Liposomal Bupivacaine Infiltration Versus Bupivacaine Hydrochloride for the Management of Unilateral Total Knee Arthroplasty in Geriatric Patients at a 287-Bed Community Hospital

Introduction: Geriatric patients receiving total knee arthroplasty (TKA) are found to have similar postoperative complications, functional scores, and perioperative mortality, as compared to younger patients. Conversely, geriatric patients often have longer lengths of stay. Periarticular injection (PAI) of liposomal bupivacaine (LB) as part of the multimodal pain management strategy is thought to improve recovery, however, mixed comparative efficacy data exists for its use in TKA.2-5. Methods: A retrospective, chart review was conducted at a 287-bed community teaching hospital. Orthopedic surgical patients who received an infiltration with liposomal bupivacaine versus bupivacaine HCl for unilateral TKA were compared. Patients identified in the electronic medical record by Diagnosis Related Group (DRG) 470—major joint replacement or reattachment of lower extremity without major complication or comorbidity codes were utilized. Patients who meet the following criteria were included: age 65 and older who underwent a TKA between 8/1/2018 to 7/31/2019 were discharged to home. Patients who have contraindications or hypersensitivity to bupivacaine formulations or a history of opioid dependence were excluded. The primary outcome is to identify whether patients who received an infiltration with liposomal bupivacaine had a lower total opioid consumption during their hospital stay. Results: A total of 114 patients who had a DRG 470 code and were above the age of 65 years were studied. There was no statistically significant difference in mean total opioid consumption (oral morphine equivalents) between the bupivacaine HCl (n = 25) and liposomal groups (n = 85) respectively, 93.76 versus 83.72 mg; P = .569. In addition, patients in both groups had similar lengths of hospital stay, 2.5 versus 3 days; P = .529 and mean pain scores until discharge 3.7 versus 4.34 on VAS; P = .305. Conclusion: The results of this drug utilization evaluation do not support a strong clinical advantage with local infiltration of liposomal bupivacaine over bupivacaine HCl in geriatric patients undergoing primary TKA surgery at this institution. There was not a statistically significant difference in mean total opioid consumption between the 2 groups. Additionally, the use of non-opioid analgesics, mean pain scores, and hospital lengths of stay were similar in both groups.