Dronabinol in Total Knee Arthroplasty (TKA)

The goal of this double-blinded randomized controlled trial is to compare whether the addition of Dronabinol compared to a placebo will affect opioid intake in patients undergoing a total knee arthroplasty. The main question it aims to answer are:

1. Does perioperative dronabinol use (starting in the immediate preoperative period (enrollment before 1 PM), with BID dosing concluding the evening of POD2) affect postoperative opioid consumption 24-48 hours following total knee arthroplasty?
2. Is there an effect of perioperative dronabinol use in the total knee arthroplasty patient on POD2 pain scores with ambulation?
3. Will hospital length of stay following total knee arthroplasty be affected in patients who use perioperative dronabinol as compared to control?
4. Does the use of perioperative dronabinol affect time to reach physical therapy discharge goals in postoperative total knee arthroplasty patients?
5. Is there a change in number of postoperative oxygen desaturation events in patients following total knee arthroplasty based on perioperative dronabinol use?

Participants will:

* Be randomized to take the dronabinol or placebo medication in 5 dosage
* Answer survey questions in regard to pain, postop nausea/vomiting, cognitive/adverse event, and outcome quality and support of decision making.
* Be connected to a Masimo to record oxygen saturation and an Actigraph to record sleep quality.

Researchers will compare two groups: 1) intervention group and 2) control group to see if dronabinol affect postoperative opioid consumption 24-48 hours following their total knee arthroplasty surgery.

The objective of this study is to examine the possible therapeutic advantages of administering perioperative dronabinol to individuals who are undergoing unilateral total knee arthroplasty (TKA). With the utilization of contemporary regional anesthetic procedures and peripheral nerve blocks, pain management is typically effective in the immediate aftermath of total knee arthroplasty (TKA) within the first day after surgery. Rebound pain is shown to occur on the second day following postoperative discharge (POD2), once the analgesic blocks administered during the procedure have ceased to be effective. Previous studies have suggested that dronabinol, a synthetic form of THC, may have potential analgesic properties. Our goal is to find out if giving dronabinol before surgery could lower the number of opioids that people need on postoperative day 2 (POD2) in people who are having total knee arthroplasty (TKA). This research could provide valuable insights into alternative pain management strategies for TKA patients, potentially minimizing opioid-related side effects and improving overall patient outcomes.

Eligibility Criteria:
Inclusion Criteria:

* Patients aged between 18-70 years old with osteoarthrosis scheduled for primary unilateral knee arthroplasty with a participating surgeon
* Planned use of regional anesthetic technique during surgery involving infiltration between the popliteal artery and the capsule of the posterior knee (IPACK), adductor canal block (ACB) and periarticular injection (PAI)
* Ability to follow study protocol

Exclusion Criteria:

* Patients less than 18 years of age or older than 70 years of age
* Contraindication to regional or neuraxial anesthetic
* Intended use of general anesthesia
* Revision surgery
* Chronic opioid use (for \>3 months prior to surgery)
* Cannabis/cannabinoid use within the last 3 months
* ASA class of IV or greater
* Active or history of major mental history (as defined by the Diagnostic and Statistical Manual of Mental Disorders-5 \[DSM-5\]; i.e. major depressive disorder, anxiety, bipolar disorder, schizophrenia)
* History of seizures
* Use of antidepressants
* Use of anticonvulsants
* Use of Coumadin
* Use of Disulfuram
* Use of Metronidazole
* Non-English speakers
* BMI ≥40