A comparative study evaluating the role of adductor canal block catheter versus intraarticular analgesic infusion on knee pain and range of motion in the immediate postoperative period: a prospective multicenter trial

Postoperative pain after total knee arthroplasty (TKA) is an important determinant of hospital stay and rehabilitation and thereby functional outcome. Adductor canal block (ACB) and intraarticular analgesic infiltration through catheters (IAC) are techniques of multimodal analgesia which have shown to control postoperative pain satisfactorily. The aim of this study is to evaluate the efficacy of ACB versus IAC in reducing immediate postoperative pain and thereby allow early rehabilitation. A multicenter quasi-experimental study was conducted on 511 patients undergoing unilateral primary TKA from March 2016 to April 2017 who either received ACB with catheter (Group I, n = 350 patients) or IAC (Group II, n = 172 patients) for postoperative pain control. All the patients were assessed for severity of pain by Visual Analogue Scale at 8, 24, 48, 72 h postoperatively and knee range of motion (ROM) on the day of discharge. There was no significant difference in pain scores on postoperative day (POD) 0 (1.09 ± 0.30 vs. 0.98 ± 0.46, p = 0.45) and POD 1 (1.21 ± 0.45 vs. 1.00 ± 0.00, p = 0.11) and in mean ROM on the day of discharge between ACB and IAC (88.40° ± 7.96° vs. 88.34° ± 5.74°; p = 0.93) groups. This study shows that both ACB and IAC provide satisfactory postoperative analgesia with sparing of quadriceps function and good knee ROM leading to early rehabilitation and reduced hospital with no advantage of one technique over another.