Inclusion Criteria:  ≥18 years old and ≤50 years old, male or female patients Patients with knee articular cartilage defect area ≥2cm2 and ≤8cm2, who can undergo microfracture surgery, no surgical contraindications Patients voluntarily participate in clinical trials, sign an informed consent form, and be able to cooperate with clinical follow-up  Exclusion Criteria:  Participants in clinical trials of other drugs or medical devices in the past 6 months Unable to accept autologous fat glue due to religion, ethnicity, etc. Injury area <2 cm2 or >8cm2 or lack of normal cartilage tissue surrounding the injury Those with compound multiple ligament injuries Those with systemic immune diseases or systemic or local infections Those with joint fibrosis, joint ankylosis, and obvious limitation of movement People with moderate to severe osteoarthritis Those who have contraindications to MRI examination Patients with hemophilia People whose general condition cannot tolerate surgery Women who are pregnant or planning to become pregnant and women who are breastfeeding Mental abnormalities and no behavioral autonomy Other circumstances in which the doctor judges that he cannot participate in the trial