Peripheral Nerve Blocks in the Preoperative Management of Hip Fractures: A Systematic Review and Network Meta-Analysis.

Study Objective: We conducted a systematic review and network meta-analysis to evaluate the comparative efficacy of peripheral nerve block types for preoperative pain management of hip fractures.

Methods: We searched Cochrane, Central Register of Controlled Trials, MEDLINE, EMBASE, ICTRP, ClinicalTrials.gov, and Google Scholar for randomized clinical trials. We included participants aged more than 16 years with hip fractures who received peripheral nerve blocks or analgesics for preoperative pain management. The primary outcomes were defined as absolute pain score 2 hours after block placement, preoperative consumption of morphine equivalents, and length of hospital stay. We used a random-effects network meta-analysis conceptualized in the Bayesian framework. Confidence of evidence was assessed using Confidence in Network Meta-Analysis (CINeMA).

Results: We included 63 randomized controlled studies (4,778 participants), of which only a few had a low risk of bias. The femoral nerve block, 3-in-1 block, fascia iliaca compartment block, and pericapsular nerve group block yielded significantly lowered pain scores at 2 hours after block placement compared with those with no block (standardized mean differences [SMD]: -1.1; 95% credible interval [CrI]: -1.7 to -0.48, [confidence of evidence: low]; SMD: -1.8; 95% CrI: -3.0 to -0.55, [low]; SMD: -1.4; 95% CrI: -2.0 to -0.72, [low]; SMD: -2.3; 95% CrI: -3.2 to -1.4, [moderate], respectively). The pericapsular nerve group block, 3-in-1 block, fascia iliaca compartment block, and femoral nerve block resulted in lower pain scores than the no-block group. Additionally, the pericapsular nerve group block yielded a lower pain score than femoral nerve block or fascia iliaca compartment block (SMD: -1.21; 95% CrI: -2.18 to -0.23, [very low]: SMD: -0.92; 95% CrI: -1.70 to -0.16, [low]). However, both the fascia iliaca compartment block and femoral nerve block did not show a reduction in morphine consumption compared with no block. To our knowledge, no studies have compared the pericapsular nerve group block with other methods regarding morphine consumption. Furthermore, no significant difference was observed between peripheral nerve blocks and no block in terms of the length of hospital stay.

Conclusions: Compared with no block, preoperative peripheral nerve blocks for hip fractures appear to reduce pain 2 hours after block placement. Comparing different blocks, pericapsular nerve group block might be superior to fascia iliaca compartment block and femoral nerve block for pain relief, though the confidence evidence was low in most comparisons because of the moderate to high risk of bias in many of the included studies and the high heterogeneity of treatment strategies across studies. Therefore, further high-quality research is needed.