Intrawound Vancomycin Decreases the Risk of Surgical Site Infection After Posterior Spine Surgery: A Multicenter Analysis

Intrawound vancomycin powder in orthopaedic surgery as surgical site wound infection prophylaxis: A meta-analysis

A meta-analysis research was executed to appraise the consequence of intrawound vancomycin powder (IWVP) in orthopaedic surgery (OPS) as surgical site wound infection (SSWI) prophylaxis. Inclusive literature research till March 2023 was carried out and 2756 interconnected researches were revised. Of the 18 picked researches enclosed 13 214 persons with OPS were in the used researches' starting point, 5798 of them were utilising IWVP, and 7416 were control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to appraise the consequence of the IWVP in OPS as SSWI prophylaxis by the dichotomous approaches and a fixed or random model. IWVP had significantly lower SSWIs (OR, 0.61; 95% CI, 0.50-0.74, P < .001), deep SSWIs (OR, 0.57; 95% CI, 0.36-0.91, P = .02), and superficial SSWIs (OR, 0.67; 95% CI, 0.46-0.98, P = .04) compared with control in persons with OPS. IWVP had significantly lower SSWIs, deep SSWIs, and superficial SSWIs compared with control in persons with OPS. However, when interacting with its values, caution must be taken and more research is needed to confirm this finding.

Risk Factors for Surgical Site Infection in Spinal Surgery and Interventions: A Retrospective Study

BACKGROUND

Surgical site infection following spinal surgery causes prolonged delay in recovery after surgery, increases cost, and sometimes leads to additional surgical procedures. We investigated risk factors for the occurrence of surgical site infection events in terms of patient-related, surgery-related, and postoperative factors.

METHODS

This retrospective study included 1000 patients who underwent spinal surgery in our hospital between April 2016 and March 2019.

RESULTS

Patient-related factors were dementia, length of preoperative hospital stay (≥ 14 days), and diagnosis at the time of surgery (traumatic injury or deformity). The one surgery-related factor was multilevel surgery (≥ 9 intervertebral levels), and the one postoperative factor was time to ambulation (≥ 7 days) were statistically significant risk factors for spinal surgical site infection.

CONCLUSION

One risk factor identified in this study that is amenable to intervention is time to ambulation. As delayed ambulation is a risk factor for postoperative surgical site infection, how medical staff can intervene in postoperative ambulation to further reduce the incidence of surgical site infection is a topic for future research.

Prevention of Surgical Site Infections in Spine Surgery: An International Survey of Clinical Practices Among Expert Spine Surgeons

STUDY DESIGN

Questionnaire-based survey.

OBJECTIVES

Surgical site infection (SSI) is a common complication in spine surgery but universal guidelines for SSI prevention are lacking. The objectives of this study are to depict a global status quo on implemented prevention strategies in spine surgery, common themes of practice and determine key areas for future research.

METHODS

An 80-item survey was distributed among spine surgeons worldwide via email. The questionnaire was designed and approved by an International Consensus Group on spine SSI. Consensus was defined as more than 60% of participants agreeing to a specific prevention strategy.

RESULTS

Four hundred seventy-two surgeons participated in the survey. Screening for Staphylococcus aureus (SA) is not common, whereas preoperative decolonization is performed in almost half of all hospitals. Body mass index (BMI) was not important for surgery planning. In contrast, elevated HbA1c level and hypoalbuminemia were often considered as reasons to postpone surgery. Cefazoline is the common drug for antimicrobial prophylaxis. Alcohol-based chlorhexidine is mainly used for skin disinfection. Double-gloving, wound irrigation, and tissue-conserving surgical techniques are routine in the operating room (OR). Local antibiotic administration is not common. Wound closure techniques and postoperative wound dressing routines vary greatly between the participating institutions.

CONCLUSIONS

With this study we provide an international overview on the heterogeneity of SSI prevention strategies in spine surgery. We demonstrated a large heterogeneity for pre-, peri- and postoperative measures to prevent SSI. Our data illustrated the need for developing universal guidelines and for testing areas of controversy in prospective clinical trials.

Intrawound Vancomycin Powder Application for Preventing Surgical Site Infection Following Cranioplasty

OBJECTIVE

Surgical site infection is the most detrimental complication following cranioplasty. In other surgical fields, intrawound vancomycin powder application has been introduced to prevent surgical site infection and is widely used based on results in multiple studies. This study evaluated the effect of intrawound vancomycin powder in cranioplasty compared with the conventional method without topical antibiotics.

METHODS

This retrospective study included 580 patients with skull defects who underwent cranioplasty between August 1, 1998 and December 31, 2021. The conventional method was used in 475 (81.9%; conventional group) and vancomycin powder (1 g) was applied on the dura mater and bone flap in 105 patients (18.1%; vancomycin powder group). Surgical site infection was defined as infection of the incision, organ, or space that occurred after cranioplasty. Surgical site infection within 1-year surveillance period was compared between the conventional and vancomycin powder groups with logistic regression analysis. Penalized likelihood estimation method was used in logistic regression to deal with zero events. All local and systemic adverse events associated with topical vancomycin application were also evaluated.

RESULTS

Surgical site infection occurred in 31 patients (5.3%) and all were observed in the conventional group. The median time between cranioplasty and detection of surgical site infection was 13 days (range, 4-333). Staphylococci were the most common organisms and identified in 25 (80.6%) of 31 cases with surgical site infections. The surgical site infection rate in the vancomycin powder group (0/105, 0.0%) was significantly lower than that in the conventional group (31/475, 6.5%; crude odds ratio [OR], 0.067; 95% confidence interval [CI], 0.006-0.762; adjusted OR, 0.068; 95% CI, 0.006-0.731; p=0.026). No adverse events associated with intrawound vancomycin powder were observed during the follow-up.

CONCLUSION

Intrawound vancomycin powder effectively prevented surgical site infections following cranioplasty without local or systemic adverse events. Our results suggest that intrawound vancomycin powder is an effective and safe strategy for patients undergoing cranioplasty.

Impact of implant metal type and vancomycin prophylaxis on postoperative spine infection: an in-vivo study

PURPOSE

To evaluate the effectiveness of vancomycin prophylaxis on spinal implant metal types.

METHODS

42 rabbits underwent posterior, single-level instrumentation at L5-L6 with stainless steel (n = 18), cobalt chrome (n = 12), or titanium (n = 12) wire. All implants were inoculated with 1 × 106 colony forming units (CFU) of methicillin-resistant S. Aureus (MRSA). In the intrawound vancomycin subgroup (n = 18, 6 from each metal type), 40 mg of vancomycin powder was placed in the wound. In the IV vancomycin subgroup (n = 6, all stainless steel), 15 mg/kg of IV vancomycin was given preoperatively. Local soft tissue and implants were harvested 1-week postoperatively and separately cultured.

RESULTS

Intrawound vancomycin significantly reduced the rate of soft tissue infection (44.4% vs 100%) and implant infection (27.8% vs 100%) (p < 0.001). Within the intrawound vancomycin subgroup, cobalt chrome implants were associated with higher median soft tissue MRSA growth (130 CFU) than stainless steel (0 CFU) or titanium (0 CFU) (p = 0.02). Cobalt chrome implants were also more likely to develop soft tissue MRSA infection (83.3%) as compared to stainless steel (16.7%) or titanium (33.3%) (p = 0.04). Median soft tissue MRSA growth among stainless steel implants without prophylaxis, with IV vancomycin, and with vancomycin powder was 1.18 × 107, 195, and 0 CFU, respectively. The rate of soft tissue MRSA infection without prophylaxis, with IV vancomycin, and with vancomycin powder was 100, 66.7, and 16.7%, respectively (p = 0.015).

CONCLUSION

Intrawound vancomycin is more effective than IV vancomycin and effectively reduces the risk of infection, but is less effective in cobalt chrome implants due to residual soft tissue infection.

Intrawound low-dose vancomycin is superior to high-dose in controlling the risk of wound dehiscence in spine surgeries

Wound complications in spine surgeries are common and serious. This study aimed to determine the risk of wound dehiscence with a low-dose of intrawound vancomycin compared to that with a high-dose and no-vancomycin and its effectiveness in the prevention of surgical site infection. Patients were categorized into 3 groups. The first group did not receive any intrawound vancomycin. In the second, patients received a high-dose of vancomycin (1 g). The third group included patients who received a low-dose of intrawound vancomycin (250 mg). Patient demographics, clinical data, and surgical data were also collected. Multivariate linear regression analysis was used to examine factors associated with dehiscence or infection. Of the 391 patients included in our study, 56 (14.3%) received a high-dose of intrawound vancomycin, 126 (32.2%) received a low-dose, and 209 (53.5%) did not receive any treatment. The overall incidence of wound dehiscence was 6.14% (24 out of 391 patients). Wound dehiscence was significantly higher (P = .039) in the high-dose vancomycin group than in the low-dose vancomycin group. The overall incidence of postoperative infection was 2.05% (8 patients) and no statistically significant differences were observed between the low-dose and high-dose vancomycin groups. Patients with higher body mass index were more likely to experience wound dehiscence and postoperative infection, irrespective of the dose of vancomycin used. The use of low-dose intrawound vancomycin (250 mg) resulted in less wound dehiscence compared with high-dose vancomycin. Further trials are required to evaluate the effectiveness of the low-dose in preventing postoperative infections.

The Effect of Local Administration of Vancomycin Suspended in Fibrin Glue for Prevention of Surgical Site Infection After Spinal Instrumentation: Comparison by Probability of Treatment Weighting Model

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To compare the surgical site infection (SSI) rate in patients undergoing spinal instrumentation surgery who received vancomycin suspended in fibrin glue at the surgical site and those who did not.

SUMMARY OF BACKGROUND DATA

The intrawound application of vancomycin powder for preventing SSI after spinal surgery remains controversial. Vancomycin suspended in fibrin glue is another option for local administration that may be effective. The present study assessed whether vancomycin suspended in fibrin glue could prevent SSI after spinal instrumentation surgery.

MATERIALS AND METHODS

We enrolled patients who underwent posterior spinal instrumentation surgery with or without fusion for degenerative conditions, spinal trauma, or tumor. A multiple logistic regression model with inverse probability of treatment weighting based on propensity score was used to assess the efficacy of vancomycin suspended in fibrin glue and to account for confounding. A secondary multivariate logistic regression analysis was performed to identify the risk factors associated with SSI.

RESULTS

Of the 264 patients enrolled in this study, 134 underwent application of vancomycin suspended in fibrin glue at the surgical site and 130 did not. The incidence of SSI was lower in patients who were treated with vancomycin suspended in fibrin glue (2.2% vs. 8.5%) even after inverse probability of treatment weighting adjustment (adjusted odds ratio: 0.25; 95% CI, 0.0768-0.91; P =0.03). Multivariate logistic regression analysis showed that the treatment with vancomycin suspended in fibrin glue was significantly associated with a lower odds of SSI (odds ratio: 0.2; 95% CI, 0.05-0.85; P =0.03).

CONCLUSIONS

The administration of vancomycin suspended in fibrin glue was significantly associated with a lower likelihood of SSI in patients undergoing spinal instrumentation surgery.

Prophylactic Application of Vancomycin Powder in Preventing Surgical Site Infections After Spinal Surgery

OBJECTIVE

We sought to analyze the preventive effect of local vancomycin powder application on surgical site infection (SSI) in spinal surgeries and provide the basis for future clinical practice.

METHODS

Through PubMed, Medline, Elsevier, and the Cochrane Library, with MeSH words "vancomycin powder," "local/intraoperative/topical/intra-wound," "spine/spinal/lumbar/cervical/thoracolumbar," "surgery," "infection," and "SSI," we searched for case-control research papers on the impact of prophylactic application of vancomycin powder on the incidence of SSI and compared the rate of infection using RevMan 5.3 meta-analysis software.

RESULTS

A total of 1950 publications were found using the mesh words, and 50 of those studies were selected for final analysis. There were 34,301 cases in total, including 14,793 cases in vancomycin group and 19,508 cases in the control group. Results of meta-analysis showed that the incidence of SSI was significantly lower in the prophylactic vancomycin powder group than the control group (P < 0.001). Further subgroup analysis showed that the incidence of SSI was significantly lower in the prophylactic vancomycin powder group than the control group in spine surgeries with internal fixation, deformity correction, and deep tissue infections (P < 0.001). Meanwhile, there were no significant differences between the 2 groups concerning patients undergoing noninstrumented spine surgeries and the incidence of superficial tissue infection.

CONCLUSIONS

Overall, prophylactic application of vancomycin powder in spinal surgery can significantly reduce the incidence of SSI in deep tissues, and this effect is more prominent in patients undergoing internal fixation and deformity correction surgeries.

Evidence-based guideline for the prevention and management of perioperative infection

BACKGROUND

We have updated the guideline for preventing and managing perioperative infection in China, given the global issues with antimicrobial resistance and the need to optimize antimicrobial usage and improve hospital infection control levels.

METHODS

We conducted a comprehensive evaluation of the evidence for prevention and management of perioperative infection, based on the concepts of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The strength of recommendations was graded and voted using the Delphi method and the nominal group technique. Revisions were made to the guidelines in response to feedback from the experts.

RESULTS

There were 17 questions prepared, for which 37 recommendations were made. According to the GRADE system, we evaluated the body of evidence for each clinical question. Based on the meta-analysis results, recommendations were graded using the Delphi method to generate useful information.

CONCLUSIONS

This guideline provides evidence to perioperative antimicrobial prophylaxis that increased the rational use of prophylactic antimicrobial use, with substantial improvement in the risk-benefit trade-off.

Interaction of basic diseases and low red blood cell count as critical murderer of wound infection after osteosarcoma resection: Wound infection after osteosarcoma resection

BACKGROUND

Surgical wound infection is one of the common complications in patients after osteosarcoma resection. It is imperative to grasp the risk factors comprehensively. Therefore, this study aimed to explore the risk factors of wound infection and deeply analyze the correlation between risk factors and wound infection.

METHODS

The study subjects were 101 patients who underwent osteosarcoma resection between April 2018 and August 2021. The diagnosis of postoperative wound infection was confirmed by postoperative observation of the incision, ultrasound imaging, and pathogenic examination. This study included a series of potential factors, mainly laboratory examination indicators and patients' general information. The statistical methods had Pearson Chi-square test, Spearman-rho correlation test, multifactorial linear regression model, logistic regression analysis, and receiver operating characteristic (ROC) curve.

RESULTS

Pearson Chi-square test and Spearman correlation test showed that red blood cell (RBC) count (P = .033) and basic diseases (P = .020) were significantly correlated with a surgical wound infection after osteosarcoma resection. Logistic regression analysis manifested that basic disease (OR = 0.121, 95% CI: 0.015-0.960, P = .046) and RBC (OR = 0.296, 95% CI: 0.093-0.944, P = .040) have a clear correlation with whether the patients have surgical wound infection after osteosarcoma resection. And the interaction of basic diseases and RBC could diagnose the surgical wound infection sensitively and accurately (AUC = 0.700, P = .014, 95% CI = 0.564-0.836) via the ROC analysis.

CONCLUSION

Patients with basic diseases and low RBC were risk factors for surgical wound infection after osteosarcoma resection.

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.

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.

Expert consensus on surgical treatment for adolescent idiopathic scoliosis in Japan

BACKGROUND

Surgical treatment for adolescent idiopathic scoliosis (AIS) has changed significantly with the advent of new medical devices and surgical procedures. Today, pre- and postoperative management differs widely between institutions. The purpose of this study is to establish consensus regarding the surgical management of AIS in Japan through the use of a questionnaire survey of experienced spine deformity surgeons.

METHODS

From February to March 2020, experienced spine deformity surgeons who perform more than 25 cases of AIS surgery annually were asked to respond to a questionnaire request regarding AIS surgical management formulated by the International Affairs Committee of the Japanese Scoliosis Society. For each of the questions, consensus was achieved upon a 70% agreement among respondents.

RESULTS

Responses were received from 25 of the 32 (78%) experienced spine deformity surgeons. The average age of the responding surgeons was 52 years with an average practice experience of 28 year. Consensus was achieved on 74 (76%) of the 97 aspects of care presented in the questionnaire and is broken down as follows: 12 of 17 items for preoperative management, all 5 items for perioperative management, 11 of 14 items for surgical technique, 9 of 15 items for implant selection, 6 of 8 items for bone grafting, 7 of 10 items for blood conservation, 5 of 7 items for postoperative management, all 17 items for postoperative evaluation, and 2 of 4 items for aftercare.

CONCLUSIONS

Expert consensus was achieved on 74 aspects of the surgical management of AIS in Japan. In implant selection and aftercare, consensus was obtained in less than 70% of the aspects, revealing differences in AIS management between institutions. These findings on AIS surgery in Japan, informed by expert opinion, will conceivably help spine deformity surgeons determine appropriate surgical management of AIS.

Surgical Site Infection Following Primary Definitive Fusion for Pediatric Spinal Deformity: A Multicenter Study of Rates, Risk Factors, and Pathogens

STUDY DESIGN

A retrospective multicenter study.

OBJECTIVE

To determine the surgical site infection (SSI) rate, associated risk factors, and causative pathogens in pediatric patients with spinal deformity.

SUMMARY OF BACKGROUND DATA

There have been no extensive investigations of the risk factors for SSI in Japan.

METHODS

Demographic data, radiographic findings, and the incidence of SSI were retrospectively analyzed in 1449 pediatric patients who underwent primary definitive fusion surgery for spinal deformity at any of 15 institutions from 2015 to 2017. SSI was defined according to the US Centers for Disease Control and Prevention guideline.

RESULTS

The incidence of all SSIs was 1.4% and that of deep SSIs was 0.76%. The most common pathogenic microbes were methicillin-resistant staphylococci (n = 5) followed by gram-negative rods (n = 4), methicillin-sensitive staphylococci (n = 1), and others (n = 10). In univariate analysis, younger age, male sex, a diagnosis of kyphosis, type of scoliosis, American Society of Anesthesiologists (ASA) class ≥3, mental retardation urinary incontinence, combined anterior-posterior fusion, greater magnitude of kyphosis, three-column osteotomy, use of blood transfusion, and number of antibiotic administration were associated with the likelihood of SSI (all P < 0.05). Multivariate logistic regression analysis identified the following independent risk factors for SSI: syndromic scoliosis etiology (vs. idiopathic scoliosis; adjusted odds ratio [OR] 16.106; 95% confidence interval [CI] 2.225-116.602), neuromuscular scoliosis etiology (vs. idiopathic scoliosis; adjusted OR 11.814; 95% CI 1.109-125.805), ASA class 3 (vs. class 2; adjusted OR 15.231; 95% CI 1.201-193.178), and administration of antibiotic therapy twice daily (vs. three times daily; adjusted OR 6.121; 95% CI 1.261-29.718).

CONCLUSION

The overall infection rate was low. The most common causative bacteria were methicillin-resistant followed by gram-negative rods. Independent risk factors for SSI in pediatric patients undergoing spinal deformity surgery were scoliosis etiology, ASA class 3, and administration of antibiotic therapy twice daily.Level of Evidence: 3.

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.

Antibacterial Activity in Iodine-coated Implants Under Conditions of Iodine Loss: Study in a Rat Model Plus In Vitro Analysis

BACKGROUND

We developed iodine-coated titanium implants to suppress microbial activity and prevent periprosthetic joint infection (PJI); their efficacy was demonstrated in animal and in vitro models. The iodine content in iodine-coated implants naturally decreases in vivo. However, to our knowledge, the effect of reduced iodine content on the implant's antimicrobial activity has not been evaluated to date.

QUESTIONS/PURPOSES

(1) How much does the iodine content on the implant surface decrease after 4 and 8 weeks in vivo in a rat model? (2) What effect does the reduced iodine content have on the antimicrobial effect of the implant against multiple bacteria in an in vitro model?

METHODS

This experiment was performed in two parts: an in vivo experiment to determine attenuation of iodine levels over time in rats, and an in vitro experiment in which we sought to assess whether the reduced iodine content observed in the in vivo experiment was still sufficient to deliver antimicrobial activity against common pathogens seen in PJI. For the in vivo experiment, three types of titanium alloy washers were implanted in rats: untreated (Ti), surface-anodized to produce an oxide film (Ti-O), and with an iodine layer on the oxidation film (Ti-I). The attenuation of iodine levels in rats was measured over time using inductively coupled plasma-mass spectrometry. Herein, only the Ti-I washer was used, with five implanted in each rat that were removed after 4 or 8 weeks. For the 4- and 8-week models, two rats and 15 washers were used. For the in vitro study, to determine the antibacterial effect, three types of washers (Ti, Ti-O, and Ti-I) (nine washers in total) were implanted in each rat. Then, the washers were removed and the antibacterial effect of each washer was examined on multiple bacterial species using the spread plate method and fluorescence microscopy. For the spread plate method, six rats were used, and five rats were used for the observation using fluorescence microscopy; further, 4- and 8-week models were made for each method. Thus, a total of 22 rats and 198 washers were used. Live and dead bacteria in the biofilm were stained, and the biofilm coverage percentage for quantitative analysis was determined using fluorescence microscopy in a nonblinded manner. Ti-I was used as the experimental group, and Ti and Ti-O were used as control groups. The total number of rats and washers used throughout this study was 24 and 213, respectively.

RESULTS

Iodine content in rats implanted with Ti-I samples decreased to 72% and 65% after the in vivo period of 4 and 8 weeks, respectively (p = 0.001 and p < 0.001, respectively). In the in vitro experiment, the Ti-I implants demonstrated a stronger antimicrobial activity than Ti and Ti-O implants in the 4- and 8-week models. Both the median number of bacterial colonies and the median biofilm coverage percentage with live bacteria on Ti-I were lower than those on Ti or Ti-O implants for each bacterial species in the 4- and 8-week models. There was no difference in the median biofilm coverage percentage of dead bacteria. In the 8-week model, the antibacterial activity using the spread plate method had median (interquartile range) numbers of bacteria on the Ti, Ti-O, and Ti-I implants of 112 (104 to 165) × 105, 147 (111 to 162) × 105, and 55 (37 to 67) × 105 of methicillin-sensitive Staphylococcus aureus (Ti-I versus Ti, p = 0.026; Ti-I versus Ti-O, p = 0.009); 71 (39 to 111) × 105, 50 (44 to 62) × 105, and 26 (9 to 31)× 105 CFU of methicillin-resistant S. aureus (Ti-I versus Ti, p = 0.026; Ti-I versus Ti-O, p = 0.034); and 77 (74 to 83) × 106, 111 (95 to 117) × 106, and 30 (21 to 45) × 106 CFU of Pseudomonas aeruginosa (Ti-I versus Ti, p = 0.004; Ti-I versus Ti-O, p = 0.009). Despite the decrease in the iodine content of Ti-I after 8 weeks, it demonstrated better antibacterial activity against all tested bacteria than the Ti and Ti-O implants.

CONCLUSION

Iodine-coated implants retained their iodine content and antibacterial activity against methicillin-sensitive S. aureus, methicillin-resistant S. aureus, and P. aeruginosa for 8 weeks in vivo in rats. To evaluate the longer-lasting antibacterial efficacy, further research using larger infected animal PJI models with implants in the joints of both males and females is desirable.

CLINICAL RELEVANCE

Iodine-coated titanium implants displayed an antibacterial activity for 8 weeks in rats in vivo. Although the findings in a rat model do not guarantee efficacy in humans, they represent an important step toward clinical 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.

Intrawound Antibiotic Powder in Acetabular Fracture Open Reduction Internal Fixation Does Not Reduce Surgical Site Infections

OBJECTIVES

To compare the risks of surgical site infection (SSI) and postoperative complications after acetabular fracture open reduction internal fixation (ORIF) in patients receiving topical intrawound antibiotic powder compared with those not receiving antibiotic powder (control group).

DESIGN

Retrospective cohort.

SETTING

Level I trauma center.

PATIENTS AND INTERVENTION

We reviewed 789 acetabular fracture ORIF cases from 2010 to 2019 at our institution, with mean follow-up of 18 months (3-112 months). Overall, 326 patients comprised the control group and 463 received topical antibiotic powder (294 vancomycin and 169 vancomycin/tobramycin).

MAIN OUTCOME MEASUREMENT

The study groups were compared for risk of SSI, seroma formation, wound dehiscence, acute kidney injury (AKI), and other postoperative complications.

RESULTS

There were 63 total SSI (8.0%), 50 (6.3%) deep SSI and 13 suprafascial SSI (1.6%) cases. There was no difference in the risk of total SSI (8.3% vs. 7.8%, P = 0.80) or deep SSI (6.1% vs. 6.5%, P = 0.64). This was confirmed by multivariate analysis adjusting for covariates (odds ratio = 0.93; 95% confidence interval, 0.52-1.67; P = 0.80). Similar results were demonstrated when comparing the control group with the vancomycin and vancomycin/tobramycin subgroups. The control group and antibiotic powder groups had similar risks of all outcomes of interest, including seroma formation (1.8% vs. 1.7%, P = 1.00), wound dehiscence (1.2% vs. 2.2%, P = 0.42), total AKI (5.2% vs. 8.2%, P = 0.12), and RIFLE classification AKI (injury; 0.9% vs. 2.2%, P = 0.50).

CONCLUSIONS

The addition of topical intrawound antibiotic powder, whether vancomycin alone or vancomycin/tobramycin before closure, does not reduce the risk of SSI after acetabular fracture ORIF compared with standard normal saline irrigation alone.

LEVEL OF EVIDENCE

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

Effect of Vancomycin Soaking on Anterior Cruciate Ligament Graft Biomechanics

PURPOSE

To evaluate the effect of soaking of anterior cruciate ligament (ACL) grafts in vancomycin solution on graft biomechanical properties at the time of implantation.

METHODS

The central third of patellar tendons was harvested from mature bovine knees and prepared as a tendon-only graft or a bone-tendon-bone (BTB) graft. Tendons were wrapped in gauze soaked in vancomycin solution (VS) (5 mg/mL) or normal saline (NS) and left to stand for 30 minutes at room temperature, simulating graft exposure times in the operating room during ACL reconstruction. Tensile testing was carried out on a materials testing system with (1) low-magnitude loading (60 N at 3 mm/s) with repeated testing of tendon-only grafts; and (2) high-magnitude loading (600 N at 10 mm/min) of BTB grafts. For tendon-only grafts, specimens were first wrapped in NS-soaked gauze and underwent testing, with repeated testing performed after wrapping in gauze soaked in VS or buffered VS (pH 7.0). For BTB grafts, specimens were randomly assigned to treatment with VS or NS.

RESULTS

For tendon-only grafts, there was no difference in Young's modulus (YM) after soaking with VS soaking (baseline, 12.69 MPa; treatment, 16.07 ± 4.44 MPa; P = .99) or buffered VS (baseline, 12.45 ± 4.55 MPa; treatment, 15.56 ± 2.83 MPa; P = .99). For BTB grafts, there were no differences in elongation strain (VS, 46.8% ± 7.0%; NS, 31.5% ± 13.5%, P = .19) or YM (VS, 158.4 ± 15.8 MPa; NS, 158.5 ± 23.3 MPa, P = .99).

CONCLUSIONS

According to controlled biomechanical tests, vancomycin soaking of patellar tendon grafts does not adversely affect time-zero material properties.

CLINICAL RELEVANCE

This study suggests that vancomycin wrapping has no immediate adverse effects on the biomechanical properties of ACL grafts. Randomized controlled trials are warranted to validate the widespread use of vancomycin soaking of tendon grafts for infection prophylaxis during ACL reconstruction.

Sustained Postoperative Fever Without Evident Cause After Spine Instrumentation as an Indicator of Surgical Site Infection

BACKGROUND

Surgical site infection after spinal instrumentation increases morbidity and mortality as well as medical costs and is a burden to both patients and surgeons. Late-onset or sustained fever increases the suspicion for comorbid conditions. This retrospective, exploratory cohort study was conducted to identify the rate of and risk factors for sustained or late-onset postoperative fever after spinal instrumentation operations and to determine its relationship with surgical site infection.

METHODS

Five hundred and ninety-eight patients who underwent lumbar or thoracic spinal instrumentation were retrospectively reviewed. The patients were divided according to (1) whether or not they had had a sustained fever (SF[+] or SF[-]) and (2) whether or not they had had a surgical site infection (SSI[+] or SSI[-]). Clinical characteristics, surgical factors, prophylactic antibiotic usage, fever pattern, and laboratory/imaging findings were recorded for all patients by electronic medical chart review.

RESULTS

In total, 68 patients (11.4%) had a sustained fever. The rate of surgical site infection was significantly higher when the patient had sustained fever (13.2% [9 of 68] compared with 0.9% [5 of 530]; p < 0.001). Comparison of the patients who had a sustained fever but no surgical site infection (SF[+], SSI[-]) and those with both a sustained fever and surgical site infection (SF[+], SSI[+]) showed that continuous fever, an increasing or stationary pattern of inflammatory markers, and a C-reactive protein (CRP) level of >4 mg/dL on postoperative days 7 to 10 were diagnostic clues for surgical site infection. The sensitivity and specificity of postoperative magnetic resonance imaging (MRI) for the detection of surgical site infection were 40.0% and 90.9%, respectively, when MRI was performed within 1 month after surgery.

CONCLUSIONS

Although most patients with sustained fever did not have surgical site infection, fever was significantly related to surgical site infection. Continuous fever, increasing patterns of inflammatory markers, and high CRP on postoperative days 7 to 10 were diagnostic clues for surgical site infection. This study demonstrated provisional results for factors that can discriminate febrile patients with surgical site infection from febrile patients without infection. Further investigation with a larger sample size is warranted for clarification.

LEVEL OF EVIDENCE

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

Diagnostic performance of suction drainage fluid culture for acute surgical site infection after aseptic instrumented spine surgery: a retrospective analysis of 363 cases

PURPOSE

Analyze the diagnostic performance of suction drainage fluid culture for acute surgical site infection, which has not been specifically reported in spine surgery patients.

METHOD

This was a retrospective single-center observational study including data from 363 patients who underwent aseptic instrumented spine surgery between 2015 and 2017. A suction drain was inserted in all cases. Data analyzed were patient age, gender, ASA score, indication for surgery (degenerative disease, tumor, trauma), spine level (cervical, thoracic, lumbar), procedure performed and spine level, operative time, body temperature, postoperative C-reactive protein time-curve, clinical aspect of surgical scar, bacteriology results of suction drainage fluid, and in case of revision surgery, lavage fluid. Major criteria for periprosthetic infection proposed by the Musculoskeletal Infection Society (MSIS) were accepted as the gold standard for the diagnosis of acute surgical site infection.

RESULTS

The overall rate of surgical site infection was 6.9% (5.76% for 1- or 2-level fusion, 5.81% for 3- or 4-level fusion, and 15.6% for 5-level fusion and above). The suction drain was withdrawn on the second postoperative day in 44.1% of cases and the third day in 39.1%. The sensitivity of suction drainage fluid culture for the diagnosis of surgical site infection was 20% [95%CI 6.8-40.7%] with a 96.2% [95%CI 93.2-97.9] specificity.

CONCLUSION

The diagnostic performance of suction drainage fluid culture after aseptic instrumented spine surgery for acute surgical site infection is insufficient to warrant its use in routine practice.

[The effectiveness of local application of vancomycin powder in the prevention of surgical site infections in spine surgery: a meta-analysis]

OBJECTIVE

To perform a meta-analysis of studies examining the effectiveness of the local application of vancomycin powder for the prophylaxis of surgical site infections (SSIs) in spine surgery.

MATERIAL AND METHODS

Retrospective cohort studies and prospective randomized clinical trials were searched for in the Pubmed, EMBASE, Cochrane Library and eLibrary databases published from 2008 to December 2018. For the resulting variables, the odds ratio and 95% confidence interval were calculated using random and fixed effects models. Estimation of the degree of heterogeneity is estimated using the coefficient I². Statistically significant differences were considered differences p<0.05.

RESULTS

The meta-analysis included 28 clinical studies that included the results of the local application of vancomycin powder in 17,469 patients after performing various spinal surgical interventions. Two publications had a prospective, randomized, controlled study design. Topical application of vancomycin powder reduces the incidence of SSIs after spine surgery (p<0.0001). The use of vancomycin powder reduces the incidence of SSIs in patients operated on with stabilizing implants (p=0.004). On the other hand, the topical application of vancomycin powder did not affect the prevalence of SSIs in respondents who were operated on without the use of stabilizing implants (p=0.12) or due to deformities of the spine (p=0.06).

CONCLUSION

Topical application of vancomycin powder is highly effective in preventing the development of SSIs in patients after spinal surgical interventions.

Does Intra-Wound Vancomycin Powder Affect the Action of Intra-Articular Tranexamic Acid in Total Joint Replacement?

The intra-articular use of tranexamic acid (TXA) has contributed to reduced blood loss in total joint arthroplasty (TJA). The purpose of this study is to assess the efficacy of simultaneously topical use of tranexamic acid and vancomycin powder within the TJA space. From 2016 to 2017, 219 consecutive total hip arthroplasties (THAs) and 272 total knee arthroplasties (TKAs) were performed in a tertiary care center, with a group of patients receiving intra-articular TXA and vancomycin, compared to patients receiving only TXA and to a control group that did not receive anything. Haemoglobin and hematocrit were measured preoperatively, on the first and third days. Transfusions and adverse events were recorded. Haemoglobin and hematocrit dropped significantly in all THA and TKA groups till the third day postoperatively, with a major reduction in the control group, compared to the other two treatment groups. Infections and thromboembolic events were similar in either group of the TJAs. In conclusion, the topical use of tranexamic acid mixed with the vancomycin powder within the joint space after the TJAs of the hip and knee did not alter the anti-fibrinolytic effect of TXA.

Factors associated with extended length of stay in patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

To investigate whether certain patient, surgical, and recovery-related factors may be associated with extended LOS following posterior spinal fusion for Adolescent Idiopathic Scoliosis (AIS). Understanding determinants of hospital length of stay (LOS) following surgical procedures is important for perioperative planning and improvements in quality of care.

METHODS

Using a private insurance claims database, AIS patients ages 10-21 that underwent posterior spinal fusion from 2010 to 2016 in the United States were identified. Extended LOS was defined as > 7.2 days (+ 1 standard deviation from the mean). Univariate and multivariate analyses were performed to identify factors associated with extended LOS. Significance was set at p < 0.05.

RESULTS

5864 patients met the inclusion criteria (mean age 14.4 ± 2.2 years; 75% girls). Mean LOS was 4.7 ± 2.5 days (median 4 days). 69% patients had 7-12 levels fused, and 25% had 13+ levels fused. On multivariate analysis, factors associated with extended LOS were: longer fusion construct (13+ levels fused) (OR 2.1, p = 0.020), thoracoplasty (OR 3.8, p < 0.001), and postoperative complications: wound problems (OR 13, p < 0.001), respiratory problems (OR 7.9, p < 0.001), urinary tract infection (OR 6.0, p < 0.001), and constipation (OR 2.4, p < 0.001). Postoperative ICU admission, female gender, and surgery performed on Wednesday were significant on univariate analysis but not on multivariate analysis. Extended LOS was associated with an increase of $50,494 in net hospital payments (p < 0.001).

CONCLUSION

Patient, surgical and recovery factors are associated with extended LOS in AIS patients who undergo posterior spinal fusion surgery. Extended LOS significantly increases healthcare spending.

LEVEL OF EVIDENCE

Level III.

Current Strategies in Prevention of Postoperative Infections in Spine Surgery

STUDY DESIGN

Narrative review.

OBJECTIVES

Postoperative surgical site infections (SSIs) are among the most common acute complications in spine surgery and have a devastating impact on outcomes. They can lead to increased morbidity and mortality as well as greater economic burden. Hence, preventive strategies to reduce the rate of SSIs after spine surgery have become vitally important. The purpose of this article was to summarize and critically analyze the available evidence related to current strategies in the prevention of SSIs after spine surgery.

METHODS

A literature search utilizing Medline database was performed. Relevant studies from all the evidence levels have been included. Recommendations to decrease the risk of SSIs have been provided based on the results from studies with the highest level of evidence.

RESULTS

SSI prevention occurs at each phase of care including the preoperative, intraoperative, and postoperative periods. Meticulous patient selection, tight glycemic control in diabetics, smoking cessation, and screening/eradication of Staphylococcus aureus are some of the main preoperative patient-related preventive strategies. Currently used intraoperative measures include alcohol-based skin preparation, topical vancomycin powder, and betadine irrigation of the surgical site before closure. Postoperative infection prophylaxis can be performed by administration of silver-impregnated or vacuum dressings, extended intravenous antibiotics, and supplemental oxygen therapy.

CONCLUSIONS

Although preventive strategies are already in use alone or in combination, further high-level research is required to prove their efficacy in reducing the rate of SSIs in spine surgery before evidence-based standard infection prophylaxis guidelines can be built.

Complexities of spine surgery in obese patient populations: a narrative review

The obese population is particularly challenging to the spine surgeon in all phases of care. A narrative literature review was performed to review difficulties in spine surgery on the obese patient population and techniques for mitigation. We specifically aimed to assess several topics with regard to this population: patient selection and preoperative care; intraoperative and surgical techniques; and postoperative care, outcomes, and complications. The literature review demonstrated that obese patients are at increased surgical risk with spine surgery due to a variety of factors at all stages of intervention. Preoperatively, obese patients have worse outcomes with physical therapy and present technical difficulties for injections. Transport to a hospital, imaging, resuscitation, and intubation are all challenged by increased body habitus. Intraoperatively, obese patients have increased operative times, blood loss, surgical site infections, and nerve palsies. Patient positioning and intraoperative imaging may be limited. Surgery itself may be technically challenging due to body habitus and minimally invasive techniques are becoming more prevalent in this population. Postoperatively, several studies demonstrate that obese patients have inferior outcomes compared with nonobese counterparts. Patient selection is a key for elective interventions, and appropriate infrastructure aids in the ultimate outcomes for both elective and nonelective surgical treatments. Overall, obese patients present several challenges to the spine surgeon, and certain precautions can be undertaken preoperatively, intraoperatively, and postoperatively to mitigate the associated risks to optimize outcomes.

Spinal Fusion Surgery and Local Antibiotic Administration: A Systematic Review on Key Points From Preclinical and Clinical Data

STUDY DESIGN

Systematic review.

OBJECTIVE

The present review of clinical and preclinical in vivo studies focused on the local antibiotic administration for surgical site infection (SSI) in spinal fusion procedures and identifying new approaches or research direction able to release antibiotics in the infected environment.

SUMMARY OF BACKGROUND DATA

SSI is a severe complication of spinal fusion procedures that represents a challenging issue for orthopedic surgeons. SSIs can range from 0.7% to 2.3% without instrumentation up to 6.7% with the use of instrumentation with significant implications in health care costs and patient management.

METHOD

A systematic search was carried out by two independent researchers according to the PRISMA statement in three databases (www.pubmed.com, www.scopus.com and www.webofknowledge.com) to identify preclinical in vivo and clinical reports in the last 10 years. Additionally, to evaluate ongoing clinical trials, three of the major clinical registry websites were also checked (www.clinicaltrials.gov, www.who.int/ictrp, https://www.clinicaltrialsregister.eu).

RESULTS

After screening, a total of 43 articles were considered eligible for the review: 36 clinical studies and seven preclinical studies. In addition, six clinical trials were selected from the clinical registry websites.

CONCLUSION

The results reported that the topical vancomycin application seem to represent a strategy to reduce SSI incidence in spine surgery. However, the use of local vancomycin as a preventive approach for SSIs in spine surgery is mostly based on retrospective studies with low levels of evidence and moderate/severe risk of bias that do not allow to draw a clear conclusion. This review also underlines that several key points concerning the local use of antibiotics in spinal fusion still remains to be defined to allow this field to make a leap forward that would lead to the identification of specific approaches to counteract the onset of SSIs.

LEVEL OF EVIDENCE

4.

Cervical laminoplasty: indication, technique, complications

Cervical laminoplasty is a non-fusion, decompression procedure for cervical spondylotic myelopathy (CSM). It is most commonly indicated for patients with multilevel stenosis who have preserved sagittal alignment and minimal to no axial neck pain related to spondylosis. Expansion of the laminar arch can allow for direct and indirect decompression of the spinal canal. Relative contraindications include those patients with significant preoperative neck pain, kyphotic alignment and substantial instability. Potential advantages over laminectomy and fusion include avoiding fusion-related complications, and the preservation of motion. Important technical considerations include meticulous extensor muscle management, with special attention being given to preserving the soft tissue attachments to C2. In the properly selected patient, outcomes are comparable, and in some studies superior, to other operations for CSM.

Operative Field Debris Often Rises to the Level of the Surgeon's Face Shield During Spine Surgery: Are Orthopedic Space Suits a Reasonable Solution?

Background

The present study intended to identify debris in the spine surgical field that frequently rises to the level of the surgeon's face during several different elective spine procedures. Unlike other areas of orthopedic surgery where infection risk is of high concern, in spine surgery the surgical team usually uses a nonsterile face mask instead of a protective space suit with a sterile face shield. It is possible that blood or bone burr particles striking the surgeon's face mask represent a potential source of infection if they ricochet back into the operative field.

Methods

We reviewed 46 consecutive, elective spine surgeries between May 2015 and August 2015 from a single-surgeon practice. For each surgery, every member of the surgical team wore sterile (space suit) personal protective equipment. After each procedure, the face shield was carefully inspected by 2 members of the surgical team to identify patient blood, tissue, or bone burr dust present on the face shield.

Results

The rate of surgeon face shield debris inspected for each case overall was 38/46 (83%). The rate of first assistant face shield debris inspected per case was 16/46 (35%). The scrub technician had a 0% rate of face mask debris on inspection. The highest debris exposure rates occurred with transforaminal lumbar interbody fusions (100%), open laminectomy and fusions (100%), and anterior cervical discectomy and fusions 43/46 (93%).

Conclusions

There is a high rate of blood and tissue debris contact that occurs during spine surgery, and it is procedure dependent. Spine surgeons may consider using sterile shields particularly in high-risk cases to protect themselves and their patients.

Level of Evidence

4.

Infectious Prophylaxis with Intrawound Vancomycin Powder in Orthopedic Surgeries: Systematic Review with Meta-Analysis

Despite many existing strategies used to reduce the rates of surgical site infection (SSI), these are still fairly frequent complications that pose a challenge for orthopedic surgeons. Therefore, the search for more effective methods of perioperative infection prophylaxis became a main subject of research, with the goal of decreasing postoperative morbidity, mortality, and costs. Thus, the present study sought to assess the effectiveness of intra-wound vancomycin powder in orthopedic surgery SSI prophylaxis. A systematic review and meta-analysis study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols 2015 (PRISMA-P 2015). A comprehensive literature search was performed to identify controlled studies on the rates of SSI with or without the local use of vancomycin powder. Exclusion and inclusion criteria were applied. A meta-analysis with random effects was performed. Out of 412 titles that met the criteria, 7 studies regarding spine surgery were included: 4 prospective and 3 retrospective studies. A total of 6,944 cases were identified, and they were divided into 2 groups: the control group (3,814 patients), to whom intrawound vancomycin was not administered, and the intervention group (3,130 patients), to who vancomycin was administered locally. We observed that 64 (2.04%) patients in the intervention group developed SSI, in contrast to 144 (3.75%) patients in the control group. The results of the meta-analysis showed that the local use of vancomycin powder had an statistically significant protective effect against SSI in cases of spine surgery, with a relative risk (RR) of 0.59 and a 95% confidence interval (95%CI) of 0.35-0.98. The use of prophylactic intrawound vancomycin powder has a protective effect against SSI in spine surgeries; however, further prospective trials are needed to endorse its use in orthopedic surgeries.

Efficacy and Cost-effectiveness of Topical Vancomycin Powder in Primary Cementless Total Hip Arthroplasty

Topical vancomycin has been shown to effectively reduce infections after spinal surgery while remaining safe and cost-effective; however, there are few studies evaluating topical vancomycin in total hip arthroplasty. The authors hypothesized that the incidence of periprosthetic joint infection would decrease with the use of topical vancomycin in total hip arthroplasty and that topical vancomycin would be cost-effective. A retrospective patient chart review was performed to evaluate consecutive primary cementless total hip arthroplasties performed in the authors' hospital system between April 2015 and December 2016. Demographic data were collected. Periprosthetic joint infection was defined by Musculoskeletal Infection Society criteria. Statistical analysis included t test, Fisher's exact test, and logistic regression. The costs of vancomycin and postoperative infection were used to determine the absolute risk reduction (1/number needed to treat) threshold needed for topical vancomycin to be cost-effective. In this study, 309 patients (55.7%) undergoing total hip arthroplasty were treated with topical vancomycin, and 246 patients (44.3%) did not receive treatment. There were 2 infections in the vancomycin group (0.6% incidence), and 4 in the no vancomycin group (1.6% incidence). There was no statistical difference in infection rate between the 2 cohorts (P=.414). The absolute risk reduction was 0.98%, and the number needed to treat with topical vancomycin was 102 patients to prevent 1 periprosthetic joint infection. Topical vancomycin ($12 per vial) resulted in an expected cost savings of $904 per patient. Topical vancomycin is inexpensive and cost-effective. Although not statistically significant, the topical vancomycin group had a 60% lower incidence of infection. Further research regarding appropriate prophylactic topical and intravenous antibiotic use is needed prior to widespread adoption. [Orthopedics. 2019; 42(5):e430-e436.].

Topical instillation of vancomycin lowers the rate of CSF shunt infections in children

INTRODUCTION

Shunt surgery in pediatric patients still bears a significant risk of infection, in addition to mechanical complications of the shunt system. Antibiotic-impregnated systems and perioperative antibiotics have been extensively studied for their potential to reduce shunt infections. We examined the effectiveness of intrawound application of vancomycin powder during shunt surgery.

PATIENTS AND METHODS

Patient records of 78 primary shunt implantations at a mean age of 40 months were reviewed. In total, 52 patients (mean age 50 months) had been treated according to standard surgical and perioperative procedures (Std), whereas 26 patients (mean age 20 months) additionally had received topical application of vancomycin powder before wound closure (Vmc). Overall infection rate was 3.8%, in Std patients 5.8%, and in Vmc patients 0%. The rates of CSF fistula and revision surgery were similar in both groups (5.8% vs 8% and 23.1% vs. 30%, respectively).

CONCLUSION

To the best of our knowledge, this is the first report on topical vancomycin instillation, indicating its efficacy for the prevention of shunt infection in pediatric patients. Further studies with a higher number of patients are needed to verify this finding.

Risk Factors for Early Infection in Pediatric Spinal Deformity Surgery: A Multivariate Analysis

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

To identify risk factors for early deep surgical site infections (SSIs; within three months of index procedure) following pediatric spinal deformity surgery.

BACKGROUND

Deep surgical site infections (SSIs) following pediatric spinal deformity surgery are a source of significant morbidity. We sought to identify independent risk factors for early infection following primary, definitive single-stage pediatric posterior spinal fusion and instrumentation (PSFI).

METHODS

A total of 616 consecutive patients (2001-2016) from an institutional prospectively maintained Pediatric Orthopaedic Spine database were identified that met inclusion criteria of definitive single-stage PSFI. Early deep SSI was defined as infection within three months of index procedure requiring surgical intervention. A multivariate analysis of demographics, comorbidities, and perioperative factors was performed and independent risk factors were identified.

RESULTS

Eleven patients (1.6%) developed an early deep SSI. Independent risk factors for SSI identified were nonidiopathic (neuromuscular, syndromic, and congenital) etiologies of scoliosis (adjusted odds ratio [aOR]: 8.384, 95% confidence interval [CI]: 1.784-39.386, p = .007) and amount of intraoperative crystalloids (aOR: 1.547 per additional liter of fluid, 95% CI: 1.057-2.263, p = .025). Mean crystalloid administered in the SSI group was 3.3 ± 1.2 L versus 2.4 ± 1.0 L in the noninfected group (p = .019). On univariate analysis, there was no significant difference in weight of patients between cohorts (p = .869) or surgery time (p = .089). There was also no significant difference in infection rates from redosing of antibiotics intraoperatively after 3 hours of surgery (p = .231).

CONCLUSIONS

Nonidiopathic scoliosis and amount of intraoperative crystalloids were independently associated with early postoperative SSI. Further investigation into intraoperative fluid management may identify modifiable risk factors for early postoperative SSI in primary pediatric spinal deformity posterior spinal fusion patients.

LEVEL OF EVIDENCE

Level III, case-control study.

Application of Vancomycin Powder to Reduce Surgical Infection and Deep Surgical Infection in Spinal Surgery: A Meta-analysis

STUDY DESIGN

This was a meta-analysis study.

OBJECTIVE

Our meta-analysis study aimed to evaluate the efficacy of vancomycin powder to reduce the surgical site infection (SSI) in spinal surgery.

SUMMARY OF BACKGROUND DATA

The SSI is a potential and devastating complication after spinal surgery. Local application of vancomycin powder is an attractive adjunctive therapy to reduce SSI in spinal surgery.

METHODS

Studies were identified from PubMed, The Cochrane Library, AMED, Web of Science, Scopus, Ovid, EMBASE, and Ebsco Medline. The fixed-effects model was used to compute the merge of relative risk and 95% confidence interval (CI). Heterogeneity tests were checked by I statistics. Subgroup analysis was performed to determine whether vancomycin powder was beneficial, that could reduce the SSI in spinal surgery, or not. Publication bias was explored by funnel plot.

RESULTS

We included 21 studies for final analysis. In our analysis, application of vancomycin powder was associated with a significantly reduced risk of SSI and deep SSI. Pooled relative risks showed significant changes: SSI, 0.36 (95% CI: 0.27-0.47, P=0.000), SSI in the instrumented group, 0.35 (95% CI: 0.25-0.49, P=0.000), SSI in the noninstrumented group, 0.39 (95% CI: 0.24-0.65, P=0.000), deep SSI, 0.28 (95% CI: 0.18-0.44, P=0.000), and the incidence pseudoarthrosis, 0.88 (95% CI: 0.35-2.21, P=0.784). In the subgroup analysis, vancomycin powder showed beneficial effects to SSI in the instrumented group. Pooled the heterogeneity: SSI (P=0.124, I=30.0%), SSI in the instrumented group (P=0.366, I=8.2%), SSI in the noninstrumented group (P=0.039, I=60.5%), deep SSI (P=0.107, I=33.5%).

CONCLUSIONS

The application of vancomycin powder could decrease the SSI and deep SSI in spinal surgery. In the subgroup, vancomycin powder is beneficial to the SSI in the instrumented group. The available evidence is too limited to make the conclusion that the use of vancomycin powder causes pseudoarthrosis in spinal surgery, its extrapolation should be carefully executed.

Vancomycin Concentrations in Paraspinal Muscles During Posterior Spinal Fusions for Neuromuscular Scoliosis

STUDY DESIGN

Prospective consecutively enrolled cohort.

OBJECTIVES

To evaluate paraspinal muscle concentration of intravenously administered vancomycin, at predetermined time points, during posterior spinal fusion (PSF) with instrumentation in neuromuscular scoliosis (NMS).

SUMMARY

Surgical site infection (SSI) after PSF for NMS can be a devastating complication, which may lead to prolonged antibiotic use, multiple additional surgical procedures, pseudarthroses, and sepsis. Because of significant morbidity of SSIs in NMS, the prophylactic use of vancomycin has been adopted at our institution as standard wound prophylaxis, despite any high-level evidence of its efficacy.

METHODS

A prospective study of 20 patients who underwent definitive PSF for NMS and received vancomycin infusion preoperatively per institutional protocol. Serum levels were obtained immediately after infusion, at surgical incision, and then at 1, 2, and 4 hours post incision. Muscle tissue samples were simultaneously obtained at incision and at 1, 2, and 4 hours post incision. Samples were analyzed by a validated liquid chromatography-tandem mass spectrometry method.

RESULTS

10 males and 10 females with a mean age of 14+11 years (9-20 years) received a mean infusion of 15.0 mg/kg vancomycin. Mean serum levels were 26.7 μg/mL after infusion, 18.1 at incision, 13.2 at 1 hour, 11.8 at 2 hours, and 7.6 at 4 hours post infusion. Mean muscle levels were 0.5 μg/mL at incision, 0.6 at 1 hour, 0.5 at 2 hours, and 0.7 at 4 hours post infusion. Mean serum levels reached minimum inhibitory concentration (MIC) for Staphylococcus aureus at incision and at all timepoints during surgery. Mean muscle vancomycin levels never reached MIC. No patients had any cardiac or kidney disease, and all patients had normal kidney function according to their preoperative laboratory values.

CONCLUSIONS

Using accepted guidelines for the administration of intravenous vancomycin preoperatively, serum levels reached MIC at incision and at all timepoints tested during PSF for neuromuscular scoliosis. At no timepoint tested did muscle levels reach MIC.

LEVEL OF EVIDENCE

Level II.

Effect of intrawound vancomycin application in spinal surgery on the incidence of surgical site infection: a meta-analysis

Background

Despite great advances in aseptic surgical techniques, surgical site infection (SSI) is still one of the main complications after spine surgery. SSI can bring tremendous physical, psychological, and economic challenges to patients. Intrawound vancomycin application is a much disputed method for the prevention of SSI after spine surgery.

Objective

The aim of this study is to review the current literature for studies on the intra-wound application of vancomycin powder and to analyze its effectiveness in the prevention of postoperative SSI.

Methods

PubMed, Medline, Elsevier, and CNKI were searched for the key words “vancomycin”, “local/intraoperative/topical/intra-wound”, “spine/spinal/lumbar/cervical/thoracolumbar surgery”, “infection”, and “SSI” in published studies on the effectiveness of intrawound vancomycin application to prevent postoperative SSI. RevMan 5.3 was used to compare the data extracted from the studies included.

Results

A total of 27 studies involving 17,321 patients were included in the final analysis. Among those patients, 7,423 patients were treated with vancomycin to prevent SSI, with 9,898 in control groups. SSI incidence after surgery in experimental groups was 0.39 times as high as control groups, and this difference was statistically significant (P<0.01). Among patients who underwent internal fixation, vancomycin application significantly reduced the incidence of postoperative SSI (OR 0.31 95% CI 0.19–0.50; P<0.01). Meanwhile, vancomycin did not affect SSI incidence in patients who did not receive internal fixation (P=0.17) or received deformity correction (P=0.25).

Conclusion

SSI incidence after spinal surgery can be significantly reduced by intrawound application of vancomycin in most circumstances. This method can be applied in various spinal procedures involving instrumentation to prevent postoperative SSI.

Effect of Intra-wound Vancomycin for Spinal Surgery: A Systematic Review and Meta-analysis

Intra-site prophylactic vancomycin in spine surgery is an effective method of decreasing the incidence of postsurgical wound infection. However, there are differences in the prophylactic programs used for various spinal surgeries. Thus, this systematic review and meta-analysis aimed to evaluate the effectiveness of using intra-wound vancomycin during spinal surgery and to explore the effects of dose-dependence and the method of administration in a subgroup analysis. A total of 628 citations or studies were searched in PubMed, Ovid, Web of Science, and Google Scholar that were published before August 2016 with the terms "local vancomycin", "intra-wound vancomycin", "intraoperative vancomycin", "intra-site vancomycin", "topical vancomycin", "spine surgery", and "spinal surgery". Finally, 19 retrospective cohort studies and one prospective case study were eligible for inclusion in the systematic review and meta-analysis. The odds of developing postsurgical wound infection without prophylactic local vancomycin use were 2.83-fold higher than the odds of experiencing wound infection with the use of intra-wound vancomycin (95% confidence interval, 2.03-3.95; P = 0.083; I² = 32.2%). The subgroup analysis including the dosage and the method of administration, revealed different results compared to previous research. The value of I² in the 1-g group was 27.2%, which was much lower than in the 2-g group (I² = 57.6%). At the same time, the value of I² was 0.0% (P = 0.792, OR = 2.70) when vancomycin powder was directly sprinkled into all layers of the wound. However, there is high heterogenicity (I² = 60.0%, P = 0.007, OR = 2.83) when vancomycin powder is not exposed to the bone graft and instrumentation. There are differences found with the method of local application of vancomycin for reducing postoperative wounds and further studies are necessary, including investigations focusing on the dose-dependent effects during spinal or the topical pharmacokinetic and other orthopaedic surgeries.

The combined administration of vancomycin IV, standard prophylactic antibiotics, and vancomycin powder in spinal instrumentation surgery: does the routine use affect infection rates and bacterial resistance?

Background

Surgical site infections (SSI) poses significant risk following spinal instrumentation surgery. The 2013 North American Spine Society (NASS) Evidence-Based Clinical Guidelines found that the incidence of SSI in spine surgery ranged from 0.7-10%, with higher rates with medical comorbidities. National guidelines currently recommend first-generation cephalosporins as first line prophylaxis. Due to an increase in MRSA cases in our institution, a combined antibiotic strategy using vancomycin IV, standard prophylactic antibiotics, and vancomycin powder was implemented for all spinal instrumentation surgeries.

Methods

All spinal instrumentation surgeries performed at this institution from 2013-2016 were identified. Chart review was then performed to identify the inclusion and exclusion criteria, demographic data, diagnosis, type of surgery performed, and bacterial culture results. Rates of SSI, as defined by the Center for Disease Control (CDC), were calculated and antibiotic resistance was determined. As control, SSIs were identified and reviewed from 2010, prior to the implementation of the combined strategy.

Results

One thousand and seventy four subjects were identified in the combined cohort. Mean age was 52.3 years, 540 males (50.2%), 534 females (49.8%). There were 960 primary surgeries (89.4%), 114 cases revision surgeries (10.6%). Cervical myelopathy (27.9%), lumbar stenosis (16.2%), lumbar spondylolisthesis (14.0%), and scoliosis (pediatric and adult)/deformity (13.7%) were leading diagnoses. The standard prophylactic antibiotic was cefazolin IV in 524 cases (48.8%), gentamicin IV in 526 cases (49.0%), vancomycin powder was used in 72.3% of cases. Four SSI cases out of 1,074 were identified (0.37%), 3 deep and 1 superficial, with no antibiotic resistance. In the control group, there were 11 infections of 892 cases (1.23%). There were significantly lower rates of SSI in the combined group versus control (P=0.05).

Conclusions

The combined antibiotic strategy led to low SSI rates in this retrospective case control study. Limitations of this study include retrospective design and small sample size. A large multicenter randomized clinical trial may provide further insight in the effectiveness of this strategy. Level of evidence 3. Clinical relevance: the combined antibiotic protocol may be considered in institutions with concern for SSI and methicillin resistant infections associated with spinal instrumentation surgeries.

Topical vancomycin and its effect on survival and migration of osteoblasts, fibroblasts, and myoblasts: An in vitro study

The purpose of this study was to examine the influence of topical vancomycin on cell migration and survival of tissue healing cells. Human osteoblasts, myoblasts and fibroblasts were exposed to vancomycin at concentrations of 1, 3, 6, or 12 mg/cm² for either a 1-h or 48-h (continuous) duration. Continuous exposure to all vancomycin concentrations significantly reduced cell survival (<22% cells survived) and migration in osteoblasts and myoblasts (P < 0.001). 1-h vancomycin exposure reduced osteoblast and myoblast survival and migration only at 12 mg/cm² (P < 0.001). Further in vivo studies are warranted to optimize the dosage of intrawound vancomycin.

Intrawound application of vancomycin changes the responsible germ in elective spine surgery without significant effect on the rate of infection: a randomized prospective study

PURPOSE

Surgical site infection (SSI) is a costly complication associated with spine surgery. The impact of intrawound vancomycin has not been strongly postulated to decrease the risk of surgical site infection. We designed study to determine whether intrawound vancomycin application reduces the risk of SSI in patients after spine surgery.

METHODS

A prospective randomized control trial study to evaluate the patients with elective spine surgery in a period of 15 month was designed. Patients were divided into two groups based on whether intrawound vancomycin was applied or not. The relative risk of SSI within postoperative 30 days was evaluated.

RESULTS

Three hundred and eighty patients were included in this study: degenerative spine pathologies and tumor 80% (304), trauma 11% (42) and deformity 9% (34). Intrawound vancomycin was used in 51% of patients. Prevalence of SSI was 2.7% in the absence of vancomycin use versus 5.2% with intrawound vancomycin. In multivariable regression model, those with higher number of levels exposed, postoperative ICU admission and obesity and use of instrumentation more than two levels had higher risk of developing SSI. In the treatment group Acinetobacter and Pseudomonas aeruginosa (20%) were the most common pathogens. In control group, Staphylococcus aureus and Acinetobacter (40%) were the most common organisms.

CONCLUSIONS

Intrawound application of vancomycin after elective spine surgery was not associated with reduced risk of SSI and return to OR associated with SSI in our patients. However, the use of intrawound vancomycin changed the responsible infection germ.

Collaboration with an infection control team for patients with infection after spine surgery

BACKGROUND

The risk of infection, including surgical site infection (SSI), after spine surgery has increased due to aging and more immunocompromised hosts. An infection control team (ICT) is responsible for management of health care-associated infections at our institution.

METHODS

The study subjects were 40 patients (18 men and 22 women with an average age of 54 years) referred to the ICT after spine surgery since 2010. Pathogenic bacteria and treatment in these cases were reviewed.

RESULTS

Collaboration with the ICT involved guidance on use of antibiotics for infection in 30 patients (16 SSI and 14 non-SSI) and a search for the infection focus for fever of unknown origin in 10 patients (7 patients were found to have urinary tract infections and 2 patients were found to have pneumonia). The detection rate of causative bacteria in ICT consultation was 88% (35 out of 40 patients). SSI patients with instrumentation involved had a significantly higher rate of methicillin-resistant Staphylococcus aureus infection compared with those without instrumentation (42% vs 13%; P < .05).

DISCUSSION

All cases of SSI with instrumentation involved were cured by ICT support without removal of instrumentation. Early assistance from the ICT was important for prevention of worsening of methicillin-resistant S aureus infection.

CONCLUSIONS

Collaboration with the ICT was helpful for detection of pathogenic bacteria and allowed appropriate use of antibiotics at an early stage.