Postoperative Surgical Site Infection After Spine Surgery: An Update From the Scoliosis Research Society (SRS) Morbidity and Mortality Database

Extended Postoperative Antibiotic Prophylaxis Is Associated with No Clinical Value and Higher Projected Cost Following Adult Spinal Surgery: A Stratified Meta-Analysis and Probability-Based Cost Projections

» We aimed to determine the cost-effectiveness of different protocols of extended postoperative antibiotic prophylaxis (E-PAP) following adult spinal surgery.

» Both stratified (randomized controlled trials only) and nonstratified (all studies) analyses demonstrated that E-PAP has no significant value in reducing the rate of surgical site infection (SSI), deep SSI, or superficial SSI.

» Notably, the E-PAP protocols were associated with a significant increase in the length of hospital stay, resulting in an additional expenditure of $244.4 per episode for the E-PAP 72 hours protocol compared with PAP 24 hours and $309.8 per episode for the E-PAP >48 hours protocol compared with PAP <48 hours.

» E-PAP does not demonstrate any significant reduction in the rate of SSIs following spine surgery. However, these extended protocols were significantly associated with an increase in the length of hospital stay and higher overall projected costs.

Microbiological Profile of Instrumented Spinal Infections: 10-Year Study at a French Spine Center

OBJECTIVE

The objective was to compare the microbiological characteristics and treatment of early and late surgical site infections (SSIs) in instrumented spinal surgery.

METHODS

Those patients admitted for SSIs in a single center between January 2010 and December 2022 were included. The subjects were divided into early (eSSIs) and late (lSSIs) SSIs, and demographic, microbiological, treatment, and follow-up data were collected.

RESULTS

Instrumented spinal surgery was performed in 2136 patients. Ninety-six cases of infections were identified (prevalence = 4.5%), with 47.9% eSSIs and 52.1% lSSIs. In 58.7% of the cases, the eSSIs were monomicrobial: Staphylococcus aureus (37%) and Enterobacterales (33.3%) were the main bacteria involved. In 66% of the cases, the lSSIs, were monomicrobial: Cutibacterium acnes (30.3%) and staphylococci were predominant. Enterobacterales were isolated in more than 70% of the polymicrobial samples in both the eSSIs and lSSIs. The treatment of the eSSIs mostly consisted of lavage-debridement surgery associated with antibiotic treatment, while the treatment of the lSSIs combined hardware removal or replacement and long-duration antibiotic treatment. A negative outcome was observed in 17.1% of the eSSIs and 5.7% of the lSSIs. Enterobacterales were associated with negative outcomes of eSSIs.

CONCLUSIONS

Enterobacterales were found in most of the polymicrobial infections regardless of the time of infection onset. Further large studies should be conducted to precisely determine the management and prevention regarding the increasing Gram-negative bacteria SSIs.

A Sodium Oxychlorosene-Based Infection Prevention Protocol Safely Decreases Postoperative Wound Infections in Adult Spinal Deformity Surgery

INTRODUCTION

This study sought to determine the efficacy of a complex multi-institutional sodium oxychlorosene-based infection protocol for decreasing the rate of surgical site infection after instrumented spinal surgery for adult spinal deformity (ASD). Infection prevention protocols have not been previously studied in ASD patients.

METHODS

A retrospective analysis was performed of patients who underwent posterior instrumented spinal fusion of the thoracic or lumbar spine for deformity correction between January 1, 2011, and May 31, 2019. The efficacy of a multi-modal infection prevention protocol was examined. The infection prevention bundle consisted of methicillin-resistant Staphylococcus aureus testing, chlorhexidine gluconate bathing preoperatively, sodium oxychlorosene rinse, vancomycin powder placement, and surgical drain placement at the time of surgery.

RESULTS

About 254 patients fit the inclusion criteria. Among these patients, nine (3.5%) experienced post-surgical deep-wound infection. Demographics and surgical characteristics amongst infected and non-infected cohorts were similar, although diabetes trended towards being more prevalent in patients who developed a postoperative wound infection (p=0.07). Among 222 patients (87.4%) who achieved a minimum of two years of follow-ups, 184 patients (82.9%) experienced successful fusion, comparing favorably with pseudarthrosis rates in the ASD literature. Rates of pseudarthrosis and proximal junction kyphosis were similar amongst infected and non-infected patients.

CONCLUSION

An intraoperative comprehensive sodium oxychlorosene-based infection prevention protocol helped to provide a low rate of infection after major deformity correction without negatively impacting other postoperative procedure-related metrics.

Preoperative Optimization: Risk Factors for Perioperative Complications and Preoperative Modification

Adult spinal deformity (ASD) is common and the complication rate in ASD surgery is high due to its invasiveness. There are several factors that increase the risk of complications with ASD surgery. These include age, past medical history, frailty, osteoporosis, or operative invasiveness. Risk factors for perioperative complications can be categorized as modifiable and non-modifiable. The purpose of this article is to present the current available evidence on risk factors for perioperative complications, with a focus on frailty, osteoporosis, surgical site infection prevention, and hip-spine syndrome. In addition, we present the latest evidence for patient-specific surgical risk assessment and surgical planning.

Local contamination is a major cause of early deep wound infections following open posterior lumbosacral fusions

PURPOSE

Postoperative surgical site infection in patients treated with lumbosacral fusion has usually been thought to be caused by perioperative contamination. With the proximity of these incisions to the perineum, this study sought to determine if contamination by gastrointestinal and/or urogenital flora should be considered as a major cause of this complication.

METHODS

We conducted a retrospective review of adults treated with open posterior lumbosacral fusions between 2014 and 2021 to identify common factors in deep postoperative infection and the nature of the infecting organisms. Cases of tumor, primary infection and minimally invasive surgery were excluded.

RESULTS

489 eligible patients were identified, 20 of which required debridement deep to the fascia (4.1%). Mean age, operative time, estimated blood loss and levels fused were similar between both groups. The infected group had a significantly higher BMI. The mean time from primary procedure to debridement was 40.8 days. Four patients showed no growth, 3 showed Staphylococcus sp. infection (Perioperative Inside-Out) requiring debridement at 63.5 days. Thirteen showed infection with intestinal or urogenital pathogens (Postoperative Outside-In) requiring debridement at 20.0 days. Postoperative Outside-In infections led to debridement 80.3 days earlier than Perioperative Inside-Out infections (p = 0.007).

CONCLUSIONS

65% of deep infections in patients undergoing open lumbosacral fusion were due to early contamination by pathogens associated with the gastrointestinal and/or urogenital tracts. These required earlier debridement than Staphylococcus sp.

INFECTIONS

There should be renewed focus on keeping these pathogens away from the incision during the early stages of wound healing.

Anesthesia and Perioperative Management for Surgical Correction of Neuromuscular Scoliosis in Children: A Narrative Review

Scoliosis is the most frequent spinal deformity in children. It is defined as a spine deviation of more than 10° in the frontal plane. Neuromuscular scoliosis is associated with a heterogeneous spectrum of muscular or neurological symptoms. Anesthesia and surgery for neuromuscular scoliosis have a higher risk of perioperative complications than for idiopathic scoliosis. However, patients and their relatives report improved quality of life after the surgery. The challenges for the anesthetic team result from the specifics of the anesthesia, the scoliosis surgery itself, or factors associated with neuromuscular disorders. This article includes details of preanesthetic evaluation, intraoperative management, and postoperative care in the intensive care unit from an anesthetic view. In summary, adequate care for patients who have neuromuscular scoliosis requires interdisciplinary cooperation. This comprehensive review covers information about the perioperative management of neuromuscular scoliosis for all healthcare providers who take care of these patients during the perioperative period, with an emphasis on anesthesia management.

Surgical Site Infection After Primary Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis: An Analysis of Risk Factors From a Nationwide Insurance Database

STUDY DESIGN

Retrospective review.

OBJECTIVE

The purpose of this study was to quantify the incidence and factors associated with surgical site infection (SSI) in pediatric patients undergoing spinal fusion for adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Infection is a morbid complication after spinal fusion. The incidence of SSI after pediatric spinal fusion is likely underestimated; the use of a national database allows for a comprehensive assessment of this rare outcome.

MATERIALS AND METHODS

The PearlDiver Database was used to identify AIS patients who underwent primary instrumented spinal fusion between 2010 and 2019 and relevant patient records were queried to identify infections within 7, 30, and 90 postoperative days. Patients with nonidiopathic scoliosis were excluded. Logistic regression was used to evaluate risk factors associated with postoperative infection.

RESULTS

Out of 9801 patients who underwent primary fusion for AIS, 44 patients (0.4%) developed an infection within 7 postoperative days. The 30 days and 90 days incidences were 1.9% and 2.7%, respectively. Within 90 days, 154 (57.7%) of the patients with infection had undergone reoperation, of whom 72 underwent multiple reoperations. Obesity and male sex ( P < 0.05) were significantly associated with postoperative infection. The length of fusion was not a significant factor in the development of SSI ( P > 0.05). Eleven patients underwent an operation requiring hardware removal within 90 days. There were no significant factors associated with those undergoing hardware removal compared with those undergoing surgical debridement.

CONCLUSIONS

The study identified a 2.7% 90 days incidence of SSI after posterior spinal fusion for AIS, with 57.7% of all infections requiring a return to the operating room. Preoperative patient-related characteristics associated with increased risk of postoperative SSI were male sex and obesity. The current study can be used to provide preoperative counseling regarding the risk of this postoperative complication.

LEVEL OF EVIDENCE

Level III.

Surgical site infection is a major risk factor of pseudarthrosis in adult spinal deformity surgery

BACKGROUND CONTEXT

Despite the evidence in appendicular skeletal surgery, the effect of infection on spinal fusion remains unclear, particularly after Adult Spinal Deformity (ASD) surgery.

PURPOSE

The purpose of this study was to determine the impact of surgical site infection (SSI) in ASD surgery fusion rates and its association with other risks factors of pseudarthrosis.

STUDY DESIGN

We conducted an international multicenter retrospective study on a prospective cohort of patients operated for spinal deformity.

PATIENT SAMPLE

A total of 956 patients were included (762 females and 194 males).

OUTCOME MEASURES

Patient's preoperative characteristics, pre and postoperative spinopelvic parameters, surgical variables, postoperative complications and were recorded. Surgical site infections were asserted in case of clinical signs associated with positive surgical samples. Each case was treated with surgical reintervention for debridement and irrigation. Presence of pseudarthrosis was defined by the association of clinical symptoms and radiological signs of nonfusion (either direct evidence on CT-scan or indirect radiographic clues such as screw loosening, rod breakage, screw pull out or loss of correction). Each iterative surgical intervention was collected.

METHODS

Univariate and multivariate analysis with logistic regression models were performed to evaluate the role of risk factors of pseudarthrosis.

RESULTS

Nine hundred fifty-six surgical ASD patients with more than two years of follow-up were included in the study. 65 of these patients were treated for SSI (6.8%), 138 for pseudarthrosis (14.4%), and 28 patients for both SSI and pseudarthrosis. On multivariate analysis, SSI was found to be a major risk factor of pseudarthrosis (OR=4.4; 95% CI=2.4,7.9) as well as other known risks factors: BMI (OR=1.1; 95% CI=1.0,1.1), smoking (OR=1.6; 95% CI=1.1,2.9), performance of Smith-Petersen osteotomy (OR = 1.6; 95% CI 1.0,2.6), number of vertebrae instrumented (OR=1.1; 95% CI=1.1,1.2) and the caudal level of fusion, with a distal exponential increment of the risk (OR max for S1=6, 95% CI=1.9,18.6).

CONCLUSION

SSI significantly increases the risk of pseudarthrosis with an OR of 4.4.

Best Practice Guidelines for Surgical Site Infection in High-risk Pediatric Spine Surgery: Definition, Prevention, Diagnosis, and Treatment

BACKGROUND

Prior "best practice guidelines" (BPG) have identified strategies to reduce the risk of acute deep surgical site infection (SSI), but there still exists large variability in practice. Further, there is still no consensus on which patients are "high risk" for SSI and how SSI should be diagnosed or treated in pediatric spine surgery. We sought to develop an updated, consensus-based BPG informed by available literature and expert opinion on defining high-SSI risk in pediatric spine surgery and on prevention, diagnosis, and treatment of SSI in this high-risk population.

MATERIALS AND METHODS

After a systematic review of the literature, an expert panel of 21 pediatric spine surgeons was selected from the Harms Study Group based on extensive experience in the field of pediatric spine surgery. Using the Delphi process and iterative survey rounds, the expert panel was surveyed for current practices, presented with the systematic review, given the opportunity to voice opinions through a live discussion session and asked to vote regarding preferences privately. Two survey rounds were conducted electronically, after which a live conference was held to present and discuss results. A final electronic survey was then conducted for final voting. Agreement ≥70% was considered consensus. Items near consensus were revised if feasible to achieve consensus in subsequent surveys.

RESULTS

Consensus was reached for 17 items for defining high-SSI risk, 17 items for preventing, 6 for diagnosing, and 9 for treating SSI in this high-risk population. After final voting, all 21 experts agreed to the publication and implementation of these items in their practice.

CONCLUSIONS

We present a set of updated consensus-based BPGs for defining high-risk and preventing, diagnosing, and treating SSI in high-risk pediatric spine surgery. We believe that this BPG can limit variability in practice and decrease the incidence of SSI in pediatric spine surgery.

LEVEL OF EVIDENCE

Not applicable.

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.

Clinical Outcome of Postoperative Surgical Site Infection in Patients with Posterior Thoracolumbar and Lumbar Instrumentation

OBJECTIVE

Postoperative surgical site infection (SSI) is associated with greater rates of disability, especially in instrumented spinal surgeries. The management of implant-associated surgical site infections (SSI) is challenging. We analyzed the data from our hospital databases to assess the incidence and characteristics related to postoperative surgical site infection (SSI) after posterior thoracolumbar and lumbar instrumentation.

METHODS

Patient demographics, infection characteristics, details of treatment, and perioperative factors were reviewed (Jan 2010 to Dec 2020). The Oswestry disability index (ODI), Patient Health Questionnaire-9 (PHQ-9), and Visual Analog Scale (VAS) scores for back and leg pain were analyzed preoperatively and postoperatively until last follow-up.

RESULTS

Of the 27,881 procedures collected from the databases, 521 were diagnosed with SSI (1.8%), and 191(36.7%) received at least one revision surgery for SSI. Infection rate was significantly higher in patients with lumbar spinal stenosis than those with scoliosis or kyphosis (P<0.01). Methicillin-sensitive Staphylococcus aureus (43.4%) was the most commonly isolated pathogen. The rate of complication secondary to antibiotics treatment was 7.8%, and long-term antibiotic suppression was reported in 15.2% of patients. Instrumentation was retained in 175 patients (91.6%) and all SSIs were controlled without recurrence during the follow-up.

CONCLUSION

Analysis of 27,881 patients showed an average SSI rate of 1.8%. Patients with deep wound SSI can be successfully treated in most cases with retention of instrumentation. Early diagnosis, positive revision surgery with strict irrigation, thorough debridement, and a long-term course of antibiotics are critical for eradicating infection, retaining implants, decreasing morbidity, and achieving wound healing.

The impact of diabetes mellitus on spinal fracture with diffuse idiopathic skeletal hyperostosis: A multicenter retrospective study

BACKGROUND

Patients with diffuse idiopathic skeletal hyperostosis (DISH) are susceptible to spinal column injuries with neurological deterioration. Previous studies indicated that the prevalence of diabetes mellitus (DM) in patients with DISH was higher than that in patients without DISH. This study investigates the impact of DM on surgical outcomes for spinal fractures in patients with DISH.

METHODS

We retrospectively evaluated 177 spinal fractures in patients with DISH (132 men and 45 women; mean age, 75 ± 10 years) who underwent surgery from a multicenter database. The subjects were classified into two groups according to the presence of DM. Perioperative complications, neurological status by Frankel grade, mortality rate, and status of surgical site infection (SSI) were compared between the two groups.

RESULTS

DM was present in 28.2% (50/177) of the patients. The proportion of men was significantly higher in the DM group (DM group: 86.0% vs. non-DM group: 70.1%) (p = 0.03). The overall complication rate was 22.0% in the DM group and 19.7% in the non-DM group (p = 0.60). Poisson regression model revealed that SSI was significantly associated with DM (DM group: 10.0% vs. non-DM group: 2.4%, Relative risk: 4.5) (p = 0.048). Change in neurological status, mortality rate, instrumentation failure, and nonunion were similar between both groups. HbA1c and fasting blood glucose level (SSI group: 7.2% ± 1.2%, 201 ± 67 mg/dL vs. non-SSI group: 6.6% ± 1.1%, 167 ± 47 mg/dL) tended to be higher in patients with SSI; however, there was no significant difference.

CONCLUSIONS

In spinal fracture in patients with DISH, although DM was an associated factor for SSI with a relative risk of 4.5, DM did not negatively impact neurological recovery. Perioperative glycemic control may be useful for preventing SSI because fasting blood glucose level was high in patients with SSI.

Addressing the Needs of the Rapidly Aging Society through the Development of Multifunctional Bioactive Coatings for Orthopedic Applications

The unprecedented aging of the world's population will boost the need for orthopedic implants and expose their current limitations to a greater extent due to the medical complexity of elderly patients and longer indwelling times of the implanted materials. Biocompatible metals with multifunctional bioactive coatings promise to provide the means for the controlled and tailorable release of different medications for patient-specific treatment while prolonging the material's lifespan and thus improving the surgical outcome. The objective of this work is to provide a review of several groups of biocompatible materials that might be utilized as constituents for the development of multifunctional bioactive coatings on metal materials with a focus on antimicrobial, pain-relieving, and anticoagulant properties. Moreover, the review presents a summary of medications used in clinical settings, the disadvantages of the commercially available products, and insight into the latest development strategies. For a more successful translation of such research into clinical practice, extensive knowledge of the chemical interactions between the components and a detailed understanding of the properties and mechanisms of biological matter are required. Moreover, the cost-efficiency of the surface treatment should be considered in the development process.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

PRESENTATION OF THE MULTICENTRIC COLLECTION SPINE SURGERY DATABASE

ABSTRACT Objectives: To present the Spine Surgery Database developed by the Brazilian Spine Study Group and the methodology involved in its creation, in addition to presenting initial informationabout the use of the database. Methods: Description of the steps for selecting the questionnaires and variables to be included in the database, initial expansion of the use of the database tophysicians close to the BSSG, a brief exploration of quality control and methods for the inclusion ofnew centers, and training on the database, in addition to a brief descriptionof some of the data included in the database. Results: Currently, the database includes 428 patients who already underwent spine surgery and 9 collection centers with at least one patient collected. Conclusion: The Brazilian Spine Study Group’s Multicentric Collection Database is a viable tool that allows patients from different sourcesto be included within a common flow. Level of Evidence V; Expert opinion.

Continuous local antibiotic perfusion for patients with surgical site infection after instrumented spinal surgery; a novel technique to retain the implants

OBJECTIVES

To describe the novel technique of continuous local antibiotic perfusion (CLAP) for a surgical site infection (SSI) after instrumented spinal surgery.

METHODS

CLAP was applied to 4 continuous patients at our institution who developed SSI after instrumented spinal surgery.

RESULTS

All 4 patients were successfully treated and the infection was controlled. The implant was retained in all patients. The duration of CLAP ranged from 2 to 3 weeks. The blood level of the antibiotic used (gentamicin) at 1 week after the initiation of CLAP did not increase in any patient. No other adverse events occurred in any patient. Dramatic improvements in laboratory parameters, including the white blood cell (WBC) counts and C-reactive protein (CRP) levels were seen in every patient at 1 week after the initiation of CLAP.

CONCLUSIONS

CLAP controlled the infection without severe adverse events in all 4 patients, and the implants were retained. Despite its cost and the discomfort of patients, CLAP may become an option for the treatment of SSIs after instrumented spinal surgery. A large number of case series are needed to verify the efficacy of CLAP for patients with SSIs after instrumented spinal surgery.

Large increase of vertebral osteomyelitis in France: a 2010-2019 cross-sectional study

Vertebral osteomyelitis (VO) represents 4-10% of bone and joint infections. In Western countries, its incidence seems to increase, simultaneously with an increasing number of comorbidities among an ageing population. This study aimed to assess the evolution of VO epidemiology in France over the 2010-2019 decade. A nationwide cross-sectional study was conducted using the French hospital discharge data collected through the French diagnosis-related groups 'Programme de Médicalisation des Systèmes d'Information'. VOs were detected with a previously validated case definition using International Classification of Diseases 10 (ICD-10) codes, implemented with the French current procedural terminology codes. The study population included all patients hospitalised in France during the 2010-2019 decade, aged 15 years old and more. Patient and hospital stay characteristics and their evolutions were described. During the study period, 42 105 patients were hospitalised for VO in France involving 60 878 hospital stays. The mean VO incidence was 7.8/100 000 over the study period, increasing from 6.1/100 000 in 2010 to 11.3/100 000 in 2019. The mean age was 64.8 years old and the sex ratio was 1.56. There were 31 341 (74.4%) patients with at least one comorbidity and 3059 (7.3%) deceased during their hospital stay. Even if rare, device-associated VOs (4450 hospital stays, 7.3%) highly increased over the period. The reliability of the method, based upon an exhaustive database and a validated case definition, provided an effective tool to compare data over time in real-life conditions to regularly update the epidemiology of VO.

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.

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.

Improved cytocompatibility and antibacterial properties of zinc-substituted brushite bone cement based on β-tricalcium phosphate

For bone replacement materials, osteoconductive, osteoinductive, and osteogenic properties are desired. The bacterial resistance and the need for new antibacterial strategies stand among the most challenging tasks of the modern medicine. In this work, brushite cements based on powders of Zinc (Zn) (1.4 wt%) substituted tricalcium phosphate (β-TCP) and non-substituted β-TCP were prepared and investigated. Their initial and final phase composition, time of setting, morphology, pH evolution, and compressive strength are reported. After soaking for 60 days in physiological solution, the cements transformed into a mixture of brushite and hydroxyapatite. Antibacterial activity of the cements against Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa bacteria strains was attested. The absence of cytotoxicity of cements was proved for murine fibroblast NCTC L929 cells. Moreover, the cell viability on the β-TCP cement containing Zn²⁺ ions was 10% higher compared to the β-TCP cement without zinc. The developed cements are perspective for applications in orthopedics and traumatology.

Risk factors for persistent coronal imbalance or revision surgery following L3 LIV selection in adolescent idiopathic scoliosis (AIS)

STUDY DESIGN

Retrospective case-control.

OBJECTIVE

To identify a cohort of patients with persistent coronal imbalance (CIB) or revision surgery 5 years following fusion to an L3 lowest-instrumented-vertebra (LIV) and determine factors that make an L3 LIV high-risk. In surgical planning for AIS, L3 is chosen over L4 whenever possible to maximize motion segments below the LIV. Though fusion to an L3 LIV is common, the rate of failure and its risk factors have not been described.

METHODS

In this analysis of prospectively-collected multi-center data of AIS patients who underwent posterior spinal fusion (PSF) to an L3 LIV, we identified patients with CIB at 5 years and/or those who required revision surgery attributable to LIV selection. Patients who were balanced at 5 years and did not require revision surgery served as controls. Pre-operative patient and radiographic variables were compared between cases and controls to identify risk factors for CIB/revision surgery.

RESULTS

We identified 646 patients with 2-year follow-up and 225 patients with 5-year follow-up, of which 11 were found to have CIB and/or revision surgery attributable to selecting L3 as the LIV. There were statistically significant differences between cases and controls with respect to several pre-operative factors, including BMI (24.5 in cases vs. 20.1 in controls; p = 0.01), Lenke curve type (81.8% Lenke 5/6 vs. 44.4%; p = 0.03), lumbar curve magnitude (56 vs. 45°; p < 0.01), TL/L apical vertebral translation (AVT) (6.2 vs. 4.1 cm; p < 0.01), L3 angulation (30° vs. 22°; p < 0.01), L3 translation (4.3 vs. 2.9 cm; p < 0.01), thoracic rib hump (7° vs. 12°; p = 0.02), lumbar rib hump (16° vs. 10°; p < 0.01), and thoracolumbar (T10-L2) kyphosis (10.5° vs. 2°; p = 0.006). Multivariate logistic regression showed that pre-operative BMI, TL/L AVT, L3 angulation, L3 translation, lumbar rib hump, and thoracolumbar kyphosis were independent predictors of CIB/revision surgery.

CONCLUSIONS

An L3 LIV is frequently successful at 5 years post-operatively. Consider an L4 LIV when: pre-operative BMI ≥ 28, L3 angulation ≥ 25°, L3 translation ≥ 4 cm, TL/L AVT ≥ 6 cm, or the lumbar curve is large (≥ 55°) and rotated (≥ 10°).

LEVEL OF EVIDENCE

Level III.

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.

The use of functionalized nanoparticles to treat Staphylococcus aureus-based surgical-site infections: a systematic review

Staphylococcus aureus-based surgical site infections have become the leading cause of failure for total joint arthroplasty operations and remain a major issue across surgical specialties. Moreover, S. aureus-based infections are becoming drastically more difficult to treat due to the development of antibiotic resistant strains and due to the bacteria's propensity to produce biofilms. The emergence of highly resistant S. aureus infections has created the need for a novel antimicrobial treatment. Functionalized nanoparticles have recently been suggested as being a viable option to fill this void due to their strong antimicrobial and antibiofilm properties. However, said research remains a novel and developing field. The presented systematic review aimed to synthesize the best and most recent evidence available to accurately direct new research towards a viable treatment mechanism. In doing so, the authors performed a comprehensive literature search as directed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The results showed that nanoparticles-particularly those including an iron-oxide component or acidic capping agent-are a viable treatment for S. aureus infections both in vivo and in vitro, and show even greater efficacy when combined with exposure to a magnetic field and irradiation.

Comparison of MRI, [18F]FDG PET/CT, and 99mTc-UBI 29-41 scintigraphy for postoperative spondylodiscitis-a prospective multicenter study

Purpose

Postoperative infection still constitutes an important complication of spine surgery, and the optimal imaging modality for diagnosing postoperative spine infection has not yet been established. The aim of this prospective multicenter study was to assess the diagnostic performance of three imaging modalities in patients with suspected postoperative spine infection: MRI, [¹⁸F]FDG PET/CT, and SPECT/CT with ^99mTc-UBI 29-41.

Methods

Patients had to undergo at least 2 out of the 3 imaging modalities investigated. Sixty-three patients enrolled fulfilled such criteria and were included in the final analysis: 15 patients underwent all 3 imaging modalities, while 48 patients underwent at least 2 imaging modalities (MRI + PET/CT, MRI + SPECT/CT, or PET/CT + SPECT/CT). Final diagnosis of postoperative spinal infection was based either on biopsy or on follow-up for at least 6 months. The MRI, PET/CT, and SPECT/CT scans were read blindly by experts at designated core laboratories. Spine surgery included metallic implants in 46/63 patients (73%); postoperative spine infection was diagnosed in 30/63 patients (48%).

Results

Significant discriminants between infection and no infection included fever (P = 0.041), discharge at the wound site (P < 0.0001), and elevated CRP (P = 0.042). There was no difference in the frequency of infection between patients who underwent surgery involving spinal implants versus those who did not. The diagnostic performances of MRI and [¹⁸F]FDG PET/CT analyzed as independent groups were equivalent, with values of the area under the ROC curve equal to 0.78 (95% CI: 0.64–0.92) and 0.80 (95% CI: 0.64–0.98), respectively. SPECT/CT with ^99mTc-UBI 29-41 yielded either unacceptably low sensitivity (44%) or unacceptably low specificity (41%) when adopting more or less stringent interpretation criteria. The best diagnostic performance was observed when combining the results of MRI with those of [¹⁸F]FDG PET/CT, with an area under the ROC curve equal to 0.938 (95% CI: 0.80–1.00).

Conclusion

[¹⁸F]FDG PET/CT and MRI both possess equally satisfactory diagnostic performance in patients with suspected postoperative spine infection, the best diagnostic performance being obtained by combining MRI with [¹⁸F]FDG PET/CT. The diagnostic performance of SPECT/CT with ^99mTc-UBI 29-41 was suboptimal in the postoperative clinical setting explored with the present study.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-020-05109-x.

Short postsurgical antibiotic therapy for spinal infections: protocol of prospective, randomized, unblinded, noninferiority trials (SASI trials)

BACKGROUND

There are several open scientific questions regarding the optimal antibiotic treatment of spinal infections (SIs) with or without an implant. The duration of postsurgical antibiotic therapy is debated.

METHODS

We will perform two unblinded randomized controlled trials (RCTs). We hypothesize that shorter durations of systemic antibiotic therapy after surgery for SI are noninferior (10% margin, 80% power, α = 5%) to existing (long) treatment durations. The RCTs allocate the participants to two arms of 2 × 59 episodes each: 3 vs. 6 weeks of targeted postsurgical systemic antibiotic therapy for implant-free SIs or 6 vs. 12 weeks for implant-related SIs. This equals a total of 236 adult SI episodes (randomization scheme 1:1) with a minimal follow-up of 12 months. All participants receive concomitant multidisciplinary surgical, re-educational, internist, and infectious disease care. We will perform three interim analyses that are evaluated, in a blinded analysis, by an independent study data monitoring committee. Besides the primary outcome of remission, we will also assess adverse events of antibiotic therapy, changes of the patient's nutritional status, the influence of immune suppression, total costs, functional scores, and the timely evolution of the (surgical) wounds. We define infection as the presence of local signs of inflammation (pus, wound discharge, calor, and rubor) together with microbiological evidence of the same pathogen(s) in at least two intraoperative samples, and we define remission as the absence of clinical, laboratory, and/or radiological evidence of (former or new) infection.

DISCUSSION

Provided that there is adequate surgical debridement, both RCTs will potentially enable prescription of less antibiotics during the therapy of SI, with potentially less adverse events and reduced overall costs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04048304. Registered on 5 August 2019.

PROTOCOL VERSION

2, 5 July 2019.

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.

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.

Preoperative measures to prevent/minimize risk of surgical site infection in spinal surgery

Background:

Multiple measures prior to spine surgery may reduce the risks of postoperative surgical site infections (SSIs).

Methods:

The incidence of SSI following spinal surgery (including reoperations and readmissions) may be markedly reduced by performing less extensive procedures and avoiding fusion where feasible. Preoperative testing up to 3 weeks postoperatively should include other studies to limit the perioperative SSI risk; cardiac stress tests (e.g., older patients/cardiac comorbidities), starting tamsulosin in males over 60 (e.g. avoid urinary retention due to benign prostatic hypertrophy), albumin/prealbumin levels (e.g., low levels increase SSI risk), and HBA1C levels to identify new/treat known diabetics (normalize/reduce preoperative levels).

Results:

Other measures include the timely administration of preoperative antibiotics (e.g., cefazolin 2 g nonpenicillin allergic), one dose of gentamicin (adjusted dose/weight), nasal cultures for methicillin-resistant Staphylococcus aureus (patients/health-care workers), and bathing 2 weeks preoperatively with chlorhexidine gluconate 4% (not just night before/morning of surgery). Additionally, prior to surgery, the following medications that increase the bleeding risk should be stopped (e.g. for varying periods); anticoagulants, antiplatelet therapies (e.g., aspirin for at least 7–10 days), nonsteroidal anti-inflammatories (NSAIDS: timing depends on the drug), vitamin E, and herbal supplements. Additionally, avoiding elective spinal surgery in morbidly obese patients and recognizing other major medical contraindications to spinal surgery should help reduce infection, morbidity, and mortality rates.

Conclusions:

Appropriate preoperative and intraoperative prophylactic maneuvers may reduce the risk of postoperative spinal SSI. Specific attention to these details may avoid infections and improve outcomes.