Intrawound application of vancomycin for prophylaxis in instrumented thoracolumbar fusions: efficacy, drug levels, and patient outcomes

A microbiology study on the wounds of pediatric patients undergoing spinal fusion for scoliosis

PURPOSE

Surgical site infection is a significant complication in posterior spinal fusion for scoliosis in pediatric and adolescent patients. Current literature demonstrates a lack of consensus regarding best prophylactic systemic and topical antibiotic regimens for reducing infection rates. This study aims to identify which common microbes are present at particular locations in the spine, and whether these are covered by our current systemic and topical antibiotic prophylaxis regimens.

METHODS

A prospective observational study at a National Children's Hospital was conducted on 21 consecutive patients who underwent elective surgery for spinal deformity. Swabs were taken from four layers of the spine, including the superficial skin surface at the start of the case (after surgical site preparation with povidone-iodine), the deep dermis, and the deep surgical bed at the end of exposure and again after the corrective maneuver prior to closure. At each layer, swabs were taken from the proximal, middle, and distal portion of the wound. Swabs were sent to the laboratory for culture and susceptibility testing.

RESULTS

Thirteen (62%) of patients had positive microbial growth. Two microbes were identified, Staphylococcus epidermidis (9.5% of patients) and Cutibacterium acnes (Propionibacterium acnes) (52% of patients). 100% of these microbes were sensitive to cefazolin and vancomycin. 3% of patients had positive growth at the skin layer, 32% positive at the dermal layer, 17% positive after exposure, and 40% positive at the conclusion of the case (p = 0.006). No difference was observed in microbial presence in the upper thoracic, lower thoracic and lumbar spine.

CONCLUSION

Despite adequate surgical site preparation and sterile procedure, microbial contamination remains abundant in the dermal layer and deeper in the spinal wound throughout the case.

Use of prophylactic perioperative antibiotics for lumbar spinal fusions: A nationwide population-based cohort study

BACKGROUND

Perioperative prophylactic antibiotic (PPA) use in spine surgery is known to reduce the rate of surgical site infections. In the past decade, several evidence-based guidelines have been published and surveillance systems to monitor the proper use of antimicrobials had been adapted by many institutes.

OBJECTIVE

To report the trends of PPA prescription in lumbar fusion surgeries nationwide in the Republic of Korea.

METHODS

This is a nationwide registry study. Using the population-based data from the Republic of Korea provided by the Korean Health Insurance Review and Assessment Service, data of all lumbar spinal fusion surgeries performed between 2010 and 2018 in adult patients (age ≥19 years) were reviewed.

RESULTS

The most frequently used antibiotics were first-generation cephalosporins, which accounted for 38.2 % of total PPA prescriptions and were prescribed in 58.96 % of lumbar fusion surgeries. A gradual increase in prescription trends was observed. The second most frequently used PPAs were second-generation cephalosporins, which showed decrease in use from 2016. The frequency of vancomycin prescriptions gradually increased over the observation period and showed an almost four-fold increase in 2018 compared to 2010. First- and second-generation cephalosporins were prescribed less frequently to patients with renal disease.

CONCLUSION

The pattern of PPA use has changed remarkably over the observation period. Furthermore, specific differences in PPA prescriptions were observed among patients with certain co-morbidities.

Efficacy and safety of intrawound antibiotics in patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis: a nationwide database study

PURPOSE

To assess the efficacy and safety of intrawound antibiotics in posterior fusions for adolescent idiopathic scoliosis (AIS).

METHODS

The NSQIP-Pediatric databases 2016-2018 were utilized. Patients 10 years of age or older with AIS who underwent posterior fusion were selected and divided into two cohorts based on the receipt of intrawound antibiotics. Patient characteristics and complications were compared. Multivariate analyses were performed to determine the efficacy and safety of intrawound antibiotics.

RESULTS

A total of 4203 patients received intrawound antibiotics while 879 patients did not. The intrawound antibiotic group had longer constructs, higher blood loss, and longer operative times, factors historically associated with higher infection rates. Those that received intrawound antibiotics had SSI rate of 0.69%, while its counterpart had 0.57% (p = 0.689). The reoperation rates were 1.12% and 1.25% (p = 0.735), for those with and without intrawound antibiotics, respectively. In multivariate analyses, intrawound antibiotics use was not found to be a significant predictor for SSI, any complications, reoperation and readmission.

CONCLUSION

The current study represents the largest AIS surgery cohort studied to evaluate the efficacy of intrawound antibiotics. Our analysis failed to demonstrate association between the use of intrawound antibiotics and reduction in SSI. While other studies have reported seroma, wound dehiscence and renal failure with the practice, we did not observe an increased rate of such complications. This study highlights the difficulty of understanding the role for individual infection prevention measures in current surgical settings, where the SSI rate for the control group was substantially lower than 1%.

Local administration of vancomycin powder in orthopaedic fracture surgery: current practice and trends

Objectives

Surgical site infections in orthopaedic trauma are a significant problem with meaningful patient and health care system-level consequences. Direct application of antibiotics to the surgical field has many potential benefits in reducing surgical site infections. However, to date, the data regarding the local administration of antibiotics have been mixed. This study reports on the variability of prophylactic vancomycin powder use in orthopaedic trauma cases across 28 centers.

Methods

Intrawound topical antibiotic powder use was prospectively collected within three multicenter fracture fixation trials. Fracture location, Gustilo classification, recruiting center, and surgeon information were collected. Differences in practice patterns across recruiting center and injury characteristics were tested using chi-square statistic and logistic regression. Additional stratified analyses by recruiting center and individual surgeon were performed.

Results

A total of 4941 fractures were treated, and vancomycin powder was used in 1547 patients (31%) overall. Local administration of vancomycin powder was more frequent in open fractures 38.8% (738/1901) compared with closed fractures 26.6% (809/3040) (P < 0.001). However, the severity of the open fracture type did not affect the rate at which vancomycin powder was used (P = 0.11). Vancomycin powder use varied substantially across the clinical sites (P < 0.001). At the surgeon level, 75.0% used vancomycin powder in less than one-quarter of their cases.

Conclusions

Prophylactic intrawound vancomycin powder remains controversial with varied support throughout the literature. This study demonstrates wide variability in its use across institutions, fracture types, and surgeons. This study highlights the opportunity for increased practice standardization for infection prophylaxis interventions.

Level of Evidence

Prognostic-III.

Does the Microflora of Surgery Site Infection Change After Prophylactic Use of Vancomycin Powder in the Spine Surgery

Study Design

Retrospective cohort study.

Objective

This study aimed to investigate the characteristics of microflora in patients with deep spinal surgical site infection (SSI) after prophylactic use of vancomycin powder (VP).

Methods

A retrospective analysis was performed on patients after spinal surgery. Patients were grouped according to whether VP use and only patients with deep SSI were included in this study. General information of the patients, the dose of vancomycin, bacterial culture results, drug sensitivity test results, and SSI treatment methods were recorded. The differences of microflora between the two groups were analyzed, and the sensitivity of bacteria in the +VP group to antibiotics was analyzed.

Results

The infection rate in the +VP group was 4.9% (56/1124) vs 6.3% (93/1476) in the No-VP group (P < 0.05). The proportion of Gram-positive bacteria (GPB) in the +VP SSIs was 55.4% vs.74.1% in the No-VP group (P < 0.05). The percentage of Gram-negative bacteria (GNB) in the +VP SSIs was 46.4% vs.30.1% in the No-VP group (P < 0.05). More dose of VP cannot decrease the SSI, but the proportion of GNB in VP >1g SSIs was higher (59.0% vs 32.4%, P < 0.05). In the +VP SSIs, all of the GNB cultured were sensitive to meropenem, and linezolid covered most of the GPB cultured.

Conclusion

Local use of vancomycin powder can reduce the incidence of SSI, but this may lead to changes in the bacterial flora. Once the SSI occurs, the case of GNB infection may be increased. The more dose of VP cannot decrease SSI but may increase the rate of GNB in the +VP SSIs. Once infections still occur after VP use, antibiotics covering GNB may be added. These findings may help guide choice of empiric antibiotics while awaiting culture data.

Effects of different doses of vancomycin powder in total knee and hip arthroplasty on the periprosthetic joint infection rate: a systematic review and meta-analysis

BACKGROUND

Periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) is a serious complication for patients. Some joint surgeons have tried to use vancomycin powder (VP) in total knee and total hip arthroplasty to prevent postoperative PJI, but its effect is still not clear. At present, there is no meta-analysis that specifically analyses the effect of different doses of vancomycin powder on the incidence of PJI.

METHODS

We carried out a search based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and identified the studies we needed. Review Manager (RevMan) 5.3 software was employed for statistical analysis.

RESULTS

The analysis of primary TKA (PTKA) showed that using 1 g (RR 0.38, 95% CI 0.22-0.67 [P = 0.0008]) and 2 g (RR 0.48, 95% CI 0.31-0.74 [P = 0.0008]) of vancomycin powder in primary TKA (PTKA) could all significantly prevent PJI. The analysis of primary THA (PTHA) showed that using 1 g (RR 0.37, 95% CI 0.17-0.80 [P = 0.01]) of vancomycin powder effectively decreased the incidence of PJI, while using 2 g (RR 1.02, 95% CI 0.53-1.97 [P = 0.94]) of vancomycin powder had no significant effect on preventing PJI. Because the data were abnormal, we believed the conclusion that using 2 g of vancomycin powder in primary THA had no effect on preventing PJI was doubtful. Using vancomycin powder in revision TKA (RTKA) significantly reduced the PJI rate (RR 0.33, 95% CI 0.14-0.77 [P = 0.01]), similar to revision THA (RTHA) (RR 0.37, 95% CI 0.14-0.96 [P = 0.04]).

CONCLUSIONS

In primary TKA, both 1 g and 2 g of vancomycin powder can effectively prevent PJI. In primary THA, using 1 g of vancomycin powder is a better choice, while the effect of using 2 g of vancomycin powder is not clear, and a more prospective randomized controlled trial should be done to verify it. In revision TKA and revision THA, vancomycin powder is a good choice to prevent PJI.

Does prophylactic local tobramycin injection lower open fracture infection rates?

Objective: To determine whether local aqueous tobramycin injection in combination with systemic perioperative IV antibiotic prophylaxis will reduce the rate of fracture-related infection (FRI) after open fracture fixation. Other Outcomes of Interest: (1) To compare fracture nonunion rates and report differences between treatment and control groups and (2) compare bacterial speciation and antibiotic sensitivity among groups that develop FRI. Design: Phase 3 prospective, randomized clinical trial. Setting: Two level 1 trauma centers. Participants: Six hundred subjects (300 in study/tobramycin group and 300 in control/standard practice group) will be enrolled and assigned to the study group or control group using a randomization table. Patients with open extremity fractures that receive definitive internal surgical fixation will be considered. Intervention: Aqueous local tobramycin will be injected into the wound cavity (down to bone) after debridement, irrigation, and fixation, following closure. Main Outcome Measurements: Outcomes will look at the presence or absence of FRI, the rate of fracture nonunion, and determine speciation of gram-negative and Staph bacteria in each group with a FRI. Results: Not applicable. Conclusion: The proposed work will determine whether local tobramycin delivery plus perioperative standard antibiotic synergism will minimize the occurrence of open extremity FRI. Level of Evidence: Level 1.

Strategies to improve bioactive and antibacterial properties of polyetheretherketone (PEEK) for use as orthopedic implants

Polyetheretherketone (PEEK) has gradually become the mainstream material for preparing orthopedic implants due to its similar elastic modulus to human bone, high strength, excellent wear resistance, radiolucency, and biocompatibility. Since the 1990s, PEEK has increasingly been used in orthopedics. Yet, the widespread application of PEEK is limited by its bio-inertness, hydrophobicity, and susceptibility to microbial infections. Further enhancing the osteogenic properties of PEEK-based implants remains a difficult task. This article reviews some modification methods of PEEK in the last five years, including surface modification of PEEK or incorporating materials into the PEEK matrix. For surface modification, PEEK can be modified by chemical treatment, physical treatment, or surface coating with bioactive substances. For PEEK composite material, adding bioactive filler into PEEK through the melting blending method or 3D printing technology can increase the biological activity of PEEK. In addition, some modification methods such as sulfonation treatment of PEEK or grafting antibacterial substances on PEEK can enhance the antibacterial performance of PEEK. These strategies aim to improve the bioactive and antibacterial properties of the modified PEEK. The researchers believe that these modifications could provide valuable guidance on the future design of PEEK orthopedic implants.

Does the use of intrawound povidone-iodine irrigation and local vancomycin powder impact surgical site infection rate in adolescent idiopathic scoliosis surgery?

PURPOSE

Surgical site infection (SSI) is a major complication after adolescent idiopathic scoliosis (AIS) surgery, with an incidence ranging from 0.5 to 7%. Intraoperative wound decontamination with povidone-iodine (PVP-I) irrigation and/or vancomycin powder in adult spinal surgery has gained attention in the literature with controversial results. The aim of this study was to investigate the impact of using intrawound PVP-I irrigation and local vancomycin powder (LVP) on the incidence of early SSI in AIS surgery.

METHODS

All AIS patients who underwent posterior spinal fusion between October 2016 and December 2019 were retrospectively reviewed. The incidence of early SSI was reported and compared between 2 groups defined by the treating spinal surgeons' preferences: group 1-intrawound irrigation with 2L of PVP-I and application of 3 g LVP before closure and control group 2-patients that did not receive either of these measures.

RESULTS

Nine early cases of SSI (2.9%) were reported among the 307 AIS posterior spinal fusion patients. Incidence of SSI in group 1 (2/178 = 1.1%) was significantly lower than in group 2 (7/129 = 5.4%; p = 0.04). There were no adverse reactions to the use of PVP-I and LVP in our study. At latest follow-up, rate of surgical revision for mechanical failure with pseudarthrosis was significantly lower in group 1 (2/178 = 1.1%) than in group 2 (9/129 = 7.0%; p = 0.01).

CONCLUSION

Intraoperative use of intrawound PVP-I irrigation and vancomycin powder is associated with a significant reduction of early SSI after AIS spine surgery.

LEVEL OF EVIDENCE IV

Retrospective study.

Is Vancomycin More Effective than Taurolidine? Comparative Analysis of Their Preventive Effect against Spinal Infection in 1000 Patients with Spinal Fusion

This study aimed to examine the effect of taurolidine irrigation on preventing surgical site infection by comparing the spinal infection rate after spinal fusion surgery using vancomycin powder application and taurolidine irrigation. Of 1081 participants, 369 underwent taurolidine irrigation, 221 underwent vancomycin powder application, and 491 were controls. Of the 20 surgical site infections (1.85%), 14 occurred in the control group (2.85%), 5 in the vancomycin group (2.26%), and 1 (0.27%) in the taurolidine group. Among the various variables, age at the time of surgery, smoking, surgical site, and hemovac removal time were significant in the univariate logistic regression. The final result was derived after variable selection using the stepwise method. In the univariate model, the odds ratios were 0.09 and 0.79 in each of the vancomycin and taurolidine groups compared to that of the control group. In the multivariate model, the odds ratios were 0.09 and 0.83 in each of the vancomycin and taurolidine groups compared to that of the control group. The preventive effect of vancomycin powder application was not statistically significant. However, the vancomycin group showed a less effective tendency than the taurolidine group. Taurolidine irrigation may be a good substitute for the vancomycin powder application.

Ex Vivo Toxicity of Commonly Used Topical Antiseptics and Antibiotics on Human Chondrocytes

Topical povidone-iodine, chlorhexidine, bacitracin, and vancomycin are commonly used antiseptic and antimicrobial agents to reduce risk and treat surgical site infections in numerous orthopedic procedures. Chondrocytes potentially may be exposed to these agents during operative procedures. The impact of these topical agents on chondrocyte viability is unclear. The goal of this study is to determine human chondrocyte viability ex vivo after exposure to commonly used concentrations of these topical antiseptic and antimicrobial agents. Human osteochondral plugs were harvested from the knee joint of a human decedent within 36 hours of death. Individual human osteochondral plugs were exposed to normal saline as a control; a range of concentrations of povidone-iodine (0.25%, 0.5%, and 1%), chlorhexidine (0.01% and 0.5%), and bacitracin (10,000 units/L, 50,000 units/L, and 100,000 units/L) for 1-minute lavage; or a 48-hour soak in vancomycin (0.16 mg/mL, 0.4 mg/mL, and 1.0 mg/mL) with nutrient media. Chondrocyte viability was evaluated with a live/dead viability assay at 0, 2, 4, and 6 days after exposure to bacitracin at 0, 3, and 6 days). Control subjects showed greater than 70% viability at all time points. Povidone-iodine, 0.5% chlorhexidine, and vancomycin showed significant cytotoxicity, with viability dropping to less than 40% by day 6. Chondrocytes exposed to 0.01% chlorhexidine maintained viability. Chondrocytes exposed to bacitracin showed viability until day 3, when there was a large drop in viability. Commonly used topical concentrations of povidone-iodine, vancomycin, and bacitracin are toxic to human chondrocytes ex vivo. A low concentration of chlorhexidine appears safe. Caution should be used when articular cartilage may be exposed to these agents during surgery. [Orthopedics. 2022;45(5):e263-e268.].

Prophylactic treatment of breast implants with a solution of gentamicin, vancomycin and cefazolin antibiotics for women undergoing breast reconstructive surgery: protocol for a randomised, double-blind, placebo-controlled trial (The BREAST-AB trial)

INTRODUCTION

Periprosthetic infection is one of the most severe complications following implant-based breast reconstruction affecting 5%-10% of the women. Currently, many surgeons apply antibiotics locally on the breast implant to reduce the risk of postoperative infection, but no randomised, placebo-controlled trials have tested the treatment's efficacy.

METHODS AND ANALYSIS

The BREAST-AB trial (BREAST-AntiBiotics) is an investigator-initiated, multicentre, randomised, placebo-controlled, double-blind trial of local treatment with gentamicin, vancomycin and cefazolin on breast implants in women undergoing implant-based breast reconstruction. The trial drug consists of 80 mg gentamicin, 1 g vancomycin and 1 g cefazolin dissolved in 500 mL of isotonic saline. The placebo solution consists of 500 mL isotonic saline. The trial drug is used to wash the dissected tissue pocket and the breast implant prior to insertion. The primary outcome is all-cause explantation of the breast implant within 180 days after the breast reconstruction surgery. This excludes cases where the implant is replaced with a new permanent implant, for example, for cosmetic reasons. Key long-term outcomes include capsular contracture and quality of life. The trial started on 26 January 2021 and is currently recruiting.

ETHICS AND DISSEMINATION

The trial was approved by the Regional Ethics Committee of the Capital Region (H-20056592) on 1 January 2021 and the Danish Medicines Agency (2020070016) on 2 August 2020. The main paper will include the primary and secondary outcomes and will be submitted to an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04731025.

Does local vancomycin powder impregnated with autogenous bone graft and bone substitute decrease the risk of deep surgical site infection in degenerative lumbar spine fusion surgery?—An ambispective study

Background

Deep surgical site infection (DSSI) is one of the most challenging complications in lumbar fusion surgery. Few investigations examined the effect of vancomycin powder mixed with autogenic bone graft (ABG) and bone substitutes on preventing DSSI in degenerative lumbar fusion surgeries as well as any interference with bony fusion. The aim of the study was to investigate the effects of ABG along with bone substitutes as a local vancomycin delivery system on preventing DSSI in lumbar instrumented fusion and compared with those who did not use vancomycin powder.

Methods

From January, 2015 through December, 2015, a one-year prospective study using vancomycin powder mixed with ABG and bone substitute for degenerative lumbar fusion surgeries as vancomycin (V) group, 1 gm vancomycin for 2 and 3-level, and 2 gm for more than 3-level instrumentation. From December, 2013 through December 2014, patients received degenerative lumbar fusion surgeries without using vancomycin before the vancomycin protocol were retrospectively enrolled as non-vancomycin (NV) group. Vancomycin concentration was checked at post-operative days 1 and 3 for both the serum and drainage. Patients’ demographic data, microbiology reports, fusion status and functional outcomes were evaluated.

Results

One hundred and ten patients were enrolled prospectively in the V group, and 86 for the NV group. After an average 41 months follow-up (range, 36–54), 3 patients (3.48%) developed postoperative DSSIs in the NV group, thereby requiring revision surgeries and parenteral antibiotics treatment versus no DSSIs (0%, 0/100) in the V group. (p = 0.048). The postoperative serum vancomycin levels were undetectable and no vancomycin related side effects was encountered. The mean vancomycin concentration of drainage at postoperative days 1 and 3 were 517.96 ± 174.4 and 220.14 ± 102.3 μg/mL, respectively. At final follow-up, there was no statistical difference observed in terms of clinical and radiologic outcomes.

Conclusions

Our vancomycin protocol may reduce the incidence of DSSI in degenerative lumbar fusion surgery without affecting bony fusion.

Level of Evidence

Level III ambispective comparative study.

Prophylactic Intrawound Vancomycin Powder in Minimally Invasive Spine Stabilization May Cause an Acute Inflammatory Response

Introduction

Surgical site infections (SSIs) with methicillin-resistant Staphylococcus aureus are serious complications of spinal instrumentation surgery. Many spine surgeons are concerned that using prophylactic vancomycin powder will lead to certain risks: the development of multidrug-resistant pathogens, anaphylactic reactions, and organ toxicity. Minimally invasive spine stabilization (MISt) is associated with shorter operation times and less blood loss and may therefore require the use of less vancomycin powder, which may reduce these risks. This retrospective comparative study of patients who underwent MISt at a single institution aimed to evaluate the complications (such as allergy, SSIs, and organ toxicity) and the local and serum levels associated with using prophylactic intrawound vancomycin powder compared with IV cefazolin alone.

Methods

Thirty-four patients received intrawound vancomycin powder (1 g) applied during wound closure in minimally invasive posterior lumbar interbody fusion (MIS-PLIF). This group was compared with 133 control patients who did not receive vancomycin. White blood cell counts and C-reactive protein (CRP) levels were measured for both groups on postoperative days (PODs) 1, 3, and 7 and were statistically analyzed. In the vancomycin group, serum vancomycin levels were measured on PODs 1, 3, 7, and 14; drain vancomycin levels and postoperative blood loss were determined on PODs 1 and 2.

Results

The CRP levels on PODs 1 and 3 were significantly higher in the vancomycin group than in the control group (P<0.001, P=0.024). In the vancomycin group, mean drain levels trended downward from 313 μg/mL (POD 1) to 155 μg/mL (POD 2). These levels correlated negatively with drain drainage volume on both days (POD 1: r=-0.48, P=0.015; POD 2: r=-0.47, P=0.019). Mean serum vancomycin levels also trended downward from 2.3 μg/mL (POD 1) to 1.7 μg/mL (POD 14).

Conclusions

Our results unexpectedly demonstrated that the local application of vancomycin powder causes an acute inflammatory response and the long-term detection of low serum vancomycin levels. Less than 1 g of intrawound vancomycin powder may be useful only at high risk of SSI.

Clinical Outcomes at One-year Follow-up for Patients With Surgical Site Infection After Spinal Fusion

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To compare health-related quality of life outcomes at one-year follow-up between patients who did and did not develop surgical site infection (SSI) after thoracolumbar spinal fusion.

SUMMARY OF BACKGROUND DATA

SSI is among the most common healthcare-associated complications. As healthcare systems increasingly emphasize the value of delivered care, there is an increased need to understand the clinical impact of SSIs.

MATERIALS AND METHODS

A retrospective 3:1 (control:SSI) propensity-matched case-control study was conducted for adult patients who underwent thoracolumbar fusion from March 2014 to January 2020 at a single academic institution. Exclusion criteria included less than 18 years of age, incomplete preoperative and one-year postoperative patient-reported outcome measures, and revision surgery. Continuous and categorical data were compared via independent t tests and χ 2 tests, respectively. Intragroup analysis was performed using paired t tests. Regression analysis for ∆ patient-reported outcome measures (postoperative minus preoperative scores) controlled for demographics. The α was set at 0.05.

RESULTS

A total of 140 patients (105 control, 35 SSI) were included in final analysis. The infections group had a higher rate of readmission (100% vs. 0.95%, P <0.001) and revision surgery (28.6% vs. 12.4%, P =0.048). Both groups improved significantly in Physical Component Score (control: P =0.013, SSI: P =0.039), Oswestry Disability Index (control: P <0.001, SSI: P =0.001), Visual Analog Scale (VAS) Back (both, P <0.001), and VAS Leg (control: P <0.001, SSI: P =0.030). Only the control group improved in Mental Component Score ( P <0.001 vs. SSI: P =0.228), but history of a SSI did not affect one-year improvement in ∆MCS-12 ( P =0.455) on regression analysis. VAS Leg improved significantly less in the infection group (-1.87 vs. -3.59, P =0.039), which was not significant after regression analysis (β=1.75, P =0.050).

CONCLUSION

Development of SSI after thoracolumbar fusion resulted in increased revision rates but did not influence patient improvement in one-year pain, functional disability, or physical and mental health status.

Systematic Review and Meta-Analysis of Intrawound Vancomycin in Total Hip and Total Knee Arthroplasty: A Continued Call for a Prospective Randomized Trial

BACKGROUND

Periprosthetic joint injection (PJI) is a rare, but life-altering complication of total joint arthroplasty (TJA). Though intrawound vancomycin powder (IVP) has been studied in other orthopedic subspecialties, its efficacy and safety in TJA has not been established.

METHODS

PubMed and MEDLINE databases were used to identify studies utilizing IVP in primary and revision total hip (THA) and knee arthroplasty (TKA). Postoperative PJI data were pooled using random effect models with results reported as odds ratios (ORs) and 95% confidence intervals (CIs). Studies were weighted by the inverse variance of their effect estimates.

RESULTS

Overall, 16 of the 1871 studies identified were pooled for final analysis, yielding 33,731 patients totally. Of these, 17 164 received IVP. In aggregate, patients who received IVP had a decreased rate of PJI (OR 0.46, P < .05). Separately, TKA and THA patients who received IVP had lower rates of PJI (OR 0.41, P < .05 and OR 0.45, P < .05, respectively). Aggregate analysis of primary TKA and THA patients also revealed a decreased PJI rate (OR 0.44, P < .05). Pooled revision TKA and THA patients had a similar decrease in PJI rates (OR 0.30, P < .05). Although no publication bias was appreciated, these findings are limited by the low-quality evidence available.

CONCLUSION

While IVP may reduce the risk of PJI in primary and revision TJA, its widespread use cannot be recommended until higher-quality data, such as that obtained from randomized control trials, are available. This study underscores the continued need for more rigorous studies before general adoption of this practice by arthroplasty surgeons.

Efficacy of Povidone Iodine Solution in the Prevention of Surgical Site Infections in Minimally Invasive Instrumented Spinal Fusion Surgery

STUDY DESIGN

A retrospective case-controlled study.

OBJECTIVES

To evaluate overall infection rate and adverse event after harvesting bone graft soaking and surgical wound irrigation by povidone iodine solution (PVI) in the minimally invasive instrumented spinal fusion surgery. In order to reduce the rate of surgical site infection in spinal surgery, surgical wound irrigation by povidone iodine solution has been well-established. However, the efficacy of autologous bone graft soaking by PVI has not been evaluated before.

METHODS

This is a retrospective cohort study. 120 patients were enrolled in the PVI group and compared with 124 patients in the historical cohort. In the PVI group, the harvesting autologous bone graft was soaking and the surgical wound was also irrigated by diluted PVI solution. The outcome measures were overall infection rate, superficial wound infection and deep infection. In addition, the delayed union of the fusion mass was also evaluated through the radiograph evaluation.

RESULTS

Both groups shared similar patient demographics instead of body mass index. The use of PVI solution had decreased the overall infection rate (0% versus 4.03%, p = 0.026) and deep infection rate (0% versus 3.23%, p = 0.047). In addition, there was no delayed bone healing in the PVI group after autologous bone graft soaking.

CONCLUSIONS

In this study, we conclude that harvested autologous bone graft after PVI soaking in spinal fusion surgery can decrease the incidence of deep infection.

Vancomycin Use in Posterior Lumbar Interbody Fusion of Deep Surgical Site Infection

Objective

To retrospectively analyze if the use of topical intraoperative vancomycin powder reduces deep surgical site infection (DSSI) after posterior lumbar interbody fusion.

Methods

All spinal surgeries for lumbar degenerative disease and underwent posterior fixation interbody fusion between January 2013 and December 2018 were reviewed. A total of 891 patients were included, of which 527 patients (treatment group) received intraoperatively topical vancomycin powder; the others were served as control group. The primary outcomes were the overall incidence of DSSI and the effect of vancomycin on its development. The secondary outcome was risk factors for DSSI. Data on the baseline characteristics, postoperative complications, perioperative risk factors, and one-year postoperative prognoses were extracted from the medical records.

Results

A total of 20 patients met the diagnostic criteria for DSSI (2.24%), of which 7 patients (1.33%) in the treatment group and 13 patients (3.57%) in the control group. There was a significant difference in the incidence of DSSI between the groups (P = 0.026). Multivariate logistic regression analysis with stepwise backward elimination showed that the local use of vancomycin powder was an independent protective factor for DSSI (odds ratio (OR): 0.25, P = 0.01), whereas high body mass index (BMI) (OR: 1.21, P = 0.005), drinking (OR: 5.19, P = 0.005), urinary tract infections (OR: 4.49, P = 0.021), diabetes mellitus (OR: 4.32, P = 0.03), and blood transfusions (OR: 3.67, P = 0.03) were independent risk factors for DSSI.

Conclusion

The intraoperative usage of vancomycin powder could reduce effectively decreases the incidence of DSSI after posterior lumbar interbody fusion for degenerative lumbar diseases. High BMI, diabetes mellitus, drinking, and urinary tract infections were independent risk factors for DSSI, whereas the local use of vancomycin protected against these factors.

Potential of Continuous Local Antibiotic Perfusion Therapy for Fracture-Related Infections

Introduction

Fracture-related infections (FRIs) are challenging for orthopedic surgeons, as conventional surgical treatment and systemic antimicrobial therapy cannot completely control local infections. Continuous local antibiotic perfusion (CLAP) is a novel and innovative therapy for bone and soft-tissue infections, and is expected to eradicate biofilms by maintaining a sustained high concentration of antimicrobial agents at the infected site. If CLAP therapy can eradicate infection even in cases with implants while preserving the implants, it would be an ideal and effective treatment for local refractory infections. This study aimed to evaluate the usefulness of novel CLAP therapy for FRIs.

Methods

Nine patients treated with CLAP therapy were retrospectively analyzed. The mean age was 65.9 (43–82) years, and the mean follow-up period was 14.9 (6–45) months. In all cases, the infected sites were related to the lower extremities (tibia, n = 6; fibula, n = 1; hip joint, n = 1; foot, n = 1). All patients underwent similar procedures for this therapy combined with negative-pressure wound therapy after thorough irrigation and debridement of infected tissues.

Results

The pathogens identified were Staphylococcus aureus (methicillin-resistant S. aureus, n = 5; methicillin-susceptible S. aureus, n = 1), Pseudomonas aeruginosa (n = 3), Enterococcus faecalis (n = 2), Corynebacterium (n = 1), and Enterobacter (n = 1); pathogens were not detected in one case. The mean duration of CLAP was 17.0 (7–35) days. In all cases, implants were preserved until bone union was achieved. Five cases relapsed; however, infection was finally suppressed in all cases by repeating this method. No side effects were observed.

Conclusion

This novel case series presents treatment outcomes using CLAP therapy for FRIs. This method has the potential to control the infection without removing the implants, because of the sustained high concentration of antimicrobial agents at the infected site, and could be a valuable treatment option for refractory FRIs with implants, in which bone union has not been achieved.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00653-5.

Use of Vancomycin Powder in Spinal Deformity Surgery in Cerebral Palsy Patients is Associated With Proteus Surgical Site Infections

PURPOSE

Surgical site infection (SSI) rates in pediatric spinal deformity surgery for cerebral palsy (CP) patients are higher than that in idiopathic scoliosis. The use of vancomycin powder is associated with decreased risk of SSI in neuromuscular patients. Prior studies in adult and pediatric early-onset scoliosis patients have shown that vancomycin powder alters microbacterial profile in patients that develop SSI. However, the effects of topical vancomycin powder on microbiology in spinal deformity surgery for CP patients has not been studied.

METHODS

An international multicenter database of CP neuromuscular scoliosis patients was used in this retrospective cohort study. All patients that underwent posterior spinal instrumented fusion for CP neuromuscular scoliosis from 2008 to 2019 were queried, and 50 cases complicated by postoperative SSI were identified. Intraoperative antibiotic details were documented in 49 cases (98.0%). Microbiology details were documented in 45 cases (91.8%). Microbiology for patients that received topical vancomycin powder were compared with patients that did not. A multivariate regression model was used to control for potential confounders.

RESULTS

There were 45 patients included in this study. There were 27 males (60.0%) and 18 females (40.0%). Mean age at surgery was 14.8±2.4 years. There were 24 patients that received topical vancomycin powder (53.3%). The mean time from index surgery to SSI was 4.3±11.3 months.On univariate analysis of microbiology cultures by vancomycin powder cohort, there were no significant differences in culture types. Proteus spp. trended on significance with association with vancomycin powder use (P=0.078). When controlling for potential confounders on multivariate analysis, intraoperative topical vancomycin powder was associated with increased risk for proteus infection (adjusted odds ratio: 262.900, 95% confidence interval: 1.806-38,267.121, P=0.028).

DISCUSSION

In CP patients undergoing pediatric spinal deformity surgery, the use of vancomycin powder was independently associated with increased risk for proteus infections. Further study into antibiotic regimens for spinal deformity surgery in the CP population should be performed.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Does cumulative topical antibiotic powder use increase the risk of drug induced acute kidney injury in fracture patients?

AIMS

There is increasing evidence to support the use of topical antibiotics to prevent surgical site infections. Although previous research suggests a minimal nephrotoxic risk with a single dose of vancomycin powder, fracture patients often require multiple procedures and receive additional doses of topical antibiotics. We aimed to determine if cumulative doses of intrawound vancomycin or tobramycin powder for infection prophylaxis increased the risk of drug-induced acute kidney injury (AKI) among fracture patients.

METHODS

This cohort study was a secondary analysis of single-centre Program of Randomized Trials to Evaluate Pre-operative Antiseptic Skin Solutions in Orthopaedic Trauma (PREP-IT) trial data. We included patients with a surgically treated appendicular fracture. The primary outcome was drug-induced AKI. The odds of AKI per gram of vancomycin or tobramycin powder were calculated using Bayesian regression models, which adjusted for measured confounders and accounted for the interactive effects of vancomycin and tobramycin.

RESULTS

Of the 782 included patients (mean age 48 years (SD 20); 59% male), 83% (n = 648) received at least one vancomycin dose (cumulative range 1 to 12 g). Overall, 45% of the sample received at least one tobramycin dose (cumulative range 1.2 to 9.6 g). Drug-induced AKI occurred in ten patients (1.2%). No association was found between the cumulative dose of vancomycin and drug-induced AKI (odds ratio (OR) 1.08 (95% credible interval (CrI) 0.52 to 2.14)). Additional doses of tobramycin were associated with a three-fold increase in the adjusted odds of drug-induced AKI (OR 3.66 (95% CrI 1.71 to 8.49)). Specifically, the risk of drug-induced AKI rose substantially after 4.8 g of tobramycin powder (7.5% (95% CrI 1.0 to 35.3)).

CONCLUSION

Cumulative doses of vancomycin were not associated with an increased risk of drug-induced AKI among fracture patients. While the risk of drug-induced AKI remains less than 4% with three or fewer 1.2 g tobramycin doses, the estimated risk increases substantially to 8% after four cumulative doses. Level of evidence: Therapeutic Level III Cite this article: Bone Jt Open 2022;3(4):284-290.

Local vancomycin therapy to reduce surgical site infection in adult spine surgery: a randomized prospective study

PURPOSE

This prospective randomized controlled trial hypothesizes that intra wound vancomycin reduces postoperative infection.

METHODS

In this RCT study, the patients were randomly divided into two groups of treatment and control. In the treatment group, 1-2 g of intra wound vancomycin was used, and no drug was used for the control group. SSI and the type of microorganism causing postoperative infection were assessed at a three-month follow-up. Factors affecting postoperative infection such as age, sex, site of operation, surgical levels, and risk factors affecting postoperative infection, such as diabetes, blood pressure, ischemic heart disease, smoking, blood transfusion, BMI, neurologic deficit, CSF leakage, UTI, COPD and surgery time were examined in two groups.

RESULTS

In this study, 375 patients, including 187patients in the treatment group and 188 patients in the control group, were studied. Among the patients, 228 had surgery without instrumentation, and 147 had surgery with instrumentation. There were 12 cases of SSI in the treatment group and 11 in the control group, and there was no statistically significant difference between the two groups. There was no difference between the two groups with and without instrumentation in the evaluation of postoperative infection. In the subgroups with and without instruments, there was no significant difference between treatment and control groups. Due to the microorganism causing the infection, gram-negative bacteria were more common in the treatment group.

CONCLUSION

Intra-wound vancomycin has no effect on SSI; in addition, it can increase the rate of gram-negative infections.

Vancomycin is effective in preventing Cutibacterium acnes growth in a mimetic shoulder arthroplasty

BACKGROUND

Intra-incisional deposition of vancomycin powder is a strategy to limit Cutibacterium acnes infection after shoulder surgery. Unfortunately, limited research exists examining the effectiveness of vancomycin in a clinically relevant joint infection model. This basic science study investigated the efficacy of vancomycin administration as prophylaxis for C acnes growth in vitro using a mimetic shoulder arthroplasty.

METHODS

A new bioartificial shoulder joint mimetic implant (S-JIM) was used to investigate the effect of vancomycin powder on C acnes growth within the first 48 hours after surgery. The impact of vancomycin was assessed on a skin-derived (ATCC 11827) C acnes strain and a periprosthetic joint infection-derived strain. C acnes strains were applied to titanium alloy foil and embedded beneath multiple layers of collagen-impregnated cellulose scaffold strips containing human shoulder joint capsular fibroblasts, facilitating the development of an oxygen gradient with an anaerobic environment around the foil and inner layers. Ten milligrams of vancomycin powder was applied between the C acnes layer and the human cell-containing scaffold strips to model direct antibiotic application, and intravenous vancomycin prophylaxis was modeled by adding vancomycin in media at 5 or 20 μg/mL. After 48 hours, the C acnes inoculum layer was subcultured from each S-JIM onto agar plates to assess the formation of viable C acnes colonies. Primary human shoulder capsule cells were assessed microscopically to detect any detrimental effects of vancomycin on cellular integrity.

RESULTS

Agar plates inoculated with extracts from untreated S-JIMs consistently resulted in the growth of large numbers of C acnes colonies, whereas treatments with vancomycin powder or vancomycin in media at 20-μg/mL dilution effectively prevented the recovery of any C acnes colonies. The lowest vancomycin dilution tested (5 μg/mL) was insufficient to prevent the recovery of C acnes colonies. Vancomycin powder had no discernible short-term impact on shoulder capsule cell morphology, and the presence of these cells had no discernible impact on vancomycin degradation over time.

CONCLUSIONS

Vancomycin administration effectively prevented C acnes growth in a bioartificial S-JIM. These results support the hypothesis that intra-incisional vancomycin application may limit C acnes prosthetic joint infections.

Intraoperative use of vancomycin paste during penile prosthesis placement: initial outcomes

Penile prosthesis implantation is a safe and effective treatment option in the management of erectile dysfunction, associated with high satisfaction and low complication rates. Infection is a rare complication (0.5-3%), but devastating for the patient and surgeon when it occurs. Adapting from other surgical disciplines, we have utilized vancomycin paste to provide prolonged focal antibiotic exposure around the penile prosthesis pump, a site prone to infection. The aim of this study is to determine the safety and efficacy of intraoperative vancomycin paste with regards to infection prevention during penile prosthesis placement. This is a multi-institutional nonrandomized retrospective IRB-approved study comparing patients who underwent placement of a primary inflatable penile prosthesis with intraoperative vancomycin paste to those without. Primary outcomes included pump fibrosis, infection, erosion, hematoma, and complete device malfunction. From April 2019 to October 2019, two surgeons utilized vancomycin paste intraoperatively during virginal penile prosthesis surgery on 90 patients, whose mean age was 60 years. These patients were compared to an historical control group that included 166 patients, also with a mean age of 60 years, who underwent the same penile prosthesis surgery between 2014 and 2017 without the paste. Among the intervention group, the overall complication rate was 1.1%, due to a scrotal hematoma. Ultimately, there was no statistically significant difference in infection rate (0% in both groups) or overall complication rate (1.1% in the intervention group compared to 1.2% in the control group). The use of vancomycin paste appears to be safe, however future prospective studies are needed to determine its efficacy in infection prevention.

Negligible Systemic Uptake of Suprafascial Vancomycin Powder Following Instrumented Posterior Spinal Fusion-Preliminary Results From A Randomized Clinical Trial (VANCO Trial)

BACKGROUND

Intrawound vancomycin powder is an emerging strategy to reduce surgical site infections (SSIs) in spine surgery. However, there are concerns relating to its safety profile and toxicity. Data on systemic uptake of suprafascially administered vancomycin powder following instrumented spinal fusion is lacking.

OBJECTIVE

To study the systemic uptake and safety of suprafascially administered vancomycin powder in the early postoperative phase following open instrumented posterior spinal fusion.

METHODS

This was a substudy of an ongoing randomized clinical trial. Eligible adult patients were randomized 1:1 to either receive suprafascial vancomycin powder before wound closure or not to receive vancomycin powder. Serum vancomycin levels were assessed on postoperative days 1 and 2, serum creatinine levels were measured pre- and post-operatively. Adverse events up to 6 wk following surgery were recorded.

RESULTS

Among 34 randomized patients (mean age 62 yr, range 31-84 yr; 18 [53%] women), 17 received vancomycin powder. No detectable serum vancomycin levels (>4.0 mg/L) were found. Proportion of adverse events per patient in the vancomycin and control group, respectively, were 29.4% (5/17) vs 11.8% (2/17) (OR 3.12; 95% CI, 0.52; 19.38; P = .398). No patient had nephrotoxicity or ototoxicity in either group.

CONCLUSION

Suprafascial vancomycin powder in open instrumented spinal fusion surgery is safe and results in negligible systemic uptake. Final results of the VANCO Trial need to be awaited for conclusive data on the efficacy of vancomycin for SSI prevention and its impact on wound healing.

Intra-wound vancomycin and tobramycin powder for infection prophylaxis in orthopaedic trauma surgery: Economically justifiable?

OBJECTIVES

There is increasing interest regarding the risks and benefits of intrawound antibiotics applied directly to surgical wounds for the prevention of infection following orthopaedic trauma surgery. The purpose of this study was to investigate the economic justifiability of vancomycin and tobramycin powders for infection prophylaxis in orthopaedic trauma surgery.

METHODS

The cost of vancomycin and tobramycin powders, infection rates and costs of treating surgical site infections were obtained from our institution's records and existing literature. A break-even analysis was then performed using vancomycin powder only, tobramycin powder only and combined vancomycin and tobramycin powders to determine the respective absolute risk reduction (ARR) in infection rate needed to make the prophylactic application of each therapy type break-even.

RESULTS

At our institutional pricing of $20.64 and $75.80 for 1g vancomycin and 1.2g tobramycin, respectively, use of each individually would be economically justified if it reduced an average infection rate of 4.3% by an ARR of 0.02% and 0.07%, respectively. Used in combination for $90.66, the ARR was 0.09%. Varying cost of treating infection from $5,000-$200,000 while maintaining cost of antibiotic powder at $90.66 demonstrated a range in ARR from 1.93% to 0.05%, respectively. At the same cost of $90.66 but varying infection rate from 1% to 25% did not affect ARR, which was constant at 0.09%.

CONCLUSIONS

Considering the cost of vancomycin and tobramycin powder at our institution, the application of these powders, whether independently or in combination, appear to be economically justifiable for infection prevention in orthopaedic trauma surgery.

Prophylactic Topical Antibiotics in Fracture Repair and Spinal Fusion

INTRODUCTION

The objective of this systematic review with meta-analysis is to determine whether prophylactic local antibiotics prevent surgical site infections (SSIs) in instrumented spinal fusions and traumatic fracture repair. A secondary objective is to investigate the effect of vancomycin, a common local antibiotic of choice, on the microbiology of SSIs.

METHODS

An electronic search of PubMed, EMBASE, and Web of Science databases and major orthopedic surgery conferences was conducted to identify studies that (1) were instrumented spinal fusions or fracture repair and (2) had a treatment group that received prophylactic local antibiotics. Both randomized controlled trials (RCTs) and comparative observational studies were included. Meta-analysis was performed separately for randomized and nonrandomized studies with subgroup analysis by study design and antibiotic.

RESULTS

Our review includes 44 articles (30 instrumented spinal fusions and 14 fracture repairs). Intrawound antibiotics significantly decreased the risk of developing SSIs in RCTs of fracture repair (RR 0.61, 95% CI: 0.40-0.93, I 2 = 32.5%) but not RCTs of instrumented spinal fusion. Among observational studies, topical antibiotics significantly reduced the risk of SSIs in instrumented spinal fusions (OR 0.34, 95% CI: 0.27-0.43, I 2 = 52.4%) and in fracture repair (OR 0.49, 95% CI: 0.37-0.65, I 2 = 43.8%). Vancomycin powder decreased the risk of Gram-positive SSIs (OR 0.37, 95% CI: 0.27-0.51, I 2 = 0.0%) and had no effect on Gram-negative SSIs (OR 0.95, 95% CI: 0.62-1.44, I 2 = 0.0%).

CONCLUSIONS

Prophylactic intrawound antibiotic administration decreases the risk of SSIs in fracture surgical fixation in randomized studies. Therapeutic efficacy in instrumented spinal fusion was seen in only nonrandomized studies. Vancomycin appears to be an effective agent against Gram-positive pathogens. There is no evidence that local vancomycin powder is associated with an increased risk for Gram-negative infection.

Use of Vancomycin Powder in the Surgical Treatment of Early Onset Scoliosis Is Associated With Different Microbiology Cultures After Surgical Site Infection

BACKGROUND

The use of vancomycin powder has been shown to decrease risk of surgical site infection (SSI) in early onset scoliosis (EOS). While there is potential benefit in SSI reduction, there is also theoretical risk in creating increased bacterial resistance to standard treatment regimens. However, the effects of topical vancomycin powder on microbiology in these patients has not been studied.

METHODS

A multicenter database for EOS patients was retrospectively analyzed. All patients that underwent surgical treatment with traditional growing rods, magnetically controlled growing rods, vertical expandable prosthetic titanium rib, and Shilla for EOS performed after 2010 were identified (n=1115). Patients that sustained at least 1 SSI after guided growth surgery were assessed (n=104, 9.3%). Patients with culture and antibiotic details were included (n=55). Patients that received vancomycin powder at index surgery were compared with patients that did not. A multivariate regression model was used to control for potential confounders.

RESULTS

There were 55 patients included in this study, including 26 males (47%) and 29 females (53%). Mean age at index surgery was 7.2±6.9 years. Vancomycin powder was utilized in 18 cases (33%). Mean time from index surgery to SSI was 2.0±1.3 years. There were 2 cases of wound dehiscence (4%), 7 cases of superficial infection (13%), and 46 cases of deep infection (84%).There were significant differences in overall microbiology results between vancomycin and no vancomycin cohorts (P=0.047). On univariate analysis, the vancomycin powder cohort had a significantly high incidence of cultures without growth (n=7, 39% vs. n=4, 11%, relative risk: 2.063, 95% confidence interval: 0.927-4.591, P=0.028). This association remained significant on multivariate analysis (adjusted odds ratio: 9.656, 95% confidence interval: 1.743-53.494, P=0.009).

CONCLUSIONS

In EOS patients undergoing procedures complicated by SSI, the use of vancomycin powder was independently associated with increased risk of no culture growth. Surgeons and infectious disease physicians should be aware and adjust diagnostic and treatment strategies appropriately.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Vancomycin Presoaking of Anterior Cruciate Ligament Tendon Grafts Is Highly Cost-Effective for Preventing Infection

PURPOSE

This study aimed to (1) determine whether intraoperative graft soaking with vancomycin is a cost-effective measure for preventing infection after arthroscopic anterior cruciate ligament (ACL) reconstruction and (2) provide an adaptable model for providers and institutions to determine the cost effectiveness of this strategy over a range of initial infection rates, infection-related care costs, and vancomycin costs.

METHODS

Baseline postoperative infection rates and the costs of antibiotics and infection-related care were gathered from the literature. The cost of treating infection was determined for 2 alternative protocols-irrigation and debridement with revision ACL reconstruction or ACL graft retention. Using a break-even economic analysis, we developed an equation to determine the absolute risk reduction (ARR) in infection rate required for the use of vancomycin graft soaking to be deemed cost-effective. To provide a widely applicable robust model, multiple simulations were performed at varying unit costs, infection rates, and ACL reconstruction postoperative infection related care costs. The number needed to treat was calculated from the ARR.

RESULTS

Intraoperative vancomycin was determined to be cost-effective if it prevents 1 infection in 550 cases (ARR = 0.182%), given costs of $24,178 and $44/1,000 mg for revision ACL reconstruction and vancomycin, respectively. If the ACL graft is retained following infection, intraoperative vancomycin was considered cost-effective if it prevents 1 infection in 146 cases (ARR = 0.685%), given costs of $6,424 and $44/1,000 mg for arthroscopic debridement and vancomycin prophylaxis, respectively. For any specific cost of treating infection and cost of vancomycin, variation in baseline infection rates did not influence the economic viability of vancomycin graft soaking. This intervention remained economically viable over a wide range of unit costs of vancomycin.

CONCLUSIONS

Through break-even economic analysis, this study demonstrates that the use of intraoperative graft preparation with vancomycin is a highly cost-effective prophylactic measure for infection prevention in arthroscopic ACL reconstruction.

LEVEL OF EVIDENCE

IV, economic analysis.

Effectiveness of topical vancomycin in the prevention of spinal surgical site infections: a retrospective cohort study

BACKGROUND

The risk of surgical site infections (SSIs), particularly methicillin-resistant Staphylococcus aureus (MRSA) SSIs, after spinal surgeries is one of the most daunting experiences to patients and surgeons. Some authors suggest applying vancomycin powder on the wound before skin closure to minimize the risk of SSIs; however, this practice is not supported by well-established evidence. This study sought to assess the effectiveness of topical (i.e. intra-wound) vancomycin in minimizing the risk of SSIs in patients who underwent spinal surgeries at a Saudi hospital.

METHODS

A retrospective cohort study was conducted using the hospital database. Patients who underwent spinal surgeries from the period of 09/2013 to 09/2019 were included and followed up (observed from the time of the surgery) to 30 days (surgeries without implants) or 90 days (with implants). The odds ratio (OR) of the primary outcome between vancomycin treated versus non-treated patients was estimated using a logistic regression model adjusting for the measured confounders. A sensitivity analysis was conducted using propensity score analysis (inverse probability of treatment weighting [IPTW] with stabilized weights) to control for confounding by indication. All study analyses were completed using RStudio Version 1.2.5033.

RESULTS

We included 81 vancomycin treated vs. 375 untreated patients with 28 infections (8/81 vs. 20/375; respectively). The adjusted OR of SSIs between the two groups was 0.40 (95% confidence interval [CI] 0.11 to 1.34). The result of the propensity score analysis was consistent (OR: 0.97 [95% CI 0.35 to 2.68]).

CONCLUSIONS

We could not find a lower association of SSIs with intra-wound vancomycin in patients who underwent spinal surgeries. Further studies are needed to assess benefits of using topical vancomycin for this indication vs. the risk of antimicrobial resistance.

Use of Vancomycin Mixed Bone Graft and Vancomycin Mixed Saline Wash Before Wound Closure Reduces the Rate of Infection in Lumbar Spine Fusion Surgery

This study aims to evaluate whether surgical site vancomycin mixed in bone grafts and local vancomycin mixed in normal saline wash before wound closure decrease the infection rates in patients undergoing lumbar spinal instrumentation and posterolateral fusion. A retrospective study was performed on cases between 2017 and 2019, who underwent lumbar spine instrumentation and posterolateral fusion for lumbar canal stenosis or listhesis. The routine prophylactic procedures were performed in all patients as per institutional protocol. Patients' records were analysed and categorised into two groups, the vancomycin group (VG), where vancomycin mixed in bone graft and normal saline wash was used at the surgical site, and the control group (CG), where vancomycin was not used. The study included 63 patients, 31 in VG and 32 in CG. There is no statistical difference in age, sex, and diabetes mellitus in both groups. A total of seven cases were infected, six in CG (6/32) and one in VG (1/31). Out of six infections in CG, three patients had diabetes and four infected cases underwent surgery for debridement. In VG, the only single case got infected and treated with intravenous antibiotics. We found that the use of vancomycin added to the bone graft and normal saline in posterior lumbar spinal instrumentation and posterolateral fusion is associated with significantly lower rates of infection (p value=0.049).

Invasive Staphylococcus aureus Infection among Patients Undergoing Elective, Posterior, Instrumented Spinal Fusion Surgeries: A Retrospective Cohort Study

Background: Post-surgical invasive Staphylococcus aureus infections among spinal fusion patients are serious complications that can worsen clinical outcomes and increase healthcare utilization. Risk of such infections at the population level remains unknown. This study assessed the post-surgical risk of invasive Staphylococcus aureus infections among patients undergoing elective posterior instrumented spinal fusion surgeries in 129 U.S. hospitals. Patients and Methods: This retrospective cohort study analyzed adult patients ≥18 years of age who underwent thoracolumbar/lumbar and cervical fusion surgeries during 2010 - 2014 using the Premier Healthcare Database, the largest hospital discharge database in the United States. Risks of blood stream infection (BSI), deep or organ/space surgical site infections (SSI) caused by Staphylococcus aureus during 90 and 180 days post-index surgery were estimated. Infections were identified based on positive culture results, related International Classification of Diseases, Ninth Revision (ICD-9) procedure codes, and specific claims information. Results: Among 11,236 patients with thoracolumbar/lumbar fusion, 90- and 180-day BSI/SSI infection risks were higher for multilevel than single level fusion (90-day, 1.52% vs. 1.07%, p = 0.05; 180-day, 1.66% vs. 1.07%, p = 0.014). Among 1,641 patients with cervical fusion, 90- and 180-day BSI/SSI infection risks were also higher in multilevel fusions but not statistically significant (90-day, 1.66% vs. 0.52%, p = 0.350; 180-day, 1.80% vs. 0.51%, p = 0.241). The risk for SSI/BSI was more than twice as high among multilevel thoracolumbar/lumbar fusion patients with more than two comorbidities than those with no comorbidity at both 90-day (2.78% vs. 1.00%, p < 0.05) and 180-day (3.01% vs. 1.10%, p < 0.05). Similar trend without statistical significance was seen in multilevel cervical fusion cohort (90-day, 2.91% vs. 1.25%, p > 0.05; 180-day, 3.88% vs. 1.41%, p > 0.05). Conclusions: The risk of BSI/SSI infection for elective posterior instrumented spinal fusions ranged between 0.5% and 2%. Higher risk was observed in multilevel thoracolumbar/lumbar surgery, with infection risk greatest in patients with more than two comorbidities. These real-world findings highlight the need for additional measures, in addition to antibiotic prophylaxis, to reduce invasive Staphylococcus aureus infections in this setting.

A narrative review of infection prevention techniques in adult and pediatric spinal deformity surgery

Spinal infections associated with pediatric and adult spinal deformity surgery are associated with postoperative morbidity and mortality along with elevated health-care costs. Prevention requires meticulous technique by the spine surgeon throughout the perioperative period. There is significant variability in the current practices of spinal deformity surgeons with regard to infection prevention, stemming from the lack of reliable evidence available in the literature. There has also been a lack of literature detailing the difference in infection rates and risk factors between pediatric and adult patients undergoing deformity correction surgery. In this narrative review we looked at 60 studies in the adult population and 9 studies in the pediatric population. Most of these studies of surgical site infections (SSI) in spinal deformity surgery have been performed in adult patients, however it is clear that the pediatric neuromuscular patient requires particular attention that we discuss in detail. This narrative review of the literature outlines evidence and compares and contrasts data for preventive strategies and modifiable risk factors to decrease rates of SSI in the pediatric and adult spinal deformity patient populations. In this review we discuss techniques relating to preoperative cleansing protocols, antibiotic administration, gentle soft tissue handling, appropriate closure, drain usage, and intraoperative technique itself to minimize EBL and operative time.

Antimicrobial prophylaxis in noninstrumented spine surgery: a prospective study to determine efficacy and drawbacks

OBJECTIVE

The authors sought to evaluate the roles of perioperative antibiotic prophylaxis in noninstrumented spine surgery (NISS), both in postoperative infections and the impact on the selection of resistant bacteria. To the authors' knowledge, only one prospective study recommending preoperative intravenous (IV) antibiotics for prophylaxis has been published previously.

METHODS

Two successive prospective IV antibiotic prophylaxis protocols were used: from 2011 to 2013 (group A: no prophylactic antibiotic) and from 2014 to 2016 (group B: prophylactic cefazolin). Patient infection rates, infection risk factors, and bacteriological status were determined.

RESULTS

In total, 2250 patients (1031 in group A and 1219 in group B) were followed for at least 1 year. The authors identified 72 surgical site infections, 51 in group A (4.9%) and 21 in group B (1.7%) (p < 0.0001). A multiple logistic regression hazard model identified male sex (HR 2.028, 95% CI 1.173-3.509; p = 0.011), cervical laminectomy (HR 2.078, 95% CI 1.147-3.762; p = 0.016), and postoperative CSF leak (HR 43.782, 95% CI 10.9-189.9; p < 0.0001) as independent predictive risk factors of infection. In addition, preoperative antibiotic prophylaxis was the only independent favorable factor (HR 0.283, 95% CI 0.164-0.488; p < 0.0001) that significantly reduced infections for NISS. Of 97 bacterial infections, cefazolin-resistant bacteria were identified in 26 (26.8%), with significantly more in group B (40%) than in group A (20.9%) (p = 0.02).

CONCLUSIONS

A single dose of preoperative cefazolin is effective and mandatory in preventing surgical site infections in NISS. Single-dose antibiotic prophylaxis has an immediate impact on cutaneous flora by increasing cefazolin-resistant bacteria.

Negative pharmacological effect on spine fusion: A narrative review of the literature of evidence-based treatment

Spine fusion surgery is commonly performed for diverse indications, the most frequent one being degenerative spine diseases. Despite the growing importance of this surgery, there is limited evidence concerning the effects of drugs on the process of spine fusion and healing. While asymptomatic sometimes, nonunion of the spine can have tremendous repercussions on the patients' quality of life and the healthcare system rendering it an "expensive complication". This literature review identifies the role of some perioperative drugs in spine fusion and reveals their potential role in pseudarthrosis of the spine. This review also benefits spine surgeons looking for current evidence-based practices. We reviewed the data related to nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, vancomycin, bisphosphonates, proton pump inhibitors (PPIs), pregabalin, and opioids. From the available experimental and clinical studies, we conclude that bisphosphonates might positively influence the process of spine fusion, while steroids and vancomycin have shown variable effects, and the remaining medications likely disturb healing and union of the spine. We recommend spine surgeons be cautious about the drugs they resort to in the critical perioperative period until further clinical studies prove which drugs are safe to be used.

Is Use of Topical Vancomycin in Pediatric Spine Surgeries a Safe Option in the Prevention of Surgical Site Infections? A Meta-analysis and Systematic Review of the Literature

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To systematically review the available articles on topical vancomycin powder (TVP) use in pediatric spine surgeries exploring the usefulness and safety of such practice.

METHODS

We conducted an independent and duplicate electronic database search in PubMed, EMBASE, and Cochrane Library till March 2020 to identify all relevant literature on the use of TVP for pediatric spine surgeries. Surgical site infection (SSI) rate, specific reported complications, reoperation rate, microbial flora pattern in reported SSIs, and safety profile were the outcomes analyzed. Analysis was performed with the R platform using OpenMeta[Analyst] software.

RESULTS

No prospective studies were available to evaluate the use of TVP in pediatric spine surgeries for the prevention of SSIs. Neither standardized protocol, nor drug dosage, nor safety profile was established for pediatric use. Three retrospective cohort studies including 824 patients (TVP/control: 400/424) were included in the meta-analysis. There was low-quality evidence suggesting no significant difference between the 2 groups in SSI rate (RR = 0.474; 95% CI = [0.106,2.112]; P = .327) with significant heterogeneity (I2 = 70.14; P = .035). The TVP group showed a significant benefit on cost analysis in one of the included studies. However, TVP did not prevent gram-negative coinfection on SSI in the TVP group.

CONCLUSION

From the literature available at present, TVP does not qualify to be recommended as a safe and useful option to prevent SSI following pediatric spine surgeries. High-quality prospective interventional studies are needed to arrive at a consensus on its use along with appropriate dosage and method of application.

The application of topical vancomycin powder for the prevention of surgical site infections in primary total hip and knee arthroplasty: A meta-analysis

BACKGROUND

Surgical site infections (SSIs), particularly periprosthetic joint infections (PJI), following a primary total joint arthroplasty (TJA) impose a major burden by increasing morbidity, mortality, disability rate, and health expenditure. Surgeons are increasingly using topical vancomycin powder as a preventative measure, but the effectiveness of this method has been debated in TJA. Thus, we designed a meta-analysis to compare the outcomes after primary TJA between a group treated with topical vancomycin powder and an untreated control group aiming to answer: (1) whether the application of topical vancomycin powder can reduce the infection rate after primary total joint replacement; (2) are the main types of pathogens causing SSIs after the application of topical vancomycin powder different from those of patients not using topical vancomycin?

MATERIALS AND METHODS

A meta-analysis was conducted in accordance with the PRISMA guidelines. We included retrospective cohort studies and prospective randomized controlled trials of patients who underwent primary total joint arthroplasty with and without vancomycin powder application before wound closure and reported the SSI rates. The English literature in the PubMed (MEDLINE), EMBASE, Web of Science, and the Cochrane Library databases was comprehensively searched. Literature search, data extraction, and quality assessment were conducted by 2 authors. The main outcomes were SSI and PJI rates, and the secondary outcome was the bacterial spectrum. Statistical analyses were performed with the Review Manager (RevMan) Version 5.3.

RESULTS

Six retrospective cohort studies and 3 prospective cohort studies with 4512 participants were included (2354 in vancomycin group and 2158 in the control group). In the TJA group, the vancomycin powder-treatment resulted in a significantly lower proportion of patients with SSIs (relative risk [RR]=0.40, 95% confidence interval [CI]=0.27-0.61 [p<0.001]) or PJI (RR=0.37, 95% CI=0.23-0.60 (p<0.001)). In the total hip arthroplasty group, the vancomycin powder treatment decreased the rate of SSIs and PJI by 66% (RR=0.34, 95% CI=0.15-0.78 [p=0.01]) and 74% (RR=0.26, 95% CI=0.10-0.67 (p=0.005)), respectively. In the total knee arthroplasty group, the vancomycin powder decreased the rate of SSIs and PJI by 67% (RR=0.43, 95% CI=0.26-0.70 [p<0.001]) and 66% (RR=0.44, 95% CI=0.25-0.77 [p=0.004]) respectively. Staphylococcus aureus (or methicillin-sensitiveStaphylococcus aureus) (6 in vancomycin group versus 11 in control group) was the most common pathogenic bacteria, followed by Staphylococcus epidermidis (1 in vancomycin group versus 2 in control group) and methicillin-resistant Staphylococcus aureus (2 in vancomycin group versus 4 in control group). Pseudomonas aeruginosa was the main gram-negative pathogen, with 3 cases in the control group and 1 case in the vancomycin powder-treatment group.

DISCUSSION

The local application of vancomycin powder could significantly decrease the rate of SSIs and PJI in primary TJA without modifying the spectrum of bacteria involved. We recommend topical administration of the vancomycin powder before wound closure after a full evaluation of the patients.

LEVEL OF EVIDENCE

III; meta-analysis.

A meta-analysis of the local application of vancomycin powder to prevent surgical site infection after spinal surgeries

Objective

This study aimed to systematically analyze the effectiveness and safety of the local application of vancomycin powder to prevent surgical site infection (SSI) after spinal surgeries and provide guidance for clinical practice.

Methods

Two researchers independently searched PubMed, Web of Science, Elsevier, and China National Knowledge Infrastructure using the MeSH terms “spinal surgery,” “vancomycin,” “local,” “topical,” “prophylactic,” “surgical site infection,” and “SSI” to identify studies published between January 2010 and January 2020 on the local application of vancomycin powder for preventing SSI after spinal surgeries. The outcome assessment indicators were analyzed using RevMan 5.3 software.

Results

Three randomized controlled trials, two prospective studies, and 26 retrospective studies were included in the current research. The results of the meta-analysis revealed significant differences between the vancomycin and control groups (non-vancomycin group) concerning the incidence of SSI (risk ratio = 0.39, 95% confidence interval = 0.28–0.55, Z = 5.46), indicating that local application of vancomycin powder can significantly reduce the incidence of SSI.

Conclusion

Local application of vancomycin powder is an effective and safe method to prevent SSI after spinal surgeries.

Effect of Intrawound Vancomycin Powder in Operatively Treated High-risk Tibia Fractures: A Randomized Clinical Trial

Importance

Despite the widespread use of systemic antibiotics to prevent infections in surgically treated patients with fracture, high rates of surgical site infection persist.

Objective

To examine the effect of intrawound vancomycin powder in reducing deep surgical site infections.

Design, Setting, and Participants

This open-label randomized clinical trial enrolled adult patients with an operatively treated tibial plateau or pilon fracture who met the criteria for a high risk of infection from January 1, 2015, through June 30, 2017, with 12 months of follow-up (final follow-up assessments completed in April 2018) at 36 US trauma centers.

Interventions

A standard infection prevention protocol with (n = 481) or without (n = 499) 1000 mg of intrawound vancomycin powder.

Main Outcomes and Measures

The primary outcome was a deep surgical site infection within 182 days of definitive fracture fixation. A post hoc comparison assessed the treatment effect on gram-positive and gram-negative-only infections. Other secondary outcomes included superficial surgical site infection, nonunion, and wound dehiscence.

Results

The analysis included 980 patients (mean [SD] age, 45.7 [13.7] years; 617 [63.0%] male) with 91% of the expected person-time of follow-up for the primary outcome. Within 182 days, deep surgical site infection was observed in 29 of 481 patients in the treatment group and 46 of 499 patients in the control group. The time-to-event estimated probability of deep infection by 182 days was 6.4% in the treatment group and 9.8% in the control group (risk difference, -3.4%; 95% CI, -6.9% to 0.1%; P = .06). A post hoc analysis of the effect of treatment on gram-positive (risk difference, -3.7%; 95% CI, -6.7% to -0.8%; P = .02) and gram-negative-only (risk difference, 0.3%; 95% CI, -1.6% to 2.1%; P = .78) infections found that the effect of vancomycin powder was a result of its reduction in gram-positive infections.

Conclusions and Relevance

Among patients with operatively treated tibial articular fractures at a high risk of infection, intrawound vancomycin powder at the time of definitive fracture fixation reduced the risk of a gram-positive deep surgical site infection, consistent with the activity of vancomycin.

Trial Registration

ClinicalTrials.gov Identifier: NCT02227446.

Intrawound vancomycin application after spinal surgery: a propensity score-matched cohort analysis

OBJECTIVE

Surgical site infection (SSI) following spine surgery is associated with increased morbidity and healthcare costs. In an effort to reduce SSI rates, the application of intrawound vancomycin powder has gained popularity. However, there is limited high-quality evidence to support the safety and efficacy of this practice. The authors sought to determine if intrawound application of vancomycin powder improves 90-day overall SSI rates.

METHODS

The authors performed a retrospective, vancomycin exposure-matched cohort study at a single tertiary care hospital over 21 months. They included all patients undergoing elective spinal surgery and stratified the patients into two groups: those who received intrawound vancomycin powder application and those who received no application of vancomycin powder. The primary outcome of interest was the 90-day overall SSI rate. Secondary outcomes included rates of superficial SSI, deep SSI, wound disruption, and a post hoc analysis of the microbiology and minimum inhibitory concentrations. Baseline patient demographics, clinical presentation, comorbidities, perioperative factors, and 90-day postoperative outcomes were manually abstracted from patient charts. To mitigate bias, we performed 1:1 matching after calculating propensity scores and identified 1 patient from the no-vancomycin cohort for each patient in the vancomycin cohort.

RESULTS

A total of 997 patients met our inclusion criteria (473 patients receiving vancomycin and 524 patients not receiving vancomycin). Propensity score matching produced 221 matched pairs. Risk-adjusted analysis demonstrated similar overall SSI rates between the groups (OR 1.9, p = 0.329). On unadjusted analysis, the overall 90-day SSI rate was greater in the vancomycin group (n = 10 [4.5%]) than in the no-vancomycin group (n = 5 [2.3%]) (p < 0.001), as were the superficial SSI rate (7 [3.2%] vs 4 [1.8%], p < 0.001), deep SSI rate (3 [1.4%] vs 1 [0.5%], p < 0.001), and wound disruption rate (5 [2.3%] vs 1 [0.5%], p < 0.001). No cultured isolate demonstrated vancomycin resistance.

CONCLUSIONS

The authors observed no difference in SSI rates after the intrawound application of vancomycin powder during spine surgery. Vancomycin use did not contribute to antimicrobial resistance; however, it may select out gram-negative bacteria and increase rates of wound disruption.

Is Propionibacterium acnes becoming the most common bacteria in delayed infections following adolescent idiopathic scoliosis surgery?

STUDY DESIGN

Retrospective review of hospital charts.

OBJECTIVE

(1) To determine the microbiological profile of patients with surgical site infections following posterior spinal fusion surgery (PSF) for Adolescent Idiopathic scoliosis (AIS). (2) To study the treatment outcome of patients with surgical site infections (SSI) following surgery for AIS. (3) To identify the key differences in presentation and management of acute and delayed SSI following AIS surgery. There has been increasing evidence of the role of P. acnes in deep surgical site infections. Literature related to this is abundant in relation to shoulder arthroplasty; however, it is sparse in relation to spine surgery.

METHODS

We conducted a retrospective review of all patients treated for AIS during a 5-year period (2010-2014) at our institution, with a minimum of 2-year follow-up after the index surgery. Patients with a postoperative infection following their index surgery were included. Charts of AIS patients with post-op infections were reviewed for details of the index surgery, time to presentation of the infection, presenting signs/symptoms, microbiology details, details of surgical and antibiotic treatment, and outcomes.

RESULTS

Nine (2.8%) post-op infections were identified out of 315 cases for AIS during this period. Seven (2.2%) involved P. acnes. Two (0.6%) involved MSSA. The average time for cultures to show growth was 6.1 days (range 5-8 days) in P. acnes group and 2-3 days in MSSA group. Patients with P. acnes infections were treated with implant removal, debridement and antibiotics. All patients achieved solid fusion except two patients from the P. acnes group had pseudoarthrosis and had to undergo revision fusion.

CONCLUSION

Propionibacterium acnes was the single most common bacteria isolated from delayed surgical site infection following PSF in AIS patients. Optimal treatment consists of debridement, implant removal and antibiotics. These patients have high incidence of pseudoarthrosis.

LEVEL OF EVIDENCE

Level IV.

Significantly Lower Infection Risk for Anterior Cruciate Ligament Grafts Presoaked in Vancomycin Compared With Unsoaked Grafts: A Systematic Review and Meta-analysis

PURPOSE

To compare postoperative infection rates following ACL reconstruction performed with grafts presoaked in vancomycin versus those without vancomycin.

METHODS

A systematic review was performed using PRISMA guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for therapeutic level I to III studies that compared outcomes of presoaking ACL grafts with vancomycin versus without vancomycin in human patients. Included graft types were tendon autografts or allografts, and included studies documented infection with a minimum follow-up of 30 days. Postoperative infection rates and knee-specific patient-reported outcome scores were extracted from each study and compared between groups. Study methodological quality was analyzed using the Methodological Index for Non-Randomized Studies (MINORS) and Modified Coleman Methodology Score (MCMS). Infection rates and retear rates were pooled and weighted for meta-analysis using a random-effects model. All P values were reported with an α level of 0.05 set as significant.

RESULTS

The initial search yielded 144 articles (44 duplicates, 100 screened, 29 full-text review). Ten articles (21,368 subjects [7,507 vancomycin and 13,861 no vancomycin], 67% males, mean ± standard deviation age 29.5 ± 1.5 years) were included and analyzed. Eight of the 10 studies included only autografts, with 94.5% of grafts being hamstring autografts. Soaking grafts in vancomycin resulted in significantly fewer infections (0.013% versus 0.77%; odds ratio 0.07; 95% confidence interval 0.03, 0.18; P < .001). Only 2 studies included patient-reported outcomes, and both demonstrated no difference in International Knee Documentation Committee scores 1 year after surgery for patients with grafts presoaked in vancomycin versus without vancomycin.

CONCLUSIONS

Soaking ACL tendon grafts with vancomycin before implantation is associated with a nearly 15 times decrease in odds of infection compared with grafts not soaked in vancomycin. Few studies investigated patient-reported outcomes and retear rates after soaking ACL grafts in vancomycin.

LEVEL OF EVIDENCE

III, systematic review of level III studies.

Impact of intrawound vancomycin powder on prevention of surgical site infection after posterior spinal surgery

OBJECTIVE

Surgical site infection (SSI) after posterior spinal surgery is one of the severe complications that may occur despite administration of prophylactic antibiotics and the use of intraoperative aseptic precautions. The use of intrawound vancomycin powder for SSI prevention is still controversial, with a lack of high-quality and large-scale studies. The purpose of this retrospective study using a propensity score-matched analysis was to clarify whether intrawound vancomycin powder prevents SSI occurrence after spinal surgery.

METHODS

The authors analyzed 1261 adult patients who underwent posterior spinal surgery between 2010 and 2018 (mean age 62.3 years; 506 men, 755 women; follow-up period at least 1 year). Baseline and surgical data were assessed. After a preliminary analysis, a propensity score model was established with adjustments for age, sex, type of disease, and previously reported risk factors for SSI. The SSI rates were compared between patients with intrawound vancomycin powder treatment (vancomycin group) and those without (control group).

RESULTS

In a preliminary analysis of 1261 unmatched patients (623 patients in the vancomycin group and 638 patients in the control group), there were significant differences between the groups in age (p = 0.041), body mass index (p = 0.013), American Society of Anesthesiologists classification (p < 0.001), malnutrition (p = 0.001), revision status (p < 0.001), use of steroids (p = 0.019), use of anticoagulation (p = 0.033), length of surgery (p = 0.003), estimated blood loss (p < 0.001), and use of instrumentation (p < 0.001). There was no significant difference in SSI rates between the vancomycin and control groups (21 SSIs [3.4%] vs 33 SSIs [5.2%]; OR 0.640, 95% CI 0.368-1.111; p = 0.114). Using a one-to-one propensity score-matched analysis, 444 pairs of patients from the vancomycin and control groups were selected. There was no significant difference in the baseline and surgical data, except for height (p = 0.046), between both groups. The C-statistic for the propensity score model was 0.702. In the score-matched analysis, 12 (2.7%) and 24 (5.4%) patients in the vancomycin and control groups, respectively, developed SSIs (OR 0.486, 95% CI 0.243-0.972; p = 0.041). There were no systemic complications related to the use of vancomycin.

CONCLUSIONS

The current study showed that intrawound vancomycin powder was useful in reducing the risk of SSI after posterior spinal surgery by half, without adverse events. Intrawound vancomycin powder use is a safe and effective procedure for SSI prevention.

COST-EFFECTIVENESS OF VANCOMYCIN POWDER FOR DEEP WOUND INFECTION PROPHYLAXIS IN SPINE FUSION

ABSTRACT Objective: To identify the cost effectiveness of vancomycin powder in the prophylaxis of posterior lumbar spine instrumentation, seeking potential savings. Methods: A retrospective, observational study was performed to evaluate the cost effectiveness. Data were retrieved from patients’ files from March 2016 to April 2017; costs were considered for the procedures, as well as which antibiotic was used. Results: A total of 184 patients were included. Of these, 102 received prophylactic treatment with 1g of cephalothin and 82 received 1g of cephalothin and 1g of vancomycin powder, which was applied to the wound prior to tissue closure. Of the 184 patients, 110 were women (59%) and 74 were men (41%), and the mean age was 55 years (24-77). The participants had a median BMI of 28.9 kg/m2 (19-39). The average cost per hospitalized patient was $3974 USD and the average cost of rehospitalization due to infection was, on average, $7700 USD. The use of vancomycin powder led to cost savings of $75,008.79 USD per 100 posterior spinal fusions performed for degenerative spine. Conclusion: The use of vancomycin powder is a cost-effective option for prophylaxis of surgical site infection in spine fusion. Level of evidence III; Economic and decision analysis.

Evaluation of Intra-Operative Topical Vancomycin and the Incidence of Acute Kidney Injury

Background: Intra-operative topical vancomycin (VAN) is a strategy used to prevent surgical site infections (SSI). Although evidence supporting efficacy in SSI prevention is evolving, data describing safety, specifically acute kidney injury (AKI), are limited. The purpose of this study was to determine AKI incidence in patients who received intra-operative topical VAN. Patients and Methods: This is a retrospective study of adult inpatient encounters in which topical VAN was administered intra-operatively as powder/paste, beads, rods/cement/spacers, or unspecified topical route from February to July 2018. Patients were excluded for AKI or renal replacement therapy (RRT) at baseline or ≤2 serum creatinine (SCr) values post-surgery. The primary outcome was AKI incidence after intra-operative topical VAN, defined as increase in SCr ≥50% or 0.5 mg/dL from baseline or RRT initiation. Secondary outcomes included analysis of AKI risk factors and SSI incidence. Acute kidney injury risk factors were analyzed using multivariable logistic regression. Results: Five hundred thirty-four patient encounters met study criteria. Powder/paste were the most common topical VAN formulations (44.8%) with median doses of 2,000 (range, 1,000-26,000) mg. Acute kidney injury incidence was 8.8%. Independent risk factors for AKI were higher Charlson comorbidity index (adjusted odds ratio [aOR], 1.20 [range, 1.06-1.36]), concomitant systemic VAN (aOR, 2.44 [range, 1.29-4.58]), and doubling of total topical VAN dose (aOR, 1.51 [range, 1.13-2.03]). Conclusions: The incidence of AKI with intra-operative topical VAN is comparable to reported rates as systemic VAN. Clinicians may consider total topical VAN dose and concomitant systemic VAN to limit AKI incidence with topical VAN use.

Locally delivered adjuvant biofilm-penetrating antibiotics rescue impaired endochondral fracture healing caused by MRSA infection

Infection is a devastating complication following an open fracture. We investigated whether local rifampin-loaded hydrogel can combat infection and improve healing in a murine model of methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis. A transverse fracture was made at the tibia midshaft of C57BL/6J mice aged 10-12 weeks and stabilized with an intramedullary pin. A total of 1 × 106 colony-forming units (CFU) of MRSA was inoculated. A collagen-based hydrogel containing low-dose (60 μg) and high-dose (300 μg) rifampin was applied before closure. Postoperative treatment response was assessed through bacterial CFU counts from tissue and hardware, tibial radiographs and microcomputed tomography (μCT), immunohistochemistry, and histological analyses. All untreated MRSA-infected fractures progressed to nonunion by 28 days with profuse MRSA colonization. Infected fractures demonstrated decreased soft callus formation on safranin O stain compared to controls. Areas of dense interleukin-1β stain were associated with poor callus formation. High-dose rifampin hydrogels reduced the average MRSA load in tissue (p < 0.0001) and implants (p = 0.041). Low-dose rifampin hydrogels reduced tissue bacterial load by 50% (p = 0.021). Among sterile models, 88% achieved union compared to 0% of those infected. Mean radiographic union scale in tibia scores improved from 6 to 8.7 with high-dose rifampin hydrogel (p = 0.024) and to 10 with combination local/systemic rifampin therapy (p < 0.0001). μCT demonstrated reactive bone formation in MRSA infection. Histology demonstrated restored fracture healing with bacterial elimination. Rifampin-loaded hydrogels suppressed osteomyelitis, prevented implant colonization, and improved healing. Systemic rifampin was more effective at eliminating infection and improving fracture healing. Further investigation into rifampin-loaded hydrogels is required to correlate these findings with clinical efficacy.

Negative pressure wound therapy does not diminish efficacy of topical antibiotic powder in a preclinical contaminated wound model

AIMS

High-energy injuries can result in multiple complications, the most prevalent being infection. Vancomycin powder has been used with increasing frequency in orthopaedic trauma given its success in reducing infection following spine surgery. Additionally, large, traumatic injuries require wound coverage and management by dressings such as negative pressure wound therapy (NPWT). NPWT has been shown to decrease the ability of antibiotic cement beads to reduce infection, but its effect on antibiotic powder is not known. The goal of this study was to determine if NPWT reduces the efficacy of topically applied antibiotic powder.

METHODS

Complex musculoskeletal wounds were created in goats and inoculated with a strain of Staphylococcus aureus modified to emit light. Six hours after contaminating the wounds, imaging, irrigation, and debridement and treatment application were performed. Animals received either vancomycin powder with a wound pouch dressing or vancomycin powder with NPWT.

RESULTS

There were no differences in eradication of bacteria when vancomycin powder was used in combination with NPWT (4.5% of baseline) compared to vancomycin powder with a wound pouch dressing (1.7% of baseline) (p = 0.986), even though approximately 50% of the vancomycin was recovered in the NPWT exudate canister.

CONCLUSION

The antimicrobial efficacy of the vancomycin powder was not diminished by the application of NPWT. These topical and locally applied therapies are potentially effective tools that can provide quick, simple treatments to prevent infection while providing coverage. By reducing the occurrence of infection, the recovery is shortened, leading to an overall improvement in quality of life. Cite this article: Bone Joint Res 2021;10(2):149-155.

Circulatory collapse during wound closure in spine surgery with an unknown cause: a possible adverse effect of topical application of vancomycin?

BACKGROUND

Vancomycin (VCM) is effective in fighting Gram-positive bacteria related severe infections, and topical application of VCM powder is widely used in orthopedic surgery to prevent wound infection. However, VCM could lead to infusion rate-dependent antibody-and complement-independent anaphylaxis reaction by inducing direct release of histamine.

CASE PRESENTATION

We retrospectively analyzed seven cases of severe hypotension and shock during wound closure or immediately after orthopedic surgery with unidentifiable reasons. We found that these cases were all associated with local application of VCM powder during wound closure process. Two patients experienced sudden cardiac arrest. Most of the cases (6/7) with circulatory collapse were discharged without severe sequelae. While one case with application of 3 g VCM developed cardiac arrest and remained in a coma due to hypoxic-hypoxic encephalopathy. The clinical presentations and the time of the shock onset were considered to be related with a VCM induced anaphylaxis reaction. However, as this was a retrospective study, and there was no laboratory examination performed, the conclusion was made upon differential diagnosis based on clinical manifestations and the timing of the shock.

CONCLUSIONS

Local application of VCM may not be as safe as was once believed and may lead to a related anaphylaxis. As VCM induced infusion-rate dependent, non-IgE mediated anaphylaxis is characterized by delayed occurrence, severe hypotension and even circulatory collapse, surgeons and anesthesiologists should be extra vigilant during and after VCM application.