Study never initiated

This is a randomized prospective outcomes study comparing two groups of patients. One group will receive liposomal bupivacaine for a periarticular injection. The other will receive ropivacaine for periarticular injection for pain relief after Total Knee Arthroplasty. the primary objective of this study is to determine if liposomal bupivacaine provides superior pain control (decreased maximal pain scores within the first 72 hours post surgery) when compared to ropivacaine when injected in a periarticular injection.

The current standard of care at our institution for pain relief in Total Knee Arthroplasty is ropivacaine injectate into the knee for acute postoperative pain relief. This provides pain relief for a duration of 6-18 hours after surgery. All patients in this study will also receive multimodal analgesia following surgery in both arms of the study. This will be the first study to prospectively analyze these two regimens.

Study group 1 (ropivacaine arm) consist of 100 mL (1 mL ketorolac, 2.5 mL morphine, 28.95 mL normal saline, 300 mcg of epinephrine, and 200 mg ropivacaine) Study group 2 will consist of 100 mL (one syringe with 50 mL total: 40 mL 0.25% bupivacaine, 300 mcg epinephrine, 1 mL ketorolac, 2.5 mL morphine, 6.5 mL normal saline) (one syringe with 50 mL total: 20 mL liposomal bupivacaine 30 mL normal saline). The periarticular injection will occur at the end of the procedure. Adequate analgesia will be defined as < 3 VAS at rest and if VAS is greater that 3 adjustments in oral or intravenous pain medications. Postoperatively the study team will evaluate for any signs of complications. Pain scores and opioid usage will be recorded daily while the subject is in the hospital. A quality of recovery survey will be completed at 72 hours post injection. All subjects will be contacted by phone at day 14 to determine if there have been any adverse events and report their pain level.

Inclusion Criteria:

• All patients undergoing primary total knee arthroplasty surgery 18-80.

Exclusion Criteria:

• Patient on chronic anticoagulation
• Allergy to local anesthetics, nsaids, or opioids
• Patients who remain intubated for one week after surgery or who are unable to provide information as to their feelings of pain post-operatively for the first week post- operatively
• Daily use of opioid for more than three weeks
• Lack of patient cooperation