Decreased risk of wound infection after posterior cervical fusion with routine local application of vancomycin powder

The Three-Month Wound Complication and Infection Rates after Vancomycin Powder and Dilute Povidone-Iodine Lavage for Infection Prophylaxis in High-Risk Total Joint Arthroplasty: A Multicenter Randomized Controlled Trial

BACKGROUND

Periprosthetic joint infection (PJI) is a high-cost and extremely morbid complication following total joint arthroplasty (TJA); thus, developing a better understanding of perioperative infection prevention strategies is prudent. Literature is mixed regarding the efficacy of vancomycin powder and dilute povidone-iodine lavage, and limited on the combination thereof. To our knowledge, no prospective orthopaedic clinical trials to date have evaluated the efficacy of local vancomycin powder, dilute povidone-iodine lavage, or a combination vancomycin-povidone-iodine-protocol (VPIP) against normal saline irrigation.

METHODS

In a large, prospective, multi-center, randomized-controlled study, four distinct infection prevention strategies were implemented in high-risk TJA patients. Local vancomycin powder, dilute povidone-iodine solution, combined VPIP, and saline control were used. Primary outcomes included PJI, wound complications, revisions, emergency department (ED) visits, readmissions, and serious adverse events within three months of index surgery. Chi-square tests were used to compare incidence rates. The criteria used for the diagnosis of PJI were the International Consensus Meeting (ICM) guidelines.

RESULTS

There were 821 total hip arthroplasty (THA) and 1,080 total knee arthroplasty (TKA) patients randomized into well-balanced study groups. In the THA and TKA cohorts, respectively, there were no statistically significant differences in rates of persistent wound drainage or dehiscence (P = 0.98, P = 0.95), cellulitis or abscess (P = 0.81, P = 0.51), 3-month infection rates (P = 0.14, P = 0.13), type of septic revisions performed (P = 0.51, P = 0.80), aseptic revision rates (P = 0.07, P = 0.90), ED visits (P = 0.61, P = 0.46), or readmissions (P = 0.78, P = 0.87) between the four treatment groups.

CONCLUSIONS

There were no statistically significant differences in PJI or other surgical outcomes following THA or TKA among the study groups. Therefore, the use of such prophylactic measures, including povidone-iodine and vancomycin powder in high-risk patients, can be left up to the surgeon or hospital discretion.

Safety and efficacy of intrawound vancomycin powder in the prevention of lumbar surgical site infection: a prospective, double-blind, randomized controlled study

BACKGROUND

To evaluate the safety and efficacy of intrawound vancomycin powder in reducing surgical site infections (SSIs) after spine surgery.

DESIGN

A prospective, double-blind, randomized controlled study.

PARTICIPANTS

Patients who underwent posterior lumbar interbody fusion (PLIF) surgery from May 2021 to September 2022.

METHODS

Patients who underwent PLIF surgery between May 2021 and September 2022 were included. Participants were randomized to the vancomycin treatment or control groups using block randomization (block size 4). Except for baseline and surgical data, the plasma levels of white blood cells, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), aspartate aminotransferase, alanine aminotransferase, and serum vancomycin concentration in the groups were analyzed on postoperative days (PODs) 1, 3, and 5. Vancomycin concentration was measured daily until the drainage tubes were removed. The primary outcomes were the 90-day vancomycin-related adverse reactions and SSI rates. Secondary outcomes were perioperative hematological parameters and vancomycin serum (drain) concentrations.

RESULTS

A total of 156 participants (78 each in each group) were analyzed by an independent researcher. The follow-up rate was 91%. All participants were followed up for at least 90 days. The 90-day SSI rate in the vancomycin group was 1.3% (1/78), comprising one case of superficial infection. The SSI rate in the control group was 10.3% (8/78), comprising seven cases of superficial infection and one case of deep infection. Compared with that in the control group, the SSI rate in the vancomycin group was decreased by 87.5%, with a statistically significant difference (RR=0.125, 95% CI=0.016-0.976). Additionally, the vancomycin group demonstrated a statistically significant decrease in serum ESR on POD 3 ( P =0.039) and CRP on POD 5 ( P =0.024) compared to the control group. The local plasma concentration of vancomycin remained elevated for at least 4 days postoperatively, while the serum concentration of vancomycin remained low. Vancomycin-associated adverse reactions were not observed.

CONCLUSION

Intrawound application of vancomycin powder is a safe and effective procedure for reducing the risk of SSI during PLIF surgery.

Local vancomycin administration in Orthopaedic Surgery - A systematic review of comparative studies

Background

There is still controversy surrounding the routine use of vancomycin locally in primary orthopaedic surgery procedures. Therefore, the aim of this review is to assess how local vancomycin impacts the rates and microbiology of surgical site infections.

Methods

A systematic electronic search of MEDLINE, EMBASE, and Web of Science was carried out for all comparative studies comparing locally applied vancomycin to control for primary orthopaedic surgery procedures published before August 14, 2022.

Results

A total of 61 studies with 65,671 patients were included for analysis. Forty-six studies used vancomycin powder, 12 studies with grafts soaked in vancomycin, two studies used vancomycin irrigation, and one study administered vancomycin interosseously. There were 15 studies (of 26) in spine surgery, five (of 14) in arthroplasty, ten (of 11) in sports medicine, and two (of five) in trauma surgery that found statistically significant decreases in overall infection rates when applying local vancomycin. Only one study (in spine surgery) found significant increases in infection rates with local vancomycin application. For spine surgery, local vancomycin application had the greatest proportion of gram-negative bacteria (40.7%) isolated compared to S. aureus (42.4%) in controls. In arthroplasty and trauma surgery, there were increases in the proportions of gram-negative bacteria when vancomycin was added. There were no reported systemic adverse reactions associated with local vancomycin use in any of the studies.

Conclusion

Applying local vancomycin during primary orthopaedic surgery procedures may reduce the rates of infections in multiple different orthopaedic specialties, particularly in spine surgery and sports medicine. However, careful consideration should be applied when administering local vancomycin during specific orthopaedic procedures given the heterogeneity of included studies and breadth of surgeries included in this review.

Level of evidence

Level III. A systematic review of level I - III studies.

Impact of Plastic Surgery and an Enhanced Prophylaxis Protocol on Cervical Spine Surgery Infection

Background: Reduction of surgical site infections (SSIs) is important in improving cervical spine surgery outcomes. Plastic surgery involvement and an enhanced modified prophylaxis protocol may reduce infection rates. Methods: A total of 962 cervical spine operations were conducted by a single surgeon (TFC). An enhanced modified prophylaxis protocol and plastic surgery were used in some operations. Differences in infection rates, surgical approach, previous operations, prophylaxis use, and plastic surgery involvement were compared using Fisher's exact tests and multivariate linear regression. Results: Four patients (0.42%) experienced SSIs. All 4 infections involved the standard protocol, posterior approach, and did not involve plastic surgery. The infection rate was lower in the enhanced protocol group when compared to the standard protocol (β -0.78, 95% CI -1.23 to -0.33, P = .0008). The enhanced protocol group had an increased percentage of operations with plastic surgery (β 0.19, 95% CI 0.10 to 0.28, P < .0001). The infection rate among the plastics group was 0.00% compared to 0.60% for the non-plastics group (P = .32). The plastics group had a lower rate of anterior approach when compared to the non-plastics group (β -0.20, 95% CI -0.24 to -0.15, P = .049). Among the posterior approach group, procedures with plastic surgery had an infection rate of 0.00% compared to 2.53% without plastic surgery (P = .13). Conclusion: The enhanced protocol was associated with a lower SSI rate and increased plastic surgery involvement. Posterior approaches were associated with increased infection rates and the likelihood of utilizing plastic surgery. Both the enhanced protocol and plastic surgery may decrease infection.

A meta-analysis examining the impact of intrawound treatment on reducing deep surgical site infections during instrumented spine surgery

The purpose of the meta-analysis was to evaluate and compare the effect of intrawound management on decreasing deep surgical site infections (SSIs) in instrumented spinal surgery (SS). The results of this meta-analysis were analysed, and the odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated using dichotomous or contentious random or fixed effect models. For the current meta-analysis, 29 examinations spanning from 2006 to 2022 were included, encompassing 11 181 people who had instrumented SS. Intrawound management had a significantly lower deep SSI when using vancomycin (OR, 0.34; 95% CI, 0.25-0.44, p < 0.001) and povidone-iodine as intrawound management (OR, 0.24; 95% CI, 0.13-0.42, p < 0.001) compared to control in instrumented SS subjects. The data that was looked at showed that using vancomycin and povidone-iodine as intrawound management had a much lower deep SSI than using a control group of instrumented SS subjects. However, given that some studies included a small number of subjects, attention should be given to their values.

Surgical site infection prophylaxis with intra-wound vancomycin powder for uninstrumented spine surgeries: a meta-analysis

PURPOSE

It is unclear if intra-wound vancomycin powder significantly reduces the infection rate for uninstrumented spine surgery. The purpose of this study is to compare the rate of surgical site infection (SSI) in uninstrumented spine surgery that used vancomycin powder against controls.

METHODS

A search was performed on PUBMED/MEDLINE, Cochrane Database and Embase on 14 October 2022. Search keywords were "vancomycin, spine surgery, uninstrumented and spinal surgery." Instrumented cases were excluded. Type of surgery, type of treatment and incidence of infection among experimental or control were recorded.

RESULTS

288 articles were obtained from a literature search. 16 studies met inclusion criteria. 6/16 studies that reported on the infection rate using vancomycin were obtained. There were 1376 control cases with 20 cases of post-operative infection (1.45% overall). There were 795 cases that received prophylactic intra-wound vancomycin powder with 10 cases of infection reported (1.26%). There was no significant difference in infections between cases that received vancomycin compared to control. On subgroup analysis, studies that had a high rate of infection (Strom and Cannon) had a significant difference on the rate of infection with the use of vancomycin compared to control.

DISCUSSION AND CONCLUSION

The current study was unable to conclude that vancomycin decreased the rate of surgical site infections. Vancomycin use may be useful in populations that have a high rate of infection. Limitations in this study include the small number of studies that report on the use of vancomycin on uninstrumented spine surgery.

Protective effect of teriparatide against vancomycin-induced cytotoxicity in osteoblasts

BACKGROUND

Intrawound vancomycin powder is effective in preventing surgical site infection after spine surgery. In a previous study, vancomycin-induced cytotoxicity in osteoblasts was investigated in vitro, and vitamin D3 was verified to be a candidate drug aiding recovery from vancomycin-induced cytotoxicity. The treatment practices involving osteogenesis-promoting drugs vary widely. Teriparatide, an anabolic agent, highly promotes bone formation by inducing osteoblast activation, increasing bone formation and mineral density, and preventing vertebral fractures. Hence, teriparatide may be administered in combination with vancomycin.

METHODS

MC3T3-E1 cells were cultured in minimum essential medium supplemented with 10% fetal bovine serum at 37 °C in a humidified incubator containing 5% CO2. The experimental concentrations of vancomycin (2500, 5000, and 7500 μg/mL) were determined based on previous reports and our preliminary experiments. Teriparatide (100 ng/mL) was administered concomitantly to prevent cytotoxicity in osteoblasts, using pulsed vancomycin for 24 h (measured at 1, 3, and 7 days). Cell numbers and morphological changes in cells treated with vancomycin or vancomycin plus 100 ng/mL teriparatide were measured. Osteoblast differentiation was assessed using alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red S staining.

RESULTS

Teriparatide showed a recovery effect when vancomycin (7500 μg/mL) was administered only for 24 h. Microscopic examination revealed that teriparatide had a protective effect on osteoblasts exposed to 7500 μg/mL vancomycin. Addition of teriparatide led to the recovery of alkaline phosphatase staining and alizarin red staining.

CONCLUSION

Vancomycin-induced cytotoxicity in osteoblasts could be inhibited by administering teriparatide concomitantly with vancomycin.

Incidence and risk factors of surgical site infection following cervical laminoplasty: A retrospective clinical study

There are many debates regarding the risk factors of surgical site infection (SSI) following posterior cervical surgery in previous studies. And, till now there is no such a study to examine cervical laminoplasty surgery. From January 2011 through October 2021, a total of 405 patients who were treated with unilateral open-door laminoplasty surgeries were enrolled in this study. We divided the patients into the SSI group and the non-SSI group and compared their patient-specific and procedure-specific factors. Univariate and multiple logistic regression analysis were performed to determine the risk factors. Of the 405 patients, 20 patients had SSI. The rate of SSI found to be 4.93%. There were significant differences between groups in the thicker subcutaneous fat thickness (FT) (p < 0.001), the higher ratio of subcutaneous FT to muscle thickness (MT) (p < 0.001), the higher preoperative Japanese Orthopaedic Association (JOA) Scores (p < 0.003), the decreased preoperative serum albumin (p < 0.001), the more postoperative drainage (p < 0.05) and the longer time of draining (p < 0.001). Logistic regression analysis of these differences showed that the higher ratio of subcutaneous FT/MT, the higher preoperative JOA scores, the decreased preoperative serum albumin and the longer time of draining were significantly related to SSI (p < 0.05). The higher ratio of subcutaneous FT/MT, the higher preoperative JOA scores, the decreased preoperative serum albumin and the longer time of draining are identified as the independent risk factors of SSI in cervical laminoplasty. Identification of these risk factors could be useful in reducing the SSI incidence and patients counselling.

Complications and Avoidance in Adult Spinal Deformity Surgery

Adult spinal deformity (ASD) is a complex disease that can result in significant disability. Although surgical treatment has been shown to be of benefit, the complication rate in the perioperative and postoperative periods can be as high as 70%. Some of the most common complications of ASD surgery include intraoperative cerebrospinal fluid leak, high blood loss, new neurologic deficit, hardware failure, proximal junctional kyphosis/failure, pseudarthrosis, surgical site infection, and medical complications. For each of these complications, one or more strategies can be utilized to avoid and/or minimize the consequences.

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.

Effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery: A meta-analysis

We performed a meta-analysis to evaluate the effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery. A systematic literature search up to July 2022 was performed and 24 137 subjects with neurosurgery at the baseline of the studies; 10 496 of them were using the powdered vancomycin, and 13 641 were not using the powdered vancomycin as a control. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery using dichotomous methods with a random or fixed-effect model. The powdered vancomycin had significantly lower surgical site wound infections after spinal surgery (OR, 0.53; 95% CI, 0.41-0.70, P < .001), deep surgical site wound infections after spinal surgery (OR, 0.45; 95% CI, 0.35-0.57, P < .001), superficial surgical site wound infections after spinal surgery (OR, 0.60; 95% CI, 0.43-0.83, P = .002), and surgical site wound infections after cranial surgery (OR, 0.37; 95% CI, 0.22-0.61, P < .001) compared to control in subjects with neurosurgery. The powdered vancomycin had significantly lower surgical site wound infections after spinal surgery, deep surgical site wound infections after spinal surgery, superficial surgical site wound infections after spinal surgery, and surgical site wound infections after cranial surgery compared to control in subjects with neurosurgery. The analysis of outcomes should be done with caution even though the low number of studies with low sample size, 3 out of the 42 studies, in the meta-analysis, and a low number of studies in certain comparisons.

Intrawound application of vancomycin reduces the proportion of fracture-related infections in high-risk tibial plateau fractures

INTRODUCTION

Despite the improvements in surgical techniques and the use of prophylactic intravenous antibiotics, the fracture-related infection (FRI) incidence after high-risk tibial plateau fractures remains high. This study aimed to evaluate the clinical effect of the intrawound application of vancomycin on the FRI after high-risk tibial plateau fracture surgery.

METHODS

A total of 243 patients who underwent high-risk tibial plateau fracture surgery from May 2013 to June 2021 were retrospectively reviewed. Of these, 233 cases were enrolled. Considering the preoperative patient condition, surgeons applied vancomycin powder directly into the surgical site before wound closure in 105 cases (intrawound application of vancomycin powder with preoperative intravenous cephalosporin). The remaining 128 cases served as the control group (preoperative intravenous cephalosporin alone). Clinical data and surgical details were recorded. The Cox proportional hazards regression analysis was used to assess risk factors for FRI. The Kaplan-Meier method and the log rank test illustrated the infection status of patients based on the application of intrawound vancomycin. The primary outcome was an FRI within one year. Secondary outcomes included bacterial culture and vancomycin-related complications.

RESULTS

Our study demonstrated a significant difference in the incidence of FRI between the vancomycin group and the control group (3.8% versus 10.9%; p=0.041). Multivariable Cox regression showed the intrawound application of vancomycin powder decreased the rate of FRI. There were no complications related to intrawound vancomycin observed during follow-up. The presence of Gram-positive FRI was higher in the control group compared with the vancomycin group.

CONCLUSIONS

Intrawound application of vancomycin was associated with a significant lower rate of FRI after high-risk tibial plateau fracture surgery compared to the control group.

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.

Effect of Vancomycin Applied to the Surgical Site on Fracture Healing in a Diabetic Rat Model

BACKGROUND

Prophylactic vancomycin treatment decreases the prevalence of surgical site and deep infections by >70% in diabetic patients undergoing reconstructive foot and ankle surgery. Thus, determining whether clinically relevant local vancomycin doses affect diabetic fracture healing is of medical interest. We hypothesized that application of vancomycin powder to the fracture site during surgery would not affect healing outcomes, but continuous exposure of vancomycin would inhibit differentiation of osteoblast precursor cells and their osteogenic activity in vitro.

METHODS

The vancomycin dose used to treat the diabetic rats was a modest increase to routine surgical site vancomycin application of 1 to 2 g for a 70-kg adult (21 mg/kg). After femur fracture in BB-Wistar type 1 diabetic rats, powdered vancomycin (25 mg/kg) was administered to the fracture site. Bone marrow and periosteal cells isolated from diabetic bones were cultured and treated with increasing levels of vancomycin (0, 5, 50, 500, or 5000 µg/mL).

RESULTS

Radiographic scoring, micro-computed tomography (µCT) analysis, and torsion mechanical testing failed to identify any statistical difference between the vancomycin-treated and the untreated fractured femurs 6 weeks postfracture. Low to moderate levels of vancomycin treatment (5 and 50 µg/mL) did not impair cell viability, osteoblast differentiation, or calcium deposition in either the periosteum or bone marrow-derived cell cultures. In contrast, high doses of vancomycin (5000 µg/mL) did impair viability, differentiation, and calcium deposition.

CLINICAL RELEVANCE

In this diabetic rodent fracture model, vancomycin powder application at clinically relevant doses did not affect fracture healing or osteogenesis.

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.

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.

Increased Surgical Site Subcutaneous Fat Thickness Is Associated with Infection after Posterior Cervical Fusion

Background: Previous literature has associated increased body mass index (BMI) with risk of surgical site infection (SSI) after posterior cervical fusion (PCF) surgery. However, few studies have examined the association between local adiposity and risk of SSI, re-admission, and re-operation after PCF. Local adiposity is easily measured on pre-operative magnetic resonance imaging (MRI) and may act as a more accurate predictor compared with BMI. Patients and Methods: Subjects undergoing PCF from 2013-2018 at a single institution were identified retrospectively. Posterior cervical subcutaneous fat thickness, paraspinal muscle thickness, and lamina-to-skin distance measurements were obtained from computed tomography (CT) or MRI scans. Subjects with active infection, malignancy, or revision procedures were excluded. Results: Two hundred five patients were included with 20 developing SSIs. Subjects with SSIs had a longer fusion construct (4.90 vs. 3.71 levels; p = 0.001), higher Elixhauser comorbidity index (ECI; 2.05 vs. 1.34; p = 0.045), had a history of diabetes mellitus (30% vs. 10.8%; p = 0.026), higher subcutaneous fat thickness (30.5 vs. 23.6 mm; p = 0.013), and higher lamina-to-skin distance (66.4 vs. 57.9 mm; p = 0.027). Subcutaneous fat thickness (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.10]; p = 0.026) and lamina-to-skin distance (OR, 1.05; 95% CI, 1.01-1.09]; p = 0.014) were associated with SSI in multivariable analysis. A subcutaneous fat thickness cutoff value of 23.2 mm had 90% sensitivity and 54.1% specificity for prediction of SSI. There was no association need for re-admission or re-operation. Conclusions: Increased posterior cervical fat may increase the risk of SSI after PCF. Pre-operative advanced imaging may be a valuable tool for assisting with patient counseling, optimization, and risk stratification.

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.

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.

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.

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.

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.

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.

Risk factors for surgical site infections following spinal column trauma in an Australian trauma hospital

BACKGROUND

There is limited, and often conflicting, data in the literature about the prevalence and risk factors for surgical site infections (SSI) in spine surgery patients, with the majority consisting of elective spine surgery cohorts. Furthermore, there is no reported Australian data regarding rates of SSI in a spinal trauma cohort. The aim of this study is to identify factors associated with SSI following spinal column trauma.

METHODS

Adult (16+ years) patients that underwent surgery following emergency admission for spinal trauma between January 2010 and December 2016 at a major trauma centre in Melbourne, Australia, were identified through the Victorian Orthopaedic Trauma Outcomes Registry. The presence of an SSI was confirmed from the electronic medical record. Patient and clinical factors were analysed by SSI status. Generalized Estimating Equations were used to model predictors of SSI, with a P-value <0.05 deemed significant.

RESULTS

Data for 458 patients and 520 surgical wounds were collected. Twenty-six (5.7%) patients developed an SSI. Staphylococcus aureus was the most common microorganism with methicillin-sensitive S. aureus found in 46% of SSI cases. A posterior surgical approach and same site reoperation were predictors of SSI with adjusted odds ratios (95% confidence intervals) of 4.26 (1.22-14.80, P = 0.02) and 4.99 (1.10-22.58, P = 0.04), respectively.

CONCLUSIONS

A posterior surgical approach and same site reoperation increased the risk of SSI after spinal trauma. Further research into modifiable associations within these and other factors will help mitigate the risk of SSI and hence decrease the personal and financial costs of this potentially devastating complication.

Vancomycin Powder Use in Fractures at High Risk of Surgical Site Infection

OBJECTIVES

To determine if the use of intrawound vancomycin powder reduces surgical-site infection after open reduction and internal fixation of bicondylar tibial plateau, tibial pilon, and calcaneus fractures.

DESIGN

Retrospective analysis.

SETTING

Level I trauma center.

PATIENTS

All fractures operatively treated from January 2011 to February 2015 were reviewed; 583 high-risk fractures were included, of which 35 received topical vancomycin powder. A previously published prospectively collected cohort of 235 similar high-risk fractures treated at our center from 2007 through 2010 served as a second comparison group.

INTERVENTION

Topical vancomycin powder at wound closure.

MAIN OUTCOME MEASUREMENTS

Deep surgical-site infection. Analyses used both univariate comparison of all patients and 1:2 matching analysis using both nearest neighbor and propensity-based matching.

RESULTS

Compared with a control group of fractures treated during the same time period without vancomycin powder, the infection rate with vancomycin powder was significantly lower [0% (0/35) vs. 10.6% (58/548), P = 0.04]. Compared with our previously published historical infection rate of 13% for these injuries, vancomycin powder was also associated with significantly decreased deep surgical-site infection (0% vs. 13%, P = 0.02). These results agreed with the matched analyses, which also showed lower infection in the vancomycin powder group (0% vs. 11%-16%, P ≤ 0.05).

CONCLUSIONS

Vancomycin powder may play a role in lowering surgical-site infection rates after fracture fixation. A larger randomized controlled trial is needed to validate our findings.

LEVEL OF EVIDENCE

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

Topical Vancomycin Powder Decreases the Proportion of Staphylococcus aureus Found in Culture of Surgical Site Infections in Operatively Treated Fractures

OBJECTIVES

To determine whether patients with operatively treated fractures and surgical site infection after use of topical vancomycin powder have a lower proportion of Staphylococcus aureus infections than patients who did not receive topical vancomycin powder.

DESIGN

Retrospective cohort study.

SETTING

Level I trauma center.

PATIENTS

Treatment group: 10 of 133 patients (145 fractures) with surgical site infections who received intrawound vancomycin powder at the time of wound closure for fracture fixation. Control group: 175 patients who sustained deep surgical site infections during the same period but did not receive vancomycin powder.

INTERVENTION

Vancomycin powder or no vancomycin powder.

MAIN OUTCOME MEASUREMENT

Proportion of patients' cultures positive for S. aureus.

RESULTS

The proportion of cultures positive for S. aureus was significantly lower in patients with surgical site infection who received vancomycin powder than in those who did not receive vancomycin powder (10% [1 of 10 patients in the treatment group] vs. 50% [87 of 175 patients in the control group]; P = 0.02). A trend was observed for a lower proportion of methicillin-resistant S. aureus (0% vs. 23%; P = 0.12).

CONCLUSIONS

Vancomycin powder might alter the bacteriology of surgical site infections and decrease the proportion in culture of the most common organism typically present after fracture surgery infection. These findings suggest that the application of vancomycin powder might change the bacteriology of surgical site infections when they occur, regardless of the effect on overall infection rates. Although our bacteriology results are clinically and statistically significant, these findings must be confirmed in larger randomized controlled trials.

LEVEL OF EVIDENCE

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

[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.

Progress not panacea: vancomycin powder efficacy and dose evaluated in an in vivo mouse model of spine implant infection

BACKGROUND

Intrawound vancomycin powder (VP) has been rapidly adopted in spine surgery with apparent benefit demonstrated in limited, retrospective studies. Randomized trials, basic science, and dose response studies are scarce.

PURPOSE

This study aims to test the efficacy and dose effect of VP over an extended time course within a randomized, controlled in vivo animal experiment.

STUDY DESIGN/SETTING

Randomized controlled experiment utilizing a mouse model of spine implant infection with treatment groups receiving vancomycin powder following bacterial inoculation.

METHODS

Utilizing a mouse model of spine implant infection with bioluminescent Staphylococcus aureus, 24 mice were randomized into 3 groups: 10 infected mice with VP treatment (+VP), 10 infected mice without VP treatment (No-VP), and 4 sterile controls (SC). Four milligrams of VP (mouse equivalent of 1 g in a human) were administered before wound closure. Bioluminescence imaging was performed over 5 weeks to quantify bacterial burden. Electron microscopy (EM), bacterial colonization assays (Live/Dead) staining, and colony forming units (CFU) analyses were completed. A second dosing experiment was completed with 34 mice randomized into 4 groups: control, 2 mg, 4 mg, and 8 mg groups.

RESULTS

The (+VP) treatment group exhibited significantly lower bacterial loads compared to the control (No-VP) group, (p<.001). CFU analysis at the conclusion of the experiment revealed 20% of mice in the +VP group and 67% of mice in the No-VP group had persistent infections, and the (+VP) treatment group had significantly less mean number of CFUs (p<.03). EM and Live/Dead staining revealed florid biofilm formation in the No-VP group. Bioluminescence was suppressed in all VP doses tested compared with sterile controls (p<.001). CFU analysis revealed a 40%, 10%, and 20% persistent infection rate in the 2 mg, 4 mg, and 8 mg dose groups, respectively. CFU counts across dosing groups were not statistically different (p=.56).

CONCLUSIONS

Vancomycin powder provided an overall infection prevention benefit but failed to eradicate infection in all mice. Furthermore, the dose when halved also demonstrated an overall protective benefit, albeit at a lower rate.

CLINICAL SIGNIFICANCE

Vancomycin powder is efficacious but should not be viewed as a panacea for perioperative infection prevention. Dose alterations can be considered, especially in patients with kidney disease or at high risk for seroma.

The effect of prophylactic vancomycin powder on infections following spinal surgeries: a systematic review

OBJECTIVEThe use of vancomycin powder in spine surgery for prophylaxis against surgical site infections (SSIs) is well debated in the literature, with the majority of studies demonstrating improvement and some studies demonstrating no significant reduction in infection rate. It is well known in certain populations that vancomycin powder reduces the general rate of infection, but its effects on reducing the rate of infection due to gram-negative pathogens are not well reviewed. The goal of this paper was to review studies that investigated the efficacy of vancomycin powder as a prophylactic agent against SSI and demonstrate whether the rate of infections by gram-negative pathogens is impacted.METHODSAn electronic search of the published literature was performed using PubMed and Google Scholar in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A variety of combinations of the search terms "vancomycin powder," "infection," "spine," "gram-negative," "prophylaxis," and "surgical site" was used. Inclusion criteria were studies that 1) described an experimental group that received intraoperative intrawound vancomycin powder; 2) included adequately controlled groups that did not receive intraoperative intrawound vancomycin powder; 3) included the number of patients in both the experimental and control groups who developed infection after their spine surgery; and 4) identified the pathogen-causing infection. Studies not directly related to this review's investigation were excluded from the initial screen. Among the studies that met the criteria of the initial screen, additional reasons for exclusion from the systematic review included lack of a control group, unspecified size of control groups, and inconsistent use of vancomycin powder in the experimental group.RESULTSThis systematic review includes 21 studies with control groups. Vancomycin powder significantly reduced the relative risk of developing an SSI (RR 0.55, 95% CI 0.45-0.67, p < 0.0001). In addition, the use of vancomycin powder did not significantly increase the risk of infection by gram-negative pathogens (RR 1.11, 95% CI 0.66-1.86, p = 0.701).CONCLUSIONSThe results of this systematic review suggest that intrawound vancomycin powder is protective against SSI. It is less clear if this treatment increases the risk of gram-negative infection. Further studies are required to investigate whether rates of infection due to gram-negative pathogens are affected by the use of vancomycin powder.

Paraspinous Muscle Flaps for the Treatment of Complex Spinal Wounds

MINI: This retrospective case series investigated paraspinous flaps for coverage of complex spinal wounds. 6.90% of patients developed postoperative wound infections and 0.00% of patients required instrumentation removal for infection. This suggests that these flaps may offer a long-term solution in wound management for patients with repeated spinal operations.

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To investigate the efficacy and complication profile of the use of paraspinous muscle flaps for closure of complex spinal wounds.

SUMMARY OF BACKGROUND DATA

Paraspinous muscle flap closure offers an innovative option in difficult-to-manage post-spinal surgery wounds. Current literature reports are mixed in terms of success and complication rates of these flap procedures, with most sources citing a wound complication rate of 20%.

METHODS

This case series investigated the hospital course of 58 patients undergoing paraspinous flap closure after spinal surgery between the years 2014 and 2018. Information gathered includes: demographics, surgery indication, location, and length of incision on the spine, nutrition labs, previous spinal surgeries, preoperative wound class, operative times, length of hospital stay, and complication rates including reoperation, wound infection, and other postoperative complications.

RESULTS

Of the 58 patients undergoing spinal muscle flap closure, 51 (87.93%) had undergone previous spinal surgery with an average of 2.12 previous surgeries in these patients. Mean albumin and prealbumin were 2.62 and 13.75, respectively. 4/58 (6.90%) developed a wound infection or experienced a continuation of their chronic osteomyelitis. Of the 57 patients that had spinal instrumentation, three (5.26%) had spinal implants removed at the time of surgery and two (3.51%) had it removed or replaced later for mechanical complications. No patients had instrumentation removed for chronic infections. One (1.72%) experienced reoperation for wound-related complications. These rates are lower than most complication rates in the current literature.

CONCLUSION

The plastic and reconstructive paraspinous muscle flap has promising results as a closure option for complex spinal wounds following neurosurgical cases. Further investigation is called for to determine the applicability of these results to the general population.

LEVEL OF EVIDENCE

4.

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.

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.

Complications following posterior cervical decompression and fusion: a review of incidence, risk factors, and prevention strategies

Posterior cervical decompression and fusion (PCF) is a common surgical technique used to treat various cervical spine pathologies. However, there are various complications associated with PCF that can negatively impact patient outcome. We performed a comprehensive literature review to identify the most common complications following PCF using PubMed, Cochrane Database of Systematic Reviews, and Google Scholar. The overall complication rates of PCF are estimated to range from about 15% to 25% in the current literature. The most common immediate complications include acute blood loss anemia, surgical site infection (SSI), C5 palsy, and incidental durotomy; the most common long-term complications include adjacent segment degeneration, junctional kyphosis, and pseudoarthrosis. Three principal mechanisms are thought to contribute to complications. First, higher number of fusion levels, obesity, and more complex pathologies can increase the invasiveness of the planned procedure, thus increase complications. Second, wound healing and arthrodesis may be impaired due to poor blood flow due to various patient factors such as smoking, diabetes, increased frailty, steroid use, and other medical comorbidities. Finally, increased biomechanical stress on the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV) may predispose patient to chronic degeneration and result in adjacent level degeneration and/or junctional problems. Reducing the modifiable risk factors pre-operatively can decrease the overall complication rate. Neurologic deficits may be reduced with adequate intraoperative decompression of neural elements. SSI may be reduced with meticulous wound closure that minimizes dead space, drain placement, and the use of intra-wound antibiotics. Careful design of the fusion construct with consideration in spinal alignment and biomechanics can help to reduce the rate of junctional problems. Spine surgeons should be aware of these complications associated with PCF and the corresponding prevention strategies optimize patient outcomes.

Measures to reduce end-of-case wound contamination: the impact of intra-wound vancomycin powder and betadine irrigation on surgical site infections in posterior spinal fusion

STUDY DESIGN

Retrospective descriptive, single-center study.

OBJECTIVES

To determine the effect of standardized intrawound vancomycin powder and betadine irrigation on surgical site infection (SSI) rates after posterior spinal fusion (PSF) in idiopathic scoliosis. Since 2005, our pediatric spine center has implemented a series of changes to lower the risk of SSI. The most recent interventions-intrawound vancomycin powder and betadine irrigation-are applied just before closure, aiming to reduce the culture-positive bacterial contamination known to occur in many cases. We sought to determine the impact of these end-of-case measures on our center's SSI rate.

METHODS

We retrospectively reviewed patients who underwent PSF for idiopathic scoliosis at our institution from January 1, 2010, to June 30, 2018, identifying all cases that returned to the operating room for surgical debridement within 90 days of PSF. Cases were surgeon-audited to ensure inclusion of all infections that met Centers for Disease Control and Prevention (CDC) criteria for acute SSI. Vertical expandable prosthetic titanium ribs, growing rods, staged procedures, and nonidiopathic cases were excluded. Annual rates of SSIs were correlated with the initiation of each SSI prevention measure.

RESULTS

Among 740 cases of PSF for idiopathic scoliosis from 2010 to 2018, the overall acute SSI rate by CDC criteria was 0.68%. The idiopathic SSI rate dropped significantly, from 1.70 to 0.20%, after the standardized introduction of intrawound vancomycin powder and betadine irrigation before closure (p < 0.04). The implementation of these end-of-case measures in 2012-2013 was soon followed by an institution best 3.5-year SSI-free period for idiopathic cases.

CONCLUSIONS

Since intrawound vancomycin powder and betadine irrigation were added to our SSI prevention bundle, we have seen a significantly lower SSI rate after PSFs for idiopathic scoliosis. These findings suggest that anti-SSI interventions to reduce wound contamination at the end of the case may have a particularly positive impact on SSI reduction.

LEVEL OF EVIDENCE

Level III, therapeutic.

Does Vitamin D3 Prevent the Inhibitory Effect of Vancomycin on Osteoblasts?

BACKGROUND

The utility of vancomycin powder to prevent surgical site infection, mainly in spinal surgery, has been widely examined, and the local administration of vancomycin powder to wounds has been reported to be effective in preventing surgical site infections after spine surgery. However, in vitro studies have shown that high local concentrations of vancomycin may inhibit osteogenesis, although it remains unclear how these high concentrations influence osteoblasts. No candidate drug has been reported to recover cytotoxicity with high concentrations of vancomycin, but we suggest that vitamin D3, which induces osteoblast proliferation, may be administrated concomitantly with vancomycin in these situations.

QUESTIONS/PURPOSES

(1) Does a high concentration of vancomycin reduce viable osteoblast numbers in cell culture compared with controls? (2) Does vitamin D3 administration confer a protective effect on osteoblasts when administered with continuous vancomycin? (3) Does vitamin D3 administration confer a protective effect on osteoblasts when administered with pulsed vancomycin (24 hours of administration)? (4) Does vitamin D3 administration confer alkaline phosphatase, mineralization, and gene expression when administered with pulsed vancomycin?

METHODS

MC3T3-E1 cells were cultured at 37° C in an α-minimum essential medium supplemented with 10% fetal bovine serum in a humidified incubator containing 5% CO2. The experimental concentrations of vancomycin (2500 μg/mL, 5000 μg/mL, and 7500 μg/mL) were determined based on previous reports and preliminary experiments. We concomitantly administered vitamin D3 (0.01 nM) to prevent cytotoxicity in osteoblasts, using two different treatments: continuous vancomycin administration (measured at 6 hours, 12 hours, 24 hours, and 72 hours) and pulsed vancomycin for 24 hours (measured at 1 days, 3 days, and 7 days). We analyzed cell numbers and morphologic changes in cells treated with vancomycin or vancomycin plus 0.01 nM vitamin D3. Osteoblast differentiation was assessed with alkaline phosphatase staining, alkaline phosphatase activity, and Alizarin red S staining.

RESULTS

The number of cells was reduced at 6 hours, 24 hours, 48 hours, and 72 hours in response to continuous vancomycin administration at 7500 µg/mL (at 72 hours, control 14.6 × 10 cells/mL ± 0.260 × 10 cells/mL, vancomycin at 0.917 × 10 cells/mL ± 0.288 × 10 cells/mL, mean difference -13.7 × 10 cells/mL ± 0.388 × 10 cells/mL [95% CI -14.5 to -12.9]; p < 0.001). Vitamin D3 did not have a protective effect when vancomycin was administered continuously at 7500 µg/mL (at 72 hours, vancomycin alone 0.917 × 10 cells/mL ± 0.288 × 10 cells/mL, vancomycin + vitamin D3 1.67 × 10 cells/mL ± 0.310 × 10 cells/mL, mean difference 0.75 × 10 cells/mL ± 0.423 × 10 cells/mL [95% CI -0.127 to 1.63]; p = 0.09).With pulsed administration for only the first 24 hours, the number of cells was reduced at 1 day, 3 days, and 7 days at 7500 μg/mL (at 7 days, control 18.6 × 10 cells/mL ± 1.29 × 10 cells/mL, vancomycin at 3.46 × 10 cells/mL ± 0.292 × 10 cells/mL, mean difference -15.1 × 10 cells/mL ±1.33 × 10 cells/mL [95% CI -17.9 to -12.4]; p < 0.001 for all). However, vitamin D3 had a recovery effect when vancomycin was administered only for 24 hours (cell number with 7500 μg/mL, day 7: vancomycin alone 3.46 × 10 cells/mL ± 0.292 × 10 cells/mL, vancomycin +vitamin D3 10.6 × 10 cells/mL ± 0.900 × 10 cells/mL, mean difference 7.13 × 10 cells/mL ± 0.946 × 10 cells/mL [95% CI 5.16 to 9.09]; p < 0.001).With the addition of vitamin D3, we observed recovery of alkaline phosphatase staining and Alizarin red staining (evidence of calcification) but no difference in the gene expression of Type I collagen (vancomycin alone 0.319 ± 0.0730, vancomycin + vitamin D3 0.511 ± 0.139, mean difference 0.192 ± 0.157 [95% CI -0.483 to 0.867]; p = 0.345), alkaline phosphatase (vancomycin alone 0.532 ± 0.0210, vancomycin + vitamin D3 0.785 ± 0.0590, mean difference 0.253 ± 0.0620 [95% CI -0.0150 to 0.521]; p = 0.0550), and cathelicidin antimicrobial peptide (vancomycin alone 0.885 ± 0.0520, vancomycin + vitamin D3 1.24 ± 0.125, mean difference 0.355 ± 0.135 [95% CI -0.0200 to 0.730]; p = 0.0580).

CONCLUSION

We found that 7500 µg/mL of vancomycin is cytotoxic to osteoblasts. Cytotoxicity could be prevented by administering vitamin D3 in combination with vancomycin.

CLINICAL RELEVANCE

The high concentrations of vancomycin routinely used clinically raises concerns related to osteoblast cytotoxicity, which may contribute to pseudoarthrosis after spinal surgery. Thus, vitamin D3, which is frequently used to treat osteoporosis, may have efficacy as a concomitantly administered drug by inducing the proliferation of osteoblasts. These results indicate that a combination therapy of vancomycin and vitamin D3 may prevent adverse events such as osteoblast cytotoxicity.

Evaluation of Cumulative and Conditional Antibiotic Release from Vancomycin-Embedded Fibrin Sealant and Its Antibacterial Activity : An In Vitro Study

Objective

Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro.

Methods

Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1–C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily.

Results

In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10–20 μg/mL) for 5 days and 4 days in assays of half and total exchange of PBS.

Conclusion

This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

Strategies of management of deep spinal infection: from irrigation and debridement to vacuum-assisted closure treatment

Postoperative surgical site problems (PSSPs) following spinal surgery may lead to patient mortality, increased treatment costs and possible recurrent medical interventions. Despite efforts to reduce spinal surgery-related infection rates, complications are common and significantly increased by patient comorbidities. Since PSSPs occur regardless of deterrent measures, it is essential to distinguish the related risk factors. Different treatment conventions for PSSPs, for example, antibiotic treatment, debridement, soft tissue care and removal of implants have been prescribed with blended outcomes. The utilization of the wound vacuum-assisted closure (VAC) system has gained increasing popularity in the management of deep wound infections after deformity surgery.

Intrasite Antibiotic Powder for the Prevention of Surgical Site Infection in Extremity Surgery: A Systematic Review

INTRODUCTION

Although the role of intrasite antibiotic powder in preventing surgical site infections (SSIs) has been extensively explored in spinal surgery, it remains underevaluated in the other orthopaedic subspecialties. This systematic review examines the utilization of intrawound antibiotic powder as a prophylactic measure against SSIs in orthopaedic procedures.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, electronic searches were conducted on Ovid MEDLINE, and PubMed. Only English language, nonspine clinical studies published before May 2018 were included.

RESULTS

The initial search identified 179 individual citations, and 11 studies met the eligibility criteria. All included studies were level III retrospective studies. Represented subspecialties included total joint arthroplasty, upper extremity, foot and ankle, and trauma. Eight studies demonstrated a statistically significant decrease in SSIs with the use of intrasite antibiotic powder.

DISCUSSION

There are no current guidelines for the use of intrasite antibiotic powder for the prevention of SSIs in orthopaedic procedures. Despite the lack of high-quality evidence available in the literature, published smaller studies do suggest a significant protective effect. However, recommendations with regard to this technique after common orthopaedic procedures cannot yet be made.

Topical vancomycin for neurosurgery wound prophylaxis: an interim report of a randomized clinical trial on drug safety in a diverse neurosurgical population

OBJECTIVE

Postoperative surgical site infections (SSIs) in neurosurgical patients carry a significant risk of increased morbidity and mortality. With SSIs accounting for approximately 20% of nosocomial infections and costing approximately $1.6 billion USD annually, there is a need for additional prophylaxis to improve current standards of care. Topical vancomycin is increasingly utilized in instrumented spinal and cardiothoracic procedures, where it has been shown to reduce the risk of SSIs. A randomized controlled trial assessing its efficacy in the general neurosurgical population is currently underway. Here, the authors report their initial impressions of topical vancomycin safety among patients enrolled during the 1st year of the trial.

METHODS

This prospective, multicenter, patient-blinded, randomized controlled trial will enroll 2632 patients over 5 years. Here, the authors report the incidence of adverse events, the degree of systemic vancomycin absorption in treated patients, and pattern changes of antibiotic-resistant profiles of Staphylococcus aureus flora among patients enrolled during the 1st year.

RESULTS

The topical vancomycin treatment group comprised 257 patients (514 total enrolled patients), of whom 2 exhibited weakly positive serum levels of vancomycin (> 3.0 mg/dl). S. aureus was detected preoperatively in the anterior nares of 35 (18.1%) patients and the skin near the surgical site of 9 (4.7%). Colonization in the nares remained for many patients (71.4%) through postoperative day 30. The authors found a significant association between preoperative S. aureus colonization and postoperative colonization. Seven methicillin-resistant isolates were detected among 6 different patients. Two isolates were detected preoperatively, and 5 were de novo postoperative colonization. No adverse responses to treatment have been reported to date.

CONCLUSIONS

The authors' data indicate that the use of topical vancomycin is safe with no significant adverse effects and minimal systemic absorption, and no development of vancomycin-resistant microorganisms.Clinical trial registration no.: NCT02284126 (clinicaltrials.gov).

Does the Application of Topical Intrawound Vancomycin Powder Affect Deep Surgical Site Infection and the Responsible Organisms after Spinal Surgery?: A Retrospective Case Series with a Historical Control Group

STUDY DESIGN

Retrospective case series with a historical control group.

PURPOSE

To compare the deep wound infection rates in patients undergoing spinal surgery with the application of topical intrawound vancomycin powder (TIVP) in the surgical site in addition to standard systemic prophylaxis with those in a matched historical cohort of patients for whom TIVP was not used.

OVERVIEW OF LITERATURE

Surgical site infection (SSI) after spine surgery is debilitating and is responsible for a significant increase in the health care costs, hospital stay, and morbidities. Although the application of TIVP before surgical closure is a promising method for reducing the SSI rate after spine surgery, its use is controversial, and currently, research trials are focusing on identifying its safety, efficacy, and the potential patient population.

METHODS

A group of 88 patients who underwent posterior spinal surgery with TIVP administration (treatment group) was compared to a historical control group of 70 patients who had received only standard systemic intravenous prophylaxis (control group) for the analysis of deep SSI rate and the involved organisms.

RESULTS

The overall rate of deep SSIs was 2.5% (4/158). All the SSIs were observed in patients who had posterior instrumentation and fusion for ≥3 levels. In the treatment group, the SSI rate was 3.4% (3/88), and the bacteria isolated were Escherichia coli (n=2) and Pseudomonas aeruginosa (n=1). In the control group, the infection rate was 1.4% (1/70), and the isolated bacteria were Morganella morganii and Staphylococcus epidermidis. No statistically significant association was found between the SSI rates of the treatment and control groups.

CONCLUSIONS

Although the difference in the SSI rates was not statistically significant, the present results suggest that TIVP administration could not reduce the risk of deep SSIs after spinal surgery. Moreover, TIVP administration might also affect the underlying pathogens by increasing the propensity for gram-negative species.

Effects of Operating Room Size on Surgical Site Infection Following Lumbar Fusion Surgery

Background

Surgical site infections (SSIs) represent a devastating complication after spine surgery. Many factors have been identified, but the influence of operating room (OR) size on infection rate has not been assessed.

Methods

Two thousand five hundred and twenty-three patients who underwent open lumbar spine fusion at a single institution between 2010 and 2016 were included. Patients were dichotomized into large versus small groups based on OR volume. Bivariate logistic regression and a final multivariate model following a multicollinearity check were used to calculate odds of infection for all variables.

Results

A total of 63 patients (2.5%) developed SSIs with 46 (73%) in the larger OR group and 17 (27%) in the smaller OR group. The rate of SSIs in larger ORs was 3.02% compared with 1.81% in smaller ORs. Significant parameters impacting SSI in bivariate analysis included an earlier year of surgery, BMI > 30, more comorbidities, more levels decompressed and fused, smoking, and larger OR volumes. Multivariate analysis identified BMI > 30, Elixhauser scores, smoking, and increasing levels decompressed as significant predictors. Topical vancomycin was found to significantly decrease rate of infection in both analyses.

Conclusions

OR size (large versus small) was ultimately not a significant predictor of infection related to rates of SSIs, although it did show a clinical trend toward significance, suggesting association. Future prospective analysis is warranted.

Level of Evidence

3.

Meta-analysis of topical vancomycin powder for microbial profile in spinal surgical site infections

OBJECTIVES

To systematically evaluate the impact of topical vancomycin powder for microbial profile in spinal surgical site infections.

METHODS

All available literature regarding the topical use of vancomycin powder to prevent postoperative spinal infections was retrieved from the MEDLINE, EMBASE, and Cochrane databases starting from the creation date and up until September 30, 2018.

RESULTS

A total of 21 studies involving 15,548 patients were reviewed. The combined odds ratio showed that topical use of vancomycin powder was effective for reducing the incidence of gram-positive bacterial infections in spinal surgical sites (OR 0.41, P < 0.00001) without affecting its efficacy in the prevention of polymicrobial infections (OR 0.30, P = 0.03). Additionally, it could significantly reduce the infection rate of methicillin-resistant staphylococcus (OR 0.34, P < 0.0001). However, topical vancomycin powder showed no advantage for preventing gram-negative bacterial infections (OR 0.94, P = 0.75).

CONCLUSIONS

Topical administration of vancomycin powder may not increase the rates of gram-negative bacterial or polymicrobial infections in spinal surgical sites. On the contrary, it can significantly reduce the infection rates of gram-positive bacteria, methicillin-resistant staphylococcus (MRS) and microorganism. Of course, the topical vancomycin powder cannot change the rates of gram-negative bacterial infections, which may be related to the antimicrobial spectrum of vancomycin. Due to the limited number of articles included in this study, additional large-scale and high-quality studies are needed to provide more reliable clinical evidence.

Intrawound vancomycin powder increases post-operative wound complications and does not decrease periprosthetic joint infection in primary total and unicompartmental knee arthroplasties

PURPOSE

A frequent reason for revision surgery after total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) is periprosthetic joint infection (PJI). The efficacy of intrawound VP in preventing PJI after primary TKA or UKA is rarely reported. The purpose of this study was to investigate the efficacy and side effects of local high-dose VP application to the joint to prevent PJI in TKA and UKA.

METHODS

From 2010 to 2017, 166 consecutive patients that underwent primary TKA or UKA were enrolled. Seventy-five patients (92 knees) did not receive VP (control group), while 90 patients (110 knees, VP group) received VP (intrawound, 1 g) before capsule closure during TKA and UKA. Aseptic wound complications, such as skin erosion, wound dehiscence, and prolonged wound healing, were evaluated within 3 months post-operatively. PJI was assessed within a year post-operatively.

RESULTS

Seven patients (7.6%) in the control group and five patients (4.5%) in the VP group had PJI. No significant differences existed in the PJI rates between the groups. Aseptic operative wound complications occurred in 4 patients (4.3%) and 13 patients (11.8%), whereas prolonged operative wound healing occurred in 3 patients (3.3%) and 14 patients (12.7%) of patients in the control and VP group, respectively. Operative wound complications were significantly frequent in the VP group.

CONCLUSIONS

Intrawound VP administration does not decrease PJI occurrence in primary TKA and significantly causes aseptic wound complications. The use of intrawound VP for the prevention of PJI after primary TKA and UKA is not recommended.

LEVEL OF EVIDENCE

Level II.

Selection pressures of vancomycin powder use in spine surgery: a meta-analysis

BACKGROUND CONTEXT

Surgical site infection (SSI) is a serious and costly complication of spine surgery. Many surgeons apply vancomycin powder to the surgical wound to prevent SSIs. While multiple studies have reported reduced rates of SSI, others have suggested that widespread use of intrawound vancomycin may increase the incidence of vancomycin-resistant, gram-negative, or polymicrobial spinal infections.

PURPOSE

To systematically review the current literature on vancomycin powder in spine surgery and its impact on SSI culture profiles.

STUDY DESIGN

Meta-analysis.

SAMPLE

We included observational studies, retrospective chart reviews, and randomized controlled trials of patients who underwent spine surgeries with and without vancomycin powder application to surgical wounds and reported SSI rates.

OUTCOME MEASURES

The primary outcome was postoperative SSIs. Subgroup analyses compared rates of postoperative SSIs.

METHODS

We performed a comprehensive search of numerous electronic databases and conference proceedings pertaining to this topic. Our meta-analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Inclusion criteria consisted of spine surgeries with or without use of vancomycin powder, case-control design, sample sizes of at least 10 in each arm, SSIs identified with bacterial cultures, and follow-up of at least 1 month. Data extracted from eligible studies included, but was not limited to, SSI rates, cultured organisms, and vancomycin powder dose. Chi-square analyses were used to assess pooled risk-estimates of intrawound vancomycin powder on reducing SSIs and selecting for gram-negative and/or polymicrobial organisms compared to controls. Pooled odds ratios, relative risks, and relative risk increase for observed outcomes were calculated. A meta-analysis was then performed with a forest plot to determine risk estimates' heterogeneity with I² index, Q-statistic, and p value under a fixed-effects model. Funnel plot was used to assess publication bias. None of the authors received funding or other support for this review.

RESULTS

After reviewing nearly 400 titles and abstracts, 28 articles met inclusion criteria. They included two randomized controlled trials, one observational study, and 25 retrospective analyses. There were 412 cases of SSI (3.8%) in the control group (N=10,846) compared to 197 SSIs (2.3%) in the vancomycin powder group (N=8,456). The pooled odds ratio was 0.60 (95% confidence intervalCI 0.51-0.71, p<.05). The rate of gram-positive SSI was significantly higher in the control group compared to the vancomycin group (70% vs. 45.1%, p<.05). The rate of gram-negative and polymicrobial SSI was significantly higher in the vancomycin group (35.8% vs. 18.5%, p<.05). The risk of developing a gram-negative or polymicrobial SSI was nearly twice (93.5% higher) in the vancomycin group. Study heterogeneity and synthesizing mostly retrospective data were primary limitations.

CONCLUSIONS

Widespread use of prophylactic intrawound vancomycin may increase the incidence of gram-negative and polymicrobial SSIs. Vancomycin powder should likely be restricted to procedures and patients most at risk for infection.

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.

Factors Associated with Deep Surgical Site Infection Following Spinal Surgery: A Pilot Study

Introduction

Surgical site infection (SSI) is the most common healthcare-related infection in surgical patients. Patients who have undergone spinal surgeries and have contracted postoperative SSI face increased morbidity and mortality, which invariably leads to additional burden on the healthcare system and higher costs. The risk factors for the increase in SSI in patients who have undergone spinal surgery have been investigated in numerous studies but no studies have been performed in Malaysia. The aim of this pilot study is to determine the incidence and factors associated with deep SSIs in patients that have undergone spinal surgeries.

Methods

This retrospective study includes all patients who underwent spinal surgeries at Tengku Ampuan Afzan Hospital, Kuantan, from 1 January 2016 to 31 December 2017. Patients with an active spinal infection, polytrauma, and open fractures were excluded from this study. Patient characteristics and laboratory investigations were extracted to determine the risk factors for deep SSI events. Associations between SSI and risk factors were analyzed with SPSS V21.0 (IBM, Armonk, NY).

Results

The univariate analysis indicated that fracture dislocation at the thoraco-lumbar junction (p=0.008) and a history of preoperative blood product transfusion (p=0.003) were associated with deep SSI. Other factors such as age (p=0.162), gender (p=0.262), body mass index (p=0.215), smoking status (0.272), number of vertebrae involved in the surgery (p=0.837), spinal cord involvement (p=0.259), postoperative hemoglobin reduction (p=0.816), and preoperative white blood cell count (p=0.278) were not associated with deep SSI.

Conclusions

This pilot study highlights the factors associated with deep SSI in spinal surgeries. A larger study is needed to further confirm these findings.

Intrawound Treatment for Prevention of Surgical Site Infections in Instrumented Spinal Surgery: A Systematic Comparative Effectiveness Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

To determine the efficacy of intrawound treatments in reducing deep surgical site infections (SSIs) in instrumented spinal surgery.

METHODS

The electronic databases MEDLINE, EMBASE, and Cochrane were systematically searched for intrawound treatments for the prevention of SSIs in clean instrumented spine surgery. Both randomized controlled trials and comparative cohort studies were included. The results of included studies were pooled for meta-analysis.

RESULTS

After full text- and reference screening, 20 articles were included. There were 2 randomized controlled trials and 18 observational studies. Sixteen studies investigated the use of intrawound antibiotics, and 4 studies investigated the use of intrawound antiseptics. The relative risk of deep SSI for any treatment was 0.26 (95% confidence interval [CI] 0.16-0.44, P < .0001), a significant reduction compared with controls receiving no treatment. For patients treated with local antibiotics the relative risk was 0.29 (95% CI 0.17-0.51, P < .0001), and patients treated with local antiseptics had a relative risk of 0.14 (95% CI 0.05-0.44, P = .0006).

CONCLUSIONS

Both the use of antibiotic and antiseptic intrawound prophylactics was associated with a significant 3 to 7 times reduction of deep SSIs in instrumented spine surgery. No adverse events were reported in the included studies.