(Disclaimer: This article is only for scientific purposes, in order to protect the patient’s privacy, the relevant information in the following content has been processed) Abstract: The patient is a 19-year-old boy, 3 years ago, activity accidentally sprained the knee joint, at that time there was no obvious discomfort. 2 years ago, the knee pain, swelling, did not pay attention to the patient. 2 months ago, the patient said the above symptoms gradually aggravated, after rest did not see obvious relief, intermittent physical therapy, treatment, pain slightly relieved, for further treatment to our hospital admitted with “right cruciate ligament sprain”. The pain was slightly relieved, and he came to our hospital for further treatment. He was admitted to the outpatient clinic with “cruciate ligament sprain of the right knee”, and was admitted to the hospital with physical and conservative treatments, which relieved the pain symptoms and restored the activities to normal. Basic information] Male, 19 years old [Type of disease] Knee cruciate ligament sprain [Hospital] The First Affiliated Hospital of Xi’an Jiaotong University [Time of consultation] June 2018 [Treatment plan] Physical therapy (acupuncture, infrared, ultrashort wave, intermediate-frequency pulsed electricity) [Treatment cycle] Hospitalization for 14 days, 1 month, 3 months outpatient follow-up [Effect of treatment] The patient’s pain symptoms are relieved, and the activities of the knee are back to normal. Initial Consultation Patient’s self-report: 3 years ago, the knee joint was accidentally sprained during the activity, and there was no obvious discomfort at that time. 2 years ago, the knee joint pain and swelling appeared, and no attention was paid to it. 2 months ago, the patient’s above mentioned symptom gradually aggravated, and did not see obvious relief after resting, and then intermittent physical therapy was carried out to alleviate the pain a little bit, and then she came to our clinic for further treatment. Physical examination: the right knee joint pressure and pain positive, lateral interstitial pressure and pain negative, hyperextension or hyperflexion pain negative, limb sensation, movement without obvious abnormalities, outpatient admitted to the hospital as “right knee cruciate ligament sprain”. After admission, relevant examinations were completed, including blood routine, urine routine, liver function, renal function, electrolytes, etc. No obvious abnormality was found. The electrocardiogram showed sinus rhythm, which was roughly normal. Fully communicate with the patient and his family about his condition, considering that the patient’s symptoms were not relieved for a long time, and that the MRI of the knee joint had no obvious organic damage, suggesting that there was a small amount of effusion in the right knee joint, and bone edema at the posterior border of the patella. We communicated with the patient about the feasibility of physical conservative treatment, and the patient agreed, so we gave him acupuncture to promote local blood circulation, infrared anti-inflammatory and pain relief, ultrashort wave to promote the regeneration of muscle tissue cells, and intermediate-frequency pulsed electrotherapy to reduce the edema, and he was admitted to the hospital and treated for 14 days, and his pain and swelling symptoms were relieved. （After receiving acupuncture, infrared ray, ultrashort wave, and intermediate frequency pulsed electric therapy, the patient’s right knee pain and swelling symptoms were relieved. Examination: right knee joint pressure pain was negative, lateral interspace pressure pain was negative, hyperextension or hyperextension pain was negative, patella floatation test was negative, limb muscle strength and tone were not abnormal, limb pain and temperature sensation was not abnormal, and bilateral knee and Achilles tendon reflexes were not abnormal. In conclusion, the patient was hospitalized for 14 days and followed up in outpatient clinic for 1 month and 3 months, the patient’s pain and swelling disappeared, and his activities returned to normal, the patient and his family were very satisfied with the treatment effect. Fourth, precautions We are glad that the patient’s pain and swelling symptoms are relieved after treatment, and we suggest that the patient should have a regular review in 1 month, 3 months, 6 months, 1 year and 3 years after discharge from the hospital. In daily life, keep emotional stability, combine work and rest, and avoid exertion, cold and so on. Minimize the weight of the knee joint, if strenuous exercise is required, it is recommended to wear a knee brace. 3 months later, it is recommended to carry out swimming exercise, which not only exercises muscle strength, but also avoids the weight of the knee joint, which may damage the knee joint. There is no contraindication to diet, you can eat healthy according to your dietary habits and ensure balanced nutrition. V. Personal perception Sprain is a common clinical problem, ankle sprain, knee sprain is often encountered in daily life, the problem should be excluded at an early stage of fracture, strict local braking, early ligament and other structures can be fully restored, if the early stage is not timely and appropriate treatment, the late stage may result in long-term chronic strain, which will have an impact on the quality of life of the patient, so the patient in the present case, for example, if there is no symptom after the injury, the patient can be treated with a special treatment. Therefore, in the case of this patient, if there are no symptoms after the injury, he should also visit the doctor for regular checkups, and if pain or swelling occurs, do not delay, early detection, early diagnosis and early treatment.