Patients undergoing surgery under general anesthesia are susceptible to pressure-induced soft tissue damage because there is no change in posture over an extended period of time. In particular, when the patient is in a prone position, unlike the supine position, the bony protruding portion of the front side must support the weight, which is more vulnerable to pressure injury. Previous studies have shown that the incidence of pressure injury during surgery varied from 5% to 66% and was more likely to occur in patients with long operating times, prone position, obesity, and poor skin condition. These pressure injuries increase postoperative complications, length of stay, and medical costs. Therefore, the investigators analyze the incidence of pressure injury in prone position and re-examine the risk factors of pressure injury.

All of the anesthetic and surgical procedures performed on the subject during the period from the time the subject enters the operating room to the time the subject go to the recovery room are the same as those for the existing spine surgery. Immediately after entering the operating room, immediately before going to the recovery room, and at postoperative day 1 and 2, the patient's systemic skin condition is assessed to determine whether pressure damage has occurred. The primary endpoint is the incidence of pressure injury in the subject compared with the incidence of pressure injury in previous studies. To identify the risk factors for the occurrence of pressure injury, the investigators will statistically analyze the data collected with the assumption that this is related.

Inclusion Criteria:

• Adults patients undergoing elective spine surgery in prone position under general anesthesia

Exclusion Criteria:

• Pre-existence of pressure injury