Posterior spinal fusion surgery (PSF) is associated with significant postoperative pain. Numerous postoperative pain management strategies have been employed for patients undergoing these procedures, including continuous narcotic infusions, intravenous patient-controlled opioid analgesia, epidural analgesia, intrathecally administered narcotics, and combinations of these regimens. Most patients at CHOP have their pain managed with intravenous patient-controlled opioid analgesia alone or in combination with a single dose of intra-operatively administered intrathecal (IT) morphine.