Evidence-based management of deep wound infection after spinal instrumentation

The role of environmental and seasonal factors in spine deep surgical site infection: the air pollution, a factor that may be underestimated

BACKGROUND

Different strategies have been described in order to reduce spine deep surgical site infection (SSI); however, non-intervenable items such as environmental factors remain as one of the main concerns for spine surgeons.

METHODS

A retrospective cohort study was designed in order to evaluate the effect of environmental factors such as temperature, humidity and particularly the air pollution index (PM 2.5) on spine surgical site infection. The files of 3609 patients who underwent spinal surgery from April 2019 to March 2022 were reviewed, and 121 patients with spine SSI were detected.

RESULTS

There was no significant relationship between mean temperature and humidity of each month with infection and type of bacteria. However, there was a significant relation between warmer season periods and infection. The rate of infection among patients was 3.25% ranged from 2.5% to 4% in colder and warmer seasons accordingly. It was determined that air pollution had a significant relationship with the infection and the type of bacteria. (p value < 0.05, R-Squared = 0.249).

CONCLUSIONS

Our study revealed a 60% increase in spine SSI during warmer seasons. There was a significant correlation between air pollution and the rate of infection. These may suggest the necessity to reduce the number of elective spine surgeries during warmer seasons and when the level of air pollutant is high.

Surgical strategies for spinal infections: A narrative review

The successful operative management of spinal infections necessitates a thoughtful approach. Ideal treatment combines the universal goals of any spine operation, which are decompression of the neural elements and stabilization of instability, with source control and eradication of infection. Techniques to treat infection have evolved independently and alongside advances in implant technology and surgical techniques. This review will seek to outline current thinking on approaches to both primary and secondary spinal infections.

Ultrasound-guided percutaneous micro-drainage tube irrigation combined with high negative pressure tube drainage versus debridement with closed suction irrigation for treating deep surgical site infection after spinal surgery

It is difficult to avoid deep surgical site infection after spinal surgery. Debridement combined with closed suction irrigation (CSI) and other treatment methods lead to greater trauma and lower satisfaction. We developed a new method for the treatment of SSI, which has the advantages of less invasiveness and lower cost. The cohort of this retrospective study comprised 26 patients with SSI after undergoing spinal surgery in our hospital from August 2017 to March 2022. The patients were divided into CSI and microtube drainage group according to treatment methods. The durations of antibiotic use and hospital stay, hospitalization costs, and functional scores during follow-up were compared between the two groups. The only baseline characteristic that differed between the two groups was sex. Infection was controlled in both groups and there were no recurrences during follow-up. However, the length of hospital stay after the first operation and the total length of stay were significantly greater in the CSI group. Hospitalization costs and antibiotic costs were significantly higher in the CSI group. Additionally, the duration of intravenous antibiotic use was significantly longer in the CSI group. Both the CSI and microtube drainage groups had significantly improved of Short Form Health Survey (SF-36) scores 6 months postoperatively. However, 3 months postoperatively, SF-36 scores were significantly lower in the CSI group. Compared with debridement followed by CSI, percutaneous micro-drainage tube irrigation combined with high negative pressure tube drainage is a more efficient and economical means of treating SSI after spinal surgery.

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.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Postoperative Spinal Implant Infections (PSII)-A Systematic Review: What Do We Know So Far and What is Critical About It?

STUDY DESIGN

Systematic review.

OBJECTIVES

Postoperative spinal implant infections (PSII) are an increasing challenge in the daily clinical routine. This review summarizes existing knowledge in the field of PSII, including definitions, epidemiology, classifications, risk factors, pathogenesis, symptoms, diagnosis, and treatment.

METHODS

A systematic review was performed using a structured PubMed analysis, based on the PRISMA criteria. The search terminology was set as: "spinal implant associated infection OR spinal implant infection OR spinal instrumentation infection OR peri spinal implant infection." PubMed search was limited to the categories randomized controlled trials (RCT), clinical trials, meta-analysis and (systematic) reviews, whereas case reports were excluded. Studies from January 2000 to December 2020 were considered eligible. A total of 572 studies were identified, 82 references included for qualitative synthesis, and 19 for detailed sub analysis (12 meta-analysis, 7 prospective RCT).

RESULTS

Structural problems in the field of PSII were revealed, including (1) limited level of evidence in clinical studies (missing prospective RCT, metanalyzes), (2) small patient numbers, (3) missing standardized definitions, (4) heterogeneity in patient groups, and (5) redundancy in cited literature.

CONCLUSION

Evidence-based knowledge about spinal implant-associated infections is lacking. All involved medical fields should come together to define the term PSII and to combine their approaches toward research, training, and patient care.

[Perforator-based keystone flap in the reconstruction of extensive tissue defects after lumbosacral spondylodesis]

BACKGROUND

Prolonged surgical site infections after spinal fusion surgery may lead to exposure of the implant due to the formation of extensive tissue defects and endanger the clinical outcome.

OBJECTIVE

This study aims to enlighten the role of the keystone perforator flap method in the reconstruction of lumbar soft tissue defects.

MATERIAL AND METHODS

The retrospective study included 11 consecutive patients with a wound dehiscence of over 6 × 6 cm defect area persisting for 2 weeks after spinal fusion. The keystone perforator flap was applied for the reconstruction of tissue defects, whereas the arterial blood supply of the flaps was based on the intramuscular and intermuscular perforating branches of the dorsal branches of the lumbar arteries.

RESULTS

The median age of our cohort was 58 years. The median body mass index (BMI) and Charlson comorbidity index (CCI) were 29.9 and 3.4, respectively. In eight cases a lumbosacral was carried out whereas in the remaining series a lumbar fusion was performed. In the course of the subsequent wound revision, on average 4 applications of negative pressure wound therapy (NPWT) were performed. The average defect size was 7.5 cm in width and 16.5 cm in length. The microbiological analysis of the tissue samples obtained intraoperatively after repeated NPWT revealed positive evidence of pathogenic bacteria in all cases. The average duration of inpatient treatment after flap surgery was 15 days, which was significantly shorter than the NPWT management of the open defect wounds (15.5 ± 2.5 vs. 37 ± 16.5, p < 0.05).

CONCLUSION

The keystone perforator flap offers a stable coverage for soft tissue defects and supports infection control after spinal fusion.

Controlling Experimental Parameters to Improve Characterization of Biomaterial Fouling

Uncontrolled protein adsorption and cell binding to biomaterial surfaces may lead to degradation, implant failure, infection, and deleterious inflammatory and immune responses. The accurate characterization of biofouling is therefore crucial for the optimization of biomaterials and devices that interface with complex biological environments composed of macromolecules, fluids, and cells. Currently, a diverse array of experimental conditions and characterization techniques are utilized, making it difficult to compare reported fouling values between similar or different biomaterials. This review aims to help scientists and engineers appreciate current limitations and conduct fouling experiments to facilitate the comparison of reported values and expedite the development of low-fouling materials. Recent advancements in the understanding of protein-interface interactions and fouling variability due to experiment conditions will be highlighted to discuss protein adsorption and cell adhesion and activation on biomaterial surfaces.

Surgical revision strategies for postoperative spinal implant infections (PSII)

Over the last years the number of spine surgeries with instrumentation has grown to an indispensable column in the treatment for different pathologies of the spine. A further increase in the incidence of instrumented spinal surgery is expected throughout the next years. Although the implementation and development of new techniques offer faster and more minimal invasive procedures, shortening surgery time, reducing soft tissue injury and revision due to hardware misplacement, the incidence of postoperative spinal implant infections (PSII) remains high. PSII related complications and revision procedures pose an enormous socioeconomic burden. Therefore, standardized strategies and protocols for treatment of PSII are urgently needed. While in former times hardware exchange or hardware removal was common practise in the field of spine surgery this approach has changed over the last years. Although the evidence from clinical studies in the field of PSII is of limited evidence, critical variables for revision strategies of PSII have been identified. Further, to quickly advance in the field of PSII it is certainly important to extrapolate and learn using data regarding the management from other fields of prosthetic joint infections. This should include clinical as well as experimental work in particular in the context of the biofilm, sonication as well as microbiological concepts. Over the last years, at our institution standardized procedures for diagnostic, surgical as well as antimicrobial treatment have been developed, based on the latest recommendations in peer-reviewed literature and our own data. Here we give an overview about surgical revision strategies for PSII and discuss the key points of our standardized protocol.

Implant-Associated Infection of Long-Segment Spinal Instrumentation: A Retrospective Analysis of 46 Consecutive Patients

Study Design

This single-center retrospective study analyzed patients with an implant-associated infection of spinal instrumentation (four or more segments) treated between 2010 and 2018.

Purpose

This study aimed to investigate the treatment of implant-associated infections of long-segment spinal instrumentation and to define risk factors for implant removal.

Overview of Literature

Implant-associated infection occurs in 0.7%–20% of spinal instrumentation. Significant blood loss, delayed reoperation, and use of effective antibiotics are reported risk factors for implant removal.

Methods

Patients with superficial infections not involving the implant were excluded. All patients received surgical and antibiotic treatments according to our interdisciplinary osteomyelitis board protocol. An infection was considered healed if a patient showed no signs of infection 1 year after termination of treatment. The patients were divided into an implant retention group and implant removal group, and their clinical and microbiological data were compared.

Results

Forty-six patients (27 women, 19 men) with an implant-associated infection of long-segment spinal instrumentation and mean age of 65.3±14.3 years (range, 22–89 years) were included. The mean length of the infected instrumentation was 6.5±2.4 segments (range, 4–13 segments). Implant retention was possible in 21 patients (45.7%); in the other 25 patients (54.3%), a part of or the entire implant required removal. Late infections were associated with implant removal, which correlated with longer hospitalization. Both groups showed high postoperative complication rates (50%) and high mortality rates (8.7%). In 39 patients (84.8%), infection was eradicated at a mean follow-up of 18.9±11.1 months (range, 12–60 months). Three patients (6.5%) were lost to follow-up.

Conclusions

Implant-associated infections of long-segment spinal instrumentations are associated with high complication and mortality rates. Late infections are associated with implant removal. Treatment should be interdisciplinary including orthopedic surgeons and clinical infectiologists.

Expandable Titanium Cages in the Emergent Treatment of Severe Spinal Deformity Secondary to Osteomyelitis: A Series of Three Complex Cases

The literature lacks robust evidence on the benefits versus risks of instrumenting and fusing the spinal column in the setting of active osteomyelitis. We report three patients with vertebral osteomyelitis and subsequent severe and complex kyphotic deformities. Patients 1 and 2 had previous instrumentation that required revision because of hardware failure in the thoracic and thoracolumbar regions, respectively. Patient 3 developed a severe cervical kyphotic deformity at 2 months after being diagnosed and treated with antibiotics for osteomyelitis, necessitating emergent instrumentation and fusion. All the three patients are doing very well so far. Spinal instrumentation and fusion for correction of kyphotic deformity is sometimes necessary in the context of active osteomyelitis and should be done emergently and without hesitation when spinal cord injury from spinal instability is of concern.

Anterior oblique retroperitoneal approach vs posterior transpedicular approach for the treatment of one- or two-level lumbar vertebral osteomyelitis: a retrospective cohort study

OBJECTIVE

To evaluate the outcomes of debridement fusion surgery between two surgical approaches for one- or two-level lumbar vertebral osteomyelitis (LVO): oblique retroperitoneal approach (ORA) and posterior transpedicular approach (PTA).

METHODS

We performed a retrospective study for adult patients with one- or two-level lumbar vertebral pyogenic spondylitis. The primary clinical outcomes included the following: surgery-related information (intra-operative blood loss, operation time, and hospital length of stay), infection control (primary failure and recurrence), and bony fusion. The secondary objective was to determine the differences between groups in mean reduction of pain characters and physical functioning.

RESULTS

The data of 80 patients were collected retrospectively. The duration of follow-up was 27.8 ± 4.7 months (range, 24-42). Intra-operative blood loss, operation time, and hospital length of stay in ORA debridement were significantly lower. Primary failure (2.3% vs 2.7%) was similar between the groups, but recurrence (13.9% vs 5.4%) had difference. Bony fusion (94.6.3% vs 86.1.%) in ORA debridement was higher than those in PTA debridement at the final follow-up. Fusion occurred at six to 14 months (mean 9.8 months). Patients in ORA group had better results in functional and pain scores in the first three months, with similar results at the final follow-up.

CONCLUSION

In summary, ORA debridement provides a quicker recovery compared with PTA debridement for one- or two-level LVO. As for the infection control and fusion rate, both debridement approaches had similar results.

Consensus on Implants in Infections After Spine Surgery

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 9 focused on implants questions in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Fate of Hardware in Spinal Infections

Background: Removal of hardware with irrigation and debridement in patients with surgical site infections (SSIs) is performed commonly. However, the removal of hardware from patients with SSIs after spinal procedures is controversial. Moreover, primary spinal infections such as spondylodiscitis may require instrumentation along with surgical debridement. The purpose of this article was to evaluate critically and summarize the available evidence related to retention of hardware in patients with deep SSIs, and the use of instrumentation in surgical treatment of primary spinal infections. Methods: A literature search utilizing PubMed database was performed. Studies reporting the management of deep SSIs after instrumented spinal procedures, and of primary spinal infections using instrumentation published in peer-reviewed journals were included. Identified publications were evaluated for relevance, and data were extracted from the studies deemed relevant. Results: Because SSIs occur typically during the early post-operative period before stable bony fusion has been achieved, the removal of instrumentation may be associated with instability of the spinal column, pseudarthrosis, progressive deformity, pain, loss of function, and deterioration in the activities of daily living (ADL). Hence, early SSIs after spinal instrumentation are usually treated without removal of hardware. Moreover, primary spinal infections such as spondylodiscitis may require surgical debridement and instrumentation in cases with associated instability. Conclusions: Retaining or using instrumentation in patients with SSIs after spinal procedures or in patients with primary spinal infections, respectively, are commonly practiced in the field of spine surgery. Further evidence is required for the development of definitive algorithms to guide spine surgeons in decision making regarding the fate of instrumentation in the treatment of spinal infections.

Early detection of deep wound infection in bladder exstrophy and hypospadias using a novel intervention

OBJECTIVE

To introduce a practical technique for the early detection and prompt management of a probable bladder dehiscence (BD) and glanular dehiscence (GD) in patients with bladder exstrophy epispadias complex (BEEC) and hypospadias.

METHOD

In this prospective study, paediatric patients with BEEC (group 1) and with proximal hypospadias (group 2) underwent body temperature measurement using a non-contact infrared radiant digital temperature measurement device in four body regions, including the surgical wound, forehead, right hand, and right foot at eight hour intervals, postoperatively. This technique was performed to detect wound temperature rises before whole body temperature rise or visible local wound skin redness, cellulitis or any sign of inflammation or wound dehiscence (WD).

RESULTS

A total of 24 paediatric patients were recruited. Temperature rise in the surgical wound area was discovered in two patients with BEEC. The temperature reached 39.2°C in the first case (12 days postoperative) and 39.4°C in the second case (16 days postoperative). Urinalysis, urine culture, and clean surgical wound sampling was performed and the presence of Gram-positive microorganisms was detected. Both patients were managed with intravenous imipenem and vancomycin. After changing the antibiotic regimen, wound temperature was gradually decreased to 37.2°C in the first patient by day 16, and to 36.9°C in the second patient by day 21, without rise in body temperature. Other patients in group 1 and all patients in group 2 had normal wound temperature fluctuations within the follow-up period.

CONCLUSION

Postoperative periodical temperature measurement by a non-contact infrared radiant digital temperature measurement device is a safe and feasible technique that has the ability to detect deep wound infection, and may prevent the occurrence of WD before any visible sign of inflammation.

[Infections after reconstructive spinal interventions : How do I deal with them?]

BASICS

Postoperative surgical site infections of the spine have been described in up to 20% of patients and can result in serious consequences for the patient and substantial treatment costs. Typical bacteria often arise from skin or fecal flora. Various risk factors for infection have been described, including obesity, diabetes, high ASA scores, as well as intraoperative factors such as heavy blood loss, dural tears, or several revision procedures. Consequently, the prophylaxis with pre- and postoperative risk minimization is of particular importance.

TREATMENT

When an infection has developed, it is important to carry out early operative revision involving tissue debridement, lavage and acquiring microbiological samples for culture. If the infection presents early, the instrumentation can often be retained. Adjuvant measures such as negative pressure wound treatment may improve the outcome. In late-onset infections, due to the biofilm production on the instrument surface or in cases of implant loosening, one should attempt to remove the instrumentation, and in cases of instability replace it. This article deals with the current literature on the subject and provides an overview of the data with regard to peri- and postoperative infections.

Surgical Site Infection as a Risk Factor for Long-Term Instrumentation Failure in Patients with Spinal Deformity: A Retrospective Cohort Study

BACKGROUND

Surgical site infection (SSI) remains a complication of spine deformity surgery. Although fusion/instrumentation failure in the setting of SSI has been reported, few studies have investigated the relationship between these entities. We examine the relationship between early SSI and fusion/instrumentation failure after instrumented fusion in patients with thoracolumbar scoliosis.

METHODS

A retrospective review of a prospectively maintained case series for patients undergoing spine surgery between January 1, 2006, and October 3, 2017. Inclusion criteria included age ≥18 years and surgery performed for correction of thoracolumbar scoliosis. Data collected included various demographic, clinical, and operative variables.

RESULTS

532 patients met inclusion criteria, with 20 (4%) experiencing SSI. Diabetes mellitus was the only demographic risk factor for increased SSI (P = 0.026). Number of fused levels, blood volume loss, and operative time were similar between groups. Fusion/instrumentation failure occurred in 68 (13%) patients, 10 of whom (15%) had SSI, whereas of the 464 patients with no fusion/instrumentation failure, only 10 (2%) had SSI (P < 0.001). Of the 20 patients with SSI, 10 (50%) had fusion/instrumentation failure, whereas in the 512 patients with no infection, only 58 (11%) had fusion/instrumentation failure (P < 0.001). Patients with infection also experienced significantly shorter time to fusion/instrumentation failure (P = 0.025), higher need for revision surgery (P < 0.001), and shorter time to revision surgery (P = 0.012).

CONCLUSIONS

Early SSI significantly increases the risk of fusion/instrumentation failure in patients with thoracolumbar scoliotic deformity, and it significantly shortens the time to failure. Patients with early SSI have a significantly higher likelihood of requiring revision surgery and after a significantly shorter time interval.

Reconstruction of Spinal Soft Tissue Defects With Perforator Flaps From the Paraspinal Region

BACKGROUND/AIM

Reconstruction of spinal soft tissue defects is challenging, especially when neural structures or prosthetic material are exposed. They should be covered with well-vascularized tissue such as paraspinal perforator flaps.

MATERIALS AND METHODS

This is a retrospective study of soft tissue reconstructions with paraspinal perforator flaps from 2011 to 2018. The technique is described and risk factors for poor wound healing were assessed. Postoperative complications are reported.

RESULTS

Twenty patients with a mean age of 63.65 years were included. Defects had an average size of 47 cm² and were mainly located in the lumbosacral region (9 patients). Twelve patients suffered from infection following spinal stabilization, seven of whom were diagnosed with osteomyelitis, two patients presented with pressure sore and one patient experienced wound dehiscence. One partial flap necrosis with a lumbar defect occurred, which required revision surgery. No total flap loss occurred. Stable, closed wounds were achieved at their final follow-up.

CONCLUSION

Perforator paraspinal flaps are suitable for immediate reconstruction of spinal defects.

Perioperative Invasive Vascular Catheterization Associated With Increased Risk of Postoperative Infection in Lumbar Spine Surgery: An Analysis of 114,259 Patient Records

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

This study's objective was to determine whether perioperative invasive vascular catheter placement, independent of comorbid conditions, modified the risk of postoperative infection in lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Infection is a risk inherent to lumbar spine surgery, with overall postoperative infection rates of 0.86%-8.5%. Patients experiencing postoperative infection have higher rates of mortality, revision surgeries, pseudarthrosis, and worsening pain and disability.

METHODS

Data were collected for patients undergoing lumbar spine surgery between January 2007 and October 2015 with records in the nationwide Humana private insurance database. Patients receiving fusion, laminectomy, and discectomy were followed for 3 months from the date of surgery for surgical site infection (SSI), 6 months for subsequent incision and drainage (I&D), and 1 year for vertebral osteomyelitis (VO). Risk factors investigated included central venous catheter and arterial-line placement.

RESULTS

Analysis of 114,259 patient records showed an overall SSI rate of 3.2% within 1 month and 4.5% within 3 months, overall vertebral osteomyelitis rate of 0.82%-0.83% within 1 year, and overall I&D rate of 2.8% within 6 months. Patients receiving a first-time invasive vascular catheter on the day of surgery were more likely to experience SSI within 1 month [risk ratios (RR), 2.5, 95% confidence interval (CI): 2.3-2.7], SSI within 3 months (RR, 2.4; 95% CI: 2.3-2.7), osteomyelitis within 1 year (RR, 4.2-4.3; 95% CI: 3.7-4.5), and undergo an I&D within 6 months (RR, 1.9; 95% CI: 1.8-2.0). These trends were consistent by procedure type and independent of the patient's weighted comorbidity index score (Charlson Comorbidity Index).

CONCLUSIONS

Perioperative invasive vascular catheterization was significantly associated with an increased the risk of postoperative infections in lumbar spine surgery, independent of a patient's concomitant comorbidities. Therefore, in patients with an indication for invasive catheterization, surgeons should consider risks and benefits of surgery carefully.

LEVEL OF EVIDENCE

Level III.

Propionibacterium acnes Infection in Disc Material and Different Antibiotic Susceptibility in Patients With Lumbar Disc Herniation

BACKGROUND

Low back pain is an important, worldwide clinical problem from which human populations are suffering. It has been suggested that Propionibacterium acnes is associated with low back pain. The objective of this clinical study is to evaluate the P. acnes infection in the disc material and antibiotic susceptibility in patients with disc herniation.

METHODS

A total of 120 patients with disc herniation surgery were enrolled in the study. The samples were excited during discectomy and then cultured in both anaerobic and aerobic incubations. Minimum inhibitory concentration (MIC) was performed for determination of antibiotic susceptibility.

RESULTS

Of 120 samples, 60 (50%) samples were positive for microorganisms. Disc herniation was at the level of L4-L5 in 63 cases and L5-S1 in 57 cases.

CONCLUSIONS

According to the results and presence of P. acnes in more than 35% of the cultured samples, the presence of P. acnes in lumbar disc herniation is a suspected element leading to this condition. After analysis of the antibiotics, the lowest MIC value was identified for amoxicillin, ciprofloxacin, erythromycin, rifampicin, tetracycline, vancomycin; the moderate MIC value was for fusidic acid; and the highest MIC value was for gentamicin and trimethoprim.

Acute spinal implant infection treated with debridement: does extended antibiotic treatment improve the prognosis?

The study aims to determine whether 8 weeks of antibiotics is non-inferior to 12 weeks in patients with acute deep spinal implant infection (SII). In the retrospective study of all SII cases (2009-2016), patients aged ≥ 15 years with microbiologically confirmed SII treated with debridement and implant retention were included. Whenever possible, tailored antibiotic treatment was used: rifampin/linezolid in gram-positive and quinolones in gram-negative infection. Patients were divided into short treatment course (8 weeks, ST group) and extended treatment (12 weeks, ET group). Primary outcome measure was percentage of cures at 1-year follow-up. One-hundred-twenty-four patients considered, 48 excluded based on the above criteria, leaving 76 patients, 28 ST and 48 ET. There were no differences in patient age, comorbidities, underlying pathologies, infection location, or surgery characteristics between groups. Surgery-to-debridement time was similar (18.5-day ST vs. 19-day ET; P = 0.96). Sixteen SII cases (21.1%) occurred with bloodstream infection. Pathogens found were Enterobacteriaceae (35, 46.1%), Staphylococcus aureus (29, 38.2%), coagulase-negative staphylococci (12, 15.8%), Pseudomonas aeruginosa (12, 15.8%), and Enterococcus faecalis (7, 9.2%). Twenty seven (35.5%) had polymicrobial infection. E. faecalis was more frequent in the ST group (7, 25% vs. 0; P < 0.001), and P. aeruginosa in ET (1, 3.6% vs. 11, 22.9%; P = 0.05). Five patients died of causes unrelated to SII. At 1-year follow-up, cure rates (21/26 ST, 80.8% vs. 39/45 ET, 86.7%; P = 0.52) and recurrences (2/26, 7.7% vs. 2/45, 4.4%; P = 0.62) were similar. Eight-week antimicrobial courses were not inferior to 12 weeks in patients with acute deep SII treated with prompt debridement, proper wound healing, and optimized antibiotics.

Postoperative Spine Infection: Diagnosis and Management

STUDY DESIGN

Review article.

OBJECTIVES

A review of the literature on postoperative spinal infections, their diagnosis, and management.

METHODS

A systematic computerized Medline literature search was performed using PubMed, Cochrane Database of Systematic Reviews, and EMBASE. The electronic databases were searched for publication dates from the last 10 years. The searches were performed from Medical Subject Headings (MeSH) used by the National Library of Medicine. Specifically, MeSH terms "spine," "infections," "management," and "diagnosis" were used.

RESULTS

Currently, the gold standard for diagnosis of postoperative spine infection is positive deep wound culture. Many of the current radiologic and laboratory tests can assist with the initial diagnosis and monitoring treatment response. Currently erythrocyte sedimentation rate, C-reactive protein, computed tomography scan, and magnetic resonance imaging with and without contrast are used in combination to establish diagnosis. Management of postoperative spine infection involves thorough surgical debridement and targeted antibiotic therapy.

CONCLUSIONS

Postoperative spine infection is a not uncommon complication following surgery that may have devastating consequences for a patient's short- and long-term health. A high index of suspicion is needed to make an early diagnosis.

Bailout Strategies and Complications Associated with the Use of Flow-Diverting Stents for Treating Intracranial Aneurysms

Background

Flow-diverting stents (FDS) have revolutionized the endovascular management of unruptured, complex, wide-necked, and giant aneurysms. There is no consensus on management of complications associated with the placement of these devices. This review focuses on the management of complications of FDS for the treatment of intracranial aneurysms.

Summary

We performed a systematic, qualitative review using electronic databases MEDLINE and Google Scholar. Complications of FDS placement generally occur during the perioperative period.

Key Message

Complications associated with FDS may be divided into periprocedural complications, immediate postprocedural complications, and delayed complications. We sought to review these complications and novel management strategies that have been reported in the literature.

Strategies for the Prevention and Treatment of Surgical Site Infection in the Lumbar Spine

Surgical site infection (SSI) following spine surgery can be devastating for both the patient and the surgeon. It leads to significant morbidity and associated health care costs, from readmissions, reoperations, and subsequent poor clinical outcomes. Complications associated with SSI following spine surgery include pseudarthrosis, neurological deterioration, sepsis, and death. Its management can be very challenging. The diagnosis of SSI involves the interpretation of combined clinical, laboratory, and occasionally radiologic findings. Most infections can be treated with an appropriate course of antibiotics and bracing if required. Surgical intervention is usually reserved for infections resistant to medical management, the need for open biopsy/culture, evolving spinal instability or deformity, and neurologic deficit or deterioration. A thorough knowledge of associated risk factors is required and patients should be stratified for risk preoperatively. The multifaceted approach of risk stratification, early diagnosis and effective treatment, is essential for successful prevention and effective treatment and crucial for a satisfactory outcome.

Instillation Negative Pressure Wound Therapy: An Effective Tool for Complex Spine Wounds

Objective: Infection prevention in spinal surgeries involving implantation of hardware is of utmost priority. Furthermore, successful eradication of infection in hardware salvage is likewise critical in maintaining the long-term retention of the spinal hardware construct. Approach: We report a retrospective case series of three cases where the utilization of a VAC with instillation (VACi) in conjunction with surgical debridement aided in infection control and eradication for both preimplantation and hardware salvage spine patients. Results: Three patients were included. In case 1, VACi was utilized in conjunction with surgical debridement and IV antibiotics in the setting of acute preoperative infection to eradicate infection and enable necessary spinal hardware implementation. Cases 2 and 3 are representative of VACi for salvage of exposed spinal hardware in both the early and delayed infection presentation settings. In both cases, patients developed postoperative infections following spinal instrumentation VACi was utilized in conjunction with surgical debridement and IV antibiotics. Hardware removal was avoided in both cases. All three patients healed completely without residual evidence of infection. Innovation: VACi showed its effectiveness in timely infection eradication before spinal hardware instrumentation and with postoperative spine hardware salvage. Conclusion: This case series demonstrates that VACi can provide infection eradication both preoperatively in high-risk surgical sites, facilitating necessary hardware implementation and postoperatively in situations of hardware salvage.

The effectiveness of pedicle screw immersion in vancomycin and ceftriaxone solution for the prevention of postoperative spinal infection: A prospective comparative study

OBJECTIVE

The aim of this study was to evaluate the efficacy of the local application of vancomycin hydrochloride (HCl)-ceftriaxone disodium hemiheptahydrate onto implants before using them to prevent postoperative infection.

METHODS

The study included 239 patients (153 women and 86 men; mean age: 48.23 ± 16.77 years) who had thoracolumbar stabilization with transpedicular screws. All surgeries were performed by the same surgeon. Patients were divided into two groups. In the group 1 (n = 104), implants were bathed in a solution of local prophylactic antibiotics for 5 seconds just before implantation. In the group 2 (n = 135), implants were not bathed before implantation. Local antibiotics used in the study was effective against gram positive bacteria (including methicillin resistant Staphylococcus aureus) and gram negative bacteria. The rate of surgical site infection and wound healing time were compared between the groups.

RESULTS

A total of 10 patients (4.1%) had deep wound infection and 20 (8.4%) had superficial infection. The most common bacteria was Staphylococcus aureus. One patient died 21 days after the surgery because of sepsis. The wound healed in a mean of 9.66 ± 2.04 days in patients who had no infection and in 32.33 ± 19.64 days in patients with infection (p < 0.001). The patients in group 1 had significantly less deep infection than the patients in group 2 (p < 0.05). However, there was no statistically significant difference between the groups for superficial infection. Patients with vertebral fracture had significantly lower deep infection rate in group 1. The deep infection rate of group 1 patients with diabetes, with bleeding of more than 2000 mL, transfused with blood transfusions above 3 units and with dural injury was significantly lower than those in the group 2. None of the patients had allergic reactions to the drugs used for local prophylaxis.

CONCLUSIONS

This study shown that bathing implants in antibiotics solution was an effective local prophylactic method to prevent deep infections in spinal surgeries with instrumentation.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Complications of percutaneous pedicle screw fixation in treating thoracolumbar and lumbar fracture

Percutaneous pedicle screw fixation (PPSF) has been a popular approach for treating thoracolumbar and lumbar fracture, and its relevant complications have been gradually recognized. This study aimed to summarize the complications of PPSF in treating thoracolumbar and lumbar fracture as well as the management and outcomes of the complications.We retrospectively analyzed the patients with thoracolumbar and lumbar fracture who were admitted to our department from February 2011 to February 2015 and underwent posterior PPSF. Information on demographics, medical comorbidities, radiographs, and treatment was obtained from hospital medical records and follow-up records. Main outcome indexes included adverse clinical and radiological outcomes during and after surgery.A total of 781 patients were included in this study. Forty-six patients (5.9%) presented with complications during or after surgery. The complications included intraoperative guide wire breakage, abdominal artery injury, spinal dura mater injury, postoperative pedicle screw misplacement, screw breakage, plug screw falling off, connecting rod loosening, poor reduction, and late infection. Among the 39 cases with postoperative complications, 14 underwent revision surgery, and the remaining patients underwent conservative treatment and presented good outcomes.PPSF is associated with the following complications: guide wire rupture, blood vessel injury, cerebrospinal fluid leakage, screw misplacement, poor reduction, failed internal fixation, and infection. A thorough preoperative evaluation, accurate operation, and timely and correct management of complications are critical to achieving satisfactory surgical outcomes.

Rescue Therapy for Procedural Complications Associated With Deployment of Flow-Diverting Devices in Cerebral Aneurysms

Flow diverting devices (FDDs) have revolutionized the treatment of morphologically complex intracranial aneurysms such as wide-necked, giant, or fusiform aneurysms. Although FDDs are extremely effective, they carry a small yet significant risk of intraprocedural complications. As the implementation of these devices increases, the ability to predict and rapidly treat complications, especially those that are iatrogenic or intraprocedural in nature, is becoming increasingly more necessary.

Our objective in this paper is to provide a descriptive summary of the various types of intraprocedural complications that may occur during FDDs deployment and how they may best be treated. A systematic and qualitative review of the literature was conducted using electronic databases MEDLINE and Google Scholar. Searches consisted of Boolean operators “AND” and “OR” for the following terms in different combinations: “aneurysm,” “endovascular,” “flow diverter,” “intracranial,” and “pipeline.”

A total of 94 papers were included in our analysis; approximately 87 of these papers dealt with periprocedural endovascular (mainly related to FDDs) complications and their treatment; 7 studies concerned background material. The main categories of periprocedural complications encountered during deployment of FDDs are failure of occlusion, parent vessel injury and/or rupture, spontaneous intraparenchymal hemorrhage, migration or malposition of the FDDs, thromboembolic or ischemic events, and side branch occlusion

Periprocedural complications occur mainly due to thromboembolic events or mechanical issues related to device deployment and placement. With increasing use and expanding versatility of FDDs, the understanding of these complications is vital in order to effectively manage such situations in a timely manner.

The Use of Vacuum Dressings for Dead Space Management in Deep Surgical Site Infections Allows Implant and Bone Graft Retention

STUDY DESIGN

Retrospective, descriptive study.

OBJECTIVES

Managing early surgical site infection following elective lumbar spine surgery remains a challenge with controversy regarding retention of instrumentation and bone graft. Wound closure may also pose considerable challenges. We aim to report on our method of managing deep surgical site infections complicating elective spine surgery with surgeon assembled deep vacuum dressings. Identification of causative organisms with their sensitivities was a secondary objective.

METHODS

Patients were identified from a prospectively maintained, single-surgeon database from 2003-2015. Patients who had an infective or trauma related diagnosis, cervical procedures, and were younger than 18 years were excluded. Records were reviewed to identify bacteriology, laboratory tests performed, antibiotics administered, and type and frequency of surgical management. One thousand two hundred twenty patients qualified for inclusion, with 19 identified as having developed acute wound sepsis.

RESULTS

All patients had surgical debridement on the day of presentation and the majority of wounds were managed with a vacuum dressing. In all but 1 patient was instrumentation retained. Specimens for culture were taken at each debridement and antibiotics changed accordingly. Patients received a minimum 6 weeks of antibiotics.

CONCLUSIONS

The management of deep surgical site infection is labor intensive and frustrating for both surgeon and patient due to the unexpected prolonged admission. Management goals are identification and eradication of the causative organism with subsequent healing of the surgical wound. This process is enhanced with the use of negative-suction dressings made from theatre stock replaced at regular intervals and allows retention of bone graft and instrumentation in the majority of cases.

The distribution of infection with Propionibacterium acnes is equal in patients with cervical and lumbar disc herniation

BACKGROUND

Cervical and back pains are important clinical problems affecting human populations globally. It is suggested that Propionibacterium acnes (P. acnes) is associated with disc herniation. The aim of this study is to evaluate the distribution of P. acnes infection in the cervical and lumbar disc material obtained from patients with disc herniation.

METHODS AND MATERIAL

A total of 145 patients with mean age of 45.21 ± 11.24 years who underwent micro-discectomy in cervical and lumbar regions were enrolled into the study. The samples were excited during the operation and then cultured in the anaerobic incubations. The cultured P. acnes were detected by 16S rRNA-based polymerase chain reaction.

RESULTS

In this study, 145 patients including 25 cases with cervical and 120 cases with lumbar disc herniation were enrolled to the study. There was no significant difference in the age of male and female patients (p = 0.123). P. acnes infection was detected in nine patients (36%) with cervical disc herniation and 46 patients (38.3%) with lumbar disc herniation and no significant differences were reported in P. acnes presence according to the disc regions (p = 0.508.). Moreover, there was a significant difference in the presence of P. acnes infection according to the level of lumbar disc herniation (p = 0.028).

CONCLUSION

According to the results, the presence of P. acnes is equal in patients with cervical and lumbar disc herniation. There was a significant difference in the distribution of P. acnes infection according to level of lumbar disc herniation.

LEVEL OF EVIDENCE

II.

Modic changes in the adjacent vertebrae due to disc material infection with Propionibacterium acnes in patients with lumbar disc herniation

INTRODUCTION

Modic changes (MCs) in vertebral bones are induced by two mechanisms of mechanical factors and infection. As Propionibacterium acnes (P. acnes) have been reported to be associated with LBP. The aim of this study is to evaluate the MCs in patients with disc herniation and positive for P. acnes.

METHODS AND MATERIAL

A total of 120 patients with disc herniation surgery were enrolled into the study. The samples were excised during discectomy and then cultured in both anaerobic and aerobic incubations. Gram staining was employed for investigation of all colonies. The cultured P. acnes were detected by 16S rRNA-based polymerase chain reaction (PCR). MCs of baseline MRI were evaluated.

RESULTS

In this study, 120 subjects (69 male and 51 female) with mean age of 43.15 ± 12.62 years were investigated. Sixty disc samples and eight muscle samples were positive for microorganisms. Moreover, 16S rDNA gene was identified in 46 (38.3%) disc samples. Moreover, 36/46 patients with P. acnes in their sample had MCs.

CONCLUSION

According to the results and presence of 36/46 MCs in patients with lumbar disc herniation, positive for P. acnes suggests that P. acnes can lead to edema on the vertebrae endplates near to infected area.

Role of Suppressive Oral Antibiotics in Orthopedic Hardware Infections for Those Not Undergoing Two-Stage Replacement Surgery

Suppressive oral antibiotics for at least three months, but not at least six months, are associated with treatment success at one year post-diagnosis of orthopedic hardware infection.

Background. The use of suppressive antibiotics in treatment of orthopedic hardware infections (OHIs), including spinal hardware infections, prosthetic joint infections, and infections of internal fixation devices, is controversial.

Methods. Over a 4-year period at 2 academic medical centers, patients with OHI who were treated with debridement and retention of hardware components, with single-stage exchange, or without surgery were studied to determine whether use of oral antibiotics for at least 6 months after diagnosis impacts successful treatment of the infection at 1 year after diagnosis.

Results. Of 89 patients in the study, 42 (47.2%) were free of clinical infection 1 year after initial diagnosis. Suppressive antibiotics used for at least 6 months after diagnosis was not associated with being free of clinical infection (adjusted odds ratio [aOR], 5.29; 95% confidence interval [CI], .74–37.80), but being on suppressive antibiotics at least 3 months after diagnosis was associated with being free of clinical infection (OR, 3.50; 95% CI, 1.30–9.43). Causative organisms impacted the likelihood of success; patients with methicillin-resistant Staphylococcus aureus as well as with Gram-negative rods were both less likely to have achieved clinical success at 1 year after surgery (aOR = 0.018, 95% CI = .0017–.19 and aOR = 0.20, 95% CI = .039–.99, respectively).

Conclusions. Oral suppressive antibiotic therapy in treatment of OHI with retention of hardware for 3 months, but not 6 months, postdiagnosis increases the likelihood of treatment success. The organisms implicated in the infection directly impact the likelihood of treatment success.

Unplanned Reoperation of Lumbar Spinal Surgery During the Primary Admission: A Multicenter Study Based on a Large Patient Population

STUDY DESIGN

A retrospective study.

OBJECTIVE

The purpose of this study was to identify the rates and reasons, and the risk factors for unplanned reoperation of lumbar spinal surgery during the primary admission in terms of a multicenter and a large patient population study.

SUMMARY OF BACKGROUND DATA

Unplanned reoperation is suggested to be a useful quality indicator for spinal surgery. However, the rates of unplanned reoperation in patients underwent lumbar spinal surgery during the primary admission are not well established.

METHODS

This study was performed to review all the patients who underwent lumbar spinal surgery at three institutions from January 2010 to April 2015. Patients with unplanned reoperations after primary surgery during the same admission were included in this study. The demographics, diagnosis, surgical procedure, and complications of patients were reviewed and statistical analysis was performed to investigate the incidences and risk factors of unplanned revision.

RESULTS

A total of 3936 patients who underwent lumbar spinal surgery from three institutions were reviewed, and 82 (2.08%) required unplanned reoperation during the primary admission because of wound infection (0.94%), screw misplacement (0.53%), cerebrospinal fluid leakage (0.27%), wound hematoma (0.18%), and neurologic deficit (0.15%). For the diagnosis, patients with lumbar spinal spondylolisthesis had a much higher rate of reoperation (4.3%) than those of lumbar stenosis (2.3%), vertebral tumor (2.2%), vertebral fracture (1.2%), and disc herniation (1.1%) with a significant difference (P < 0.001). The revision rate was significantly higher in patients underwent posterior lumbar interbody fusion than those received transforaminal lumbar interbody fusion (P = 0.007).

CONCLUSION

Unplanned reoperation rate of lumbar spinal surgery was 2.08% and the most common reasons for it were wound infection and screw misplacement. Patients with a diagnosis of lumbar spinal spondylolisthesis or who underwent posterior lumbar interbody fusion were more likely to required unplanned reoperation during the primary admission.

LEVEL OF EVIDENCE

4.

Antibiotic duration and timing of the switch from intravenous to oral route for bacterial infections in children: systematic review and guidelines

Few studies are available to inform duration of intravenous antibiotics for children and when it is safe and appropriate to switch to oral antibiotics. We have systematically reviewed antibiotic duration and timing of intravenous to oral switch for 36 paediatric infectious diseases and developed evidence-graded recommendations on the basis of the review, guidelines, and expert consensus. We searched databases and obtained information from references identified and relevant guidelines. All eligible studies were assessed for quality. 4090 articles were identified and 170 studies were included. Evidence relating antibiotic duration to outcomes in children for some infections was supported by meta-analyses or randomised controlled trials; in other infections data were from retrospective series only. Criteria for intravenous to oral switch commonly included defervescence and clinical improvement with or without improvement in laboratory markers. Evidence suggests that intravenous to oral switch can occur earlier than previously recommended for some infections. We have synthesised recommendations for antibiotic duration and intravenous to oral switch to support clinical decision making and prospective research.

Orthopedic Prosthetic Infections: Diagnosis and Orthopedic Salvage

Orthopedic hardware infections are much feared and costly complications that can occur when these devices are implemented both in traumatic cases as well as in joint replacement surgery. Because these infections can lead to great morbidity, it is important to understand their pathophysiology as well as the principles behind their diagnosis and initial treatment. Plastic surgeons are frequently consulted as part of a multidisciplinary team to provide stable soft tissue coverage of the associated defects that result from these infections. A review of the existing literature was performed to identify the potential causes of these infections, to provide established diagnostic criteria guidelines, and to explain how these prosthetic infections are managed from an orthopedic surgery perspective prior to consulting the plastic surgery team.