Effectiveness of Exparel Anesthetic Administered by the Surgeon During Knee Surgery

Inclusion Criteria: Inclusion Criteria:

Subjects must meet all of the following inclusion criteria to be eligible for participation:

1. Subjects ages 18 or older at screening 2. Indicated to undergo primary unilateral total knee arthroplasty under spinal anesthesia 3. Primary indication for TKA is degenerative osteoarthritis of the knee 4. American Society of Anesthesiologists (ASA) physical status 1, 2, or 3 (see Appendix 6) 5. Able to provide informed consent, adhere to the study schedule, and complete all study assessments 6. Body Mass Index (BMI) ≥18 and <40 kg/m2

Exclusion Criteria:

• Subjects who meet any of the following exclusion criteria will not be eligible forparticipation in this study:

1. Allergy, hypersensitivity, intolerance, or contraindication to any of the studymedications for which an alternative is not named in the protocol (e.g.,amide-type local anesthetics, opioids, bupivacaine HCl, NSAIDs)

2. Planned concurrent surgical procedure (e.g., bilateral TKA)

3. Undergoing unicompartmental TKA or revision TKA

4. Concurrent painful physical condition (e.g. arthritis, fibromyalgia, cancer)that may require analgesic treatment with NSAIDs or opioids in the post dosingperiod for pain that is not strictly related to the knee surgery and which, inthe Investigator's opinion, may confound the post dosing assessments

5. Inadequate sensory function below the knee as assessed by the Investigator

6. History of contralateral TKA within 1 year

7. Previous open knee surgery on the knee being considered for TKA. Priorarthroscopy is permitted

8. History of, suspected, or known addiction to or abuse of illicit drug(s),prescription medicine(s), or alcohol within the past 2 years

9. Administration of an investigational drug within 30 days or 5 eliminationhalf-lives of such investigational drug, whichever is longer, prior to studydrug administration, or planned administration of another investigationalproduct or procedure during the subject's participation in this study

10. Previous participation in an EXPAREL study

11. Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in theopinion of the Investigator, could interfere with study assessments orcompliance

12. Currently pregnant, nursing, or planning to become pregnant during the study

13. Clinically significant medical disease that, in the opinion of theInvestigator, would make participation in a clinical study inappropriate. Thisincludes diabetic neuropathy, coagulation or bleeding disorders, severeperipheral vascular disease, renal insufficiency, hepatic dysfunction or otherconditions that would constitute a contraindication to participation in thestudy.

14. Any use of marijuana [including Tetrahydrocannabinol (THC) and Cannabidiol (CBD)] within 30 days prior to randomization, or planned use during the courseof the study

15. Chronic opioid use (average ≥30 oral morphine equivalents/day) within 30 daysprior to surgery