Local infiltration analgesia versus femoral nerve block in total knee arthroplasty: a meta-analysis.

INTRODUCTION: Local infiltration analgesia (LIA) and femoral nerve block (FNB) are both used for the pain management after total knee arthroplasty (TKA). Controversy still remains regarding the optimal technique for pain relief in patients undergoing TKA. The purpose of this meta-analysis was to compare the analgesia achieved with LIA and the one from FNB following TKA.

HYPOTHESIS: LIA achieves better pain control than FNB in patients with TKA.

METHODS: Databases, including Pubmed, EMBASE, the Cochrane Library and Web of Science were comprehensively searched to identify studies comparing LIA with FNB for patients with TKA. Two reviewers independently selected trials, extracted data, and assessed the methodological qualities of included studies. Data were analyzed by RevMan 5.2.

RESULTS: Nine RCTs involving 782 patients were included. LIA achieved more rapid pain relief (VAS) at 6h postoperatively [SMD6h=-0.92, 95% CI (-1.38, -0.47)] than FNB. There were no significant differences at 24h and 48h [SMD24h=-0.03, 95% CI (-0.46, 0.40); SMD48h=0.28, 95% CI (-0.35, 0.91)], VAS with activity at 24h and 48h [SMD6h=-0.54, 95% CI (-1.62, 0.54); SMD24h=-0.22, 95% CI (-1.41, 0.96); SMD48h=-0.08, 95% CI (-0.52, 0.69)], opioid consumption at 24h and 48h [SMD24h=-0.24, 95% CI (-0.82, 0.34); SMD48h=0.15, 95% CI (0.25, 0.54)] and length of hospital stay [MD=-0.52, 95% CI (-1.13, 0.09)].

DISCUSSION: LIA may be the better choice in the pain management of TKA for it could achieve fast pain relief and is easier to perform than FNB for patients with TKA.

LEVEL OF EVIDENCE: Level II, meta-analysis and systematic review.