The purpose of this study was to investigate the preemptive effect of ultrasound guided popliteal scistic nerve block on postoperative acute pain in patients with bilateral hallux valgus.

After induction of general anesthesia, the leg to be operated first is decided randomly. After the operation of one leg is completed, PSNB is performed on both legs with 0.2% Ropivacaine and surgery is started on the remaining legs.

When the surgery is over, check to see which foot pain begins first, how strong the pain is, and whether there are any side effects.

Inclusion Criteria:

1. adults between the ages of 20 and 80
2. bilateral hallux valgus surgery on the same day
3. ASA class 1 or 2
4. Patients who have voluntarily agreed in writing to participate in the trial

Exclusion Criteria:

1. Patient with side effects on local anesthetics or steroids
2. Patient who are taboo of peripheral nerve block such as blood clotting disorder, infection, etc.
3. Patients with uncontrolled medical or psychiatric problem
4. Patient does not agree to participate in the study
5. Patients who are pregnant or lactating