The AO system, which emerged in the late 1960s and has been maturing since then, includes theoretical principles, methods, equipment and devices, and is devoted to the study of the principles and theories of internal fixation of fractures, the promotion of their application and the development of devices for their application. The anatomical continuity and mechanical integrity of the fracture are therefore regained through anatomical repositioning and strong fixation. Fracture healing under these conditions is direct healing, i.e., one-stage healing. Therefore, the two main technical features of the AO technique are the achievement of strong fixation by compression and the achievement of one-stage healing of the long diaphysis by strong fixation. As early as 1958, the AO school proposed four principles of fracture treatment: 1) anatomical alignment of the fracture; 2) strong internal fixation; 3) non-invasive technique; 4) early active and painless movement of the injured limb. Long-term clinical practice has confirmed that some fairly complex fractures have been treated with AO with satisfactory results, but at the same time, some serious defects of AO technique have been gradually revealed, especially the problem of stress masking. BO is a new view of osteotomy based on the original emphasis on biomechanical fixation, which gradually evolved to a biological, physiological and rational view of osteotomy. The connotation of biological fixation is to pay full attention to the local soft tissue blood flow, strong fixation without pressure. Some of the methods under the BO concept were improved or innovated after recognizing the severe atrophy of the bone in close contact with the fixation and the obscuring effect caused by strong fixation. The main methods are improvement of fixation, repositioning method, fixation method, and fixation mode. CO is the combination of Chinese and Western medicine in the treatment of fractures, which is now known as Chinese osteopathy. Its guiding ideology is “combination of movement and static, tendon and bone, internal and external treatment, and cooperation between doctors and patients”. This is also a gradual development from the traditional Chinese medicine orthopedic treatment of blood circulation, removing blood stasis, creating new blood stasis, combining movement and static, combining tendons and bones; connecting flesh and bone, binding tendons to bones, removing decay and creating muscle, simmering pus and growing flesh. In contrast to the above-mentioned AO and BO fracture treatment system, the combined Chinese and Western medicine treatment of fracture is based on this, following the principles of elastic fixation, limited fixation, combination of movement and static, both internal and external treatment, advocating the second stage of fracture healing, focusing on protecting the local blood flow of the fracture and strengthening functional exercise, combined with clinical practice and put forward a new concept of treating fracture. CO system treatment principle: With the cooperation of limited surgery, complex fractures are changed into simple fractures, and non-superarticular external fixation is used to enable patients to exercise early. This transformation makes the CO system change from the original bloodless therapy to blood therapy. fracture healing mode of CO system: large amount of external bone scab growth without atrophy of the outer 1/4 of the cortex on the fracture side. herbal application of CO system: the principle of herbal application of fracture is to promote blood circulation at the fracture site to increase local blood flow, promote hematoma mechanization, osteoblast proliferation, and accelerate external bone scab formation. The principle of herbal application in open wounds is to regulate local immune function and promote wound healing by using various cytokines. biomechanical basis of CO system: accelerated fracture healing mode by elastic fixation under the condition of maintaining micro-movement of the fracture break end.