Clinically, scars are divided into the following types: 1. Superficial scars: Mostly seen in abrasions, formed by skin breakage and infection, these scars are slightly rough in appearance, sometimes with hyperpigmentation or pigment loss, but locally soft, without functional fall hindrance, and generally without special treatment. Clinically, they are commonly seen in skin abrasions, superficial skin infections, and shallow II degree burns. 2. Atrophic scars: they are mostly flat in appearance, flush with or slightly lower than the normal skin surface, with smooth and shiny surface of the atrophic scars, hypopigmentation showing white, and a few areas of hyperpigmentation showing dark brown. They do not cause functional impairment. Facial ones can be treated with fractional excision, scar excision or local flap transfer to improve the appearance. If scar excision flap transplantation is performed, it is advisable to use it with caution because the skin color changes in the long term after the skin flap becomes viable and it is difficult to predict whether the expected purpose of the surgery can be achieved. 3.Depressed scars have a scar surface significantly lower than the surrounding normal skin, mostly caused by healing trauma of skin, subcutaneous tissue or deep tissue defects, and can also be caused by more extensive tissue defects caused by severe septic infection of the soft tissue of the skin. Treatment of depressed scars: If the area is small, local tissue filling method can be used for treatment. If the area is larger and deeper depressed short scars, if the wound of excised scars cannot be directly sutured, then skin flap or myocutaneous flap surgery is needed, and repair of deep tissue such as tendon, nerve, bone and other defects is needed to restore function and improve appearance. 4.Proliferative scars: Proliferative scars are often found in traumas where the depth of injury is only to the dermis. The difference between proliferative scars and normal scars lies only in the thickening of collagen fibers in the deep part of the scar, which are irregularly arranged, or rippled or twisted into a rope shape. The anabolic metabolism of collagen is hyper-continuous and exceeds the rate of catabolism, resulting in the formation of a large number of collagen fibers over a considerable period of time, the common cause of which is related to the presence of certain local or systemic triggering trapped elements. Local factors: foreign bodies, inflammation, talcum powder on gloves during dressing changes, cotton fibers, thread knots, and certain chemicals. In addition, keratin precipitated by cell destruction is also a local factor that stimulates scar proliferation. Systemic factors: For example, pregnant women and patients with hyperthyroidism are prone to hyperplastic scars, while hyperplastic scars are rarely seen in the elderly. 5, keloid scars: keloid scars are scars characterized by persistent enlargement. It is also known as crab foot swelling because it often appears to infiltrate the surrounding sound skin and has a crab foot-like image. They are generally divided into two types: 1) tumor type; 2) infiltrative type. The etiology is related to systemic factors, idiosyncratic physical qualities, minor injuries, mosquito bites, vaccinations, and ear piercings can form keloids. Local factors: such as foreign bodies, inflammation, local pulling, etc. tend to induce proliferative tendencies. 6. Webbed scars: They are shaped like duck webbing, so they are called webbed scars. They are commonly found in the inner and outer canthus, nasolabial folds, corners of the mouth, palm side of fingers, tiger’s mouth, nostrils, urethral opening, vaginal opening, perineum and other parts. Webbed scars in joint areas cause joint flexion contracture and restriction of extension, affecting the form and function. Webbed scars are best treated by “Z” orthopedic surgery. 7.Bridge-shaped scars: The ends of the scars are connected to the surrounding skin by the tips, and the shape resembles a bridge. 8.Contracture scars with myofibroblasts. The proportion of myofibroblasts in the scar increases and contraction occurs, leading to the appearance of clinical symptoms. Timing of surgery: generally not easy to be too early, should wait for the scar to stabilize and enter the mature stage, after the base is loosened. Release of contracture is the key to successful surgical treatment. In the initial postoperative period, braking should be performed to ensure smooth healing of the grafted skin or repaired tissue, and the limb should be in a functional position. The later stage should be active with functional exercises.