Effect of Intrawound Vancomycin Powder on the Pathogen Spectrum and Antimicrobial Susceptibility of Postoperative Infections in Elective Lumbar Fusion
Spine · 30 Jul 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
Many spine surgeons already use intrawound vancomycin powder for SSI prophylaxis, and this trial addresses a lingering safety worry from retrospective data that it might shift infections toward resistant or gram-negative organisms.
The evidence
This is a secondary microbiological analysis of a randomised trial of 292 patients undergoing elective posterior lumbar interbody fusion, comparing standard IV antibiotics alone versus IV antibiotics plus 1g of intrawound vancomycin powder. Among the 22 patients who developed any surgical site infection, gram-positive organisms still dominated in both groups (87.5% control vs 100% vancomycin, p=1.000), all tested isolates remained fully vancomycin-susceptible, and rates of non-wound infections like UTIs were similar between groups (5.3% vs 4.3%, p=0.788).
Gram-positive proportion of culture-positive SSI isolates: Risk difference 12.5 (95% CI unavailable; units not reported).
Why this rigour score?
RCTDesign starting point: 59.5
Raised the score
- Prospectively registered+5.1
- Compared against current standard of care+3.4
Lowered the score
- Per-protocol analysis only−6
- 12-month follow-up−5.1
Score capped at 40. The conclusions are not supported by the reported results.
Methods at a glance
Recorded assessment- Outcome assessors blindedNot reported
- Allocation concealedNot reported
- Random sequence generatedNot reported
- Intention-to-treat analysisNot met
- Adequate statistical powerNot reported
- 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
- Compared against current standard of care
- +3.4
- Per-protocol analysis only
- −6
- 12-month follow-up
- −5.1
- 5% loss to follow-up
- +0.2
- Prospectively registered
- +5.1
- No correction for multiple comparisons
- −3.4
- Reverse fragility index 6
- +3.4
- Journal prior (not an observed method)
- +0.5
- Methodological cap
- −17.7
- Final rigour score rounded
- 40 / 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.If gram-positive organisms and preserved vancomycin susceptibility remain the norm regardless of intrawound vancomycin use, should empiric antibiotic choice for suspected post-fusion SSI change at all based on prophylaxis history?
2.Given the very small number of culture-positive infections in this cohort, how much weight should surgeons place on this reassurance when deciding whether to continue routine intrawound vancomycin powder in lumbar fusion?
Original publication title
Effect of Intrawound Vancomycin Powder on the Pathogen Spectrum and Antimicrobial Susceptibility of Postoperative Infections in Elective Lumbar Fusion