IV vs Oral Acetaminophen in Spine Fusion Perioperative Care

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