Continuous adductor canal block following total knee arthroplasty provides a better analgesia compared to single shot: A prospective randomized controlled trial

OBJECTIVE: The aim of this study was to compare single-shot adductor canal block and continuous infusion adductor canal block techniques in total knee arthroplasty patients. METHODS: We prospectively randomized 123 patients who were scheduled for unilateral primary total knee arthroplasty surgery into single shot (n = 60; mean age: 67.1 ± 6.9 years) and continuous (n = 63; mean age: 66.9 ± 6.8 years) adductor canal block groups. Postoperative visual analog scale pain scores, need for additional opioids and functional results as; timed up and go test, the 30-s chair stand test, 5 times sit-to-stand test, the 6-min walking test, the time to active straight leg raise, time to walking upstairs, maximal flexion at the time of discharge, duration of stay in hospital were compared between the two groups. RESULTS: Pain scores were lower in the continuous adductor canal block group as compared to the single-shot adductor canal block group throughout the postoperative period (p = 0.001). Rescue analgesia was required for 6 (10%) patients in the single shot group and for 1 (1.59%) patient in the continuous group (p = 0.044). Patients in the continuous adductor canal block group displayed better functional results than the single-shot adductor canal block group with respect to active straight-leg rise time (25.52 ± 4.56 h vs 30.47 ± 8.07 h, p = 0.001), 6-min walking test (74.52 ± 29.38 m vs 62.18 ± 33.32 m, p = 0.035) and maximal knee flexion degree at discharge (104.92 ± 5.35° vs 98.5 ± 7.55°, p = 0.001). There was no significant difference between the two groups for other functional and ambulation scores. CONCLUSION: Pain control following total knee arthroplasty was found to be better in those patients treated with continuous adductor canal block as compared to those treated with single-shot adductor canal block. Patients treated with continuous adductor canal block also displayed better ambulation and functional recovery following total knee arthroplasty. LEVEL OF EVIDENCE: Level I, Therapeutic Study.