Knee osteoarthritis is a leading cause of disability around the world. Traditionally, total knee arthroplasty (TKA) is the gold standard treatment; however, unicompartmental knee arthroplasty (UKA) has emerged as a less-invasive alternative to TKA. Patients with UKAs participate earlier with physical therapy (PT), have decreased complications, and faster discharges (1, 2). As UKA has evolved, so has computer navigation and robotic technology. The Robotic Assisted UKA combines the less invasive approach of the UKA with accurate and reproducible alignment offered by a robotic interface (3)(Figure1). A key part of a patient's satisfaction is perioperative pain control. Femoral nerve blocks (FNB) are commonly performed to provide analgesia, though they cause quadriceps weakness which limits PT (4). An alternative is the adductor canal block (ACB) which provides analgesia while limiting quadriceps weakness (4). The adductor canal is an aponeurotic structure in the middle third of the thigh containing the femoral artery and vein, and several nerves innervating the knee joint including the saphenous nerve, nerve to the vastus medialis, medial femoral cutaneous nerve, posterior branch and occasionally the anterior branch of the obturator nerve (5). In a multi-modal approach with Orthopedic Surgery, Regional Anesthesia, and PT departments, an early goal directed plan of care was developed to study ACB in UKA with a focus on analgesia effectiveness and PT compliance rates. Following IRB approval, we performed a case series including 29 patients who received a single shot ACB. Primary outcomes were distance walked with PT on postoperative day (POD) 0 and 1 and discharge day. Our secondary outcomes included Visual Analog Scale (VAS) scores in the post-anesthesia care unit (PACU), 8 and 24 hours postoperatively and oral morphine equivalents required for breakthrough pain.Introduction
Methods
Total joint arthroplasty is one of the most common procedures performed in orthopaedic surgery. Over 600,000 total hip and total knee replacements are performed in the United States each year. At our 550 bed tertiary care facility, 437 total knee arthroplasties were performed in 2010 and 426 in 2011. Tranexamic acid is an antifibrinolyic synthetic derivative of aminocaproic acid used to prevent hemorrhage in patients undergoing surgical procedures. Several studies show decreased blood loss in patients receiving both intravenous and topical tranexamic acid. Beginning in 2011, our surgeons began using topical tranexamic acid in an irrigation solution of 3 grams in 100 mL of normal saline after implant placement and prior to closure of the incision. Our study is a retrospective review comparing patients receiving total knee arthroplasties before and after the institution of tranexamic acid. The purpose of our study was to assess estimated perioperative blood loss, determining the cost effectiveness of using tranexamic acid while comparing adverse effects of using topical tranexamic acid in total knee arthroplasty. Our study includes 683 primary total knees, 373 that received did not receive topical tranexamic acid and 310 that did, from January 1, 2010 to October 31, 2011. There were no demographic differences between the 2 groups. Topical tranexamic acid significantly (p<0.0001) decreased blood loss in patients receiving primary total knee arthroplasties. There were no differences between groups in thromboembolic events or joint infections. Tranexamic acid significantly (p<0.0001) decreased both blood bank cost and total cost of stay resulting in nearly $1,500 savings per patient to our institution.
