Surgical indications for replantation of severed thumb (1) Replantation of severed thumb The thumb is the most important in performing hand functions, so it should be considered as a priority in replantation, and every effort should be made to repair the thumb at an early stage. If the condition of the severed thumb is not good, the severed index finger can be transposed and replanted on the thumb, and the thumb can be replanted or reconstructed after transferring the radial nerve vascular bundle of the index finger or performing vascular transplantation. (2) Replantation of the remaining four fingers From the functional point of view, the index and middle fingers are more important, and the severed index and middle fingers should be reimplanted if they are available. The other fingers should not be reimplanted in general, except for the special needs of occupation or other factors. The reason is that the limitation of the range of motion of the finger joints after replantation will affect the function of the whole hand. (3) Replantation of end-joint severance Mainly refers to the severance of the distal interphalangeal joint, because the loss of the end-joint has little effect on the function of the hand, so replantation is not recommended. In addition to the functional needs of some special occupations of the patient, psychological and cosmetic requirements, replantation can also be tried. (4) Re-implantation of fingers immersed in certain liquids Wrongly immersed in hypotonic, isotonic, hypertonic or certain disinfectant solutions, or improperly preserved, ice cubes melted and ice water immersed. Due to the cellular semi-permeable membrane, hypotonic night makes the cells swell with edema, hypertonic solution dehydrates the cells, and certain disinfectant solutions, such as ethanol, benzalkonium bromide, thimerosal, etc., directly damage the cells of vascular endothelium and other tissues. Depending on their type, concentration and length of immersion, the degree of damage varies and also has different effects on survival. Reimplantation can be tried when conditions allow. (5) Treatment of carpometacarpal destructive injury Severe injury or severance of the carpometacarpal or along with the distal part of the forearm, while several fingers in the distal part are still intact, at this time, the crushed carpometacarpal part can be removed, and after thorough debridement, the more intact fingers are chosen to be fixed in the ulna and radius, respectively, for replantation to the metacarpal position. However, not everyone can successfully replant a broken finger, and there are contraindications to such surgery. There are contraindications to the surgery: (1) Those who suffer from systemic diseases, poor health, or serious organ damage, and are not allowed to perform the surgery for a long time, should not be replanted. (2) The broken finger with multiple fractures or severe soft tissue injury. (3) If the integrity of the vascular bed of the finger is severely damaged, such as the severed finger caused by crush injury, it shows subcutaneous petechial hemorrhage on both sides of the finger, and even if the blood vessel is connected, it is still difficult for the replanted finger to survive due to extensive blood leakage and thrombosis in soft tissue. (4) If the time limit for replantation is too long and the tissue has degenerated, it is not suitable for replantation. Without refrigeration, the ischemia of the severed finger may still survive for 24 hours, and the time limit for replantation can be extended to more than 30 hours if the finger is refrigerated immediately after the injury. However, the shorter the ischemia time, the higher the survival rate of replantation; conversely, the longer the ischemia time, the lower the survival rate of replantation. After knowing the symptoms and contraindications of finger replantation surgery, readers should pay attention to the fact that if you have an accident like a broken finger, you should pick up your broken finger and go to a regular hospital in time to ensure that the function of your finger can be restored. You should also be careful not to handle your broken finger without permission to avoid causing more damage to your finger.