Comparison of Shoulder Field Anaesthesia (SFA) with Interscalene Block (ISB) for Analgesia After Arthroscopic Shoulder Surgery
Journal of Bone and Joint Surgery · 16 Oct 2026
† Impact is the editorial-priority score. All scores are out of 100. Clinical is a stored clinical-importance score from the earlier method; it has not been recalculated.
Why it matters
Interscalene blocks routinely paralyze the ipsilateral hemidiaphragm, so a surgeon-performed lung-sparing alternative matters for patients with poor respiratory reserve and for centres without ultrasound-guided regional anaesthesia.
The evidence
This single-centre randomised trial of 80 adults having arthroscopic shoulder surgery compared a surgeon-injected, landmark-guided shoulder field anaesthesia (SFA) with an ultrasound-guided interscalene block (ISB). Mean pain over 48 hours differed by -0.824 NRS points (ISB minus SFA; 95% CI -1.853 to 0.206). The authors read this as noninferiority against a 1.5-point margin, but the bound that matters for SFA being worse (SFA pain 1.853 points higher) actually crosses that margin, so noninferiority is not clearly shown. ISB gave clearly lower pain at 4 and 8 hours; hospital stay was shorter with SFA, and the only Horner syndrome and ICU respiratory events occurred after ISB.
A coherent primary effect estimate is unavailable. Clinical relevance does not estimate treatment benefit.
Why this rigour score?
RCTDesign starting point: 59.5
Raised the score
- Blinded outcome assessment+6.8
- Adequately powered+6
Lowered the score
No negative adjustments recorded.
Methods at a glance
Recorded assessment- Outcome assessors blindedMet
- Allocation concealedMet
- Random sequence generatedNot reported
- Intention-to-treat analysisMet
- Adequate statistical powerMet
- Prospective registrationMet
Not reported does not mean not done. Checks have different weights; this is not a count of boxes ticked.
See the full score breakdown
- Study design starting point
- 59.5
- Concealed allocation
- +5.1
- Compared against current standard of care
- +3.4
- Blinded outcome assessment
- +6.8
- Intention-to-treat analysis
- +3.4
- 0% loss to follow-up
- +1.7
- Adequately powered
- +6
- Prospectively registered
- +5.1
- Final rigour score rounded
- 91 / 100
Study design sets the starting point and a ceiling of 96. Recorded methods then adjust the score. Points are shown to one decimal place; the final score uses unrounded values.
Checklist from the stored appraisal. “Not met” describes the recorded criterion; it does not always produce a deduction. This overview supports reading the full study.
For journal club
1.For a patient with COPD or obesity undergoing rotator cuff repair, how would you weigh the clearly worse early (4 to 8 hour) pain with SFA against the phrenic nerve risk of an interscalene block?
2.How should counselling about the first postoperative night and rebound pain differ for a patient receiving SFA versus ISB, and what breakthrough analgesia plan would you set up?
Original publication title
Comparison of Shoulder Field Anesthesia (SFA) with Interscalene Block (ISB) for Analgesia After Arthroscopic Shoulder Surgery