Continuous Epidural Analgesia and Continuous Femoral Nerve Block for Postoperative Pain after Unilateral Total Knee Arthroplasty: A Prospective Cohort Study

Abstract

Introduction: Total Knee Arthroplasty (TKA) surgeries are associated with moderate to severe postoperative pain. Inadequate analgesia leads to patient distress, suboptimal knee mobilisation and complications due to delayed rehabilitation. Peripheral nerve blocks and central neuraxial techniques are in the vanguard of various analgesic strategies to minimise pain after TKA. Aim: To compare the effects of Continuous Epidural Analgesia (CEA) and Continuous Femoral Nerve Block (CFNB) on postoperative analgesia, knee rehabilitation and adverse effects after TKA surgeries. Materials and Methods: A prospective cohort study was conducted among 90 patients undergoing unilateral TKA at the Government Medical College, Kozhikode, Kerala, India. They were divided into two groups of 45 each. CEA (Group E) and CFNB (Group F) were given for postoperative pain management. Effectiveness of postoperative analgesia was measured by Numerical Rating Scale (NRS) scores at 6, 12, 24, 48 and 72 hours and also by need for rescue analgesics during the first 48 hours. Postoperative knee rehabilitation indices were measured on 1st, 2nd and 3rd Postoperative Days (POD). Incidence of adverse effects in each group was also noted. Continuous variables were analysed using students t-test, categorical variables using Chi-square test and NRS scores using Mann Whitney U test. Results: NRS scores were similar in both CEA (E) and CFNB (F) groups. On POD 1, 75.6% of group E and 71.1% of group F (p=0.630), on POD 2, 71.1% of group E and 68.9% of group F (p=0.818) and on POD 3, 62.2% of group E and 66.7% of group F (p=0.66) achieved specific rehabilitation indices. There was no statistically significant difference in pain scores, rescue analgesic requirement and rehabilitation indices between the two groups. No significant adverse effects were noted in either group. Conclusion: CFNB is as effective as continuous epidural block for postoperative analgesia and knee rehabilitation after TKA without any significant side-effects.