Knee pain is a very common clinical condition. Due to the complex structure of the knee joint, in addition to the bony structures, there are menisci, intra-articular cruciate ligaments, extra-articular collateral ligaments and attached muscle fascia. Therefore, the etiology of knee pain varies. Sprains are the most common cause of knee pain and are easy to diagnose. However, diagnosing the exact extent of the injury is not easy. A typical injury will result in a tear of the collateral ligament on the outside of the joint, requiring 3 to 4 weeks of rest, and medical advice is to immobilize in a cast or brace. However, it is often difficult for patients to accept that a cast is not necessary because there is no fracture. A torn ligament that does not heal will not hurt later, but will have recurring residual pain and an imbalance in the joint’s muscle strength that may accelerate degeneration. More severe sprains can also lead to meniscal tears and even cruciate ligament injuries. This is mostly seen in young people with sports activities. But early in the injury these problems are not easily detected. Often, if there is still discomfort after a month of conservative treatment, an MRI is needed to clarify. Even sometimes, MRI has some false results and is not very accurate. However, the results of this type of injury are more serious and usually require surgical intervention due to inadequate blood supply, except for minor meniscal tears that can repair themselves. Fasciitis is another common type of knee pain cause. Patients have pain with joint movement and a pressure point can be felt on either side of the joint, which is often fasciitis. Hot compresses, creams and rest are the easiest category to treat. For middle-aged and older people, especially women, degenerative osteoarthritis is the most common type. Many women experience knee discomfort after the age of 40 and feel joint pain after long walks. There are two agreed causes: degenerative strain on the joints after years of use, and the tendency of women to develop osteoporosis due to hormonal changes around the time of menopause. Joint pain is the earliest manifestation, at this time conservative treatment can be effective, and should be prevented by exercise to accelerate degeneration. Such as joint heat, massage, blood circulation and stasis creams, quadriceps exercises. With the aggravation of the lesion, there will be difficulty in going up and down stairs, inability to squat completely, and pain in the joint after more activities. At this time, conservative treatment is possible, mainly based on pain management. Oral medications include Xilabao and Tongan, etc. External ointments such as Qizheng pain relief patch and golden ointment are also effective, as are intra-articular injections (injections include hormones, anesthetics and sodium hyaluronate). Pain is actually a protective reaction of the body, alerting you that something is wrong with the joint, that it should be used carefully, and that it should be repaired. So pain management is only temporary and symptomatic. At this time, arthroscopic surgery can also be performed to remove the hyperplastic synovium and detached cartilage, as well as old meniscal injuries and wear and tear that may be combined, which can relieve pain and even last for several years after surgery if care is taken. In the most severe cases, the joint is painful even when inactive, deformed and swollen, and radiographs show narrowing of the joint space and severe osteophytes. Surgical pathology will reveal bone growth, cartilage exfoliation, and exposed subchondral bone. The only treatment at this stage is joint replacement, in addition to pain relief. It is important to emphasize that although most patients have satisfactory results, total knee arthroplasty is not a perfect surgical procedure, and first of all, attention should be paid to the selection of indications, otherwise it will definitely affect the outcome. Secondly, attention should be paid to individualized treatment. The entire knee replacement operation is procedural, but for each specific patient, there are some special circumstances. Only with a detailed preoperative examination, careful review of the films, and individualized intraoperative management is it possible to make each patient as happy as possible after surgery. When it comes to joint replacement, many people are afraid of it and find it difficult to accept. There is another type of surgery that is orthopedic, called a covertry osteotomy. The surgery is much smaller than arthroplasty and the recent results are satisfactory. Tibial osteotomy was a valuable procedure for patients with hemi-lateral osteoarthritis of the knee. The purpose of this osteotomy is to shift the weight-bearing line of the knee from one half of the lesion to the other half. The literature reports that nearly 70-80% of patients with osteotomies improve after surgery. The indications for osteotomy now depend on the age of the patient and the extent of the lesion shown on the x-ray. In principle, osteotomy is an option for patients with inversion or valgus of the knee, even if they are elderly. It is particularly suitable for middle-aged and elderly patients who require to maintain their active and mobile lifestyle and who have minor but significant joint deformities.