The role of ultrasound-guided single-shot femoral and sciatic nerve blocks on pain management after total knee arthroplasty

Abstract

Background: Peripheral nerve blocks reduce postoperative pain and opioid consumption after total knee arthroplasty (TKA). The aim of this study was to evaluate the effects of single-shot femoral nerve and sciatic nerve blocks on postoperative pain management and opioid consumption after TKA.

Methods: This study included 100 patients who underwent TKA between July 2015 and September 2017. Fifty patients received pre-operative, single-injection, ultrasound-guided femoral and sciatic nerve blocks (Group 1) and 50 did not (Group 2). Multimodal analgesia was otherwise identical, and oxycodone was administered either intravenously or orally if the patients complained of postoperative pain ≥6 on the visual analog scale (VAS). Postoperative VAS scores, opioid consumption, and the fear of future TKA were compared between the groups.

Results: The mean VAS in the first 18 postoperative hours was significantly lower in Group 1 (P ≤ 0.002). The mean amount of oxycodone taken in the first three postoperative days was significantly lower in Group 1 (P = 0.001). Patient fear of future TKA at 14 days postoperatively was significantly lower in Group 1 (P = 0.027).

Conclusions: Pre-operative ultrasound-guided, single-shot femoral and sciatic nerve blocks afforded effective pain control in the first 18 h after TKA, and significantly reduced oxycodone consumption in the first three postoperative days.

Keywords: Femoral nerve block; Oxycodone; Postoperative pain; Sciatic nerve block; Total knee arthroplasty; Ultrasound.