Local Infiltration Analgesia With and Without EXPAREL Following Total Knee Arthroplasty

On Day 0, eligible subjects will be randomized 1:1 to two treatment groups. Subjects in Group 1 will receive local infiltration analgesia (LIA) with EXPAREL 266 mg in 20 mL admixed with bupivacaine hydrochloride (HCl) 0.5% in 20 mL and expanded in volume with 80 mL normal saline (total volume of 120 mL). Subjects in Group 2 will receive LIA with bupivacaine HCl 0.5% in 20 mL expanded in volume with 100 mL normal saline (total volume of 120 mL). Investigators will use their usual surgical technique to perform the TKA. Study drug will be administered using six 20 cc syringes with 22-gauge needles prior to wound closure. Each stick should deliver approximately 1-1.5 cc to the intended area. The tissue should visibly expand with minimal leakage. Study drug should be injected in the prescribed locations based on the areas of highest nerve density. Infiltration Technique Prior to cementation Syringe #1: Posterior capsule (8-10 sticks medial and 8-10 sticks lateral). Syringe #2: Femur medial and lateral periosteum, posterior periosteum, suprapatellar/quadriceps tendon (20 sticks). Syringe #3: Tibia fat pad (5 sticks); pes anserinus, medial collateral ligament, and gutter (15 sticks). Syringe #4: Circumferential periosteum (15-20 sticks). After cementation Syringe #5: Midline quadriceps tendon (10 sticks); retinaculum, medial gutter, femoral to tibia (10 sticks). Syringe #6: Lateral gutter, femoral to tibial (10 sticks); subcutaneous/closure (10 sticks). In addition to LIA, all study participants will receive a standardized approach for managing postsurgical pain that includes a scheduled multimodal pain regimen including adjunctive analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), and rescue analgesics as needed. Postsurgical clinical assessments will include pain intensity scores using a 10-cm visual analog scale (VAS); overall benefit of analgesia score (OBAS) questionnaire; total postsurgical opioid consumption; physical therapy assessment; nurse's satisfaction with overall analgesia; and discharge readiness. Adverse events (AEs) will be recorded from the time the informed consent form is signed through postsurgical Day 29. Postsurgical health economic outcome assessments will include hospital length of stay (LOS), use of skilled nursing facility, outpatient physical therapy use, hospital readmissions, and use of other health services following discharge (phone calls related to postsurgical pain, unscheduled visits related to postsurgical pain, and visits to emergency department) through postsurgical Day 29. A follow-up visit will be scheduled for all subjects on postsurgical Day 14. A follow-up phone call will be made on postsurgical Day 29 to all subjects who received study drug to assess for AEs.