Should Femoral Nerve Blocks and Adductor Canal Blocks Be Used in Pediatric or Adolescent Anterior Cruciate Ligament Reconstruction?: A Systematic Review.

Abstract

Background: Achieving adequate pain control is vital for proper rehabilitation, satisfaction, and earlier discharge after anterior cruciate ligament reconstruction. Opioids have traditionally been used for this purpose, however, can be associated with various negative outcomes. As such, multimodal analgesia was introduced to reduce postoperative opioid use. Regional nerve blocks constitute one modality of multimodal analgesia, with femoral nerve blocks (FNBs) and adductor canal blocks (ACBs) being standard. This review sought to evaluate the utility and adverse effects of FNBs and ACBs relative to controls, alternative regional anesthesia options, and each other in pediatric or adolescent anterior cruciate ligament reconstruction (ACLR).

Methods: Three databases were searched on January 31, 2024. The authors adhered to the PRISMA and R-AMSTAR guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The definition of pediatric was considered to be a mean age of 18 years or younger. Data on demographics, operative and anesthetic details, strength and functional outcomes, postoperative opioid consumption, revision rates and return to sport (RTS) rates, and Visual Analogue Scale (VAS) scores were extracted.

Results: Eleven studies (1 level I, 10 level III) comprising 5453 patients were included in this review (54.1% female), with a mean age of 16.3 (range of means: 15.0 to 16.9) years. Two studies compared FNB with and without a sciatic-nerve block (SNB), finding lower opioid consumption ( P =0.007) and VAS scores ( P <0.0001) in the postanesthesia care unit (PACU) in the FNB + SNB group. Three studies compared FNB or ACB with controls, with no studies reporting a benefit in rates of RTS, isokinetic quadriceps or hamstrings strength, or functional test performance. There were minimal differences when comparing continuous and single nerve blocks and FNB with ACB.

Conclusion: There is inconclusive evidence investigating the role of FNB and ACB in pediatric or adolescent ACLR. The addition of a SNB to FNB may result in improvements in opioid consumption and VAS scores in the early postoperative period. There was minimal evidence in support of continuous blocks over single-shot blocks. Future studies should compare the use of ACB, FNB, and no blocks for pediatric or adolescent ACLR, with primary endpoints of acute pain control, postoperative opioid use, and the presence of longer-term motor deficits.

Level of evidence: Level III.