Major purpose of this research is to evaluate the effect and usefulness of Buprenorphine transdermal system (MTDS) among the patients with lumbar spinal disease who was performed the single-level posterior lumbar fusion.

After surgery, all the patients apply the patient-controlled analgesia. After three days of surgery, patients are divided into two groups.Group A is an experimental group that administer the BTDS after surgery, and Group B is a control group that take tramadol analgesics. If the patient's pain score exceeds the NRS 4, they can take the additional rescue medicine, acetaminophen.

After the surgery, patient's pain score and quality of life would be recorded sequentially. The time of recording is postoperative 36 hours, 72 hours, 7 days, 2 weeks, 4 weeks, and 3 months, respectively.

Inclusion Criteria:

• adults over 20 years
• taking the lumbar spinal surgery : single-level, posterior fusion
• stay in hospital more than 2 days after operation

Exclusion Criteria:

• pregnancy or breast-feeding
• allergy or contraindication to buprenorphine
• patient with decreased lung function
• patient with taking MAO inhibitor or anticonvulsant
• patient with brain lesion, or severe liver disease
• dependence in opioid drugs
• taking muscle relaxant or tranquilizer
• patient had taken buprenorphine preoperatively
• taking strong opioids before enrolling the study
• another severe source of pain except lumbar spine
• severe cardiovascular, pulmonary, or renal compromised patients