To help curb the use of opioid medications following orthopedic surgery investigators have developed a new multi-modal pain pathway. Investigators aim to compare this regimen with and without the inclusion of opioid medications. This study will be performed in a randomized, double-blinded, placebo-controlled fashion in patients undergoing primary total knee or total hip arthroplasty. Investigators hypothesize that the opioid devoid pathway will show equivalent pain scores to the pathway that includes opioids while also having less constipation, nausea, and vomiting following surgery. If successful, this would create a dramatic decrease in opioid consumption following orthopedic surgery while still providing appropriate pain relief to patients.

• Aim 1 will be to compare the postoperative pain levels both in the hospital setting as well as daily for two weeks following discharge between patients in the opioid treatment group and those in the non-opioid treatment group. This will be performed with clinical exams while in the hospital and with phone surveys on discharge. Results will be recorded using the Visual Analog Scale for pain scores.
• Aim 2 will be to compare the overall morphine equivalents used during hospitalization between the opioid and non-opioid treatment groups. This will be calculated based on the amount of intravenous breakthrough narcotic pain medication used in the hospital setting (divided by the total number of post-surgery hospitalization hours to account for varying lengths of stay). Investigators will also measure the total number of opioid pills (these would be placebo pills for the non-opioid group) consumed during the first two weeks post-discharge, and the post-surgery day on which opioid pills were discontinued, and compare these outcomes between the opioid and non-opioid groups.
• Aim 3 will be to compare postoperative constipation, nausea, and vomiting between the two treatment groups. This will be assessed with daily clinical examinations while in the hospital and with daily phone surveys on discharge. Constipation will be recorded as presence or absence, while nausea and vomiting will be measured using the Postoperative Nausea and Vomiting Scale.
• Aim 4 will be to compare the length of post-surgery hospitalization between the two treatment groups.

Inclusion Criteria:

1. Age > 18 and < 90 years.
2. Willing to participate in the study and competent to provide informed consent.
3. Willing to comply with protocol procedures.
4. Has an underlying diagnosis of osteoarthritis indicated for knee arthroplasty.

Exclusion Criteria:

1. A diagnosis of renal or liver disease
2. If a patient has a contraindication to receiving a spinal anesthetic or pain catheter
3. The patient must not have taken any narcotic medications during the 3 months leading up to the surgery
4. The patient must not be allergic or intolerant to a medication used in the multi-modal pain pathway
5. Revision hip or knee arthroplasty
6. If a patient is being treated under worker's compensation
7. If a patient has diabetes
8. Unable to take Aspirin 325 mg twice daily for deep venous thromboprophylaxis

The oxycodone and placebo tablets will be encapsulated by the research pharmacy prior to dispensing for blinding purposes.