There have been successful cases of arm transplantation, but it has not been widely carried out all over the world. The main reasons for this include insufficient donor resources, severe immune reaction, difficult surgery, and poor postoperative functional recovery. 1. Insufficient donor resources: Compared with liver, kidney, lung and other resource-constrained donors, arm donors are even fewer, which brings serious difficulties to theoretical research and surgical operation. 2. Severe immune response:Compared with mature transplantation procedures such as liver transplantation and kidney transplantation, arm transplantation lacks mature immunosuppression experience, coupled with the small number of donors and the small volume of surgery, making the development of appropriate immunosuppression protocols require greater costs. 3. Difficulty of surgery:The complex anatomy of the arm, in addition to bone tissue, also includes nerves, blood vessels, muscles, fascia, etc., the anastomosis is difficult, due to the short time of limb preservation, the need for doctors to complete the surgery in a short period of time, resulting in further increase in the difficulty of surgery. 4. Poor postoperative functional recovery:Due to the arm blood vessels are mostly peripheral blood vessels, the limb survival rate is relatively low, coupled with the immune response and bone and soft tissue healing, postoperative exercise difficulties, which will result in poor function. Although there are cases of successful implementation of arm transplantation, but the sample size is small, and after long-term follow-up, the patient satisfaction rate is not high, it is not widely carried out at present, and further research is needed.