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Updated: Sep 5, 2026
Clinical Efficacy of Small Needle Knife Therapy on Stage I-II Frozen Shoulder
Published on: November 17, 2023
Single-shot versus continuous inter-scalene blockade in primary shoulder arthroplasty: a systematic review and
Carlos Torrez1, Bryan J M van de Wall1, Elena Rippen1
1Department of Orthopedic and Trauma Surgery, Lucerne Cantonal Hospital, Lucerne, Switzerland; Faculty of Health Sciences and Medicine, University of Lucerne, Lucerne, Switzerland.
Background:
The optimal regional anesthesia strategy for anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty (aTSA/rTSA) remains a subject of debate. While single-shot inter-scalene blocks (SSIBs) are often limited by short duration and potential rebound pain, continuous inter-scalene catheters (CICs) are associated with higher complication rates and procedural complexity. This meta-analysis evaluates the effectiveness and safety of both techniques, specifically investigating the impact of the local anesthetic agent.
Methods:
A systematic search was conducted in PubMed, Embase, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing and Allied Health Literature through March 2026 for randomized controlled trials and observational studies. The primary outcome was pain intensity (Visual Analogue Scale, Numeric Rating Scale) at 24 hours. Secondary outcomes included opioid consumption, length of hospital stay, technical and block-related complications, and procedural costs.
Results:
Seven studies involving 2,639 patients were included (1,182 SSIBs and 1,457 CICs). No statistically significant global difference was found regarding 24-hour pain scores (mean difference [MD], -0.23; P = .70) or opioid consumption (P = .91). In sub-group analysis, the CIC was associated with lower pain scores when standard local anesthetics were used (MD, 1.18; P < .001), whereas the SSIB with liposomal bupivacaine was associated with borderline lower pain scores (MD, -1.02; P = .05); however, these differences lie at the lower margin of published thresholds for a minimal clinically important difference in acute post-operative pain. A post hoc analysis at 48 hours (3 studies, 695 patients) showed no significant difference (MD, -0.81; P = .20). The SSIB was associated with a more than 4-fold lower rate of technical and block-related complications (0.4% vs. 4.6%; risk ratio, 0.22; P = .005). No significant difference was observed in the length of hospital stay (P = .45); material costs, compared descriptively, were higher for CICs ($357-$474) than those for SSIBs ($24-$190).
Conclusion:
At 24 hours, the SSIB was associated with analgesia comparable with to the CIC, with the direction of effect depending on the local anesthetic agent used. The SSIB was associated with significantly fewer technical and block-related complications and lower material costs. These findings suggest a favorable risk-benefit profile of SSIB for primary shoulder arthroplasty although outcomes beyond 48 hours require further investigation.
