It takes 4-6 weeks to recover from post-patellar fat pad injury. Fat pad injury can be treated by the following methods: first, manual massage, localized kneading and pressure on the fat pad to cause mild pain, 200-500 times continuously, 2-4 times a day, 15 days as a course of treatment. Second, closed injection, to find the fat pad pain points, local injection of lidocaine hydrochloride and trimethoprim mixture, once a week, 3 times a course of treatment. Third, if conservative treatment is not good, arthroscopic subsynovial fat pad excision can be used instead, and postoperative muscle strength and intensity training around the knee joint can be insisted upon. After conservative or surgical treatment, the posterior patellar fat pad injury will usually recover basically completely in about 4-6 weeks.