Single-shot perineural femoral nerve block and falls after lower limb orthopaedic surgery: a systematic review and meta-analysis.

BACKGROUND

Single-shot femoral nerve block (sFNB) is a popular orthopaedic analgesic modality, and although block-induced quadriceps muscle weakness is widely acknowledged, an increase in fall risk remains a contentious issue. This systematic review and meta-analysis was conducted to explore the early postoperative modification of fall, buckling, and near-fall risk after sFNB.

METHODS

This review adhered to MECIR and PRISMA recommendations and was prospectively registered with PROSPERO (CRD42023477892). Electronic databases (MEDLINE, EMBASE, CINAHL, and CENTRAL), citations, and alternative repositories were systematically searched, with independent reviewers evaluating and extracting randomised controlled trial data, allowing a pooled risk ratio (RR) and 95% confidence interval to be determined for each outcome. Evidence certainty was summarised using the Grading of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

An increased risk of falls was noted following sFNB provision when compared with all non-motor block techniques (adductor canal/iliopsoas plane block and local anaesthetic infiltration) combined (RR, 2.75; P=0.02), neuraxial blockade (RR, 6.35; P=0.03), and systemic analgesia (RR, 6.43; P=0.03). Overall, across 31 trials, sFNB recipients exhibited a significant, dose-dependent increase in fall risk compared with non-recipients (RR, 3.62; 95% confidence interval, 1.83-7.19; P=0.0002; absolute risk increase, 0.9% [0.3-2%]), with a further five and four studies also demonstrating an increased risk of buckling (RR, 5.95) and near-falls (RR, 4.56), respectively.

CONCLUSIONS

Compared with techniques that avoid femoral nerve inhibition, there is moderate-quality evidence that sFNB increases fall risk and very-low-quality evidence that sFNB increases buckling and near-fall risk in the early convalescent phase. Appreciation and disclosure of these risks may promote safer rehabilitation pathways.

SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023477892).