Subjects will be divided into two groups, Group A (control) to receive 20ml of saline while Group B (study) to receive 20ml of liposomal bupivacaine into the posterior capsular space during total knee arthroplasty. Patients from both groups will receive a femoral nerve block with catheter placement for continuous infusion of local anesthetic. All subjects will have access to rescue analgesics after surgery. Multimodal analgesia will supplement pain as per standard care by the anesthesia team. Tylenol Orally 1g three times daily (not to exceed 4g in 24hrs), oxycontin 10mg orally, twice/day, Celebrex 200 mg orally once a day and Percocet 5/325 prn will serve as this multimodal approach. The time, day and number of requests for break through (additional) analgesia will be noted by both anesthesia team and primary care team. Pain scores will be assessed using a 0 - 10 numeric scale. Pain will be assessed for the following intervals: hospital arrival, post anesthesia care unit (PACU) arrival, 2, 4, 8, 12, 24, 48, 72, hours later and after hospital discharge 10 +/- 5 days after the block. Pain inquiries will assess both posterior and anterior aspects of the knee. Pain at rest and for simple leg movements (knee extension, straight leg raise) to fully ambulatory will be noted. These assessments will be made in conjunction with rehabilitation and physical therapy specialists.