Epidemiology of Deep Surgical Site Infections After Pediatric Spinal Fusion Surgery

Topical vancomycin powder for the prevention of surgical site infections in spinal deformity surgery: a systematic review and meta-analysis

PURPOSE

To assess the effectiveness and safety of topical vancomycin powder (VP) in preventing surgical site infections (SSIs) in spinal deformity surgeries.

METHODS

A literature search was conducted on Web of Science, PubMed, and Cochrane Library databases for comparative studies of VP in spinal deformity surgeries published before February 2024. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed study quality, and extracted data. Data analysis was performed using Review Manager 5.4 software.

RESULTS

Of all 143 papers screened, a meta-analysis was conducted on 10 articles, which included a total of 8,166 surgeries. The results of the meta-analysis indicated that the incidence of deep SSI in VP group was 0.28 times that in non-VP group (p < 0.001). In the subgroup analysis, VP treatment significantly reduced the risk of deep SSI in both adult spinal deformity (ASD) (RR 0.40, 95% CI 0.21-0.77, p = 0.006) and pediatric scoliosis (PS) (RR 0.25, 95% CI 0.16-0.38, p < 0.001) surgeries. However, this effect was not observed in neuromuscular scoliosis (NMS) patients (RR 0.66, 95% CI 0.26-1.66, p = 0.38). Bacterial culture results indicated that VP treatment significantly reduced polymicrobial infections (p = 0.007) and gram-positive infections (p = 0.001).

CONCLUSION

From the literature available at present, VP was associated with reduced deep SSIs rates in spinal deformity patients. However, particular attention should be paid to the lack of the effectiveness of VP in NMS patients. The current literature did not report local cytotoxicity or renal toxicity related to VP in spinal deformity patients.

Risk stratification for early postoperative infection in Pediatric spinal deformity correction: development and validation of the Pediatric scoliosis infection risk score (PSIR score)

BACKGROUND CONTEXT

Postoperative infection after spinal deformity correction in pediatric patients is associated with significant costs. Identifying risk factors associated with postoperative infection would help surgeons identify high-risk patients that may require interventions to minimize infection risk.

PURPOSE

To investigate risk factors associated with 30-day postoperative infection in pediatric patients who have received posterior arthrodesis for spinal deformity correction.

STUDY DESIGN/SETTING

Retrospective review of prospectively collected data.

PATIENT SAMPLE

The National Surgical Quality Improvement Program Pediatric database for years 2016-2021 was used for this study. Patients were included if they received posterior arthrodesis for scoliosis or kyphosis correction (CPT 22,800, 22,802, 22,804). Anterior only approaches were excluded.

OUTCOME MEASURES

TThe outcome of interest was 30-day postoperative infection.

METHODS

Patient demographics and outcomes were analyzed using descriptive statistics. Multivariable logistic regression analysis using likelihood ratio backward selection method was used to identify significant risk factors for 30-day infection to create the Pediatric Scoliosis Infection Risk Score (PSIR Score). ROC curve analysis, predicted probabilities, and Hosmer Lemeshow goodness-of-fit test were done to assess the scoring system on a validation cohort.

RESULTS

A total of 31,742 patients were included in the study. The mean age was 13.8 years and 68.7% were female. The 30-day infection rate was 2.2%. Reoperation rate in patients who had a post-operative infection was 59.4%. Patients who had post-operative infection had a higher likelihood of non-home discharge (X2 = 124.8, p < 0.001). In our multivariable regression analysis, high BMI (OR = 1.01, p < 0.001), presence of open wound (OR = 3.18, p < 0.001), presence of ostomy (OR = 1.51, p < 0.001), neuromuscular etiology (OR = 1.56, p = 0.009), previous operation (OR = 1.74, p < 0.001), increasing ASA class (OR = 1.43, p < 0.001), increasing operation time in hours (OR = 1.11, p < 0.001), and use of only minimally invasive techniques (OR = 4.26, p < 0.001) were associated with increased risk of 30-day post-operative infection. Idiopathic etiology (OR = 0.53, p < 0.001) and intraoperative topical antibiotic use (B = 0.71, p = 0.003) were associated with reduced risk of 30-day postoperative infection. The area under the curve was 0.780 and 0.740 for the derivation cohort and validation cohort, respectively.

CONCLUSIONS

To our knowledge, this is the largest study of risk factors for infection in pediatric spinal deformity surgery. We found 5 patient factors (BMI, ASA, osteotomy, etiology, and previous surgery, and 3 surgeon-controlled factors (surgical time, antibiotics, MIS) associated with risk. The Pediatric Scoliosis Infection Risk Score (PSIR) Score can be applied for risk stratification and to investigate implementation of novel protocols to reduce infection rates in high-risk patients.

Plastic surgeon closure is comparable to orthopedic closure when a perioperative optimization protocol is instituted for pediatric patients with neuromuscular scoliosis

BACKGROUND CONTEXT

Since 2015, plastic multilayer closure (PMC) has been gaining attraction due to improved wound healing outcomes for medically complex patients. Plastic multilayer closure has been readily used for complex spine surgery closures in patients susceptible to wound healing issues (ie, dehiscence, surgical site infection [SSI]). However, PMC requires extensive soft tissue manipulation compared with standard orthopedic spine surgeon closure (SOC) and can result in extended operative times, increased transfusion rates, and more frequent returns to the operating room.

PURPOSE

From 2016 to 2019, our institution implemented a perioperative protocol designed to decrease postoperative complication rates in NMS patients. A retrospective cohort study was performed to determine if PMC imparted advantages over SOC above and beyond that from the perioperative protocol.

STUDY DESIGN/SETTING

Retrospective study at a single academic institution.

PATIENT SAMPLE

Eighty-one pediatric patients with neuromuscular scoliosis undergoing spinal fixation surgery.

OUTCOME MEASURES

Postoperative wound complications such as surgical site infection, hematoma, and superficial/deep dehiscence were the main outcome measures. Respiratory and neuromuscular complications along with duration of surgery were also recorded.

METHODS

A retrospective review was conducted of NMS patients undergoing spinal fixation at a single academic pediatric hospital over 4 years. Cases were labeled as SOC (n=41) or PMC (n=40) based on the closure technique applied. Reported 90-day complications were evaluated as the primary outcome.

RESULTS

Of the 81 reviewed patients, 45 reported complications, roughly equal between the study groups. While we found no statistically significant differences in rates of postoperative complications or SSIs, SOC cases were 30 minutes shorter on average with fewer returns to the operating room for additional surgery.

CONCLUSIONS

With the implementation of our perioperative protocol for NMS patients, PMC did not result in fewer complications than SOC but the surgeries did take longer.

Surgical site infection in pediatric spinal fusion surgery revisited: outcome and risk factors after preventive bundle implementation

Background

Surgical site infections (SSI) contribute to significant morbidity, mortality, length of stay, and financial burden. We sought to evaluate the incidence and risk factors of surgical site infection following pediatric spinal fusion surgery in patients for whom standard perioperative antibiotic prophylaxis and preventive strategies have been implemented.

Methods

We conducted a retrospective study of children aged <18 years who underwent spinal fusion surgery from January 2017 to November 2021 at a quaternary academic pediatric medical center. Univariable analysis was used to evaluate associations between potential risk factors and SSI.

Results

Of 1111 patients, 752 (67.6%) were female; median age was 14.2 years. SSI occurred in 14 patients (1.3%). Infections were superficial incisional (n=2; 14.3%), deep incisional (n=9; 64.3%), and organ/space (n=3; 21.4%). Median time to SSI was 14 days (range, 8 to 45 days). Staphylococcus aureus and Escherichia coli were the most frequently-isolated bacteria. Potential risk factors for SSIs included low body weight (Odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-0.99, p=0.026), ASA classification of ≥3 (OR 24.53, 95%CI 3.20-188.22, p=0.002), neuromuscular scoliosis (OR 3.83, 95%CI 3.82-78.32, p<0.001), prolonged operative time (OR 1.56, 95%CI 1.28-1.92, p<0.001), prolonged anesthetic time (OR 1.65, 95%CI 1.35-2.00, p<0.001), administration of prophylactic antibiotic ≥60 minutes before skin incision (OR 11.52, 95%CI 2.34-56.60, p=0.003), and use of povidone-iodine alone for skin preparation (OR 5.97, 95%CI 1.27-28.06, p=0.024).

Conclusion

In the context of a robust bundle for SSI prevention; low body weight, ASA classification of ≥3, neuromuscular scoliosis, prolonged operative and anesthetic times, administration of prophylactic antibiotic ≥60 minutes before skin incision, and use of povidone-iodine alone for skin preparation increased the risk of SSI. Administration of prophylactic antibiotic within 60 minutes of skin incision, strict adherence to high-risk preventive protocol, and use of CHG-alcohol could potentially reduce the rate of SSI.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Study Design

Retrospective cohort study.

Objective

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

Methods

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

Results

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

Conclusion

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE IV

Retrospective study.

Allogeneic Red Blood Cell Transfusion and Infectious Complications Following Pediatric Spinal Fusion: NSQIP-P Analysis

Substantial bleeding occurs during spinal fusion surgery in the pediatric population, and many patients receive allogeneic red blood cell transfusion (ARBT) for the treatment of resulting perioperative anemia. ARBT is thought to increase vulnerability to postoperative infections following major surgical procedures, but studies of this relationship in children undergoing spinal fusion have yielded conflicting results.

Incidence, Management and Outcome of Delayed Deep Surgical Site Infection Following Spinal Deformity Surgery: 20-Year Experience at a Single Institution

STUDY DESIGN

A retrospective study.

OBJECTIVES

To investigate the incidence, management and outcome of delayed deep surgical site infection (SSI) after the spinal deformity surgery.

METHODS

This study reviewed 5044 consecutive patients who underwent spinal deformity corrective surgery and had been followed over 2 years. Delayed deep SSI were defined as infection involving fascia and muscle and occurring >3 months after the initial procedure. An attempt to retain the implant were initially made for all patients. If the infection failed to be eradicated, the implant removal should be put off until solid fusion was confirmed, usually more than 2 years after the initial surgery. Radiographic data at latest follow-up were compared versus that before implant removal.

RESULTS

With an average follow-up of 5.3 years, 56 (1.1%) patients were diagnosed as delayed deep SSI. Seven (12.5%) patients successfully retained instrumentation and there were no signs of recurrence during follow-up (average 3.4 years). The remaining patients, because of persistent or recurrent infection, underwent implant removal 2 years or beyond after the primary surgery, and solid fusion was detected in any case. However, at a minimum 1-year follow-up (average 3.9 years), an average loss of 9° in the thoracic curve and 8° in the thoracolumbar/lumbar curves was still observed.

CONCLUSIONS

Delayed deep SSI was rare after spinal deformity surgery. To eradicate infection, complete removal of implant may be required in the majority of delayed SSI. Surgeons must be aware of high likelihood of deformity progression after implant removal, despite radiographic solid fusion.

Association of Methicillin-Resistant Coagulase-Negative Staphylococci on Preoperative Skin and Surgical Site Infection in Patients Undergoing Spinal Surgery: A Retrospective Cohort Study

Introduction

The aim of this study was to investigate the association of methicillin-resistant coagulase-negative staphylococci (MRCNS) on preoperative skin and surgical site infections (SSIs) in patients undergoing spinal surgery.

Methods

A total of 507 cases (239 males and 268 females; mean age: 56.1 years) were included in this retrospective study, using prospectively collected data. All patients underwent skin culturing of the surgical site preoperatively. To identify independent risk factors for SSIs as the dependent variable, sequential multivariate logistic regression analyses were conducted. Age, sex, body mass index, presence of rheumatoid arthritis (RA), steroid uses, the American Society of Anesthesiologists Physical Status (ASA-PS) ≥3, MRCNS-positivity on skin bacterial culture, instrumentation, and Japanese Orthopedic Association (JOA) score were used as independent variables.

Results

Preoperatively, MRCNS was detected from skin culture in 50 (9.9%) cases. The frequency of RA, steroid uses, and ASA-PS ≥3 was significantly higher in MRCNS-positive cases than in MRCNS-negative cases. There were 21 (4.1%) post-spinal surgery SSI cases. Multivariate logistic regression analyses revealed that JOA scores (odds ratio (OR), 0.864; 95% confidence interval (CI), 0.764-0.977) and MRCNS-positivity (OR, 5.060; 95% CI, 1.787-14.323) were significantly associated with SSIs.

Conclusions

Preoperatively, the incidence of MRCNS was 9.9%; it was the most common cause of postoperative SSIs. MRCNS-positivity was the most associated factor for SSIs.

Staphylococcus aureus infections after elective pediatric surgeries

Objective:

To determine the 180-day cumulative incidence of culture-confirmed Staphylococcus aureus infections after elective pediatric surgeries.

Design:

Retrospective cohort study utilizing the Premier Healthcare database (PHD).

Setting:

Inpatient and hospital-based outpatient elective surgical discharges.

Patients:

Pediatric patients <18 years who underwent surgery during elective admissions between July 1, 2010, and June 30, 2015, at any of 181 PHD hospitals reporting microbiology results.

Methods:

In total, 74 surgical categories were defined using ICD-9-CM and CPT procedure codes. Microbiology results and ICD-9-CM diagnosis codes defined S. aureus infection types: bloodstream infection (BSI), surgical site infection (SSI), and other types (urinary tract, respiratory, and all other). Cumulative postsurgical infection incidence was calculated as the number of infections divided by the number of discharges with qualifying elective surgeries.

Results:

Among 11,874 inpatient surgical discharges, 180-day S. aureus infection incidence was 1.79% overall (1.00% SSI, 0.35% BSI, 0.45% other). Incidence was highest among children <2 years of age (2.76%) and lowest for those 10–17 years (1.49%). Among 50,698 outpatient surgical discharges, incidence was 0.36% overall (0.23% SSI, 0.05% BSI, 0.08% others); it was highest among children <2 years of age (0.57%) and lowest for those aged 10–17 years (0.30%). MRSA incidence was significantly higher after inpatient surgeries (0.68%) than after outpatient surgeries (0.14%; P < .0001). Overall, the median days to S. aureus infection was longer after outpatient surgery than after inpatient surgery (39 vs. 31 days; P = .0116).

Conclusions:

These findings illustrate the burden of postoperative S. aureus infections in the pediatric population, particularly among young children. These results underscore the need for continued infection prevention efforts and longer-term surveillance after surgery.

Silver carboxylate-doped titanium dioxide-polydimethylsiloxane coating decreases Cutibacterium acnes adherence and biofilm formation on polyether ether ketone

BACKGROUND CONTEXT

Cutibacterium acnes (C. acnes) is a gram-positive facultative anaerobe found in the deep sebaceous follicles of the skin on the shoulder and back. C. acnes has been increasingly recognized as a pathogen in spinal surgical site infection (SSI) especially in the presence of instrumentation.

PURPOSE

This study assesses whether a silver carboxylate-doped titanium dioxide-polydimethylsiloxane (TiO₂-PDMS) coating can decrease C. acnes adherence and biofilm formation on PEEK and four other commonly used spinal implant materials, stainless steel, cobalt chromium, titanium, and titanium alloy.

STUDY DESIGN

We compared the adherence of C. acnes over 24 hours between uncoated, 95:5 TiO₂ to PDMS ratio with 10× silver carboxylate coating and a 100% silver carboxylate coating on each implant material, which were uniformly saw cut and sterilized. Implants were then subjected to scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM).

METHODS

Samples were coated using 95:5 TiO₂-PDMS 10× silver carboxylate, 100% silver carboxylate, or left uncoated. C. acnes was applied onto the samples and allowed to adhere for periods of 4, 8, 12, 16, or 20 hours. Nonadherent bacteria were then washed from the samples. These samples were then allowed to continue incubating for a total of 24 hours. SEM and confocal laser scanning microscope were used to visualize all samples for the presence of biofilm and quantification of C. acnes adherence at each time point.

RESULTS

The 95:5 TiO₂-PDMS 10× silver carboxylate coating was able to significantly decrease C. acnes adherence on PEEK after 8, 12, 16, and 20 hours of adherence. No statistical difference was found between the 95:5 TiO₂-PDMS 10× silver carboxylate coating and the 100% silver carboxylate positive control. We previously observed extensive C. acnes biofilm formation on uncoated PEEK, but none on PEEK coated with either the 95:5 TiO₂-PDMS 10× silver carboxylate or 100% Ag coating . Furthermore, no biofilm formation was observed on stainless steel, cobalt chromium, titanium, and titanium alloy coated with 95:5 TiO₂-PDMS 10× silver carboxylate or 100% Ag coating.

CONCLUSION

A 95:5 TiO₂-PDMS 10× silver carboxylate coating decreases C. acnes adhesion and prevents biofilm formation on PEEK and other common orthopedic implant materials.

CLINICAL SIGNIFICANCE

A 95:5 TiO₂-PDMS 10× silver carboxylate coating may help decrease spinal SSI due to C. acnes, especially in procedures with instrumentation.

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

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

Prevention of surgical site infections in pediatric spines: a single-center experience

PURPOSE

To describe the potential issues in the methodology of surgical site infection (SSI) prevention and how it was investigated and corrected in a single institution.

METHODS

A pediatric orthopedic unit experienced an increase of SSI, concerning up to 10% of scoliosis surgery cases from 2011 to 2013. An institutional procedure of multimodal and interdisciplinary risk evaluation was initiated, including a review of the literature, a morbi-mortality meeting, internal and external audits concerning the hygiene conditions in the operating room, the antibiotic prophylaxis, patients, and sterile material pathways. Several preventive actions were implemented, including the improvement of air treatment in the operating room, wound irrigation with 2L of saline before closure, application of topic vancomycine in the wound, verification of doses and timing of antibiotics injection, and use of waterproof bandages. We compared the rates of spine SSI before (retrospective group, 2011-2013) and after the implementation of various preventive measures (prospective group, 2014-2018).

RESULTS

SSI occurred in 12 patients (6 idiopathic and 6 neuromuscular) out of 120 operated on (93 idiopathic, 18 neuromuscular, 9 others) in the retrospective group and 2 (both neuromuscular) out of 196 (150 idiopathic, 33 neuromuscular,13 others) in the prospective group (10% vs 1%, odds ratio=9.7, p=0.001). The groups were comparable for age, etiology, duration of surgery, body mass index, American Society of Anesthesiologists score, number of levels fused, and blood loss (p>0.2).

CONCLUSION

The systematic analysis of SSI allowed for the understanding of the failures and correcting them. The current process is effectively preventing SSI.

LEVEL OF EVIDENCE

3: prospective series with case-control analysis.

Antibiotic prophylaxis in high-risk pediatric spine surgery: Is cefazolin enough?

STUDY DESIGN

Retrospective study.

OBJECTIVE

To describe pathogens found in SSI during pediatric-instrumented spine surgery, and to assess the relationship between pathogens and the etiology of the spinal deformity. Surgical site infection (SSI) after pediatric spine fusion is a well-known complication with incidence rates between 0.5 and 42%, associated with the patient underlying disorder. Pathogens involved in SSI seem to be related to patient characteristics, such as the etiology of the spinal deformity. GNB (gram-negative bacilli) are more frequent in neuropathic, muscular, and syndromic conditions. High-risk pediatric patients with a spine deformity undergoing instrumented surgery might benefit from receiving perioperative intravenous prophylaxis for GNB.

METHODS

We conducted a retrospective study at our tertiary-care pediatric hospital from January 2010 to January 2017. We reviewed records of all episodes of SSI that occurred in the first 12 months postoperatively. All patients who underwent instrumented spine surgery were included in this study.

RESULTS

We assessed 1410 pediatric-instrumented spine surgeries; we identified 68 patients with deep SSIs, overall rate of 4.8%. Mean age at instrumented spine surgery was 12 years and 9 months. Time elapsed between instrumented surgery and debridement surgery was 28.8 days. Cultures were positive in 48 and negative in 20. Of the 48 positive culture results, 41 (72%) were GNB, 12 (21%) gram-positive cocci (GPC), three (5%) gram-positive anaerobic cocci (GPAC), and one (2%) coagulase-negative staphylococci (CoNS). Of the 68 patients with primary SSIs, 46 were considered to have a high risk of infection, which reported GNB in 81%, GPC in 15%, GPAC in 2%, and CoNS in 2%.

CONCLUSION

Cefazolin prophylaxis covers GPC and CoNS, but GNB with unreliable effectiveness. Gram-negative pathogens are increasingly reported in SSIs in high-risk patients. Adding prophylaxis for GNB in high-risk patients should be taken into account when considering spine surgery.

LEVEL OF EVIDENCE

IV.

Is Cutibacterium acnes early surgical site infection rate related to the duration of antibiotic prophylaxis in adolescent idiopathic scoliosis surgery?

PURPOSE

Cutibacterium acnes (C. acnes) is a gram-positive anaerobic bacillus located in pilosebaceous glands, usually responsible for late postoperative surgical site infections (SSI). A recent study performed in our institution highlighted an unexpected emergence of C. acnes early SSI. One potential explanation was the change of the perioperative antibioprophylaxis (ATB) protocol, which switched from 48 h postoperative cefamandole to intraoperative only cefazoline. The aim of this study was therefore to investigate the influence of the ATB duration on the occurrence of C. acnes early SSI, by comparing the incidence rates during 3 consecutive ATB protocols.

METHODS

Between January 2007 and September 2017, all patients who underwent posterior fusion for AIS were retrospectively reviewed. Early C. acnes SSI were reported and compared between 3 periods, during which the ATB protocols were modified. January 2007-February 2012: Intraoperative Cefamandole continued 48 h (protocol 1) March 2012-August 2016: Single shot of intraoperative Cefazoline (protocol 2) September 2016-September 2017: Intraoperative Cefazoline continued 48 h (protocol 3).

RESULTS

Fifty-three early SSI (7.2%) were reported among the 732 posterior AIS fusions included. Global incidence of C. acnes infection was 2.9%. The incidence of C. acnes in early SSI increased from 0 to 4.9% between protocol 1 and 2, but was reduced to 1.7% with protocol 3.

CONCLUSIONS

Early C acnes SSI can be explained by the difficulty to eradicate this pathogen with current skin preparation procedures and some Beta-lactam antibiotics tolerance. Longer duration antibioprophylaxis is preferable to prevent from early C. acnes SSI.

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.

Deep Infections After Pediatric Spinal Arthrodesis: Differences Exist with Idiopathic, Neuromuscular, or Genetic and Syndromic Cause of Deformity

BACKGROUND

Little is known about the rates, timing, and causative microorganisms of deep surgical site infections after spinal arthrodesis in patients with genetic and syndromic scoliosis compared with patients with adolescent idiopathic scoliosis and kyphosis or patients with neuromuscular scoliosis.

METHODS

We reviewed data from 1,353 patients who were <21 years of age and had undergone spinal arthrodesis for deformity correction by 1 surgeon from 2000 to 2015. Deformity causes were genetic, idiopathic, or neuromuscular. We identified patients who had undergone an unplanned surgical procedure for a deep surgical site infection that was early (≤90 days after the procedure) or late (>90 days after the procedure). We compared deep surgical site infection rates, timing, and causative microorganisms by deformity cause.

RESULTS

Deep surgical site infections occurred in 65 patients (4.8%): 4.2% for patients with genetic and syndromic scoliosis, 2.7% for patients with adolescent idiopathic scoliosis and kyphosis, and 10.0% for patients with neuromuscular scoliosis. Of the deep surgical site infections, 26 (40%) occurred early and 39 (60%) occurred late. The median times to deep surgical site infection onset were 51 days (range, 7 days to 7 years) in patients with genetic and syndromic scoliosis, 827 days (range, 10 days to 12 years) in patients with adolescent idiopathic scoliosis and kyphosis, and 45 days (range, 13 days to 6 years) in patients with neuromuscular scoliosis. Seventy-six microorganisms (41 gram-positive and 35 gram-negative) were isolated from 47 children with positive cultures; the most common was coagulase-negative Staphylococcus (n = 13). The ratio of gram-positive to gram-negative microorganisms was highest in patients with adolescent idiopathic scoliosis and kyphosis (4:1) and lowest in patients with genetic and syndromic scoliosis (0.5:1). In genetic and syndromic scoliosis, both early and late deep surgical site infections were more frequently caused by gram-negative bacteria. In neuromuscular scoliosis, early deep surgical site infections were more frequently caused by gram-negative bacteria, and late deep surgical site infections were more frequently caused by gram-positive bacteria. In adolescent idiopathic scoliosis and kyphosis, both early and late deep surgical site infections were more commonly caused by gram-positive bacteria. Methicillin-resistant Staphylococcus aureus was identified in 2 late deep surgical site infections in patients with neuromuscular scoliosis.

CONCLUSIONS

Deep surgical site infections were more common in genetic and syndromic scoliosis than in adolescent idiopathic scoliosis and kyphosis, but less common than in neuromuscular scoliosis. Adolescent idiopathic scoliosis and kyphosis had the highest ratio of late to early deep surgical site infections. Patients with genetic and syndromic scoliosis had predominantly gram-negative microorganisms, particularly in early deep surgical site infections. Methicillin-resistant S. aureus infection was rare, occurring in only 2 patients with neuromuscular scoliosis. Gram-negative and gram-positive prophylactic antibiotics may be indicated for patients with genetic and syndromic scoliosis after spinal arthrodesis.

LEVEL OF EVIDENCE

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

Clinical Characteristics and Outcomes of Staphylococcus aureus Implant-associated Infections in Children

BACKGROUND

Staphylococcus aureus is a significant cause of implant-associated infections (IAIs). Data detailing the optimal treatment of IAIs are lacking in children. We describe the clinical features and outcomes of pediatric patients with S. aureus IAIs seen at Texas Children's Hospital.

METHODS

Patients and their isolates were identified from a S. aureus surveillance database from 2008 to 2016 in Houston, TX. Demographic and clinical data were collected retrospectively. Fisher's exact was used for statistical analysis.

RESULTS

Forty-five patients with 47 IAIs were identified. Most patients had an infected orthopedic implant: 22 (47%) spinal rods and 19 (40%) with other orthopedic hardware. Thirty (64%) IAIs developed within 90 days of implant placement. Six patients had polymicrobial infections and 3 patients were bacteremic. Of the 47 IAI isolates, 34 (72%) were methicillin-susceptible S. aureus (MSSA) and 13 (28%) were methicillin-resistant S. aureus. All children underwent surgical irrigation, debridement and antibiotic therapy. Of the 47 IAI episodes, 22 of the implants were removed at time of initial presentation, 7 implants had delayed removal, and 18 implants remained in place. Successful treatment was achieved in all patients with immediate implant removal (22/22) and in 83% of patients with implant retention (15/18), including 10 patients with early postoperative infections (<3 months) and 5 patients with late postoperative infections (>3 months). Four patients had recurrence of infection.

CONCLUSIONS

The majority of S. aureus IAIs were methicillin-susceptible S. aureus. All children with immediate implant removal and most children with retained implants were treated successfully with surgery and antibiotic therapy.

Antibacterial coating of implants: are we missing something?

Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user's cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma. Cite this article: C. L. Romanò, H. Tsuchiya, I. Morelli, A. G. Battaglia, L. Drago. Antibacterial coating of implants: are we missing something? Bone Joint Res 2019;8:199-206. DOI: 10.1302/2046-3758.85.BJR-2018-0316.

Does Staphylococcus aureus nasal decontamination affect the rate of early surgical site infection in adolescent idiopathic scoliosis surgery?

PURPOSE

Surgical site infection (SSI) is a main complication after adolescent idiopathic scoliosis (AIS) surgery. Nasal colonization with S. aureus is a known risk factor for developing nosocomial infections in cardiac surgery. However, the risk in orthopedic surgery remains unclear, especially in spine surgery. This study aims to report the efficacy of a preoperative nasal decontamination program in S. aureus carriers on the incidence of early SSI after AIS posterior surgery.

METHODS

Between January 2014 and July 2017, all AIS patients were screened preoperatively with nasal swabs and decontaminated if positive 5 days before surgery. Early SSI was identified, and microorganisms findings were analyzed within nasal carriage and compared to a previous series published before the decontamination program (2007-2011).

RESULTS

Among the 331 AIS posterior fusion performed during the study period, incidence of positive nasal swab was 23% (n = 75). Those were preoperatively decontaminated. In comparison with the period before the nasal decontamination program, incidence of S. aureus early SSI significantly decreased from 5.1 to 1.3%, p < 0.05. None of those S. aureus decontaminated patients had an early S. aureus SSI. In all cases of S. aureus infections, S. aureus nasal screening was negative with a mean delay of 315 days (± 115) before surgery, which was significantly different from the global cohort (104 days ± 67, p < 0.05).

CONCLUSIONS

Preoperative S. aureus nasal decontamination was associated with a significant decrease in S. aureus SSI. Optimal delay of nasal screening needs to be optimized in order to diagnose intermittent S. aureus carriers. These slides can be retrieved under Electronic Supplementary Material.

Deep postoperative spine infection treated by negative pressure therapy in patients with progressive spinal deformities

BACKGROUND

The aim of the study is to review the outcome of using the VAC system in children and adolescents who have developed postoperative spinal infection after posterior instrumented spinal fusion, and to evaluate whether this technique is also feasible in patients treated with posterior instrumented fusion with polyester sublaminar bands.

METHODS

A total of 11 out of 118 consecutive children and adolescents (5 males) with deep postoperative spinal infection were identified; infections were categorised as early (acute), delayed (subacute) or late (chronic) according to time of onset. Irrespective of the etiology and the onset, all the deep infections were managed with the reported technique. All the patients had regular clinical and radiological follow-up.

RESULTS

Eight out of 11 patients developed an early (72.7%), 2 a delayed (18.2%) and 1 a late deep postoperative infection (9.1%); 7 out of 11 (63.6%) showed severe mental compromise. No statistically significant differences were observed for mean number of VAC dressing changes (p = 0.81) and mean length of hospitalisation comparing patients with early infection versus patients with delayed or late infections (p = 0.32). Mean number of VAC dressing changes (p = 0.02) and mean number of hospitalisation days (p = 0.05) were higher in patients with underlying neurological disorders than in those without, while mean length of hospitalisation was longer in neuromuscular patients.

CONCLUSIONS

The application of the VAC system, as an adjunct to surgical debridement and adequate antibiotic therapy, is a reliable method for the treatment of postoperative infection in children and adolescents undergoing spinal instrumentation and fusion. It can reduce the need for further complex soft-tissue procedure, removal of hardware with consequent loss of correction, and pseudoarthrosis. Finally, the use of VAC therapy is not contraindicated in patients treated with hybrid constructs with sublaminar bands.

LEVEL OF EVIDENCE

III.

Propionibacterium acnes infections in patients with idiopathic scoliosis: a case-control study and review of the literature

PURPOSE

Surgical site infection (SSI) caused by Propionibacterium acnes is an infrequent but devastating complication after spinal fusion. The purpose of this study was to identify risk factors for SSI with Propionibacterium acnes after spinal fusion for juvenile and adolescent idiopathic scoliosis (JIS and AIS).

METHODS

A case-control study was performed. Each case was matched 2:1 for age, gender and diagnosis. Retrospective chart review was performed to obtain relevant demographic, surgical and clinical data for all cases and controls. Statistical analysis included paired t-test and McNemar test, as well as exact logistic regression and robust regression models.

RESULTS

This study included ten infection cases (eight AIS, two JIS) and 20 controls (16 AIS, four JIS). In total, six infected cases presented within two weeks of the index procedure (acute infection) and four infected cases presented more than one year from the index procedure (delayed infection). The most common presentation for acute infections was wound drainage, while back pain was more common in delayed infections. All infections were successfully treated with surgical irrigation and debridement and postoperative antibiotics. Hardware was removed for patients with delayed infections. The strongest risk factor for infection was increased requirement for blood transfusion, but it did not reach statistical significance.

CONCLUSION

SSI with Propionibacterium acnes is an important complication after spinal fusion for idiopathic scoliosis. These infections can be successfully treated, but larger studies are needed to further identify risk factors and establish standardized guidelines for the treatment and prevention of this complication.

Prevention of Surgical Site Infection in Spine Surgery

BACKGROUND

Spine surgery is complicated by an incidence of 1% to 9% of surgical site infection (SSI). The most common organisms are gram-positive bacteria and are endogenous, that is are brought to the hospital by the patient. Efforts to improve safety have been focused on reducing SSI using a bundle approach. The bundle approach applies many quality improvement efforts and has been shown to reduce SSI in other surgical procedures.

OBJECTIVE

To provide a narrative review of practical solutions to reduce SSI in spine surgery.

METHODS

Literature review and synthesis to identify methods that can be used to prevent SSI.

RESULTS

SSI prevention starts with proper patient selection and optimization of medical conditions, particularly reducing smoking and glycemic control. Screening for staphylococcus organisms and subsequent decolonization is a promising method to reduce endogenous bacterial burden. Preoperative warming of patients and timely administration of antibiotics are critical to prevent SSI. Skin preparation using chlorhexidine and alcohol solutions are recommended. Meticulous surgical technique and maintenance of sterile techniques should always be performed. Postoperatively, traditional methods of tissue oxygenation and glycemic control remain essential. Newer wound care methods such as silver impregnation dressing and wound-assisted vacuum dressing are encouraging but need further investigation.

CONCLUSION

Significant reduction of SSIs is possible, but requires a systems approach involving all stakeholders. There are many simple and low-cost components that can be adjusted to reduce SSIs. Systematic efforts including understanding of pathophysiology, prevention strategies, and system-wide quality improvement programs demonstrate significant reduction of SSI.