Efficacy of Single-Shot Adductor Canal Block Combined With Posterior Capsular Infiltration on Postoperative Pain and Functional Outcome After Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Study

Adductor canal block (ACB) may preserve muscle strength and promote faster recovery than other methods of analgesia following total knee arthroplasty (TKA). However, there are contradictory reports on the efficacy of ACB. Here, we evaluated the efficacy of single-shot ACB combined with posterior capsular infiltration (PCI) vs multimodal periarticular infiltration analgesia in treating postoperative pain.

This study involved patients undergoing unilateral primary TKA at our institution from January 2018 to January 2019. Patients were randomized into 2 groups, one of which was treated with ACB combined with PCI, and the other with periarticular infiltration analgesia. Primary outcomes included postoperative pain as assessed by the visual analog scale (VAS) and consumption of morphine hydrochloride. The secondary outcome was functional recovery, as assessed by range of knee motion, quadriceps strength, and daily ambulation distance. Tertiary outcomes included the duration of hospital stay and postoperative adverse effects.

Patients treated with ACB and PCI had lower resting VAS scores at 8 and 24 hours after surgery, and lower VAS scores during motion within 48 hours after surgery. Patients treated with ACB and PCI also consumed less morphine. There was no difference in functional recovery, duration of hospitalization, or incidence of adverse events.

The ACB combined with PCI can reduce postoperative pain sooner after TKA without affecting postoperative functional recovery and increasing complications.