This is a randomized prospective outcomes study comparing two groups of patients. One group will receive liposomal bupivacaine plus bupivacaine and the other will receive bupivacaine alone in interscalene blocks when undergoing total shoulder arthroplasty. The purpose of the study is to determine if LB plus bupivacaine provides superior pain control compared to bupivacaine alone when injected in an interscalene block for patients undergoing total shoulder arthroplasty surgery.

Liposomal bupivacaine (LB) is a long acting local anesthetic. It is liposome encapsulated bupivacaine which allows for prolonged release of bupivacaine over a 72-hour period. Bupivacaine is a medium acting local anesthetic which provides between 6 and 24 hours of analgesia when used in a peripheral nerve block. Both medications are standard of care for use in interscalene blocks here at the U of MN.

LB has not been adequately studied in peripheral nerve blocks and has yet to be studied for use in interscalene blocks for Total Shoulder Arthroplasty (TSA) patients. It has been studied in Rotator Cuff Repairs (RCR) surgery and showed superior analgesia compared to bupivacaine.

The purpose of the study is to determine if LB plus bupivacaine provides superior pain control compared to bupivacaine alone when injected in an interscalene block for patients undergoing total shoulder arthroplasty surgery.

Inclusion Criteria:

• All adult patients aged greater than 18 years of age that are undergoing total or reverse total shoulder arthroplasty

Exclusion Criteria:

• Patients with allergy to local anesthetics, daily use of opioids for more than 3 weeks prior to surgery, patient refusal, patient with coagulopathy, non-english speaking patients, and those who do not have access to a telephone.

Total of 75 included here due to dropouts along the way

72 hours