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 for participation in this study: 1. Allergy, hypersensitivity, intolerance, or contraindication to any of the study medications 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 dosing period for pain that is not strictly related to the knee surgery and which, in the 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. Prior arthroscopy 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 elimination half-lives of such investigational drug, whichever is longer, prior to study drug administration, or planned administration of another investigational product 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 the opinion of the Investigator, could interfere with study assessments or compliance 12. Currently pregnant, nursing, or planning to become pregnant during the study 13. Clinically significant medical disease that, in the opinion of the Investigator, would make participation in a clinical study inappropriate. This includes diabetic neuropathy, coagulation or bleeding disorders, severe peripheral vascular disease, renal insufficiency, hepatic dysfunction or other conditions that would constitute a contraindication to participation in the study. 14. Any use of marijuana \[including Tetrahydrocannabinol (THC) and Cannabidiol (CBD)\] within 30 days prior to randomization, or planned use during the course of the study 15. Chronic opioid use (average ≥30 oral morphine equivalents/day) within 30 days prior to surgery