Single-Shot Versus Continuous Interscalene Blockade in Primary Shoulder Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Observational Studies.

At 24 hours, single-shot interscalene blocks was associated with analgesia comparable to continuous interscalene catheters, with the direction of effect depending on the local anesthetic agent used.

single-shot interscalene blocks was associated with significantly fewer technical and block-related complications and lower material costs.

These findings suggest a favorable risk-benefit profile of single-shot interscalene blocks for primary shoulder arthroplasty, although outcomes beyond 48 hours require further investigation.

LEVEL OF EVIDENCE: Level III, Systematic Review/Meta-Analysis, Treatment Study.