Comparison of intra-articular analgesia and femoral nerve block for postoperative pain relief in unilateral total knee arthroplasty: A randomized clinical study

Background and Aims: Femoral nerve block (FNB) and intra-articular analgesia (IAA) are used for postoperative analgesia after total knee arthroplasty (TKA). Aims and Objectives: We aimed to determine the better technique among the two, with regard to duration and quality of postoperative analgesia along with 24-h rescue analgesic consumption. The functional recovery in the early postoperative period was also assessed. Settings and Design: This was a prospective double-blind study comprising 40 American Society of Anesthesiologists I–III patients undergoing elective TKA who were randomly assigned to two groups (n = 20). Methodology: In Group A, 20 mL ropivacaine 0.5%, containing dexmedetomidine (1 μg.kg− 1), was given by FNB, and in Group B, intra-articular administration of the same drug was done. Analgesic effect was evaluated by measuring the Visual Analog Scale (VAS) and duration of analgesia. Quadriceps muscle strength was noted. Statistical Analysis: Observation data obtained were reported as mean value and analyzed using Student's t-test or Wilcoxon/Mann–Whitney rank test. Results: The mean VAS on passive movement at the 2nd, 6th, and 16th h postoperatively was 1.75 ± 0.44, 2.90 ± 0.72, and 2.75 ± 0.44 in Group A as compared to 2.25 ± 0.72, 4.30 ± 2.05, and 2.20 ± 0.77 in Group B (P = 0.026, 0.043, and 0.014, respectively). In Group A, the first request for analgesic (rescue analgesic) was at 637 ± 119 min and the total consumption of tramadol was 50.00 mg. In Group B, the first request for analgesic was at 404.44 ± 136 min, with a total dose of 63.89 mg. The P value for the time of rescue analgesic was <0.001, while for total drug consumption, it was 0.018. Conclusion: We concluded that the duration and quality of analgesia (VAS) were significantly superior and rescue analgesic requirement less in patients who received FNB as compared to IAA.