injury score is ≤ II; There is no history of trauma or fracture of the ipsilateral knee joint; The medial collateral ligament or the lateral collateral ligament is not damaged or only slightly damaged (no more than degree I).  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); Cartilage defect area is greater than 2 cm2 or Outerbridge damage score> Grade II.