Assessment of liposome bupivacaine infiltration versus continuous femoral nerve block for postsurgical analgesia following total knee arthroplasty: a retrospective cohort study

Abstract

Objective: Perioperative pain management is an important aspect of recovery from total knee arthroplasty (TKA) because severe pain can delay ambulation and hospital discharge. The objective of this retrospective sequential cohort study was to determine the impact of local infiltration analgesia using liposome bupivacaine (Exparel1) when compared with a continuous femoral nerve block (FNB) following TKA.Methods: This retrospective cohort study included consecutive patients who underwent TKA between April 2011 and April 2014, and received one of three interventions. Study Group A received adductor canal infiltration with bupivacaine HCl and knee infiltration with liposome bupivacaine. Study Group B received adductor canal infiltration with liposome bupivacaine and knee infiltration with liposome bupivacaine. The control group received a continuous FNB with ropivacaine HCl delivered via an elastomeric pump. Numeric pain rating scores (NPRS), distance walked, length of stay (LOS), and dose of narcotic medication were the key efficacy variables of interest.Results: A total of 237 patients were included in this study: 98 in Group A, 34 in Group B, and 105 controls. On postoperative day (POD) 0, mean (standard deviation [SD]) NPRSs were similar between Group A (1.8 [1.7]), Group B (2.7 [1.8]), and the control group (2.3 [2.4]). Significantly (p < 0.05) more patients in Group A (58%) and Group B (44%) walked on POD0 than in the control group (0%); almost all patients walked on POD1. The mean (SD) distance walked was also significantly greater (p < 0.05) on POD1 in Group A (193 [203] feet) and Group B (211 [144] feet) than in the control group (46 [73] feet). Mean (SD) LOS was significantly (p < 0.05) shorter in Group B (2.2 [1.2] days), than in the control group (3.2 [0.7] days) and Group A (3.0 [1.7] days).Conclusions: Local infiltration analgesia using liposome bupivacaine was associated with improved ambulation and shorter LOS following TKA when compared with continuous FNB in this retrospective cohort study.