Editorial Commentary: Is It Time for the Vancomycin Wrap to Become a Universal Recommendation for the Prevention of Septic Arthritis Following Anterior Cruciate Ligament Reconstruction?

Vancomycin Graft Presoaking in Anterior Cruciate Ligament Reconstruction Surgery Is Associated with a Lower Risk of Graft Rerupture as Compared With No Vancomycin Presoaking: Systematic Review and Meta-analysis

BACKGROUND

To determine whether there is any difference in graft rerupture rates and clinical outcomes between cases having vancomycin graft presoaking vs. no vancomycin presoaking in anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

Systematic review and meta-analysis. PubMed, Embase, CINAHL, and Cochrane CENTRAL were searched. Full published studies reporting on the relation between vancomycin graft presoaking and rates of graft rerupture and/or clinical outcomes in ACLR surgery vs. no vancomycin graft presoaking were included. Data extraction and quality appraisal were performed. Meta-analysis was conducted using a random effects model. The study's protocol was prospectively registered with PROSPERO (CRD42021290608).

RESULTS

The literature search identified 907 records. After removing duplicates and those not meeting inclusion criteria, 8 studies were included. Meta-analysis showed that the estimated risk of hamstring graft rerupture was lower in cases presoaked with vancomycin vs. those having no presoaking (3.2% vs. 6.2% rerupture rate, risk ratio [RR] = 0.507, 95% CI, 0.39-0.737, p < 0.001). Similarly, the estimated risk of graft rerupture was lower in cases presoaked with vancomycin vs. those having no presoaking when the analysis included various ACL graft types (2.7% vs. 3.9% rerupture rate, RR = 0.557, 95% confidence interval [CI], 0.403-0.771, p < 0.001). Meta-analysis also showed that vancomycin graft presoaking was associated with similar International Knee Documentation Committee scores as compared with no presoaking when looking at hamstring grafts (estimated mean difference 0.112, 95% CI, -2.359 to 2.582, p = 0.929) or when considering various graft types (estimated mean difference 0.933, 95% CI, -0.140 to 2.006, p = 0.088).

CONCLUSION

Vancomycin graft presoaking is a safe practice and does not compromise ACL graft rerupture rates or clinical outcomes.

LEVEL OF EVIDENCE

Level IV. See Instructions for Authors for a complete description of levels of evidence.

Semitendinosus tendons are commonly contaminated with skin flora during graft harvest for anterior cruciate ligament reconstruction

PURPOSE

To investigate the rate of bacterial contamination of semitendinosus (ST) tendons during graft harvest in anterior cruciate ligament reconstruction (ACLR), in order to precisely specify the underlying pathogens and obtain data on their susceptibility to potential antibiotics.

METHODS

In a prospective study, a total of 59 consecutive patients undergoing primary ACLR were recruited from one centre. No patient had history of previous surgery to the knee or showed clinical signs of infection. Four tissue samples of harvested ST tendons for anterior cruciate ligament (ACL) autografts (case group; ST) were examined for evidence of bacterial colonisation and compared to four tissue samples of the native ACL as negative controls (control group; ACL). Three of the respective samples were subjected to cultural microbiological examination and one to 16S rRNA-PCR. Antibiotic susceptibility testing was performed for each pathogen that was identified.

RESULTS

A total of 342 samples were analysed by culture. Significantly more patients showed a positive culture of the ST (33.9%; n = 20/59) compared to 3.4% of patients (n = 2/59) with positive culturing of the ACL (p < 0.0001). Including 16S rRNA-PCR, in a total of 42.4% (25/59) of patients, bacteria were detected in at least one ST sample either by PCR and/or culture. All species found (n = 33) belong to the typical skin flora with Staphylococcus epidermidis (39.4%; n = 13/33) being the most common species, followed by Staphylococcus capitis (24.2%; n = 8/33). All tested isolates (n = 29) were susceptible to vancomycin (29/29, 100%), 69% (n = 20/29) to oxacillin and 65.5% (n = 19/29) to clindamycin.

CONCLUSION

ST autografts for ACLR were commonly contaminated with skin commensal bacteria during harvest. One-third of the isolates showed resistance to typical perioperative intravenous antibiotics, whereas all isolates were sensitive to vancomycin. Therefore, routine prophylactic decontamination of all hamstring autografts before implantation should be recommended, preferably with topical vancomycin.

LEVEL OF EVIDENCE

Level III.

In Vitro Study of Gentamicin Elution from Tendon Grafts

Background

Though vancomycin-soaked graft reduces the infection rate after ACL reconstruction, concerns exist regarding this usage. Gentamicin has been used for graft soakage with satisfactory clinical results but gentamicin's elution characteristics are unknown.

Methods

Thirty Bovine tendon grafts were harvested from ten limbs under sterile conditions. Three tendons from each of the limbs were allotted into three groups and soaked in either saline, gentamicin or vancomycin. Pre-soakage and post-soakage swabs were cultured. Soaked grafts were immersed in a 10 ml saline solution for 5 min (initial washout) and then in another 10 ml saline solution (sustained release) for 10 min. No 1 Whatman filter paper was immersed in the solutions and placed on culture plates streaked with coagulase-negative Staphylococcus aureus (CONS) and methicillin-resistant Staphylococcus aureus (MRSA), and inhibition was noted. The difference between the two proportions was assessed by two proportion t-test for p < 0.05.

Results

No organism was cultured in the pre-soakage or post-soakage swab in any specimen. Specimens from one limb were excluded since saline-soakage showed inhibition. Elution from gentamicin-soaked graft inhibited CONS in eight out of nine samples in initial washout and all samples in sustained release solution but inhibited MRSA only in one sample in sustained release solution and the initial washout solution. Vancomycin elution inhibited both organisms in all samples.

Conclusions

Gentamicin elution from tendon graft achieves minimal inhibitory concentration against susceptible organisms. Though its clinical utility is restricted by limited antimicrobial spectrum, and it could be used where the risk of contamination by MRSA is low.

A Review of Evidence for Infection Reduction With Vancomycin-treated Anterior Cruciate Ligament Grafts

Septic arthritis after anterior cruciate ligament (ACL) reconstruction is a rare but devastating complication. Several risk factors and known sources of infection have been identified in the literature. There is growing interest and supportive evidence for a targeted invention aimed at graft decontamination, which has led some surgeons to adopt the use of antibiotic solution soaks and/or wraps applied to ACL grafts before graft implantation in an attempt to reduce the risk of postoperative infection. Despite this, adoption of this technique remains relatively low among surgeons because of a variety of factors: (1) lack of awareness, (2) confusion over optimal protocols, (3) concern for graft viability and clinical outcomes, and (4) efforts to minimize the cost of surgery. However, recently published literature demonstrates notable risk reduction for infection, acceptable safety, no detrimental effect on clinical outcomes, and overall cost-effectiveness with the use of vancomycin graft soaks and wraps. Currently, there is a lack of consensus for clinical protocols, and the protocol that is most efficacious remains unclear. The purpose of this review article was to present the current evidence for ACL graft treatment with vancomycin for the prevention of postoperative infection.

The role of vancomycin-soaking of the graft in anterior cruciate ligament reconstruction

Approximately 1% of anterior cruciate ligament reconstruction (ACLR) procedures develop septic arthritis despite intravenous antibiotic prophylaxis and other preventive measures. Infection is most commonly due to contamination during autograft harvest and preparation by introducing bacteria into the knee during graft insertion. Pre-soaking ACL grafts in 5 mg/mL vancomycin ("vancomycin wrap") has been utilised to eradicate such bacterial contamination. Many level III studies have reported a marked decrease in infection rates with no increase in graft failure rates. However, the lack of prospective randomised control trials and these studies' heterogeneity do not allow a universal recommendation for vancomycin pre-soaking of all grafts during ACLR. Randomised controlled trials are needed to confirm efficacy in reducing sepsis rates.

Vancomycin Soaking Is Highly Cost-Effective in Primary ACLR Infection Prevention: A Cost-Effectiveness Study

BACKGROUND

Although presoaking grafts in vancomycin has been demonstrated to be effective in observational studies for anterior cruciate ligament reconstruction (ACLR) infection prevention, the economic benefit of the technique is uncertain.

PURPOSE

To 1) determine the cost-effectiveness of vancomycin presoaking during primary ACLR to prevent postoperative joint infections and 2) to establish the break-even cost-effectiveness threshold of the technique and determine its cost-effectiveness across various international health care settings.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

A Markov model was used to determine cost-effectiveness and the incremental cost-effectiveness ratio of additional vancomycin presoaking compared with intravenous antibiotic prophylaxis alone. A repeated search of the PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials databases, using the same criteria as a recent meta-analysis, was completed. A repeated meta-analysis of 9 cohort studies (level 3 evidence) was completed to determine the odds ratio of infection with vancomycin presoaking compared with intravenous antibiotics alone. Estimated costs of the vancomycin technique, treatment of infection, and further surgery were sourced from local hospitals and literature. Transitional probabilities for further surgery, including revision reconstruction and primary arthroplasty, were obtained from the literature. Probabilistic sensitivity analyses and a 1-way sensitivity analysis were performed to evaluate the ACLR infection rate break-even threshold for which the vancomycin technique would be no longer cost-effective.

RESULTS

The vancomycin soaking technique provides expected cost savings of $660 (USA), A$581 (Australia), and €226 (Spain) per patient. There was an improvement in the quality-adjusted life-years of 0.007 compared with intravenous antibiotic prophylaxis alone (4.297 vs 4.290). If the infection rate is below 0.014% with intravenous antibiotics alone, the vancomycin wrap would no longer be cost-effective.

CONCLUSION

The vancomycin presoaking technique is a highly cost-effective method to prevent postoperative septic arthritis after primary ACLR.

Presoaking ACL Grafts in Vancomycin Decreases the Frequency of Postoperative Septic Arthritis: A Cohort Study of 29,659 Patients, Systematic Review, and Meta-analysis From the SANTI Study Group

Background:

Presoaking anterior cruciate ligament (ACL) grafts in vancomycin has been reported to reduce the occurrence of septic arthritis (SA). However, strong recommendations for its universal use have been precluded by concerns regarding the fragility of previous meta-analyses.

Purpose:

The primary objective was to investigate whether presoaking ACL grafts in vancomycin was associated with a reduction in the rate of SA in a large series of patients. The secondary objective was to perform an updated systematic review and meta-analysis to determine the efficacy of vancomycin in reducing the rate of SA.

Study Design:

Cohort study and systematic review; Level of evidence, 3.

Methods:

A retrospective analysis of patients who underwent primary ACL reconstruction (ACLR) at our institution was undertaken. Rates of postoperative SA were determined and analyzed according to whether patients had received grafts presoaked in vancomycin. A systematic review of the literature and meta-analysis was performed. Odds ratios (ORs) for the risk of SA were calculated according to the inverse variance approach. Results were presented using forest plots, funnel plots, and the fragility index.

Results:

A total of 5300 patients underwent primary ACLR during the study period. The rate of SA was 0.34% (11/3228) in the control group and 0.05% (1/2072) in the presoaked group. There was a 5-fold greater risk of SA in patients who did not receive grafts presoaked in vancomycin (OR, 5.13 [95% CI, 1.16-48.30]; P = .04). Overall, 11 studies were included in the systematic review (29,659 ACLR procedures). The meta-analysis demonstrated a significantly greater risk of SA in those patients who did not receive grafts presoaked in vancomycin (OR, 14.39 [95% CI, 5.90-35.10]; fragility index = 23). This finding held true for the subpopulation receiving hamstring tendon grafts (fragility index = 16), but only a trend was demonstrated for bone–patellar tendon–bone grafts.

Conclusion:

The meta-analysis demonstrated that presoaking ACL grafts in vancomycin was associated with significant reductions in the rates of SA when all graft types were analyzed together. This finding held true specifically for hamstring tendon autografts. The fragility index of these findings allows for a strong recommendation for the universal use of vancomycin presoaking. However, it should be noted that only a trend toward reduced SA rates was demonstrated with presoaking bone–patellar tendon–bone autografts in vancomycin.