Risk Factors and Prevention of Surgical Site Infections Following Spinal Procedures

Optimal time window for initiating cefuroxime surgical antimicrobial prophylaxis in spinal fusion surgery: a nested case-control study

BACKGROUND CONTEXT

Surgical site infections (SSI) are one of the common complications following spinal fusion surgery. Unfortunately, several studies had shown conflicting results regarding optimal timing of surgical antimicrobial prophylaxis (SAP) administration. Due to limitations in population homogeneity and sample size, these studies have not provided significant statistical correlations or clear practical recommendations.

PURPOSE

The purpose of the study was to investigate the impact of timing of cefuroxime SAP on the risk of SSI in patients undergoing spinal fusion surgery, and to determine the optimal timing of administration.

DESIGN

Retrospective nested case-control study.

PATIENT SAMPLE

We retrospectively analyzed consecutive patients who underwent spinal fusion surgery at our institution between October 2011 and October 2021.

OUTCOME MEASURE

In the current study, the primary outcome measure was SSI.

METHODS

This was a retrospective nested case-control study. All consecutive patients who underwent spinal fusion surgery at our institution between October 2011 and October 2021 formed a retrospective cohort. For each SSI case, 2 controls free of SSI at the time of the index date of their corresponding case were selected, matched by age, sex, and calendar year. Electronic record and radiographic data were reviewed retrospectively in electronic database. SAP related data included timing of administration, preoperative dose, intraoperative second dose, and postoperative use. To examine the effects of mismatched variables, we further adjusted for possible confounding factors using conditional logistic regression models. Subsequently, subgroup analyses were conducted to assess the robustness of the statistical associations.

RESULTS

According to the preplanned statistical scheme and matching factors, we matched 236 controls for these SSI cases, and the subsequent statistical analysis was performed on these 354 patients. After adjusting for confounding factors, the results indicated that the risk of SSI was 70% higher in the group receiving SAP 31 to 60 minutes before incision compared to the group receiving SAP 0 to 30 minutes before incision (OR=1.732, 95%CI 1.031-2.910, p=.038). Additionally, the risk of SSI was 150% higher in the group receiving SAP 61 to 120 minutes before incision compared to the group receiving SAP 0 to 30 minutes before incision (OR=2.532, 95%CI 1.250-5.128, p=.010). In subgroup analysis, this statistical trend persisted for both deformity surgeries and different SSI classifications.

CONCLUSION

Administering cefuroxime SAP within 30 minutes before skin incision significantly reduces the risk of SSI, whether they are deep or superficial, in spinal fusion surgery. This pattern remains consistent among spinal deformity patients.

Microbial spectrum, patient-specific factors, and diagnostics in implant-related postoperative spondylodiscitis

Aims

Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date.

Methods

Patients treated for IPOS from January 2006 to December 2020 were included. Patient demographics, parameters upon admission and discharge, radiological imaging, and microbiological results were retrieved from medical records. CT and MRI were analyzed for epidural, paravertebral, and intervertebral abscess formation, vertebral destruction, and endplate involvement. Pathogens were identified by CT-guided or intraoperative biopsy, intraoperative tissue sampling, or implant sonication.

Results

A total of 32 cases of IPOS with a mean patient age of 68.7 years (37.6 to 84.1) were included. Diabetes, age > 60 years, and history of infection were identified as risk factors. Patient presentation upon admission included a mean body temperature of 36.7°C (36.1 to 38.0), back pain at rest (mean visual analogue scale (VAS) mean 5/10) and when mobile (mean VAS 6/10), as well as elevated levels of CRP (mean 76.8 mg/l (0.4 to 202.9)) and white blood cell count (mean 9.2 units/nl (2.6 to 32.8)). Pathogens were identified by CT-guided or conventional biopsy, intraoperative tissue sampling, or sonication, and Gram-positive cocci presented as the most common among them. Antibiotic therapy was established in all cases with pathogen-specific treatment in 23 (71.9%) subjects. Overall 27 (84.4%) patients received treatment by debridement, decompression, and fusion of the affected segment.

Conclusion

Cases of IPOS are rare and share similarities with spontaneous spondylodiscitis. While procedures such as CT-guided biopsy and sonication are valuable tools in the diagnosis of IPOS, MRI and intraoperative tissue sampling remain the gold standard. Research on known principles of PJI such as implant retention versus implant exchange need to be expanded to the field of spine surgery.

Effectiveness of prophylactic intranasal photodynamic disinfection therapy and chlorhexidine gluconate body wipes for surgical site infection prophylaxis in adult spine surgery

BACKGROUND

Current measures to prevent spinal surgical site infection (SSI) lack compliance and lead to antimicrobial resistance. We aimed to examine the effectiveness of bundled preoperative intranasal photodynamic disinfection therapy (nPDT) and chlorhexidine gluconate (CHG) body wipes in the prophylaxis of spine SSIs in adults, as well as determine our institutional savings attributable to the use of this strategy and identify adverse events reported with nPDT-CHG.

METHODS

We performed a 14-year prospective observational interrupted time-series study in adult (age > 18 yr) patients undergoing emergent or elective spine surgery with 3 time-specific cohorts: before rollout of our institution's nPDT-CHG program (2006-2010), during rollout (2011-2014) and after rollout (2015-2019). We used unadjusted bivariate analysis to test for temporal changes across patient and surgical variables, and segmented regression to estimate the effect of nPDT-CHG on the annual SSI incidence rates per period. We used 2 models to estimate the cost of nPDT-CHG to prevent 1 additional SSI per year and the annual cumulative cost savings through SSI prevention.

RESULTS

Over the study period, 13 493 patients (mean 964 per year) underwent elective or emergent spine surgery. From 2006 to 2019, the mean age, mean Charlson Comorbidity Index (CCI) score and mean Spine Surgical Invasiveness Index (SSII) score increased from 48.4 to 58.1 years, from 1.7 to 2.6, and from 15.4 to 20.5, respectively (p < 0.001). Unadjusted analysis confirmed a significant decrease in the annual number (74.6 to 26.8) and incidence (7.98% to 2.67%) of SSIs with nPDT-CHG (p < 0.001). After adjustment for mean age, mean CCI score and mean SSII score, segmented regression showed an absolute reduction in the annual SSI incidence rate of 3.36% per year (p < 0.001). The estimated annual cost to prevent 1 additional SSI per year was about $1350-$1650, and the estimated annual cumulative cost savings were $2 484 856-$2 495 016. No adverse events were reported with nPDT-CHG.

CONCLUSION

Preoperative nPDT-CHG administration is an effective prophylactic strategy for spinal SSIs, with significant cost savings. Given its rapid action, minimal risk of antimicrobial resistance, broad-spectrum activity and high compliance rate, preoperative nPDT-CHG decolonization should be the standard of care for all patients undergoing emergent or elective spine surgery.

Effects of extended oral antibiotic prophylaxis on surgical site infections after instrumented spinal fusion: a cohort study of 901 patients with a minimum follow-up of 1 year

BACKGROUND AND PURPOSE

We aimed to determine whether an extended oral antibiotic prophylaxis protocol may reduce the rate of surgical site infection (SSI) in patients undergoing instrumented spinal fusion.

PATIENTS AND METHODS

This retrospective cohort study comprise 901 consecutive patients subjected to spinal fusion between September 2011 and December 2018 with a minimum 1-year follow-up. 368 patients operated on between September 2011 and August 2014 were administered standard intravenous prophylaxis. 533 patients operated on between September 2014 and December 2018 were administered an extended protocol with 500 mg of oral cefuroxime axetil every 12 hours (clindamycin or levofloxacin in allergic individuals) until the removal of sutures. SSI was defined following the Centers for Disease Control and Prevention criteria. The association between risk factors and the incidence of SSI was evaluated by odds ratio (OR) with a multiple logistic regression model.

RESULTS

The bivariate analysis showed a statistically significant association between SSI and the type of prophylaxis used ("extended"' = 1.7% vs. "standard" = 6.2%, p= 0.001), with a lower proportion of superficial SSIs with the extended regimen (0.8% vs. 4.1%, p = 0.001). The multiple logistic regression model showed an OR = 0.25 (95% confidence interval [CI] 0.10-0.53) for extended prophylaxis and an OR = 3.5 (CI 1.3-8.1) for non-beta-lactams antibiotics.

CONCLUSION

Extended antibiotic prophylaxis seems to be associated with a reduction in the incidence of superficial SSI in instrumented spine surgery.

Does Nasal Screening for Methicillin-Resistant Staphylococcus aureus (MRSA) Prevent Deep Surgical Site Infections for Elective Cervical Spinal Fusion?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The objective of this study was to determine the relationship between nasal methicillin-resistant Staphylococcus aureus (MRSA) testing and surgical site infection (SSI) rates in the setting of primary posterior cervical instrumented spine surgery.

SUMMARY OF BACKGROUND DATA

Preoperative MRSA screening and decolonization has demonstrated success for some orthopedic subspecialties in prevention of SSIs. Spine surgery, however, has seen varied results, potentially secondary to the anatomic and surgical heterogeneity of the patients included in prior studies. Given that prior research has demonstrated greater propensity for gram positive SSIs in the cervical spine, we sought to investigate if MRSA screening would be more impactful in the cervical spine.

MATERIALS AND METHODS

Adult patients undergoing primary instrumented posterior cervical procedures from January 2015 to December 2019 were reviewed for MRSA testing <90 days before surgery, preoperative mupirocin, perioperative antibiotics, and SSI defined as operative incision and drainage (I&D) <90 days after surgery. Logistic regression modeling used SSI as the primary outcome, MRSA screening as primary predictor, and clinical and demographic factors as covariates.

RESULTS

This study included 668 patients, of whom MRSA testing was performed in 212 patients (31.7%) and 6 (2.8%) were colonized with MRSA. Twelve patients (1.8%) underwent an I&D. On adjusted analysis, preoperative MRSA testing was not associated with postoperative I&D risk. Perioperative vancomycin similarly had no association with postoperative I&D risk. Notably, 6 patients (50%) grew methicillin sensitive Staphylococcus aureus from intraoperative cultures, with no cases of MRSA.

CONCLUSIONS

There was no association between preoperative nasal MRSA screening and SSIs in primary posterior cervical instrumented procedures, nor was there any association between vancomycin or infection rate. Furthermore, there was a preponderance of gram positive infections but none caused by MRSA. Given these findings, the considerable cost and effort associated with MRSA testing in the setting of primary posterior cervical instrumentation may not be justified. Further research should investigate if higher-risk scenarios demonstrate greater utility of preoperative testing.

The Diagnostic Value of Blood Next-Generation Sequencing in Early Surgical Site Infection After Spine Surgery

Objective

To determine the diagnostic value of blood next-generation sequencing (NGS) in early surgical site infection after spine surgery. Because the blood is sterile in healthy individuals, it is expected that blood NGS is both sensitive and specific for the detection of infection.

Methods

A total of 28 patients with definitive spinal surgical site infections and controls (n=30) were retrospectively included. The postoperative results of NGS and culture on different samples, such as blood and drainage fluid, were obtained and compared to evaluate the diagnostic value of blood NGS. The diagnostic value parameters (sensitivity, specificity, etc.) were calculated.

Results

Among the four bacteriological exam methods, blood NGS was both sensitive and specific for the determination of infection after spine surgery. The sensitivities of blood and drainage fluid NGS were similar (0.82 vs 0.89, P=0.617). However, the specificities of the two assessments differed, which were 0.97 for blood NGS and 0.40 for drainage fluid NGS (P<0.001). The sensitivities of bacterial culture were lower than those of NGS (blood: 0.82 vs 0.25, P<0.001; drainage fluid: 0.89 vs 0.61, P<0.001), regardless of the sample type. However, the specificities of bacterial culture were equal to or higher than those of NGS (blood: 0.97 vs 0.97, P=1.000; drainage fluid: 0.40 vs 0.80, P=0.002).

Conclusion

This article emphasizes the superiority of blood NGS in infection detection and bacterial determination in patients undergoing spine surgery. Compared with traditional drainage fluid bacterial culture and NGS, blood NGS was more sensitive and specific, and its extensive application could be expected.

Spinal infection with intraspinal abscess or empyema and acute myelopathy: comparative analysis of diagnostics, therapy, complications and outcome in primary care

INTRODUCTION

This study on pyogenic spinal infections with intraspinal epidural involvement (PSI +) compared the outcome of patients with spinal cord injury (SCI) to those without (noSCI) taking diagnostic algorithm, therapy, and complications into account.

METHODS

Patients were enrolled in an ambispective study (2012-2017). Diagnostic and therapeutic algorithms, complications, and neurological outcome were analyzed descriptively. Survival was analyzed applying Kaplan-Meier method and Cox regression.

RESULTS

In total, 134 patients with a median (IQR) age of 72 (61-79) years were analyzed. Baseline characteristics were similar between the SCI (n = 55) and noSCI (n = 79). A higher percentage of endocarditis (9% vs. 0%; p = 0.03) was detected in the noSCI group. The majority (81%) received combinatorial therapy including spinal surgery and antibiotic treatment. The surgery complication rate was 16%. At discharge, improvement in neurologic function was present in 27% of the SCI patients. Length of stay, duration of ventilation and the burden of disease-associated complications were significantly higher in the SCI group (e.g., urinary tract infection, pressure ulcers). Lethality risk factors were age (HR 1.09, 95% CI 1.02-1.16, p = 0.014), and empyema/abscess extension (≥ 3 infected spinal segments, HR 4.72, 95% CI 1.57-14.20, p = 0.006), dominating over additional effects of Charlson comorbidity index, SCI, and type of treatment. The overall lethality rate was 11%.

CONCLUSION

PSI + are associated with higher in-hospital mortality, particularly when multiple spinal segments are involved. However, survival is similar with (SCI) or without myelopathy (noSCI). If SCI develops, the rate of disease complications is higher and early specialized SCI care might be substantial to reduce complication rates.

The Temporality of Deep Surgical Site Infection Rates Following Spinal Laminectomy and Fusion

BACKGROUND

Deep surgical site infections (dSSI) following spinal laminectomy and fusion are serious complications associated with poor patient outcomes. The objective of this study is to investigate the monthly and seasonal variability of dSSI rates following common spinal surgeries to investigate the "July effect," which refers to the alleged increase in adverse health outcomes due to new hospital trainees at the beginning of the academic year.

METHODS

We performed a retrospective analysis of patients who had a dSSI following laminectomy (without fusion) or spinal fusion (with or without laminectomy) at a single large urban academic medical center between January 2009 and August 2018. The change in dSSI rate over the entire study period was calculated. The monthly and seasonal variability of dSSI were assessed using a Poisson regression model to assess for the presence of the July effect.

RESULTS

A total of 7931 laminectomies and 14,637 spinal fusions were reviewed. The average dSSI rates following laminectomy and spinal fusion were 0.46 (SD, 0.47) and 1.26 (SD, 0.86) per 100 patients, respectively. The rate of dSSI following spinal fusion significantly decreased over the study period (rate ratio [RR] = 0.89, 95% CI 0.84-0.94, P < 0.01). With summer as the reference season, there were significantly lower dSSI rates following spinal fusions performed in the fall (RR = 0.62, 95% CI 0.39-0.98, P = 0.04 ). With July as the reference month, there was a significantly higher dSSI rate in April following spinal fusions.

CONCLUSION

The overall decrease in dSSI rate over the study period is consistent with previous reports. The monthly analysis revealed no significant differences in either procedure, calling into question the July effect.

CLINICAL RELEVANCE

This study is relevant to practicing spinal surgeons and can inform surgeons about seasonal data regarding dSSIs.

LEVEL OF EVIDENCE: 3

Loop and drain technique for prevention of surgical site infection in upper gastrointestinal surgery

INTRODUCTION

Hepatobiliary and pancreatic surgery is frequently complicated by surgical site infections (SSI) with significant postoperative morbidity and mortality rates contributing to the economic burden on healthcare. Advancements in operative techniques to prevent SSI are gaining traction in clinical practice. This study compares the effectiveness of the 'loop and drain technique (LDT)', a combination method utilizing a continuous subcutaneous vessel loop and subcuticular suture for surgical wound closure in patients undergoing upper gastrointestinal surgery at a Metropolitan Hospital in Sydney.

METHODS

A retrospective review of patients who underwent an upper gastrointestinal procedure was conducted at Bankstown-Lidcombe hospital between 2017 and 2019. There were 77 patients in the LDT group and 123 patients included in the control group. The primary outcome assessed was the rate of SSI. Secondary outcomes included length of stay (LOS) and drainage of surgical site infections.

RESULT

Two hundred adult patients were treated for an upper gastrointestinal procedure. The most common operation was a Whipple procedure (35.0%). The rate of SSI was 12.5% with all these patients receiving intravenous antibiotics. The LDT cohort had a significantly lower rate of SSI compared to their counterparts (3.9% vs. 17.9%, P = 0.004).

CONCLUSION

The LDT method is associated with a decreased incidence of SSI and should be considered as a cost-effective operative technique to improve patient outcomes after upper gastrointestinal surgery.

Severe complication subsequent to surgical site infection after cervical laminoplasty: a case report

INTRODUCTION

Surgical site infections (SSI) following spinal surgery can result in serious complications. Although early detection and intensive care are essential to minimize possible sequelae, more than one surgical intervention is required to alleviate the infection in some cases.

CASE PRESENTATION

A 66-year-old man with long-standing Parkinson's disease (PD) developed SSIs after cervical laminoplasty. Despite surgical debridement and irrigation, his neurological status worsened severely and anterior infectious involvement at the C4-5 level was identified by magnetic resonance imaging. He underwent another urgent surgery for anterior debridement and iliac bone grafting. His laboratory results gradually normalized with antibiotic therapy, and his neurological status improved. One year after surgery, he was ambulatory with walker assistance. However, his right hand remained difficult to control with significant sensory loss and numbness.

DISCUSSION

To our knowledge, this is the first case of SSI that extended rapidly to the anterior side despite immediate and intensive treatment in a patient with PD after laminoplasty. During SSI treatment, meticulous observation should be performed to check for exacerbations.

CORRELATION OF POSTOPERATIVE INFECTION WITH THE ETIOLOGY OF THE DISEASE IN SPINAL SURGERY WITH INSTRUMENTATION

ABSTRACT Objective: To evaluate the epidemiological characteristics of postoperative infection in surgeries of the spine with instrumentation in our service, and whether there is a correlation between the rate of postoperative infection and the etiology of the indication for the primary surgical procedure. Methodology: A retrospective search through medical records of patients who underwent spinal surgery with instrumentation in our hospital between 2015 and 2019 was performed, and the ones that evolved with acute or chronic postoperative infection with need for surgical cleaning to resolve it were selected. Cases of non-instrumented surgery, primary infection of the spine (osteomyelitis and spondylodiscitis) and superficial infection of the surgical wound without the need for surgical cleaning were excluded. Results: The rate of postoperative infection was 11.6%. In this group of patients who evolved with this complication, most were submitted to surgery primarily for trauma (38.9%), followed by degenerative disease (30.8%), neoplasm (19.2%), and deformity (15, 4%). However, when we analyzed these patients comparing them with the total number of cases of spinal surgery with instrumentation performed in the period, we obtained a higher prevalence of infection in patients operated for deformity (17.6%), followed by degenerative disease (13%), neoplasm (11.4%) and trauma (9.9%). This difference did not prove to be statistically significant (p = 0.79), nor the correlation with sex and age. Conclusion: In our study, proportionally, there was a difference in the prevalence of postoperative infection according to the etiological indication, being higher in cases operated for deformity, mainly due to neuromuscular disease. Level of evidence IV; A case series therapeutic study.

Nasal screening for methicillin-resistant Staphylococcus aureus does not reduce surgical site infection after primary lumbar fusion

BACKGROUND CONTEXT

Preoperative methicillin-resistant Staphylococcus aureus (MRSA) testing and decolonization has demonstrated success for arthroplasty patients in surgical site infections (SSIs) prevention. Spine surgery, however, has seen varied results.

PURPOSE

The purpose of this study was to determine the impact of nasal MRSA testing and operative debridement rates on surgical site infection after primary lumbar fusion.

STUDY DESIGN/SETTING

Retrospective cohort study and/or Consolidated medical enterprise PATIENT SAMPLE: Adult patients undergoing primary instrumented lumbar fusions from January 2015 to December 2019 were reviewed.

OUTCOME MEASURES

The primary outcome was incision and drainage performed in the operating room within 90 days of surgery.

METHODS

MRSA testing <90-day's before surgery, mupirocin prescription <30-day's before surgery, perioperative antibiotics, and Elixhauser comorbidity index were collected for each subject. Bivariate analysis used Wilcoxon rank-sum testing and logistic regression modeling Multivariable logistic regression modeling assessed for associations with MRSA testing, intravenous vancomycin use, and I&D rate.

RESULTS

The study included 1,884 patients for analysis, with mean age of 63.1 (SE 0.3) and BMI 29.5 (SE 0.1). MRSA testing was performed in 755 patients (40.1%) and was more likely to be performed in patients with lower Elixhauser index scores (OR 0.98, 95% CI 0.96-0.99, p=.021) on multivariable analysis. Vancomycin use increased significantly over time (OR 1.49 and/or year, 95% CI 1.3-1.8, p<.001) despite no change in mupirocin or I&D rates. MRSA testing, mupirocin prescriptions, perioperative parenteral vancomycin use, and intrawound vancomycin powder use had no impact on I&D rates. I&D risk was associated with higher BMI (OR 1.06, 95% CI 1.02-1.12, p=.009) and higher number of blood product units transfused (OR 1.23, 95% CI 1.03-1.46, p=.022).

CONCLUSIONS

The present study demonstrates no impact on surgical I&D rates from the use of preoperative MRSA testing. Increased BMI and transfusions were associated with operative I&D rates for surgical site infection. As a result of the hospital directive, vancomycin use increased over time with no associated change in infection rates, underscoring the need for focused interventions, and engagement with antibiotic stewardship programs.

Bacterial adhesion on spinal implants: An in vitro study of "hot spots"

Few studies evaluated bacterial colonization of spinal implants from a "topographic" point of view. This lack of knowledge could hinder the development of more effective strategies in the prevention and treatment of postoperative spinal infections. The aim of this in vitro study was the analysis of the adhesion pattern of sessile cells on conventional spinal implants, to identify "hot spots" on implants where bacterial adhesion could be favored. Clinically relevant Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa isolates were grown on commercially available end product spinal implants. To identify sessile cells attached to implant surfaces, confocal laser scan microscopy was used. Different areas from the spinal instrumentations (both Ti and CoCr) were selected for biofilm quantification. Bacterial biofilm was markedly increased in the cut of the rods, both Ti and CoCr, as the uneven surface deriving from the cut might foster cell adhesion. Though not statistically significant, a difference was observed between the rod and the area of the notch, possibly as a consequence of the smoothening effect deriving from the bending of the rod. Finally, the amount of biofilm produced on cobalt-chromium surfaces was always more significant than that formed on titanium surfaces. This study highlights how bacterial adhesion through biofilm formation is favored on the surfaces of higher irregularity and that staphylococci are able to increase sessile biomass on CoCr surfaces. These preliminary results show how surface modifications on the implants may play a key role in bacterial adhesion, opening an exciting field for future research.

Smoking Is an Independent Risk Factor for 90-Day Readmission and Reoperation Following Posterior Cervical Decompression and Fusion

BACKGROUND

Posterior cervical decompression and fusion (PCF) is a common procedure used to treat various cervical spine pathologies, but the 90-d outcomes following PCF surgery continue to be incompletely defined.

OBJECTIVE

To identify risk factors associated with 90-d readmission and reoperation following PCF surgery.

METHODS

Adults undergoing PCF from 2012 to 2020 were identified. Demographic and radiographic data, surgical characteristics, and 90-d outcomes were collected. Univariate analysis was performed using Student's t-test, chi square, and Fisher exact tests as appropriate. Multivariable logistic regression models with lasso penalty were used to analyze various risk factors.

RESULTS

A total of 259 patients were included. The 90-d readmission and reoperation rates were 9.3% and 4.6%, respectively. The most common reason for readmission was surgical site infection (SSI) (33.3%) followed by new neurological deficits (16.7%). Patients who smoked tobacco had 3-fold greater odds of readmission compared to nonsmokers (odds ratio [OR]: 3.48; 95% CI 1.87-6.67; P = .0001). Likewise, the most common reason for reoperation was SSI (33.3%) followed by seroma and implant failure (25.0% each). Smoking was also an independent risk factor for reoperation, associated with nearly 4-fold greater odds of return to the operating room (OR: 3.53; 95% CI 1.53-8.57; P = .003).

CONCLUSION

Smoking is a significant predictor of 90-d readmission and reoperation in patients undergoing PCF surgery. Smoking cessation should be strongly considered preoperatively in elective PCF cases to minimize the risk of 90-d readmission and reoperation.

Surgical Site Infection, Readmission, and Reoperation After Posterior Long Segment Fusion

STUDY DESIGN

Retrospective case series.

OBJECTIVE

We sought to identify risk factors associated with surgical site infection (SSI) after posterior long segment spinal fusion (PLSF).

SUMMARY OF BACKGROUND DATA

Patients who undergo PLSF may be at elevated risk of SSI. Identifying factors associated with SSI in these operations can help risk stratify patients and tailor management.

METHODS

We analyzed PLSFs-seven or more levels-at our institution from 2000 to 2015. Data on patients' clinical characteristics, procedural factors, and antimicrobial management were collected. Multivariable analysis identified factors independently associated with outcomes of interest.

RESULTS

In 628 cases, SSI was associated with steroid use (P = 0.024, odds ratio [OR] = 2.54) and using cefazolin (P < 0.001, OR = 4.37) or bacitracin (P = 0.010, OR 3.49) irrigation, as opposed to gentamicin or other irrigation. Gram-positive infections were more likely with staged procedures (P = 0.021, OR 4.91) and bacitracin irrigation (P < 0.001, OR = 17.98), and less likely with vancomycin powder (P = 0.050, OR 0.20). Gram-negative infections were more likely with a history of peripheral arterial disease (P = 0.034, OR = 3.21) or cefazolin irrigation (P < 0.001, OR 25.47). Readmission was more likely after staged procedures (P = 0.003, OR = 3.31), cervical spine surgery (P = 0.023, OR = 2.28), or cefazolin irrigation (P = 0.039, OR = 1.85). Reoperation was more common with more comorbidities (P = 0.022, OR 1.09), staged procedures (P < 0.001, OR = 4.72), cervical surgeries (P = 0.013, OR = 2.36), more participants in the surgery (P = 0.011, OR = 1.06), using cefazolin (P < 0.001, OR = 3.12) or bacitracin (P = 0.009, OR = 3.15) irrigation, and higher erythrocyte sedimentation rate at readmission (P = 0.009, OR = 1.04). Washouts were more likely among patients with more comorbidities (P = 0.013, OR = 1.16), or who used steroids (P = 0.022, OR = 2.92), and less likely after cervical surgery (P = 0.028, OR = 0.24). Instrumentation removal was more common with bacitracin irrigation (p = 0.013, OR = 31.76).

CONCLUSION

Patient factors, whether a procedure is staged, and choice of antibiotic irrigation affect the risk of SSI and ensuing management required.Level of Evidence: 4.

Web-Based Calculator Predicts Surgical-Site Infection After Thoracolumbar Spine Surgery

BACKGROUND

Surgical-site infection (SSI) after spine surgery leads to increased length of stay, reoperation, and worse patient quality of life. We sought to develop a web-based calculator that computes an individual's risk of a wound infection following thoracolumbar spine surgery.

METHODS

We performed a retrospective review of consecutive patients undergoing elective degenerative thoracolumbar spine surgery at a tertiary-care institution between January 2016 and December 2018. Patients who developed SSI requiring reoperation were identified. Regression analysis was performed and model performance was assessed using receiver operating curve analysis to derive an area under the curve. Bootstrapping was performed to check for overfitting, and a Hosmer-Lemeshow test was employed to evaluate goodness-of-fit and model calibration.

RESULTS

In total, 1259 patients were identified; 73% were index operations. The overall infection rate was 2.7%, and significant predictors of SSI included female sex (odds ratio [OR] 3.0), greater body mass index (OR 1.1), active smoking (OR 2.8), worse American Society of Anesthesiologists physical status (OR 2.1), and greater surgical invasiveness (OR 1.1). The prediction model had an optimism-corrected area under the curve of 0.81. A web-based calculator was created: https://jhuspine2.shinyapps.io/Wound_Infection_Calculator/.

CONCLUSIONS

In this pilot study, we developed a model and simple web-based calculator to predict a patient's individualized risk of SSI after thoracolumbar spine surgery. This tool has a predictive accuracy of 83%. Through further multi-institutional validation studies, this tool has the potential to alert both patients and providers of an individual's SSI risk to improve informed consent, mitigate risk factors, and ultimately drive down rates of SSIs.

BMI Does Not Affect Complications or Patient Reported Outcomes After Lumbar Decompression Surgery

STUDY DESIGN

This is a retrospective comparative review.

OBJECTIVE

The objective of this study was to identify the influence of body mass index (BMI) on postsurgical complications and patient reported outcomes measures (PROMs) following lumbar decompression surgery.

SUMMARY OF BACKGROUND DATA

Current literature does not accurately identify the impact of BMI on postsurgical complications or outcomes.

MATERIALS AND METHODS

Records from a single-center, academic hospital were used to identify patients undergoing 1 to 3-level lumbar decompression surgery. Patients under 18 years of age, those undergoing surgery for infection, trauma, tumor, or revision, and those with <1-year follow-up were excluded. Patients were split into groups based on preoperative BMI: class I: BMI <25.0 kg/m; class II: BMI 25.0-29.9 kg/m; class III: BMI 30.0-34.9 kg/m; and class IV: BMI >35.0 kg/m. Absolute PROM scores, the recovery ratio and the percent of patients achieving minimum clinically important difference between groups were compared and a multiple linear regression analysis was performed.

RESULTS

A total of 195 patients were included with 34 (17.4%) patients in group I, 80 (41.0%) in group II, 49 (25.1%) in group III, and 32 (16.5%) in group IV. Average age was 60.0 (58.0, 62.0) years and average follow-up was 13.0 (12.6, 13.4) months. All patients improved significantly within each group, except for class III and class IV patients, who did not demonstrate significant improvements in terms of Mental Component Score (MCS-12) scores (P=0.546 and 0.702, respectively). There were no significant differences between BMI groups for baseline or postoperative PROM values, recovery ratio, or the percent of patients reaching minimum clinically important difference. Multiple linear regression analysis revealed that BMI was not a significant predictor for change in outcomes for any measure. The 30-day readmission rate was 6.2% and overall revision rate at final follow-up was 5.1%, with no significant differences between groups.

CONCLUSION

This study's results suggest that BMI may not significantly affect complications or patient outcomes at 1-year in those undergoing lumbar decompression surgery.

LEVEL OF EVIDENCE

Level III.

Negative pressure wound therapy in spinal fusion patients

Post-operative wound complications are some of the most common acute complications following spine surgery. These surgical site infections (SSI) contribute to increased healthcare related costs. Negative pressure wound therapy (NPWT) has long been used for treatment of soft tissue injury or defects. NPWT may reduce the incident of SSI following spinal fusion procedures; however, its potential applications need further clarification. Thus, we conducted a retrospective analysis of two cohorts to compare NPWT to traditional sterile dressings following spinal fusions in regards to post-operative outcomes. Following institutional review board approval, 42 patients who had a NPWT were matched by type of surgery to 42 patients who had traditional dressings. A retrospective chart-review was completed. Outcome measures, particularly SSI and need for reoperation, were analyzed using one-way ANOVA for both univariate and multivariate analysis. When controlled for sex and body-mass index, the use of a NPWT was independently correlated with decreased SSI (P = .035). Superficial dehiscence, seroma, need for additional outpatient care, and need for operative revision were all found to occur at higher rates in the traditional dressing cohort. Closed incisional negative pressure wound therapy provides a cost-effective method of decreasing surgical site infection for posterior elective spine surgeries.

Preoperative Urinary Tract Infection Increases Postoperative Morbidity in Spine Patients

STUDY DESIGN

Retrospective review.

OBJECTIVE

Compare postoperative infection rates and 30-day outcomes in spine surgery patients with and without a preoperative urinary tract infection (UTI).

SUMMARY OF BACKGROUND DATA

There is mixed evidence regarding safety and risks when operating on spine patients with a preoperative UTI.

METHODS

Using data from the American College of Surgeons National Surgical Quality Improvement Program, we identified all adult patients undergoing spine surgery between 2012 and 2017 with a preoperative UTI. Patients with other preoperative infections were excluded. Our primary outcome was any postoperative infection (pneumonia, sepsis, surgical site infection, and organ space infection). Our secondary outcomes included surgical site infections, non-infectious complications, return to operating room, and 30-day readmission and mortality. We used univariate, then multivariate Poisson regression models adjusted for demographics, comorbidities, laboratory values, and case details to investigate the association between preoperative UTI status and postoperative outcomes.

RESULTS

A total of 270,371 patients who underwent spine surgery were analyzed. The most common procedure was laminectomy (41.9%), followed by spinal fusion (31.7%) and laminectomy/fusion (25.6%). Three hundred fourty one patients had a preoperative UTI (0.14%). Patients with a preoperative UTI were more likely to be older, female, inpatients, emergency cases, with a higher American Society of Anesthesiologists score, and a longer operating time (for all, P < 0.001). Patients with a preoperative UTI had higher rates of infectious and non-infectious complications, return to operating room, and unplanned readmissions (for all, P < 0.001). However, there was no significant difference in mortality (0.6% vs. 0.2%, P = 0.108). Even after controlling for demographics, comorbidities, labs, and case details, preoperative UTI status was significantly associated with more postoperative infectious complications (incidence rate ratio [IRR]: 2.88, 95% confidence interval [CI]: 2.25-3.70, P < 0.001).

CONCLUSION

Preoperative UTI status is significantly associated with postoperative infections and worse 30-day outcomes. Spine surgeons should consider delaying or cancelling surgery in patients with a UTI until the infection has cleared to reduce adverse outcomes.

LEVEL OF EVIDENCE

3.

Infection prevention in cervical spine surgery

Surgical site infections (SSI) following cervical spine surgery can lead to significant patient morbidity and costs. Prevention of SSIs is multifactorial and can be divided in to preoperative patient optimization and intraoperative surgical factors. We performed a literature review to identify methods that can be used to prevent SSI development specifically in the cervical spine. We also present specific surgical pearls and techniques that have the potential to significantly decrease rates of cervical SSIs.

Surgical Site Infection Prevention Following Spine Surgery

STUDY DESIGN

Literature review.

OBJECTIVES

Surgical site infection (SSI) following spine surgery leads to significant patient morbidity, mortality, and increased health care costs. The purpose of this article is to identify risk factors and strategies to prevent SSIs following spine surgery, with particular focus on avoiding infections in posterior cervical surgery.

METHODS

We performed a literature review and synthesis to identify methods that can be used to prevent the development of SSI following spine surgery. Specific pearls for preventing infection in posterior cervical spine surgery are also presented.

RESULTS

SSI prevention can be divided into patient and surgeon factors. Preoperative patient factors include smoking cessation, tight glycemic control, weight loss, and nutrition optimization. Surgeon factors include screening and treatment for pathologic microorganisms, skin preparation using chlorhexidine and alcohol, antimicrobial prophylaxis, hand hygiene, meticulous surgical technique, frequent irrigation, intrawound vancomycin powder, meticulous multilayered closure, and use of closed suction drains.

CONCLUSION

Prevention of SSI following spine surgery is multifactorial and begins with careful patient selection, preoperative optimization, and meticulous attention to numerous surgical factors. With careful attention to various patient and surgeon factors, it is possible to significantly reduce SSI rates following spine surgery.

Burkholderia cepacia as a cause of pyogenic spondylodiscitis in immunocompetent patients: a single-institution case series and literature review

Burkholderia cepacia is an important pathogen of humans in both immunocompromised and hospitalized patients. This uncommon pathogen is established to be the cause of pyogenic spondylodiscitis in only seven cases in the medical literature. Here, we report the cases of four patients who were diagnosed over two years period with Burkholderia cepacia spondylodiscitis and were successfully managed by appropriate antimicrobial treatment after open surgical biopsy was done for debridement and microbiological identification.