The Statistical Fragility of Single-Bundle vs Double-Bundle Autografts for ACL Reconstruction: A Systematic Review of Comparative Studies

Background: The statistical significance of a given study outcome can be liable to small changes in findings. P values are common, but imperfect statistical methods to convey significance, and inclusion of the fragility index (FI) and fragility quotient (FQ) may provide a clearer perception of statistical strength. Purpose/Hypothesis: The purpose was to examine the statistical stability of studies comparing primary single-bundle to double-bundle anterior cruciate ligament reconstruction (ACLR) utilizing autograft and independent tunnel drilling. It was hypothesized that the study findings would be vulnerable to a small number of outcome event reversals, often less than the number of patients lost to follow-up. Study Design: Systematic review; Level of evidence, 2. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors searched PubMed for comparative studies and randomized controlled trials (RCTs) published in select journals, based on impact factor, between 2005 and 2020. Risk-of-bias assessment and methodology scoring were conducted for the included studies. A total of 48 dichotomous outcome measures were examined for possible event reversals. The FI for each outcome was determined by the number of event reversals necessary to alter significance. The FQ was calculated by dividing the FI by the respective sample size. Results: Of the 1794 studies screened, 15 comparative studies were included for analysis; 13 studies were RCTs. Overall, the mean FI and FQ were 3.14 (IQR, 2-4) and 0.050 (IQR, 0.032-0.062), respectively. For 72.9% of outcomes, the FI was less than the number of patients lost to follow-up. Conclusion: Studies comparing single-bundle versus double-bundle ACLR may not be as statistically stable as previously thought. Comparative studies and RCTs are at substantial risk for statistical fragility, with few event reversals required to alter significance. The reversal of fewer than 4 outcome events in a treatment group can alter the statistical significance of a given result; this is commonly less than the number of patients lost to follow-up. Future comparative study analyses might consider including FI and FQ with P values in their statistical analysis.

Pain Following Single-bundle versus Double-bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review

BACKGROUND: Double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) has been known to result in better functional outcomes, joint stability, and lower revision rates compared to single-bundle (SB) ACLR. However, given the increased invasiveness and damage to the surrounding tissue area, it is proposed that it may be associated with increased pain. AIM: This review aims to gather all studies and literature that reported pain as an outcome when comparing SB versus DB ACLR. METHODS: Literature searching was conducted across seven search engines for studies reporting pain as an outcome and comparing SB versus DB ACLR. RESULTS: Eight studies met the eligibility criteria and were included in the study. Overall, the studies show variable findings regarding pain in DB compared to SB ACLR, with the only statistically significant results from two studies indicating that DB ACLR is associated with more pain than SB ACLR. CONCLUSION: Based on the limited evidence available, no conclusions can be made regarding the pain experienced between people receiving either procedure. This constitutes a need for additional studies with increased follow-up time periods, larger sample size, and better study design.

Dual antibiotic prevention bundle is associated with decreased surgical site infections

BackgroundGynecologic oncology surgery is associated with a wide variation in surgical site infection risk. The optimal method for infection prevention in this heterogeneous population remains uncertain.Study DesignA retrospective cohort study was performed to compare surgical site infection rates for patients undergoing hysterectomy over a 1-year period surrounding the implementation of an institutional infection prevention bundle. The bundle comprised pre-operative, intra-operative, and post-operative interventions including a dual-agent antibiotic surgical prophylaxis with cefazolin and metronidazole. Cohorts consisted of patients undergoing surgery during the 6 months prior to this intervention (pre-bundle) versus those undergoing surgery during the 6 months following the intervention (post-bundle). Secondary outcomes included length of stay, readmission rates, compliance measures, and infection microbiology. Data were compared with pre-specified one-sided exact test, Chi-square test, Fisher’s exact test, or Kruskal–Wallis test as appropriate.ResultsA total of 358 patients were included (178 PRE, 180 POST). Median age was 58 (range 23–90) years. The post-bundle cohort had a 58% reduction in surgical site infection rate, 3.3% POST vs 7.9% PRE (−4.5%, 95% CI −9.3% to −0.2%, p=0.049) as well as reductions in organ space infection, 0.6% POST vs 4.5% PRE (−3.9%, 95% CI −7.2% to −0.7%, p=0.019), and readmission rates, 2.2% POST vs 6.7% PRE (−4.5%, 95% CI −8.7% to −0.2%, p=0.04). Gram-positive, Gram-negative, and anaerobic bacteria were all prevalent in surgical site infection cultures. There were no monomicrobial infections in post-cohort cultures (0% POST vs 58% PRE, p=0.04). No infections contained methicillin-resistant Staphylococcus aureus.ConclusionImplementation of a dual antibiotic infection prevention bundle was associated with a 58% reduction in surgical site infection rate after hysterectomy in a surgically diverse gynecologic oncology practice.