This is a randomized prospective study of 60 patients undergoing total knee arthroplasty evaluating the clinical outcomes of liposomal bupivacaine periarticular injections (PAI) when compared to single shot adductor canal block using bupivacaine HCl.

Total knee arthroplasty(TKA) is an effective solution for end stage arthritis of the knee; however, post-surgical pain can be difficult to manage and the optimal peri-operative pain management strategy has not been established. This study serves to evaluate the clinical outcomes of liposomal bupivacaine PAI when compared to single shot adductor canal block using bupivacaine HCl in patients undergoing a TKA. The investigators hypothesized that peri-articular injection with liposomal bupivacaine would not be inferior to an adductor canal block using bupivacaine HCl. A total of 60 patients were recruited. Thirty patients were randomized to receive intraoperative liposomal bupivacaine periarticular injection, and another thirty patients randomized to receive a pre-operative adductor canal block using bupivacaine. Both groups otherwise received standard pain management strategies peri-operatively. The primary outcome of interest was post-operative pain, which was measured using the Visual Analog Scale (VAS). Secondary measures included changes in patient function which was measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), knee range of motion, post-operative ambulation distance, and hospital length of stay.

Inclusion Criteria:

1. Patients undergoing unilateral primary total knee arthroplasty for end stage osteoarthritis or rheumatoid arthritis.
2. All adults > 18 years of age.

Exclusion Criteria:

1. Not cleared by PCP and appropriate specialists to undergo TKA (Check No if patient has been cleared.)
2. Adults undergoing bilateral primary total knee arthroplasties.
3. Women who are pregnant.
4. Women who are breastfeeding.
5. Inability to receive successful spinal anesthesia.
6. Allergy to amide anesthetics.
7. Inability to receive IV tranexamic acid.
8. Patients who are unable to speak English.
9. Patients who are less than 66kg.
10. Patients who are opioid dependent. We define opioid dependency as patients who are on a long-acting narcotic or patients who are taking more than six tablets of hydrocodone 5mg or equivalent.

Individual participant data to be available up to 7 years.