Retrospective evaluation of the effect of femoral nerve block and periarticular infiltration block on postoperative analgesia in total knee arthroplasty

Introduction and Objective: In this retrospective observational study, we aimed to evaluate the effect of periarticular infiltration block (PAIB) in addition to femoral nerve block (FSB) on postoperative analgesia in patients undergoing total knee arthroplasty (TKA). Materials and Methods: After obtaining ethical approval, the records of patients who underwent TKA between January 1, 2023, and October 1, 2024, were reviewed. A total of 134 patients were included: those who received both FSB and PAIB (Group 1, n=73) and those who received FSB alone (Group 2, n=61). Patient demographics, including age, sex, height, weight, and body mass index (BMI), were recorded. Intraoperative blood pressure, heart rate, and SpO2 values were also documented. Resting and movement visual analog scale (VAS) scores were recorded preoperatively and at 2, 4, 6, 12, and 24 hours postoperatively, as well as on postoperative day 2. Postoperative additional analgesic requirements, total morphine consumption, and any complications were noted. Preoperative and postoperative hemoglobin values, along with the amount of blood and blood products used postoperatively, were recorded. Surgical duration, anesthesia time, tourniquet time, and PACU length of stay were also evaluated. Results: Resting VAS scores at 4 hours postoperatively were significantly lower in Group 1 compared to Group 2 (p<0.05); however, resting and movement VAS scores at other time points were similar between the groups. Postoperative morphine consumption was significantly lower in Group 1 than in Group 2 (p<0.05). Mean postoperative hemoglobin levels were significantly reduced compared to preoperativelevels in both groups (p<0.05). Both intraoperative blood loss and the number of administered erythrocyte suspensions were significantly lower in Group 1 (p<0.05). Postoperative complications were similar between the groups. Conclusion: In patients underwent TKA, the combined use of FSB and PAIB did not significantly affect resting or movement VAS scores but was associated with reduced opioid consumption and lower surgery-related blood loss. Keywords: Total knee arthroplasty, Femoral nerve block, Periarticular infiltration block, Postoperative pain