Postoperative Spine Infection: Diagnosis and Management

Safety of mapping the motor networks in the spinal cord using penetrating microelectrodes in Yucatan minipigs

OBJECTIVE

The goal of this study was to assess the safety of mapping spinal cord locomotor networks using penetrating stimulation microelectrodes in Yucatan minipigs (YMPs) as a clinically translational animal model.

METHODS

Eleven YMPs were trained to walk up and down a straight line. Motion capture was performed, and electromyographic (EMG) activity of hindlimb muscles was recorded during overground walking. The YMPs underwent a laminectomy and durotomy to expose the lumbar spinal cord. Using an ultrasound-guided stereotaxic frame, microelectrodes were inserted into the spinal cord in 8 animals. Pial cuts were made to prevent tissue dimpling before microelectrode insertion. Different locations within the lumbar enlargement were electrically stimulated to map the locomotor networks. The remaining 3 YMPs served as sham controls, receiving the laminectomy, durotomy, and pial cuts but not microelectrode insertion. The Porcine Thoracic Injury Behavioral Scale (PTIBS) and hindlimb reflex assessment results were recorded for 4 weeks postoperatively. Overground gait kinematics and hindlimb EMG activity were recorded again at weeks 3 and 4 postoperatively and compared with preoperative measures. The animals were euthanized at the end of week 4, and the lumbar spinal cords were extracted and preserved for immunohistochemical analysis.

RESULTS

All YMPs showed transient deficits in hindlimb function postoperatively. Except for 1 YMP in the experimental group, all animals regained normal ambulation and balance (PTIBS score 10) at the end of weeks 3 and 4. One animal in the experimental group showed gait and balance deficits by week 4 (PTIBS score 4). This animal was excluded from the kinematics and EMG analyses. Overground gait kinematic measures and EMG activity showed no significant (p > 0.05) differences between preoperative and postoperative values, and between the experimental and sham groups. Less than 5% of electrode tracks were visible in the tissue analysis of the animals in the experimental group. There was no statistically significant difference in damage caused by pial cuts between the experimental and sham groups. Tissue damage due to the pial cuts was more frequently observed in immunohistochemical analyses than microelectrode tracks.

CONCLUSIONS

These findings suggest that mapping spinal locomotor networks in porcine models can be performed safely, without lasting damage to the spinal cord.

Surgical site infection following isolated lumbar discectomy increases odds of revision lumbar surgery within first 6 months, but not beyond

BACKGROUND CONTEXT

Lumbar discectomy is a commonly performed surgery following which surgical site infection (SSI) may occur. Prior literature has suggested that, following SSI related to lumbar fusion, the rate of subsequent lumbar surgeries is increased over prolonged periods of time. This has not been studied specifically for lumbar discectomy.

PURPOSE

To define factors associated with SSI following lumbar discectomy and determine if subsequently matched cohorts with and without SSI have differential rates of subsequent lumbar surgery beyond irrigation and debridement (I&Ds) over time.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Adult patients undergoing isolated primary lumbar laminotomy/discectomy were identified from the 2010-2021 M157 PearlDiver database. Exclusion criteria included: age<18 years, preoperative diagnosis of infection, neoplastic, or traumatic diagnoses within 90 days prior to index surgery, additional spinal surgeries on the same day as lumbar discectomy, and not being active in the database for at least 90 days postoperative. From this study population, those who developed SSI were identified based on undergoing I&D within 90 days after surgery. Those with versus without SSI were then matched 1:4 based on age, sex, Elixhauser Comorbidity Index (ECI), and obesity.

OUTCOME MEASURES

Following initial I&D, incidence of revision lumbar surgery (revision lumbar discectomy, lumbar laminectomy, lumbar fusion) out to 5 years after lumbar discectomy.

METHODS

Following index isolated lumbar discectomy, those with versus without SSI requiring I&D were matched and compared for incidence of secondary surgery in defined time intervals (0-6 months, 6-12 months, 1-2 years, 2-5 years) using multivariable logistic regression, controlling for patient age, sex, ECI, and obesity status.

RESULTS

Of 323,025 isolated lumbar discectomy patients, SSI requiring I&D was identified for 583 (0.18%). Multivariable analysis revealed several independent predictors of these SSIs: younger age (odds ratio [OR] 0.85 per decade increase), ECI (OR 1.22 per 2-point increase), and obesity (OR 1.30). Following matching of those with versus without SSI requiring I&D, rates of subsequent surgery beyond I&D were compared. Those with SSI had significantly increased odds of lumbar revision in the first six months (OR 5.26, p<.001), but not 6-12 months (p=.462), 1-2 years (p=.515), or 2-5 years (p=.677).

CONCLUSIONS

Overall, SSI requiring I&D is a rare postoperative complication following lumbar discectomy. If occurring, subsequent surgery beyond I&D was higher in the first 6 months, but then not increased at subsequent time points out to five years.

Logistic regression model predicts early surgical site infection after spinal fusion: a retrospective cohort study

OBJECTIVE

This study aimed to develop a diagnostic model for predicting early surgical site infection (SSI) based on postoperative inflammatory markers after spinal fusion surgery.

METHODS

In this retrospective study, we analysed the trends of inflammatory markers between SSI and non-SSI groups. The data were randomly divided into training cohort and validation cohort (ratio 7:3). The variables for SSI were analysed using stepwise logistic regression to develop the prediction model. To evaluate the model, we analysed its sensitivity, specificity, positive predictive value, negative predictive value, as well as the area under the curve in the validation cohort. Calibration plots and decision curve analysis were employed to assess the calibration and clinical usefulness of the model.

FINDINGS

We observed significant changes in inflammatory markers on the seventh day after surgery. The prediction model included four variables on the seventh day after surgery: body temperature, C-reactive protein, erythrocyte sedimentation rate and neutrophil counts. After binary processing of these data, the simplified model achieved an area under the curve of 0.86 (95% confidence interval (CI): 0.81-0.92) in the training cohort and 0.9 (95% CI: 0.82-0.98) in the validation cohort. Calibration plots and decision curve analysis demonstrated that the proposed model was effective for the diagnosis of SSI.

CONCLUSION

We developed and validated a prediction model for diagnosing early infection after spinal fusion.

In Vivo Comparison of Positive Microbial Culture by Wound Irrigation Methods: Biportal Endoscopic Versus Open Microscopic Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

This study aimed to evaluate the risk factors and prevalence of intraoperative contamination (IoC) through the microbial culture of superficial and deep samples obtained during surgery.

SUMMARY OF BACKGROUND DATA

Surgical site infection (SSI) in spinal surgery is a serious complication. The prevalence of IoC may differ based on surgical approach and technique, even in the setting of the same procedure.

MATERIALS AND METHODS

In this in vivo study, microbial cultivation was performed with superficial (ligamentum flavum, LF) and deep (nucleus pulposus, NP) surgical specimens to evaluate IoC in 132 patients undergoing single-level transforaminal lumbar interbody fusion (TLIF). Biportal endoscopic -TLIF was performed under continuous wound irrigation (group A, n=66), whereas open microscopic (OM) TLIF was performed under intermittent wound irrigation (group B, n=66). LF and NP specimens were homogenized, gram stained, and cultured in aerobic and anaerobic media for 14 days. Microbial culture results and the occurrence of SSI in the two groups were assessed. The χ 2 test and Fisher exact test were used to determine significant differences among categorical variables. Logistic regression analysis was used to assess the influence of patient characteristics on the prevalence of positive microbial cultures.

RESULTS

Of the 132 patients, 34 (25.8%) had positive microbial cultures, and positive culture required an incubation period of 72 hours to 2 weeks in all these patients except for three. Overall, positive culture was significantly higher in group B than in group A ( P =0.029). The subgroups of LF- and NP-positive cultures were 18.18% (n=24) and 12.88% (n=17), respectively; the SSI was 0.76% (n=1). Group A had a significantly lower subgroup of NP-positive culture than group B ( P =0.035). OM technique was an independent risk factor associated with overall positive culture ( P <0.05). The most common microorganism was Cutibacterium acnes ( C. acnes ).

CONCLUSIONS

Biportal endoscopic-TLIF with continuous wound irrigation showed significantly lower overall and NP-positive cultures than OM-TLIF with intermittent irrigation. The most common strain of positive culture was C. acnes .

LEVEL OF EVIDENCE

2.

Negative pressure wound therapy in the management of postoperative spinal wound infections: a systematic review

INTRODUCTION

Postoperative wound infection after spinal surgery might be a challenge to manage. A wide range of procedures have been described for managing infected spinal wounds. An increasingly common procedure in the management of surgical site infections (SSI) is negative pressure wound therapy (NPWT), also known as vacuum-assisted closure. As there is a paucity of clear clinical advice the present investigation aims to update current evidence on the use of NPWT to manage postoperative SSI occurring after instrumented spine surgery.

METHODS

This systematic review was conducted according to the preferred reporting Items for systematic reviews and meta-analyses: the 2020 PRISMA statement. In January 2024, the following databases were accessed: PubMed, Web of Science, and Google Scholar. No time constraint was set for the search. All the clinical studies investigating the unique use of NPWT in treating postoperative spinal wound infections were accessed.

RESULTS

A total of 381 patients were included in the present study. Of them 52.5% (200 of 381 patients) were women. The mean age was 52.2 ± 15.2 years. The average length of the NPWT was 21.2 days (range 7-90 days).

CONCLUSION

NPWT could be a valuable adjuvant therapy for the management of SSI after spine surgery. Additional high-quality investigations are required to assess the efficacy and safety of NPWT in SSI after spine surgery, especially if combined with contraindications or risk factors, such as the presence of intraoperative CSF leak.

LEVEL OF EVIDENCE

Level IV, Systematic review.

Reactive Oxygen Species (ROS)-Mediated Antibacterial Oxidative Therapies: Available Methods to Generate ROS and a Novel Option Proposal

The increasing emergence of multidrug-resistant (MDR) pathogens causes difficult-to-treat infections with long-term hospitalizations and a high incidence of death, thus representing a global public health problem. To manage MDR bacteria bugs, new antimicrobial strategies are necessary, and their introduction in practice is a daily challenge for scientists in the field. An extensively studied approach to treating MDR infections consists of inducing high levels of reactive oxygen species (ROS) by several methods. Although further clinical investigations are mandatory on the possible toxic effects of ROS on mammalian cells, clinical evaluations are extremely promising, and their topical use to treat infected wounds and ulcers, also in presence of biofilm, is already clinically approved. Biochar (BC) is a carbonaceous material obtained by pyrolysis of different vegetable and animal biomass feedstocks at 200-1000 °C in the limited presence of O2. Recently, it has been demonstrated that BC's capability of removing organic and inorganic xenobiotics is mainly due to the presence of persistent free radicals (PFRs), which can activate oxygen, H2O2, or persulfate in the presence or absence of transition metals by electron transfer, thus generating ROS, which in turn degrade pollutants by advanced oxidation processes (AOPs). In this context, the antibacterial effects of BC-containing PFRs have been demonstrated by some authors against Escherichia coli and Staphylococcus aureus, thus giving birth to our idea of the possible use of BC-derived PFRs as a novel method capable of inducing ROS generation for antimicrobial oxidative therapy. Here, the general aspects concerning ROS physiological and pathological production and regulation and the mechanism by which they could exert antimicrobial effects have been reviewed. The methods currently adopted to induce ROS production for antimicrobial oxidative therapy have been discussed. Finally, for the first time, BC-related PFRs have been proposed as a new source of ROS for antimicrobial therapy via AOPs.

A Case of Suspected Neurosarcoidosis Evading Diagnosis With Cervical Biopsy

Neurosarcoidosis is a rare manifestation of sarcoidosis, posing diagnostic challenges due to its varied clinical presentation and the lack of definitive diagnostic tests. We present a case of a 46-year-old African American female with progressive ascending bilateral sensory loss, weakness, and a bifrontal headache. Despite undergoing extensive diagnostic workup including cerebrospinal fluid analysis, neuroimaging, and bronchoscopic evaluation, a definitive diagnosis remained elusive. The patient underwent an open cervical spinal cord biopsy, which did not yield conclusive evidence of neurosarcoidosis. Subsequent complications included suspicion of an epidural abscess and post-operative cervical kyphosis. This case underscores the diagnostic dilemma and potential complications associated with the evaluation and management of neurosarcoidosis, highlighting the importance of a multidisciplinary approach in such cases.

Superinfections of the Spine: A Single-Institution Experience

Background/Objectives: A superinfection occurs when a new, secondary organism colonizes an existing infection. Spine infections are associated with high patient morbidity and sometimes require multiple irrigations and debridements (I&Ds). When multiple I&Ds are required, the risk of complications increases. The purpose of this study was to report our experience with spine superinfections and determine which patients are typically affected. Methods: A retrospective case series of spine superinfections and a retrospective case-control analysis were conducted. Data were collected manually from electronic medical records. Spine I&Ds were identified. Groups were created for patients who had multiple I&Ds for (1) a recurrence of the same causative organism or (2) a superinfection with a novel organism. Preoperative demographic, clinical, and microbiologic data were compared between these two outcomes. A case series of superinfections with descriptive data was constructed. Lastly, two illustrative cases were provided in a narrative format. Results: A total of 92 patients were included in this analysis. Superinfections occurred after 6 out of the 92 (7%) initial I&Ds and were responsible for 6 out of the 24 (25%) repeat I&Ds. The preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) of the patients with a superinfection were significantly lower than those in the control group (p = 0.022 and p = 0.032). Otherwise, the observed differences in the preoperative variables were not statistically different. In the six cases of superinfection, the presence of high-risk comorbidities, a history of substance abuse, or a lack of social support were commonly observed. The superinfecting organisms included Candida, Pseudomonas, Serratia, Klebsiella, Enterobacter, and Staphylococcus species. Conclusions: Superinfections are a devastating complication requiring reoperation after initial spine I&D. Awareness of the possibility of superinfection and common patient archetypes can be helpful for clinicians and care teams. Future work is needed to examine how to identify, help predict, and prevent spine superinfections.

Interleukin-6 as a critical inflammatory marker for early diagnosis of surgical site infection after spine surgery

PURPOSE

Early diagnosis of surgical site infections (SSIs) could prevent surgical revision. Inflammatory markers (IMs), such as procalcitonin (PCT), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α), seem more accurate in diagnosing SSI than C-reactive protein (CRP) and white blood cell (WBC) count. The aim was to compare the predictive values of CRP, WBC count, PCT, IL-6, and TNF-α in SSI detection.

METHODS

A total of 130 patients undergoing dorsal spondylodesis from 2019 to 2024 were enrolled in a prospective diagnostic study at a maximum care spine center. IMs were measured preoperatively and on the postoperative days (PODs) 1, 2, 3, 5, and 7. Patients with high suspicion of SSI underwent revision surgery. SSI was diagnosed when the microbiological evidence was positive. Patients were divided a posteriori into the non-infection and infection groups.

RESULTS

IMs of 118 patients (66.9 ± 13.0 years, 61.0% females) were measured. Fifteen of the 118 patients (12.7%) developed an SSI. The groups differed with respect to existing hypertension, number of instrumented segments, region of surgery, CRPPOD1,7, PCTPOD7, and IL-6POD3,5,7. Binary logistic regression for SSI detection including these parameters showed an area under the curve (AUC) of 0.88 (95% CI 0.79-0.98; P < 0.001). The main effect for SSI detection was maintained by IL-6POD7 (odds ratio = 1.13; 95% CI 1.05-1.23; P = 0.001), which itself showed an AUC of 0.86 (95% CI 0.75-0.97).

CONCLUSION

Compared to CRP, WBC count, PCT, and TNF-α, IL-6 seems to be the critical IM for the early detection of an SSI.

TRIAL REGISTRATION

drks.de: DRKS00033773, date of registration: 29.02.2024, retrospectively registered; Postoperative Markers of Inflammation in Spine Surgery (POMIS) Trial.

Cutibacterium acnes in spine surgery: pathophysiology, diagnosis, and treatment

Cutibacterium acnes (C. acnes) previously named Propionibacterium acnes (P. acnes) has been increasingly recognized by spine surgeons as a cause of indolent post-surgical spinal infection. Patients infected with C. acnes may present with pseudarthrosis or nonspecific back pain. Currently, microbiological tissue cultures remain the gold standard in diagnosing C. acnes infection. Ongoing research into using genetic sequencing as a diagnostic method shows promising results and may be another future way of diagnosis. Optimized prophylaxis involves the use of targeted antibiotics, longer duration of antibiotic prophylaxis, antibacterial-coated spinal implants, and evidence-based sterile surgical techniques all of which decrease contamination. Antibiotics and implant replacement remain the mainstay of treatment, with longer durations of antibiotics proving to be more efficacious. Local guidelines must consider the surge of antimicrobial resistance worldwide when treating C. acnes.

Post-Discectomy Infection: A Critical Review and Suggestion of a Management Algorithm

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42-73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2-4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management.

Efficacy of prophylactic use of intraoperative vancomycin powder in preventing surgical site infection in neurological surgeries in Irrua, Nigeria: A randomized controlled study

PURPOSE

The objective was to determine the efficacy of intraoperative vancomycin powder in preventing SSIs in neurological surgeries.

METHODS

A prospective randomized controlled study of patients who had clean cranial and non-implant spine surgeries at the Irrua Specialist Teaching Hospital, Irrua, Nigeria from February 1, 2021 to January 31, 2022. Patients were randomized into two groups. Group A patients had prophylactic intraoperative vancomycin powder applied to the surgical bed before wound closure while group B patients did not. Patients in both groups were followed up for 30 days post-operatively for evidence of SSI. The occurrence of SSIs was determined using clinical and laboratory parameters. Baseline characteristics, operative details, rates of wound infection, and microbiological data for each case were recorded. Data was analyzed using Statistical Package for Scientific Solution (SPSS) version 23 software.

RESULTS

Forty-two patients were randomized into 2 groups of 21 patients each. The age range of the patients was 20 to 80 years. The majority of the patients were males (32 out of 42). The mean age of patients in group A was 48.05 ± 17.03 years, while group B had a mean age of 45.95 ± 19.14 years. The mean Body Mass Index of patients in groups A and B were 23.92 ± 5.21 and 23.21 ± 3.99 respectively. Seven out of 21 patients (33.3 %) in the control group ( group B) had superficial SSIs while no patient in the experimental group had SSI, p-value < 0.05. The organisms cultured were Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus.

CONCLUSION

Intraoperative vancomycin powder was effective in reducing the rate of SSIs following neurological surgeries and without adverse drug reactions.

SPECT/CT and PET/CT for the Evaluation of Persistent or Recurrent Pain After Spine Surgery: A Systematic Review and Case Series

OBJECTIVE

The differential diagnosis for postoperative back pain is broad, and conventional imaging modalities are not always conclusive. Therefore, we performed a systematic review of the literature and present case studies describing the use of single-photon emission CT (SPECT)/CT or positron emission tomography (PET)/CT in the diagnosis of back pain following spine surgery.

METHODS

A systematic review was conducted according to PRISMA guidelines across 5 databases. Relevant keywords included PET/CT, bone SPECT/CT, and pseudarthrosis. The studies were assessed for diagnostic accuracy of the imaging technologies.

RESULTS

A total of 2,444 studies were screened, 91 were selected for full-text review, and 21 were ultimately included. Six retrospective studies investigated the use of SPECT/CT with a total sample size of 309 patients. Two of these studies used SPECT/CT to predict screw loosening in over 50% of patients. Eight studies examined the use of 18-fluoride sodium fluoride (18F-NaF) PET/CT. Among these studies, measures of diagnostic accuracy varied but overall demonstrated the ability of 18F-NaF PET/CT to detect screw loosening and pseudarthrosis. Seven studies examined 18F-fluorodeoxyglucose (FDG) PET/CT and supported its utility in the diagnosis of postoperative infections in the spine.

CONCLUSIONS

PET/CT and SPECT/CT are useful in the evaluation of postoperative pain of the spine, especially in patients for whom conventional imaging modalities yield inconclusive results. More diagnostic accuracy studies with strong reference standards are needed to compare hybrid imaging to conventional imaging.

Imaging assessment of spine infection

This article comprehensively reviews current imaging concepts in spinal infection with primary focus on infectious spondylodiscitis (IS) as well as the less common entity of facet joint septic arthritis (FSA). This review encompasses the multimodality imaging appearances (radiographs, CT, MRI, and nuclear imaging) of spinal infection-both at initial presentation and during treatment-to aid the radiologist in guiding diagnosis and successful management. We discuss the pathophysiology of spinal infection in various patient populations (including the non-instrumented and postoperative spine) as well as the role of imaging-guided biopsy. We also highlight several non-infectious entities that can mimic IS (both clinically and radiologically) that should be considered during image interpretation to avoid misdiagnosis. These potential mimics include the following: Modic type 1 degenerative changes, acute Schmorl's node, neuropathic spondyloarthropathy, radiation osteitis, and inflammatory spondyloarthropathy (SAPHO syndrome).

Remove the infected interbody cage using endoscopy in lumbar spine revision surgery: A case series and technique report

BACKGROUND

Current revision surgery to remove the infected interbody cage following transforaminal lumbar interbody fusion (TLIF) surgery is challenging and traumatic. The purpose of this study is to introduce a novel surgical technique to remove the infected interbody cage for chronic infection.

METHODS

Three patients with chronic infection following TLIF surgery underwent revision surgery. Instrumentations were removed and a spinal endoscope was obliquely inserted to the disc space through the initial annular breach. Under endoscope, the cage was found, released, turned around, and dragged to the posterior edge of the disc space. The cage was then removed without distracting the dural sac and nerve roots. For two cases, appropriately sized structural iliac bone grafts were used for interbody fusion without extra instrumentations.

RESULTS

Using endoscope, the interbody cage was easy to identify and expose without disrupting the dural sac and nerve roots. With various endoscopic tools, the cage was easily released and removed. In this case series, the infected interbody cage was removed within thirty minutes without dural sac rupture and nerve root injury. The infection was controlled after the surgery, and the patients obtained good clinical outcomes. At 6-month follow-up, bony fusion was achieved in two patients who underwent interbody fusion.

CONCLUSIONS

This endoscopy assisted technique simplified the revision surgery for chronic infection followed TLIF surgery, with the advantages of no disruption of the neural tissues, bright surgical field and complete disc debridement.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Post-operative C-reactive protein and white blood cells changes pattern following spinal deformity surgery and its clinical correlation

OBJECTIVE

Following the changing pattern of post-operative CRP and WBC counts and compare them to the patient's clinical condition to find which one is better for early detection of early infection.

METHODS

A total of 50 patients who underwent spinal deformity correction surgery without clinical signs of infection such as fever, wound redness, or discharge were enrolled in this prospective study. The C-reactive protein (CRP) and white blood cell (WBC) counts were measured the 2nd and 7th post-operative days. We try to detect the type of correlation between both CRP and WBCs level and clinical condition of patient regarding wound local condition.

RESULTS

All cases showed high CRP by the 2nd day post-operative which decreased significantly but not reaching normal levels even by the 7th day. All cases showed elevated WBCs count by the 2nd day which decreased to normal levels by the 3rd day in 86% of patients, and by the 7th day, 94% of cases showed normal levels. In addition, WBCs in the 2nd day post-operative significantly positive correlated with fusion level and operative time. There was no significant correlation between WBCs and blood transfusion or age. No significant correlation between CRP and number of fusion levels, blood transfusion nor operative time.

CONCLUSION

WBCs count returned earlier to normal levels than CRP in our cases, so monitoring early changes in the 1st week in WBCs count pattern is more indicative of an ongoing infectious process.

In Vitro and In Vivo Evaluation of Ultrasound-Triggered Release From Novel Spinal Device

OBJECTIVES

Bacterial infection following spinal fusion is a major clinical concern with up to 20% incidence. An ultrasound-triggered bulk-release system to combat postsurgical bacterial survival was designed and evaluated.

METHODS

Polylactic acid (PLA) clips were loaded with vancomycin (VAN) and microbubbles (Sonazoid, GE HealthCare) in vitro. Stability was determined over 14 days. VAN-loaded clips were submerged in water and insonated using a Logiq E10 scanner (GE HealthCare) with a curvilinear C6 probe. Doppler-induced VAN release was quantified using spectrophotometry. For in vivo testing, clips were loaded with methylene blue (MeB) solution and Sonazoid. These clips were implanted into a rabbit along the spine at L2 and L5, as well as a pig at L1 and L3, then insonated in Doppler mode using the C6 probe.

RESULTS

Sonazoid microbubbles were better preserved when incubated in VAN compared with distilled water at 4°C, 25°C, and 37°C incubation temperatures (P = .0131). Contrast enhancement was observed from both solutions when incubated at 4°C storage conditions. Insonated clips achieved average cumulative VAN release of 101.8 ± 2.8% (81.4 ± 2.8 mg) after 72 hours. Uninsonated clips had only 0.3 ± 0.1% (0.3 ± 0.1 mg) average cumulative VAN release (P < .0001). Clips retrieved from the rabbit did not rupture with insonation nor produce MeB staining of surrounding tissues. In the pig, the PLA film was visibly ruptured and MeB tissue was observed following insonation, whereas the uninsonated clip was intact.

CONCLUSION

These results demonstrate ultrasound-triggered release of an encapsulated prophylactic solution and provide an important proof-of-concept for continuing large animal evaluations for translational merit.

Surgical treatment of Candida albicans spondylodiscitis

Introduction

Spinal infection poses a demanding diagnostic and treatment problem for which a multidisciplinary approach with spine surgeons, radiologists, and infectious disease specialists is required. Infections are usually caused by bacterial microorganisms, although fungal infections can also occur. Most patients with spinal infections diagnosed in the early stages can be successfully managed conservatively with antibiotics, bed rest, and spinal braces. In cases of gross or pending instability, progressive neurological deficits, failure of conservative treatment, spinal abscess formation, severe symptoms indicating sepsis, and failure of previous conservative treatment, surgical treatment is required.

Case presentation

A 64-year-old male presented to the Outpatient Department with a complaint of pain in bilateral upper extremities for 4 months. The pain was shooting in type, radiating to bilateral arms, forearms, and hands with no aggravating and relieving factors. He is a known case of carcinoma pyriform sinus for which he underwent various cycles of chemotherapy. Ten years later, a tracheostomy was performed for laryngeal edema, and again, an endoscopic gastrostomy was performed due to feeding difficulties. He then developed fever and cervical pain along with pain in the bilateral upper extremities. An infectious etiology was suspected for which multiple antibiotics were started with no positive response. An MRI was performed, which was suggestive of spondylodiscitis probably of tubercular origin. A biopsy was done to confirm the diagnosis, following which antitubercular (HRZE) therapy was started. He was also treated with Duloxetine and gabapentin, which resulted in minor improvements. Subsequent MRIs showed diffuse involvement of the multiple cervical vertebrae along with cord compression. Two stages of anterior corpectomy followed by posterior instrumentation were done. Following the procedure, the patient developed an infection, which was managed with antibiotics. The titanium implant was not removed. A muscle graft was planned with the pectoralis muscle and flap closure was done. The tissue was also sent for Gram stain, AFB stain, and GeneXpert, which showed normal findings. Finally, in tissue culture, Candida albicans was isolated. On performing the enzyme immunoassay test, it was found to be Aspergillus (Galactomannan antigen) positive as well. Antitubercular treatment was stopped. Then, he was managed with an antifungal, oral voriconazole, for the duration of 1 and a half years.

Clinical discussion

Patients diagnosed with Candida spondylodiscitis tend to have favorable outcomes, likely linked to timely identification, thorough surgical debridement, and proper azole medication. Our case achieved success by promptly identifying and confirming it through tissue culture, detecting spinal cord compression, decompressing it, and initiating specific antifungal treatment. A delay in commencing antifungal therapy has been associated with poorer outcomes, especially in neurological health. Our patient received voriconazole for a full year, suggesting that favorable outcomes are achievable for fungal spondylodiscitis with swift and appropriate surgery and antifungal medication.

Conclusion

In summary, evaluation for fungal infection is essential in all cases of unexplained spinal infection in immunocompromised patients, regardless of presentation. If the antifungal treatment proves ineffective, a surgical approach is typically employed for the management of fungal spondylodiscitis. Our report details a successful case of fungal spondylodiscitis treated with a surgical approach and highlights the potential for a fungal infection to be a causative factor in noncompressive myelopathy, which may be sometimes mistaken for radiation myelitis.

Topical streptomycin irrigation of lesions to prevent postoperative site infections in spinal tuberculosis: a retrospective analysis

PURPOSE

In spinal tuberculosis surgery, topical administration of drugs to the lesion is a preventive treatment measure. The aim is to achieve better bacterial inhibition and to prevent complications. As one of the most common complications after spinal tuberculosis surgery, many factors can lead to surgical site infection (SSI). No definitive reports of local streptomycin irrigation of the lesion and SSI of spinal tuberculosis have been seen. This study analyzed data related to surgical site infections (SSI) after the treatment of spinal tuberculosis using this regimen.

METHODS

In this study, 31 were in the observation group (streptomycin flush) and 34 in the control group (no streptomycin flush). All patients received the same standard of perioperative care procedures. General information, operative time, intraoperative bleeding, ESR and CRP at one week postoperatively, time on antibiotics, total drainage, days in hospital, incision infection rate and secondary debridement rate were compared between the two groups.

RESULTS

Patients in both groups completed the surgery successfully. The ESR and CRP levels in the observation group were lower than those in the control group one week after surgery (p < 0.05); the duration of postoperative antibiotics and hospital stay were lower than those in the control group (p < 0.05); the incidence of SSI in the two groups was 5.88% and 6.45% respectively, with no significant difference (p > 0.05).

CONCLUSION

The use of topical streptomycin irrigation of the lesion during surgical procedures for spinal tuberculosis had no significant effect on the incidence of SSI, however, it helped to control the level of infection in the postoperative period and reduced the length of time patients had to use postoperative antibiotics and the number of days they stayed in hospital. Future prospective randomised controlled trials in more centres and larger samples are recommended.

Predicting deep surgical site infection in patients receiving open posterior instrumented thoracolumbar surgery: A-DOUBLE-SSI risk score - a large retrospective multicenter cohort study in China

BACKGROUND

To develop a practical prediction model to predict the risk of deep surgical site infection (SSI) in patients receiving open posterior instrumented thoracolumbar surgery.

METHODS

Data of 3419 patients in four hospitals from 1 January 2012 to 30 December 2021 were evaluated. The authors used clinical knowledge-driven, data-driven, and decision tree model to identify predictive variables of deep SSI. Forty-three candidate variables were collected, including 5 demographics, 29 preoperative, 5 intraoperative, and 4 postoperative variables. According to model performance and clinical practicability, the best model was chosen to develop a risk score. Internal validation was performed by using bootstrapping methods.

RESULTS

After open posterior instrumented thoracolumbar surgery, 158 patients (4.6%) developed deep SSI. The clinical knowledge-driven model yielded 12 predictors of deep SSI, while the data-driven and decision tree model produced 11 and 6 predictors, respectively. A knowledge-driven model, which had the best C-statistics [0.81 (95% CI: 0.78-0.85)] and superior calibration, was chosen due to its favorable model performance and clinical practicality. Moreover, 12 variables were identified in the clinical knowledge-driven model, including age, BMI, diabetes, steroid use, albumin, duration of operation, blood loss, instrumented segments, powdered vancomycin administration, duration of drainage, postoperative cerebrospinal fluid leakage, and early postoperative activities. In bootstrap internal validation, the knowledge-driven model still showed optimal C-statistics (0.79, 95% CI: 0.75-0.83) and calibration. Based on these identified predictors, a risk score for deep SSI incidence was created: the A-DOUBLE-SSI (Age, D [Diabetes, Drainage], O [duration of Operation, vancOmycin], albUmin, B [BMI, Blood loss], cerebrospinal fluid Leakage, Early activities, Steroid use, and Segmental Instrumentation) risk score. Based on the A-DOUBLE-SSI score system, the incidence of deep SSI increased in a graded fashion from 1.06% (A-DOUBLE-SSIs score ≤8) to 40.6% (A-DOUBLE-SSIs score>15).

CONCLUSIONS

The authors developed a novel and practical model, the A-DOUBLE-SSIs risk score, that integrated easily accessible demographics, preoperative, intraoperative, and postoperative variables and could be used to predict individual risk of deep SSI in patients receiving open posterior instrumented thoracolumbar surgery.

2022 SPILF - Clinical Practice guidelines for the diagnosis and treatment of disco-vertebral infection in adults

These guidelines are an update of those made in 2007 at the request of the French Society of Infectious Diseases (SPILF, Société de Pathologie Infectieuse de Langue Française). They are intended for use by all healthcare professionals caring for patients with disco-vertebral infection (DVI) on spine, whether native or instrumented. They include evidence and opinion-based recommendations for the diagnosis and management of patients with DVI. ESR, PCT and scintigraphy, antibiotic therapy without microorganism identification (except for emergency situations), therapy longer than 6 weeks if the DVI is not complicated, contraindication for spinal osteosynthesis in a septic context, and prolonged dorsal decubitus are no longer to be done in DVI management. MRI study must include exploration of the entire spine with at least 2 orthogonal planes for the affected level(s). Several disco-vertebral samples must be performed if blood cultures are negative. Short, adapted treatment and directly oral antibiotherapy or early switch from intravenous to oral antibiotherapy are recommended. Consultation of a spine specialist should be requested to evaluate spinal stability. Early lifting of patients is recommended.

Postoperative spine surgical site infections: high rate of failure of one-stage irrigation and debridement

BACKGROUND CONTEXT

Following spine surgery, postoperative surgical site infection (SSI) is a rare but potentially devastating complication. Previous studies have assessed risk factors for spine SSI and one aimed to develop risk stratification tool to assess management options, but this tool has not been externally validated or regularly used.

PURPOSE

The current study aimed to investigate the rate of SSI following elective spine surgery, surgical management pursued, and success of traditionally utilized one-stage of irrigation and debridement (I&D) with closure over drains.

STUDY DESIGN

Retrospective case-control study.

PATIENT SAMPLE

Adult, elective spine surgeries performed at a single academic institution between 2013 and 2021 were evaluated. Patients who developed SSI requiring surgical intervention were identified.

OUTCOME MEASURES

Those who underwent initial management with I&D and closure over drains were assessed for need of subsequent I&D (considered failure of initial infection management).

METHODS

Of spine surgeries meeting inclusion criteria, those with SSI were identified and management was characterized. For those who did and did not fail attempted one stage I&D with closure over drains, pre-operative and surgical variables from the index procedure as well as infection characteristics were assessed and compared with univariable and multivariable analyses.

RESULTS

Of 11,023 elective spine surgeries, SSI was identified for 76 (0.7%). For initial management, I&D with closure over drains was used for 66 (86.8%) while I&D and wound vacuum management was used 10 (13.2%). Failure of attempted one stage I&D (requiring subsequent I&D procedure) was identified for 18 (27% of those undergoing I&D and closure over drains). Of multiple patient, surgical, and infection characteristics, the only factor identified as independently predictive of one stage I&D failure was presence of bacteremia (odds ratio [OR] 38.3, p=0.0007). Within the sub-cohort of patients with bacteremia, failure of attempted one stage I&D was noted for 80%.

CONCLUSION

Less than one percent of a large cohort of patients undergoing spine surgery were found to develop SSIs. Of those undergoing attempted one stage I&D, most patient, surgical, and infection variables did not influence outcome of the intervention. However, those with bacteremia were at 38.3 times greater odds of failing attempted one-stage I&D. These results suggest considering delayed closure approaches in these cases.

Incidence and local risk factors of infection after anterior sub-axial cervical spine surgery: retrospective database analysis of 4897 consecutive procedures

INTRODUCTION

The anterior cervical spine approach is safe and effective in many cervical spine pathologies. It is considered one of the most common approaches in spine surgery. Postoperative infections after anterior cervical surgery are rare but serious.

MATERIALS AND METHODS

This study is a retrospective database analysis. In this study, the incidence, and the local risk factors of postoperative infection after anterior-only sub-axial cervical spine surgery in a high-volume spine center were analyzed. The data of patients operated in a teaching hospital is electronically stored in a comprehensive medical database program. Postoperative infection after anterior cervical surgery from C2 to C7 was calculated and analyzed. In the study period, 4897 patients were operated. Twenty-four infections after a primary aseptic operation were detected. Independent local risk factors were estimated.

RESULTS

Postoperative infection occurred in 24/4897 patients (0.49%). The incidence of infection after cervical trauma was 3% (7/229), after spinal cord injury 4.3% (2/46), with myelopathy 1.98% (11/556), and after revision surgery 1.25% (7/560). The incidence showed a significant increase (p = 0.00, 0.01, 0.02). In 14 of the postoperatively infected patients (58.3%) an oesophageal injury was diagnosed. Odds ratios (OR) with a confidence interval (CI) of 95% was calculated. Independent risk factors for the postoperative infections were: Cervical trauma (OR 8.59, 95% CI 3.52-20.93), revision surgery (OR 3.22, 95% CI 1.33-7.82), The presence of cervical myelopathy (OR 6.71, 95% CI 2.99-15.06), and spinal cord injury (OR 9.33, 95% CI 2.13-40.83).

CONCLUSIONS

Postoperative infection after anterior cervical surgery is low (0.49%). In addition to the general risk factor for infection, the local risk factors are trauma, myelopathy, spinal cord injury, and revision surgeries. In the case of postoperative infection, an oesophageal injury should be excluded.

Risk Factors and Outcomes of Central Nervous System Infection After Spinal Surgery: A Retrospective Cohort Study

OBJECTIVE

To investigate the risk factor associated with central nervous system infection, a rare and dire complication after spinal surgery.

METHODS

Univariate and multivariate logistic regression analyses were performed to screen for the independent risk factors. According to the different administration methods of antibiotics, patients were divided into intravenous and intrathecal groups. The differences in time needed for body temperature, white blood cells (WBC), and C-reactive protein (CRP) to return to normal and the time of antibiotic application were compared between the 2 groups. In addition, the differences in WBC, neutrophil ratio, CRP, procalcitonin in blood, and WBC in cerebrospinal fluid were compared before intrathecal injection, after the first one, and the last one. The incidence of complications in the 2 groups was observed.

RESULTS

Dural tears, laminectomy, and operation time >3 hours were identified as independent risk factors. The time needed for body temperature, WBC, and CRP to return to normal and the antibiotic application time were significantly different between the 2 groups (all P < 0.05). Before and after the first intrathecal injection and after the last intrathecal injection, the differences in WBCs, neutrophil ratios, CRP, procalcitonin in blood, and cerebrospinal fluid-WBC were statistically significant in overall and pairwise comparisons (P < 0.05). Complications occurred in 2 and 14 cases, respectively.

CONCLUSIONS

The independent risk factors for central nervous system infection after spinal surgery were a dural tear, laminectomy, and operation time > 3 hours. Combined intravenous and intrathecal injections of antibiotics led to a better effect than intravenous injection alone; however, this approach was associated with more complications.

Full-endoscopic spine surgery diminishes surgical site infections - a propensity score-matched analysis

BACKGROUND CONTEXT

Surgical site infections (SSI) are one the most frequent and costly complications following spinal surgery. The SSI rates of different surgical approaches need to be analyzed to successfully minimize SSI occurrence.

PURPOSE

The purpose of this study was to define the rate of SSIs in patients undergoing full-endoscopic spine surgery (FESS) and then to compare this rate against a propensity score-matched cohort from the National Surgical Quality Improvement Program (NSQIP) database.

DESIGN

This is a retrospective multicenter cohort study using a propensity score-matched analysis of prospectively maintained databases.

PATIENT SAMPLE

One thousand two hundred seventy-seven non-instrumented FESS cases between 2015 and 2021 were selected for analysis. In the nonendoscopic NSQIP cohort we selected data of 55,882 patients.

OUTCOME MEASURES

The occurrence of any SSI was the primary outcome. We also collected any other perioperative complications, demographic data, comorbidities, operative details, history of smoking, and chronic steroid intake.

METHODS

All FESS cases from a multi-institutional group that underwent surgery from 2015 to 2021 were identified for analysis. A cohort of cases for comparison was identified from the NSQIP database using Current Procedural Terminology of nonendoscopic cervical, thoracic, and lumbar procedures from 2015 to 2019. Trauma cases as well as arthrodesis procedures, surgeries to treat pathologies affecting more than 4 levels or spine tumors that required surgical treatment were excluded. In addition, nonelective cases, and patients with wounds worse than class 1 were also not included. Patient demographics, comorbidities, and operative details were analyzed for propensity matching.

RESULTS

In the non-propensity-matched dataset, the endoscopic cohort had a significantly higher incidence of medical comorbidities. The SSI rates for nonendoscopic and endoscopic patients were 1.2% and 0.001%, respectively, in the nonpropensity match cohort (p-value <.011). Propensity score matching yielded 5936 nonendoscopic patients with excellent matching (standard mean difference of 0.007). The SSI rate in the matched population was 1.1%, compared to 0.001% in endoscopic patients with an odds ratio 0.063 (95% confidence interval (CI) 0.009-0.461, p=.006) favoring FESS.

CONCLUSIONS

FESS compares favorably for risk reduction in SSI following spinal decompression surgeries with similar operative characteristics. As a consequence, FESS may be considered the optimal strategy for minimizing SSI morbidity.

Does Postoperative Spine Infection Bacterial Gram Type Affect Surgical Debridement or Antibiotic Duration?

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The aim was to evaluate differences in readmission rates, number of debridements, and length of antibiotic therapy when comparing bacterial gram type following lumbar spinal fusion infections.

SUMMARY OF BACKGROUND DATA

Surgical site infections (SSIs) after spinal fusion serve as a significant source of patient morbidity. It remains to be elucidated how bacterial classification of the infecting organism affects the management of postoperative spinal SSI.

METHODS

Patients who underwent spinal fusion with a subsequent diagnosis of SSI between 2013 and 2019 were retrospectively identified. Patients were grouped based on bacterial infection type (gram-positive, gram-negative, or mixed infections). Poisson regressions analyzed the relationship between the type of bacterial infection and the number of irrigation and debridement (I&D) reoperations, and the duration of intravenous (IV) antibiotic therapy. Significance was set at P <0.05.

RESULTS

Of 190 patients, 92 had gram-positive (G+) infections, 57 had gram-negative (G-) infections, and 33 had mixed (M) infections. There was no difference in 30 or 90-day readmissions for infection between groups (both P =0.051). Patients in the M group had longer durations of IV antibiotic treatment (G+: 46.4 vs. G-: 41.0 vs. M: 55.9 d, P =0.002). Regression analysis demonstrated mixed infections were 46% more likely to require a greater number of debridements ( P =0.001) and 18% more likely to require an increased duration of IV antibiotic therapy ( P <0.001), while gram-negative infections were 10% less likely to require an increased duration of IV antibiotic therapy ( P <0.001) when compared with G- infections.

CONCLUSION

Spinal SSI due to a mixed bacterial gram type results in an increased number of debridements and a longer duration of IV antibiotics required to resolve the infection compared with gram-negative or gram-positive infections.

LEVEL OF EVIDENCE

Level III.

A Case of Fungemia Caused by Postoperative Chronic Lumbar Intervertebral Disc Infection

Postoperative surgical site infection is one of the serious postoperative complications of spine surgery, especially fungal infections. Late-stage surgical site fungal infections often lack typical clinical symptoms and have a variable clinical presentation. In this case, the patient was a senior patient with usually only tolerable pain and discomfort, which was detected 2 years after the first surgery. Such cases are even rarer for fungal bloodstream infections caused by delayed postoperative chronic fungal osteomyelitis and deserve further study for early identification and intervention to minimize harm.

Clinical Outcomes at One-year Follow-up for Patients With Surgical Site Infection After Spinal Fusion

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To compare health-related quality of life outcomes at one-year follow-up between patients who did and did not develop surgical site infection (SSI) after thoracolumbar spinal fusion.

SUMMARY OF BACKGROUND DATA

SSI is among the most common healthcare-associated complications. As healthcare systems increasingly emphasize the value of delivered care, there is an increased need to understand the clinical impact of SSIs.

MATERIALS AND METHODS

A retrospective 3:1 (control:SSI) propensity-matched case-control study was conducted for adult patients who underwent thoracolumbar fusion from March 2014 to January 2020 at a single academic institution. Exclusion criteria included less than 18 years of age, incomplete preoperative and one-year postoperative patient-reported outcome measures, and revision surgery. Continuous and categorical data were compared via independent t tests and χ 2 tests, respectively. Intragroup analysis was performed using paired t tests. Regression analysis for ∆ patient-reported outcome measures (postoperative minus preoperative scores) controlled for demographics. The α was set at 0.05.

RESULTS

A total of 140 patients (105 control, 35 SSI) were included in final analysis. The infections group had a higher rate of readmission (100% vs. 0.95%, P <0.001) and revision surgery (28.6% vs. 12.4%, P =0.048). Both groups improved significantly in Physical Component Score (control: P =0.013, SSI: P =0.039), Oswestry Disability Index (control: P <0.001, SSI: P =0.001), Visual Analog Scale (VAS) Back (both, P <0.001), and VAS Leg (control: P <0.001, SSI: P =0.030). Only the control group improved in Mental Component Score ( P <0.001 vs. SSI: P =0.228), but history of a SSI did not affect one-year improvement in ∆MCS-12 ( P =0.455) on regression analysis. VAS Leg improved significantly less in the infection group (-1.87 vs. -3.59, P =0.039), which was not significant after regression analysis (β=1.75, P =0.050).

CONCLUSION

Development of SSI after thoracolumbar fusion resulted in increased revision rates but did not influence patient improvement in one-year pain, functional disability, or physical and mental health status.

Laminectomy Versus Laminectomy with Fusion for Intradural Extramedullary Tumors: A Systematic Review and Meta-Analysis

OBJECTIVE

The primary objective of our systematic review and meta-analysis was to systematically compare the reported outcomes between laminectomy and laminectomy with fixation/fusion (LF) for the treatment of intradural extramedullary tumors (IDEMTs). Our secondary objective was to compare the outcomes between different laminectomy exposure techniques.

METHODS

PubMed and Embase were queried for literature on laminectomy and LF for IDEMTs. Reports of transforaminal approaches, interlaminar approaches, corpectomy, pediatrics patients, intramedullary tumors, technical studies, animal or cadaver studies, and literature reviews were excluded. The outcome measures recorded were pain, neurologic function, functional independence, cerebrospinal fluid leak, and wound infection. Where possible, the laminectomy technique (partial laminectomy [PL] vs. total laminectomy [TL]) was specified. Stata, version 17, was used for the fixed effects inverse variance meta-analysis.

RESULTS

Of 1849 reports assessed, 17 were included. The meta-analysis revealed that laminectomy (PL or TL) resulted in higher rates of postoperative sagittal instability compared with LF (odds ratio, 1.81; P < 0.001). No differences in any other postoperative outcome were observed between laminectomy and LF (P = 0.44). The systematic review also revealed no differences in postoperative pain, neurologic function, or functional independence or disability between PL and TL. Some evidence suggested that TL might result in greater rates of sagittal instability compared with PL.

CONCLUSIONS

No differences between LF, PL, or TL in pain, neurologic deficit, functional independence, cerebrospinal fluid leak, or wound infection were reported. Laminectomy had greater odds of sagittal instability compared with LF. Patients with preoperative sagittal instability requiring extensive removal of the posterior spinal column to achieve adequate resection of large tumors might benefit from LF.

Baclofen Pump Use: Complications After Growth-friendly Instrumentation for Early-onset Scoliosis

BACKGROUND

Patients with early-onset scoliosis (EOS) and spasticity may receive treatment with an intrathecal baclofen pump. We assessed how baclofen pumps are associated with the odds of complications and secondary interventions after growth-friendly (GF) spine surgery for EOS and analyzed infectious complications within the pump cohort.

METHODS

Using a prospectively maintained, international multicenter database, we studied patients with neuromuscular EOS with baclofen pumps who underwent GF spine surgery from 2002 through 2019 (n=25). Baclofen pumps were implanted before GF instrumentation in 18 patients, during in 2 patients, and after in 5 patients. Patients with existing pumps at initial GF spine surgery were matched 1:3 with 54 patients (control group) without pumps according to treatment center, year of surgery, diagnosis, surgery type, and preoperative curve magnitude. Univariate analysis and multivariate logistic regression were performed to compare complications and secondary interventions between the 2 cohorts.

RESULTS

Patients with baclofen pumps had 4.8 times the odds [95% confidence interval (CI): 1.5-16] of experiencing any complication within 1 year after initial GF spine surgery compared with controls. During mean follow-up of 6.9±4.3 years, they had 4.7 times the odds (95% CI: 1.3-16) of deep surgical site infection and 5.6 times the odds (95% CI: 1.2-26) of spinal rod removal after any complication. Differences in rates of mechanical complication, such as rod migration and breakage, were nonsignificant between the 2 groups. For the 9 patients (50%) with pumps who experienced infections, the most common microorganisms were Staphylococcus aureus (4 patients) and Pseudomonas aeruginosa (2). The pump/catheter was revised or removed, in addition to antibiotic therapy or surgical irrigation and debridement, in 2 patients.

CONCLUSIONS

Among patients with neuromuscular EOS, those with baclofen pumps are much more likely to experience complications within 1 year after GF spine surgery. They are also more likely to have deep surgical site infections, with S. aureus and P. aeruginosa being the most common causative organisms, and to require spinal rod removal.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Risk Factors for Postoperative Deep Infection after Instrumented Spinal Fusion Surgeries for Degenerative Spinal Disease: A Nationwide Cohort Study of 194,036 Patients

Previous studies to identify risk factors for postoperative deep infection following instrumented spinal fusion surgery for degenerative spinal disease are based on insufficient information and have limited use in clinical practice. This study aims to fill this gap by assessing the risk factors and their adjusted relative risks through a comprehensive analysis, including all core information. In this nationwide, population-based, cohort study, data were obtained from the Korean National Health Insurance claims database between 1 January 2014, and 31 December 2018. This study included a cohort of 194,036 patients older than 19 years, who underwent instrumented spinal fusion surgery for degenerative spinal disease. We divided this population into cases (patients with postoperative deep infection) and controls (patients without postoperative deep infection); risk factors for postoperative deep infection were determined by multivariable analysis. The definition of postoperative deep infection varied, and sensitivity analyses were performed according to each definition. The estimates of all the statistical models were internally validated using bootstrap samples. The study included 767 patients (0.39%) with postoperative deep spinal infections and 193,269 controls. The final multivariable model identified the following variables as significant risk factors for postoperative deep infection: age between 60–69 years (OR = 1.6 [1.1–2.3]); age between 70–79 years (OR = 1.7 [1.2–2.5]); age > 80 years (OR = 2.1 [1.3–3.2]); male sex (OR = 1.7 [1.5–2.0]); rural residence (OR = 1.3 [1.1–1.5]); anterior cervical approach (OR = 0.2 [0.1–0.3]); posterior cervical approach (OR = 0.5 [0.2–1.0]); multiple approaches (OR = 1.4 [1.2–1.6]); cerebrovascular disease (OR = 1.5 [1.2–1.8]); peripheral vascular disease (OR = 1.3 [1.1–1.5]); chronic pulmonary disease (OR = 1.2 [1.0–1.4]); rheumatologic disease (OR = 1.6 [1.3–2.1]); liver disease (OR = 1.4 [1.1–1.7]); diabetes (OR = 1.5 [1.3–1.7]); hemiplegia or paraplegia (OR = 2.2 [1.5–3.3]); allogenous transfusion (OR = 1.6 [1.3–1.8]); and use of systemic steroids over 2 weeks (OR = 1.5 [1.1–2.0]). Our results, which are based on homogenous patient groups, provide clinicians with an acceptable tool for comprehensive risk assessment of postoperative deep infection in patients who will undergo instrumented spinal fusion surgery for degenerative spinal disease.

Clostridium perfringens in the spine: A rare cause of post-surgical infection

Background:

Post-surgical infections of the spine occur in from 0% to 18% of cases. Postoperative spine infections due to Clostridium Perfringens (CP) resulting in necrotizing fasciitis are extremely rare. However, since they may be fatal, early and definitive treatment is critical.

Case Description: A

62-year-old male with a T8-T9 Type C fracture, in ASIA Grade “E” (neurologically intact) underwent a posterior T6-T10 arthrodesis. However, 2 weeks postoperatively, he developed a postoperative thoracic wound infection; the cultures were positive for CP. As the patient developed necrotizing fasciitis, emergent debridement, negative pressure continued drainage, and initiation of appropriate antibiotic therapy were critical.

Conclusion:

Postoperative spinal infections due to CP with accompanying necrotizing fasciitis are extremely rare. As these infections may be fatal, they must be rapidly diagnosed and treated.

Effect of Duration of Symptoms on the Clinical and Functional Outcomes of Lumbar Microdiscectomy: A Randomized Controlled Trial

Objectives

The objective is to determine whether the preoperative duration of symptoms can affect the clinical and functional outcomes after microdiscectomy.

Method

This study is a single blind randomized controlled trial with level 1 evidence. From 3 January 2016 to 15 February 2017, 122 adult patients with symptomatic lumbar disc herniation were divided randomly by computer system into three groups were treated by microdiscectomy at 6 weeks, 3 months and 6 months from onset of symptoms respectively. Ninety‐seven patients, age (19–47) years, 42 males and 55 females, were analyzed at the end of this study with 3 years of follow up. Primary outcome measures are Oswestry Disability Index (ODI), Roland‐Morris Questionnaire (RMQ) and Visual Analogue Scale (VAS) for back pain and leg pain. Secondary outcome measures are post‐operative complications, length of hospital stay and time of return to daily activities.

Results

There was significant difference in VAS for back pain among study groups (P = 0.002) at 2 weeks). There were significant differences in VAS for leg pain among study groups (P < 0.001) at 2 weeks and at 3 months (P = 0.003). There was significant difference in ODI among study groups at 2 weeks, 3, 6 months, 1, 2 and 3 years (P = 0.037 at 2 weeks and P < 0.001 at other periods of assessments) and we found that the mean of ODI in group 6 weeks was better than group 3 months and this was better than group 6 months in all periods of assessment. Group 6 weeks was better than group 3 months and this was better than group 6 months in postoperative improvements regarding RMQ with significant difference at 2 weeks postoperatively (P < 0.001) and at 3 months postoperatively (P < 0.001).

Conclusion

Duration of preoperative symptoms, in patients with lumbar disc herniation, can affect the clinical and functional outcomes after lumbar microdiscectomy as the shorter duration of symptoms resulted in better postoperative clinical and functional outcomes.

The Impact of Surgical Site Infection on Patient Outcomes After Open Posterior Instrumented Thoracolumbar Surgery for Degenerative Disorders

BACKGROUND

Few reports in the literature have described the long-term outcome of postoperative infection from the patient perspective. The aim of the present study was to determine if complicated surgical site infection (SSI) affects functional recovery and surgical outcomes up to 2 years after posterior instrumented thoracolumbar surgery for the treatment of degenerative disorders.

METHODS

This retrospective cohort study involved patients who had been enrolled in a previous randomized controlled trial that examined antibiotic use for open posterior multilevel thoracolumbar or lumbar instrumented fusion procedures. In the present study, patients who had SSI (n = 79) were compared with those who did not (n = 456). Patient-reported outcome measures (PROMs) included the Oswestry Disability Index (ODI), leg and back pain scores on a numeric rating scale, Short Form-12 (SF-12) summary scores, and satisfaction with treatment at 1.5, 3, 6, 12, and 24 months. Surgical outcomes included adverse events, readmissions, and additional surgery.

RESULTS

The median time to infection was 15 days. Of the 535 patients, 31 (5.8%) had complicated infections and 48 (9.0%) had superficial infections. Patients with an infection had a higher body mass index (BMI) (p = 0.001), had more commonly received preoperative vancomycin (p = 0.050), were more likely to have had a revision as the index procedure (p = 0.004), had worse preoperative mental functioning (mental component summary score, 40.7 ± 1.6 versus 44.1 ± 0.6), had more operatively treated levels (p = 0.024), and had a higher rate of additional surgery (p = 0.001). At 6 months after surgery, patients who developed an infection scored worse on the ODI by 5.3 points (95% confidence interval [CI], 0.4 to 10.1 points) and had worse physical functioning by -4.0 points (95% CI, -6.8 to -1.2 points). Comparison between the groups at 1 and 2 years showed no difference in functional outcomes, satisfaction with treatment, or the likelihood of achieving the minimum clinically important difference (MCID) for the ODI.

CONCLUSIONS

SSI more than doubled the post-discharge emergency room visit and additional surgery rates. Patients with SSI initially (6 months) had poorer overall physical function representing the delay to recovery; however, the negative impact resolved by the first postoperative year.

LEVEL OF EVIDENCE

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

ACR Appropriateness Criteria® Suspected Spine Infection

Spine infection is both a clinical and diagnostic imaging challenge due to its relatively indolent and nonspecific clinical presentation. The diagnosis of spine infection is based upon a combination of clinical suspicion, imaging evaluation and, when possible, microbiologic confirmation performed from blood cultures or image-guided percutaneous or open spine biopsy. With respect to the imaging evaluation of suspected spine infection, MRI without and with contrast of the affected spine segment is the initial diagnostic test of choice. As noncontrast MRI of the spine is often used in the evaluation of back or neck pain not responding to conservative medical management, it may show findings that are suggestive of infection, hence this procedure may also be considered in the evaluation of suspected spine infection. Nuclear medicine studies, including skeletal scintigraphy, gallium scan, and FDG-PET/CT, may be helpful in equivocal or select cases. Similarly, radiography and CT may be appropriate for assessing overall spinal stability, spine alignment, osseous integrity and, when present, the status of spine instrumentation or spine implants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Spondylodiscitis treated with freeze-dried bone allograft alone or combined with autograft: A randomized and blinded trial

PURPOSE

To compare the bone fusion of freeze-dried allograft alone versus freeze-dried allograft combined autograft in spinal instrumentation due to spondylodiscitis.

METHODS

A randomized prospective trial of patients with spondylodiscitis treated with surgical debridement and spinal fixation with freeze-dried bone allograft and autograft (Group 1) or freeze-dried bone allograft alone (Group 2) was performed. Patient follow-up was assessed with a CT-scan for bone fusion; consecutive serum inflammatory marker detection (C-reactive protein, [CRP], and erythrocyte sedimentation rate, [ESR]) and clinical assessment (pain, functional disability, and spinal cord injury recovery) were other outcome parameters. The primary outcome was the grade of bone allograft integration with the scale of Tan (which ranges from 1 to 4, with lower scores indicating a better fusion rate) at 1 year after surgery.

RESULTS

A total of 20 patients were evaluated, 13 (65%) men and 7 (35%) women with a mean age of 47.2 (±14.3) years. Homogeneous distribution of demographic data was observed. A similar satisfactory bone graft fusion grade was observed in both graft groups at 1 year after surgery (p = 1.0000). Serum inflammatory markers gradually decreased in both groups after surgical intervention (CRP, p < 0.001; ESR, p < 0.01). At one-year follow-up, gradual improvement of pain, functional disability, and neurological spinal injury recovery in both graft groups were achieved.

CONCLUSION

Freeze-dried allograft alone could be a therapeutic option for spinal fixation surgery due to spondylodiscitis since it achieves a satisfactory graft fusion rate and clinical improvement.

LEVEL OF EVIDENCE

Level 1. Treatment.

REGISTER

NCT03265561.

Deep Spinal Infection after Outpatient Epidural Injections for Pain: A Retrospective Sample Cohort Study Using a Claims Database in South Korea

BACKGROUND

Deep spinal infection is a devastating complication after epidural injection. This study aimed to investigate the incidence of deep spinal infection primarily after outpatient single-shot epidural injection for pain. Secondarily, this study assessed the national trends of the procedure and risk factors for said infection.

METHODS

Using South Korea's National Health Insurance Service sample cohort database, the 10-yr national trend of single-shot epidural injections for pain and the incidence rate of deep spinal infection after the procedure with its risk factors were determined. New-onset deep spinal infections were defined as those occurring within 90 days of the most recent outpatient single-shot epidural injection for pain, needing hospitalization for at least 1 night, and receiving at least a 4-week course of antibiotics.

RESULTS

The number of outpatient single-shot epidural injections per 1,000 persons in pain practice doubled from 40.8 in 2006 to 84.4 in 2015 in South Korea. Among the 501,509 injections performed between 2007 and 2015, 52 cases of deep spinal infections were detected within 90 days postprocedurally (0.01% per injection). In multivariable analysis, age of 65 yr or more (odds ratio, 2.91; 95% CI, 1.62 to 5.5; P = 0.001), living in a rural area (odds ratio, 2.85; 95% CI, 1.57 to 5.0; P < 0.001), complicated diabetes (odds ratio, 3.18; 95% CI, 1.30 to 6.7; P = 0.005), multiple epidural injections (three times or more) within the previous 90 days (odds ratio, 2.34; 95% CI, 1.22 to 4.2; P = 0.007), and recent use of immunosuppressants (odds ratio, 2.90; 95% CI, 1.00 to 6.7; P = 0.025) were significant risk factors of the infection postprocedurally.

CONCLUSIONS

The incidence of deep spinal infection after outpatient single-shot epidural injections for pain is very rare within 90 days of the procedure (0.01%). The data identify high-risk patients and procedure characteristics that may inform healthcare provider decision-making.

EDITOR’S PERSPECTIVE

Optimal microbiological sampling for the diagnosis of osteoarticular infection

Infection is a dire complication afflicting every field of orthopaedics and traumatology. If specific clinical, laboratory and imaging parameters are present, infection is often assumed even in the absence of microbiological confirmation. However, apart from confirming infection, knowing the exact infecting pathogen(s) and their antimicrobial susceptibility patterns is paramount to help guide treatment. Every effort should therefore be undertaken with that goal in mind.Not all microbiological findings carry the same relevance, and knowing exactly how and where a sample was collected is key. Several different sampling techniques are available, and one must be aware of both advantages and limitations. Microbiological sampling alternatives in some of the most common clinical scenarios such as native and prosthetic joint infections, osteomyelitis and fracture-related infections, spinal and diabetic foot infections will be discussed.Orthopaedic surgeons should also be aware of basic laboratory sample processing techniques as they have a direct impact on the way specimens should be dealt with and transported to the laboratory. Only by knowing these basic principles will surgeons be able to participate in the multidisciplinary discussion and decision making around how to interpret microbiological findings in each specific patient. Cite this article: EFORT Open Rev 2021;6:390-398. DOI: 10.1302/2058-5241.6.210011.

Imaging Assessment of the Postoperative Spine: An Updated Pictorial Review of Selected Complications

Imaging of the postoperative spine requires the identification of several critical points by the radiologist to be written in the medical report: condition of the underlying cortical and cancellous bone, intervertebral disc, and musculoskeletal tissues; location and integrity of surgical implants; evaluation of the success of decompression procedures; delineation of fusion status; and identification of complications. This article presents a pictorial narrative review of the most common findings observed in noninstrumented and instrumented postoperative spines. Complications in the noninstrumented spine were grouped in early (hematomas, pseudomeningocele, and postoperative spine infection) and late findings (arachnoiditis, radiculitis, recurrent disc herniation, spinal stenosis, and textiloma). Complications in the instrumented spine were also sorted in early (hardware fractures) and late findings (adjacent segment disease, hardware loosening, and implant migration). This review also includes a short description of the most used diagnostic techniques in postoperative spine imaging: plain radiography, ultrasound (US), computed tomography (CT), magnetic resonance (MR), and nuclear medicine. Imaging of the postoperative spine remained a challenging task in the early identification of complications and abnormal healing process. It is crucial to consider the advantages and disadvantages of the imaging modalities to choose those that provide more accurate spinal status information during the follow-up. Our review is directed to all health professionals dealing with the assessment and care of the postoperative spine.

Postoperative lymphocyte percentage and neutrophil-lymphocyte ratio are useful markers for the early prediction of surgical site infection in spinal decompression surgery

PURPOSE

Although the neutrophil-lymphocyte ratio (NLR) is a simple biomarker for inflammation, its diagnostic value for predicting surgical site infection (SSI) after spinal decompression surgery has not been extensively investigated. We aimed to determine the predictive value of NLR for SSI in patients undergoing spinal decompression surgery.

METHODS

We performed a retrospective observational study of patients who underwent spinal decompression surgery. Consecutive 254 patients were divided into an SSI group and a non-SSI group based on the presence of SSI. We evaluated which markers, including NLR, differed significantly between groups. We then determined the diagnostic cutoff values of these markers for the prediction of SSI based on the significance in the univariate analysis.

RESULTS

The incidence of SSI was 7 of 254 patients (2.8%). Univariate analysis showed that there were significant differences in the C-reactive protein (CRP) level at 1 day postoperatively; neutrophil and lymphocyte percentage and NLR at 3-4 days postoperatively; and CRP level, white blood cell count, neutrophil count and percentage, lymphocyte percentage, and NLR at 6-7 days postoperatively between SSI and non-SSI groups. Among these markers, the cutoff values of lymphocyte percentage and NLR at 3-4 days postoperatively for the prediction of SSI were ≤15.1% and ≥4.91, respectively. The cutoff values of lymphocyte percentage and NLR at 6-7 days postoperatively were ≤19.8% and ≥3.21, respectively.

CONCLUSIONS

Lymphocyte percentage and NLR at 3-4 and 6-7 days postoperatively were useful markers for the early prediction of SSI in patients who had undergone spinal decompression surgery. These parameters may aid in identifying patients at higher risk of SSI after spinal decompression surgery.

C-reactive protein in spinal surgery: more predictive than prehistoric

PURPOSE

In spinal surgery, surgical site infections (SSI) after dorsal spondylodesis lead to severe short- and long-term complications. Despite various clinical and serological evidence, the detection of a postoperative SSI remains crucial. In this retrospective cohort study, we determined the prognostic value of C-reactive protein (CRP) kinetics after open reduction and dorsal spondylodesis in the development of a SSI.

METHODS

We retrospectively analyzed 192 patients from 2016 to 2018 undergoing open reduction and dorsal spondylodesis with and without SSI for 20 days at a level-I trauma center and assessed their serological and clinical characteristics.

RESULTS

On day 7 and 8 after surgery, patients who developed a SSI displayed significantly higher CRP levels. A second peak after the initial maximum of CRP and a restricted failure to decline as well as a maximum CRP of more than 225 mg/l predict an infectious complication with a sensitivity of 92.9%, and a specificity of 78.2%. A binary logistic regression leads to 85.7% and 69.7%, respectively. A one-phase decay exponential regression can predict 75.6% of the variance after the initial peak of CRP.

CONCLUSION

Our study demonstrates a high value of postoperative CRP kinetics in SSI detection after dorsal spondylodesis. Moreover, we observed typical CRP levels with a specific course as indicative predictors that may facilitate an early SSI detection in clinical practice.

Unplanned hospital readmission after surgical treatment for thoracic spinal stenosis: incidence and causative factors

BACKGROUND

To assess the incidence and causative factors of unplanned hospital readmission within 90 days after surgical treatment of thoracic spinal stenosis (TSS).

METHODS

Hospital administrative database was queried to identify patients who underwent surgical treatment of TSS from July 2010 through December 2017. All unplanned readmissions within 90 days of discharge were reviewed for causes and the rate of unplanned readmissions was calculated. Patients of unplanned readmission were matched 1:3 to a control cohort without readmission.

RESULTS

Twenty-one patients (incidence of 1.7 % in 1239 patients) presented unplanned hospital readmission within a 90-day period and enrolled as the study group, 63 non-readmission patients (a proportion of 1: 3) were randomly selected as the control group. Causes of readmission include pseudomeningocele (8 patients; 38 %), CSF leakage combined with poor incision healing (6 patients; 29 %), wound dehiscence (2 patient; 9 %), surgical site infection (2 patients; 9 %), spinal epidural hematoma (1 patient; 5 %), inadequate original surgical decompression (2 patients; 9 %). Mean duration from re-admission to the first surgery was 39.6 ± 28.2 days, most of the patients readmitted at the first 40 days (66.7 %, 14/21 patients). When compared to the non-readmitted patients, diagnosis of OPLL + OFL, circumferential decompression, dural injury, long hospital stay were more to be seen in readmitted patients.

CONCLUSIONS

The incidence of 90-day unplanned readmission after surgical treatment for TSS is 1.7 %, CSF leakage and pseudomeningocele were the most common causes of readmission, the peak period of readmission occurred from 10 to 40 days after surgery, patients should be closely followed up within this period.

Future directions of postoperative spinal implant infections

This article outlines some promising future concepts against postoperative spinal implant infections on the basis of today available literature. The ever-adapting bacteria causing this common complication compel a corresponding continuous research about best effective treatment. The aim is to give a perspective on several future attack-points: surgical infection prevention strategies such as technical optimization of implants and surgical technique; faster diagnostic tools to detect infection, especially in the context of late infections with low-virulent germs and with regard to decision-making in the course of the surgical workflow; and combined surgical and medical treatment options against implant infections. The surgical treatment section will also state open issues concerning implant removal, and the medical treatment section will give an outlook to promising medical alternatives in a post-antibiotic era. To keep up in this field will be important to retain spine surgery in the future as the state-of-the-art treatment option for mandatory spinal interventions in the presence of tumor or trauma and even more so as an attractive option for patients with degenerative spinal disorder for improvement of their life quality.

Antibiotic treatment of postoperative spinal implant infections

Postoperative spinal implant infection (PSII) is a serious complication after spinal surgery. It is associated with increased morbidity and mortality for affected patients as well as significant costs for the healthcare system. Due to the formation of biofilm on foreign material, both diagnosis and treatment of PSII can pose a considerable challenge. Modern treatment protocols allow efficient eradication and good clinical outcomes in the majority of patients. In this article, we review the current antibiotic treatment concepts for PSII including the correct choice of antibiotics and their combination. In cases of late-onset PSII where the implants can be removed, two weeks of intravenous (IV) antibiotics followed by 4 weeks of oral antibiotics seem appropriate. If the implant needs to be retained, a 2-week IV antibiotic treatment should be followed by 10 weeks of oral antibiotic therapy with biofilm activity or, in case of problematic pathogens, a long-term suppression therapy. Initial empiric antibiotic therapy should cover staphylococci, streptococci, enterococci and Gram-negative bacilli as the most common pathogens. Antibiotic adjustments according to the type of pathogen and its antimicrobial susceptibility are essential for successful eradication of infection.

Comprehensive treatment algorithm of postoperative spinal implant infection

Postoperative spinal implant infection (PSII) is a commonly found and serious complication after instrumented spinal surgery. Whereas early-onset PSII usually can be diagnosed by clinical symptoms, the diagnosis of late-onset PSII can be often made only by examination of intraoperatively collected samples. The treatment of PSII consists of surgical and antibiotic therapy schemes. In case of early PSII, the retention of spinal implants is a feasible option, whereas late PSII is usually treated by one-staged exchange of the spinal implants. Radical debridement of surrounding tissue should be performed in any case of PSII. The antibiotic treatment depends on either the implants can be removed or need to be retained or exchanged, respectively. If the causative pathogens are sensitive for biofilm-active antibiotic agents, the duration of antibiotic treatment amounts to 12 weeks with retention of spinal implants. In case of problematic pathogens, the application of antibiotics needs to be prolonged for an individual duration. Antibiotic treatment should always be initiated with an intravenous application for at least 2 weeks.

Sustained Postoperative Fever Without Evident Cause After Spine Instrumentation as an Indicator of Surgical Site Infection

BACKGROUND

Surgical site infection after spinal instrumentation increases morbidity and mortality as well as medical costs and is a burden to both patients and surgeons. Late-onset or sustained fever increases the suspicion for comorbid conditions. This retrospective, exploratory cohort study was conducted to identify the rate of and risk factors for sustained or late-onset postoperative fever after spinal instrumentation operations and to determine its relationship with surgical site infection.

METHODS

Five hundred and ninety-eight patients who underwent lumbar or thoracic spinal instrumentation were retrospectively reviewed. The patients were divided according to (1) whether or not they had had a sustained fever (SF[+] or SF[-]) and (2) whether or not they had had a surgical site infection (SSI[+] or SSI[-]). Clinical characteristics, surgical factors, prophylactic antibiotic usage, fever pattern, and laboratory/imaging findings were recorded for all patients by electronic medical chart review.

RESULTS

In total, 68 patients (11.4%) had a sustained fever. The rate of surgical site infection was significantly higher when the patient had sustained fever (13.2% [9 of 68] compared with 0.9% [5 of 530]; p < 0.001). Comparison of the patients who had a sustained fever but no surgical site infection (SF[+], SSI[-]) and those with both a sustained fever and surgical site infection (SF[+], SSI[+]) showed that continuous fever, an increasing or stationary pattern of inflammatory markers, and a C-reactive protein (CRP) level of >4 mg/dL on postoperative days 7 to 10 were diagnostic clues for surgical site infection. The sensitivity and specificity of postoperative magnetic resonance imaging (MRI) for the detection of surgical site infection were 40.0% and 90.9%, respectively, when MRI was performed within 1 month after surgery.

CONCLUSIONS

Although most patients with sustained fever did not have surgical site infection, fever was significantly related to surgical site infection. Continuous fever, increasing patterns of inflammatory markers, and high CRP on postoperative days 7 to 10 were diagnostic clues for surgical site infection. This study demonstrated provisional results for factors that can discriminate febrile patients with surgical site infection from febrile patients without infection. Further investigation with a larger sample size is warranted for clarification.

LEVEL OF EVIDENCE

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

Preoperative Urinary Tract Infection Increases Postoperative Morbidity in Spine Patients

STUDY DESIGN

Retrospective review.

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

3.

Real-world experience of the role of 18F FDG PET-computed tomography in chronic spinal implant infection

OBJECTIVES

The presence of postinstrumentation back pain in patients after undergoing spinal surgery is a well established phenomenon. So too is the presence of infection, both overt and subclinical which can be a source of pain. The accurate assessment of infection in patients with spinal implants in situ and no overt radiological or biochemical abnormalities frequently presents a diagnostic challenge. We present our experience spanning 5 years of using 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (18F FDG PET)-computed tomography (CT) scans to aid the diagnostic process in treating presumed low-grade chronic implant infection.

METHODS

We undertook a retrospective analysis of all patients with spinal implants in place who were referred for 18F FDG PET-CT imaging over a 5-year period. All available images, case notes and laboratory results were reviewed.

RESULTS

Data pertaining to 49 patients were analysed, with infection diagnosed on 18F FDG PET-CT in 24 (45%) of those sent for scanning. Fifteen patients in the cohort underwent revision surgery, and 11 of whom had been diagnosed as infected on PET-CT. Confirmation of infection with positive microbiological sampling occurred in 8/11 giving a positive predictive value of 0.72 in our series.

CONCLUSION

We present a real-world experience of using 18F FDG PET-CT as a diagnostic tool in the evaluation of patients with chronic pain after undergoing spinal implantation. We have found PET-CT to be a promising modality and would recommend multicentre collaboration to ensure reproducibility across more centres.