The most accurate way to know the degree of knee osteoarthritis is to directly see the articular cartilage surface of the knee joint. Arthroscopy can do this, and it is the most ideal way at present without cutting off the joint and causing little trauma.

Arthroscopy can not only see the situation in the joint cavity, but also wash the knee joint with sterile saline under arthroscopy, clean up synovial debris and cartilage debris in the joint, and drill holes in severely worn and rough parts to promote the repair of new cartilage. Of course, the new cartilage is different from the original cartilage. It is fibrocartilage rather than "original" hyaline cartilage. Fibrocartilage is far inferior to hyaline cartilage in biomechanical function, but it can compensate and delay the further destruction of cartilage.

Therefore, many patients with knee osteoarthritis have achieved good short-term results after arthroscopic surgery. Arthroscopic surgery can temporarily relieve the symptoms of osteoarthritis, and in some patients, this symptom relief can last for a long time. However, arthroscopic surgery cannot be 100% effective. Even if the operation is successful, it can only alleviate the condition and cannot solve the problem fundamentally. Most patients with knee osteoarthritis have improved after arthroscopic surgery, and a few patients have not improved.

Arthroscopy can also be used when the joint is locked by free cartilage or bone fragments. It is also suitable for arthroscopic surgery if steroid drugs are injected into the joint cavity three times a year 1-3 times to relieve symptoms.

2. Osteotomy

Osteotomy is suitable for the joint bearing line is not straight, the load distribution is uneven, one side is overloaded and the other side is intact, or the knee is varus and valgus. Osteotomy can correct the abnormal force line, make the relatively complete articular surface bear more weight, improve the bearing state of the joint, and thus relieve the symptoms. In principle, tibial osteotomy should be done for genu varus and supracondylar osteotomy should be done for femur for genu valgus. Tibial osteotomy is divided into high osteotomy at the upper end of tibia and low osteotomy at the upper end of tibia. The specific surgical method should be decided by the doctor according to the specific situation of the patient.

Osteoarthritis often affects the medial space of knee joint more than the lateral space, resulting in a slight bow leg in the appearance of lower limbs, which is medically called genu varus deformity. It causes the load-bearing line of the lower limb to move inward and pass through the medial space of the knee joint instead of the middle, so that more pressure acts on the medial articular surface, which eventually leads to more serious pain and faster degeneration of the medial knee joint.

In this case, it is necessary to readjust the angle of the lower limb load-bearing line and move the load-bearing line to the lateral space of the knee joint, which may transfer most of the load-bearing force to the relatively healthy lateral space, thus alleviating the pain of the medial space and delaying the degeneration process of the medial space. This operation is called "osteotomy of the upper tibia". The classic surgical method is to cut a wedge-shaped bone block from the lateral side of the upper end of the tibia, so that the genu varum of the lower limb becomes mild genu valgus. Pain can generally be relieved after operation, but it may not be completely eliminated.

The advantage of this operation is that it is more suitable for patients with genu varus, who are active and unwilling to accept artificial joint replacement. Once the osteotomy is healed, the activity level will be unrestricted. However, for patients with osteoarthritis, the effect of proximal tibial osteotomy is also temporary. It is generally believed that this kind of operation can buy time for patients before the artificial joint is finally replaced. If the operation is successful, the effect can last for about 5-8 years.

3. Cartilage plasty

In the past, chondroplasty refers to surgical removal of degenerated articular cartilage surface and hardened subchondral bone plate, or drilling holes in subchondral bone plate to promote cartilage repair. Although fibrocartilage is repaired instead of normal articular cartilage, fibrocartilage plays a compensatory role to some extent and can delay the destruction of joints.

Recently, the concept of chondroplasty has changed. Firstly, the degenerated cartilage was removed under arthroscopy, and a small amount of healthy and normal articular cartilage tissue was taken. Normal articular cartilage tissue was cultured in the laboratory for two weeks, and then transplanted into the joint. The cultured cartilage tissue can stimulate the regeneration of the original damaged cartilage tissue. This operation has a good effect on the treatment of cartilage defects in young people with early osteoarthritis, but the effect on elderly patients with osteoarthritis is not clear. Limited by conditions, this kind of operation has not been widely carried out in China at present.

4. Debridement of joint

Joint debridement is suitable for patients over 40 years old with joint swelling and pain, obvious bone hyperplasia at the joint edge, loose bodies in the joint and poor conservative treatment effect. Patients who are unwilling or unable to do artificial joint replacement can also choose this operation.

Surgery is mainly to remove inflammatory synovial tissue, hyperplastic bone spurs and ruptured meniscus, remove loose bodies, and completely remove mechanical obstacles and irritants. At present, hospitals with good technical conditions all perform joint debridement under arthroscope without cutting the joint. But joint debridement can only relieve symptoms. After several years, hyperosteogeny will continue to occur, and joint pain and dysfunction may recur. Therefore, patients should try to avoid postoperative overload and insist on functional exercise to prolong the time of symptom relief.

5. Joint fusion

This kind of operation is to remove the articular surface and fuse the bones, which can relieve the pain and restore the stable bearing capacity, but it is suitable for young heavy manual workers at the expense of joint activities.

With the appearance of artificial joint, this kind of operation has been done less and less, but joint fusion still has its special value. Due to the limitation of China's national conditions, especially in remote rural areas, patients do not have the conditions for artificial joint replacement, and joint fusion is a better choice. In the face of those patients who have failed in artificial joint replacement, joint fusion can be the only choice.

6, artificial joint replacement

The ultimate solution of knee osteoarthritis is to replace the articular surface with artificial knee joint. Generally, only patients over the age of 60 will consider artificial joint replacement. For young patients, artificial joint replacement is generally not considered unless there is no other choice.