The treatment of upper extremity scarring is relatively complicated because the upper extremity is a relatively exposed part of the body and plays a large role in daily life, but at the same time the morphology of the upper extremity dictates that the amount of tissue available is very small. Regarding the timing of surgery and the priority of treatment: Since contracture of the scar is a progressive process, for scars on the upper extremity joints (such as the common webbed scar), if not treated in a timely manner, secondary damage may occur as time goes on. In pediatric and developmental adolescents, burn scar deformities in the joint may also affect the normal development of the skeleton and further aggravate the deformity. Therefore, the time for scar repair varies for each part of the upper extremity. The axillary and elbow scar deformities are usually repaired six months to one year after the burn injury is cured, while severe scar contracture should be released earlier because it obviously affects joint activities. Hand scar deformity, especially dorsal hand scar contracture, secondary bone and joint deformity is much more serious than palm scar contracture, and the revision surgery should be performed within six months after the burn healing, and for children, the revision surgery can be considered three months after the trauma healing. For the treatment of severe upper extremity scar, functional restoration should be the main treatment, and cosmetic repair should be the supplement. About surgical modalities: 1, Z-formation and five-flap method: For small axillary and elbow strip scars, if there is more normal skin or looser scar around the scar, Z-formation or five-flap method can be used to repair the scar contracture deformity. 2.Local expander treatment: For smaller range forearm or upper arm keloid, local expansion flap treatment can be applied if the adjacent expansion flap can provide sufficient area. 3.Local rotational flap: For more extensive axillary scar, more severe scar contracture deformity, or large area of shoulder and upper arm scar, if there is healthy skin or thinner and softer atrophic scar in the adjacent parts such as chest and back, the adjacent axial flap can be applied for repair. Common flaps include expanded or underexpanded latissimus dorsi flap and expanded or underexpanded scapular flap to transfer normal tissue from the back to the axilla, thus repairing the contracture deformity of the axilla. 4.Distant flap such as abdominal (expanded) flap: for large area of forearm (including elbow) scar, if local expander cannot be treated, distant flap can be applied for repair. It is common to have an expanded thoracoabdominal flap, i.e., a dilator is placed in advance on the patient’s abdomen, and after the expansion is completed, the expanded thoracoabdominal flap is applied to repair the scar on the forearm. 5. scar adhesion release with free implant or free flap: In case of extensive scar adhesions where neither of the above two methods is applicable and there is no available normal skin adjacent to the scar, the scar should be released and the wound repaired with free implant or free flap. Functional exercise: Timely and effective functional training is an indispensable measure to restore the function of the upper extremity after upper limb joint scar surgery. Some patients need to continue physiotherapy and physical therapy to promote the functional recovery of the affected limb and consolidate the effect of surgery. After exercise, the motor function of patients can be greatly improved, and some of them can be completely restored to normal.