The purpose of this observational study is to investigate the impact of fentanyl matrix on improvement of pain and functioning in spinal disorder-related chronic pain.

This study is a prospective, open-label, non-interventional study. The objective of the study is to investigate the impact of fentanyl matrix on improvement of pain and functioning after 8-week treatment of fentanyl matrix in the patients who complained of spinal disorder-related chronic pain in clinical practice according to the investigator's discretion. The primary endpoint is a percent of pain intensity difference between baseline and week 8 of the study. Each patients will evaluate their pain intensity every 28 days during the 8 weeks. The secondary objectives are to observe the change in the following variables after administrating fentanyl matrix; K-ODI (Korean version - Oswestry Disability Index) score, sleep disturbance, disturbance of activities of daily living and disturbance of social activities. In addition, Investigator and patient global assessment, patient preference, CGI-I (Clinical Global Impression - Improvement) and Adverse Events will be investigated. LDK: Lumbar degenerative kyphosis, CRPS: Complex Regional Pain SYndrome, FBSS: Failed Back Surgery Syndrome Observational Study - No investigational drug administered

Inclusion Criteria:

• Patients who complain of spinal disorder-related chronic pain persisting for 3 months or longer
• Patients who can fully observe the overall clinical study requirements including K-ODI completion at the investigator's discretion
• Patients who complain of severe pain (NRS score = 7) because pain was not treated enough with the previous analgesic
• Patients who have never been administered fentanyl matrix over the last one month

Exclusion Criteria:

• Patients with a history of the drug or alcohol abuse in the past or now
• Childbearing women who are pregnant or likely to be pregnant during the study period and male patients who are neither infertile nor willing to refrain from sexual relations but whose partner does not conduct an effective contraception (implant, injections, oral contraceptives, intrauterine device, etc.)
• Patients who are unable to use a transdermal system due to skin disease
• Patients with serious mental disorder
• Patients with history of hypersensitivity to opioid analgesics
• Patients with history of CO2 retention
• Patients who are not eligible for the study participation based on warnings, precautions and contra medications in the package insert of the study drug at the investigator's discretion

Patients who had unsatisfactory treatment with previous medication (severe pain: NRS = 7) and no experience with fentanyl matrix will be eligible