The United States is currently experiencing an explosive opioid epidemic. In 2014 alone, 28,647 Americans died from an opioid associated overdose; the annual death toll has increased by over 300% since 2000. The epidemic poses a complex scenario for physicians administering treatment for postoperative pain, as opioids are key analgesic agents in treating moderate to severe pain. In order to reduce the patients risk for long term opioid use and the associated side effects, physicians have begun shifting to multimodal analgesic approaches to treat postoperative pain. These approaches have been found to be similarly efficacious, while also reducing opioid usage and associated side effects, such as: nausea, vomiting, and ileus.

This study proposes a multimodal analgesic approach, which the investigators believe will reduce short and long term opioid usage, the associated side effects, and the financial burden. Intravenous acetaminophen is an effective medication for both primary and adjunctive pain management, however its use is limited by a high cost to perceived benefit ratio. Oral acetaminophen is a relatively inexpensive option, although perhaps less effective than the IV option, and also often not feasible to utilize in the immediate post-operative period when patients are unable to safely swallow pills. The hypothesis of this investigation is to understand if adding intravenous acetaminophen to the perioperative care regimen after lumbar spinal surgery will result in improved pain management in the perioperative period while decreasing opioid usage and related complications.

Inclusion Criteria:

• Diagnosis of spinal stenosis of the lumbar spine with degenerative spondylolisthesis
• Skeletally mature adults between the ages of 18-85 years at the time of surgery
• The greater of the patients right and left VAS leg pain, or back pain, score is > 40 mm on a 100 mm scale
• Has attempted conservative therapy
• Psychosocially, mentally, and physically able to fully comply with this protocol, including adhering to scheduled visits, treatment plan, completing forms, and other study procedures
• Personally signed and dated informed consent document prior to any study-related procedures indicating that the patient has been informed of all pertinent aspects of the study

Exclusion Criteria:

• Any evidence of a prior/current fracture, compromised vertebra, current or past trauma, or tumor at affected level or the spinous processes at the adjacent levels
• Revision of prior fusion attempt at the level being operated on
• Cauda Equina Syndrome defined as neural compression causing neurogenic bowel (rectal incontinence) or bladder dysfunction (bladder retention or incontinence)
• Significant peripheral neuropathy or acute denervation secondary to radiculopathy, caused by conditions other than spinal stenosis
• Significant peripheral vascular disease (diminished dornails pedis or tibial pulses)
• Morbid obesity, defined as BMI > 40 kg/m2; or underweight, defined as BMI < 18.5 kg/m2
• Active systematic or local infection
• Active Viral Hepatitis (receiving medical treatment within 1 year); or any other acute hepatitis within the past 6 months
• Immunocompromised such as but not limited to Acquired Immunodeficiency Syndrome (AIDS), HIV infection, Severe Combined Immunodeficiency Syndrome, Thymic Hypoplasia
• Insulin dependent diabetes mellitus or any other medical conditions that would represent a significant increase in surgical risk or interfere with normal healing
• Immunologically suppressed, or has received systemic steroids, excluding nasal steroids, at any dose for >1 month within last 12 months
• History of Paget's disease, osteomalacia, or osteoporosis with a DEXA t-score less than or equal to -2.5
• Active malignancy. A patient with a history of any invasive malignancy (except non-melanoma skin cancer), unless treated with curative intent and there has been no clinical signs or symptoms of the malignancy >5 years
• Any current history of substance abuse (e.g., recreational drugs, narcotics, or alcohol)
• History of psychosocial disorders that could prevent accurate completion of self-reporting assessment scales
• Previous known allergy to acetaminophen
• Women who are pregnant or lactating
• Patients involved in active litigation relating to his/her spinal condition
• Patients taking >30mg/day of oral morphine sulfate, or the equivalent of this daily for more than 3 months
• Patient is unable to ingest orally administered medication
• Patient receiving autologous Iliac Crest bone graft (ICBG)
• Known intolerance of or true allergy to hydromorphone or oxycodone.
• History of moderate to severe Cirrhosis, defined as Child Pugh score of class B, C, or D
• History of Hemochromatosis or Porphyria
• Patient taking Isoniazid or barbiturates