Clinical assessment and medical treatment of spine infections

Advances in diagnosis and management of atypical spinal infections: A comprehensive review

Atypical spinal infections (ASIs) of the spine are a challenging pathology to management with potentially devastating morbidity and mortality. To identify patients with atypical spinal infections, it is important to recognize the often insidious clinical and radiographic presentations, in the setting of indolent and smoldering organism growth. Trending of inflammatory markers, and culturing of organisms, is essential. Once identified, the spinal infection should be treated with antibiotics and possibly various surgical interventions including decompression and possible fusion depending on spine structural integrity and stability. Early diagnosis of ASIs and immediate treatment of debilitating conditions, such as epidural abscess, correlate with fewer neurological deficits and a shorter duration of medical treatment. There have been great advances in surgical interventions and spinal fusion techniques for patients with spinal infection. Overall, ASIs remain a perplexing pathology that could be successfully treated with early diagnosis and immediate, appropriate medical, and surgical management.

Diagnostic Approach and Differences between Spinal Infections and Tumors

STUDY DESIGN

A systematic review of the literature about differential diagnosis between spine infection and bone tumors of the spine.

BACKGROUND AND PURPOSE

The differential diagnosis between spine infection and bone tumors of the spine can be misled by the prevalence of one of the conditions over the other in different areas of the world. A review of the existing literature on suggestive or even pathognomonic imaging aspects of both can be very useful for correctly orientating the diagnosis and deciding the most appropriate area for biopsy. The purpose of our study is to identify which imaging technique is the most reliable to suggest the diagnosis between spine infection and spine bone tumor.

METHODS

A primary search on Medline through PubMed distribution was made. We identified five main groups: tuberculous, atypical spinal tuberculosis, pyogenic spondylitis, and neoplastic (primitive and metastatic). For each group, we evaluated the commonest localization, characteristics at CT, CT perfusion, MRI, MRI with Gadolinium, MRI diffusion (DWI) and, in the end, the main features for each group.

RESULTS

A total of 602 studies were identified through the database search and a screening by titles and abstracts was performed. After applying inclusion and exclusion criteria, 34 articles were excluded and a total of 22 full-text articles were assessed for eligibility. For each article, the role of CT-scan, CT-perfusion, MRI, MRI with Gadolinium and MRI diffusion (DWI) in distinguishing the most reliable features to suggest the diagnosis of spine infection versus bone tumor/metastasis was collected.

CONCLUSION

Definitive differential diagnosis between infection and tumor requires biopsy and culture. The sensitivity and specificity of percutaneous biopsy are 72% and 94%, respectively. Imaging studies can be added to address the diagnosis, but a multidisciplinary discussion with radiologists and nuclear medicine specialists is mandatory.

A clinical prediction model to differentiate tuberculous spondylodiscitis from pyogenic spontaneous spondylodiscitis

BACKGROUND

Microbiological diagnosis of tuberculous spondylodiscitis (TS) and pyogenic spontaneous spondylodiscitis (PS) is sometime difficult. This study aimed to identify the predictive factors for differentiating TS from PS using clinical characteristics, radiologic findings, and biomarkers, and to develop scoring system by using predictive factors to stratify the probability of TS.

METHODS

A retrospective single-center study. Demographics, clinical characteristics, laboratory findings and radiographic findings of patients, confirmed causative pathogens of PS or TS, were assessed for independent factors that associated with TS. The coefficients and odds ratio (OR) of the final model were estimated and used to construct the scoring scheme to identify patients with TS.

RESULTS

There were 73 patients (51.8%) with TS and 68 patients (48.2%) with PS. TS was more frequently associated with younger age, history of tuberculous infection, longer duration of symptoms, no fever, thoracic spine involvement, ≥3 vertebrae involvement, presence of paraspinal abscess in magnetic-resonance-image (MRI), well-defined thin wall abscess, anterior subligamentous abscess, and lower biomarker levels included white blood cell (WBC) counts, erythrocyte-sedimentation-rate (ESR), neutrophil fraction, and C-reactive protein (all p < 0.05). Multivariate logistic regression analysis revealed significant predictors of TS included WBC ≤9,700/mm3 (odds ratio [OR] 13.11, 95% confidence interval [CI] 4.23-40.61), neutrophil fraction ≤78% (OR 4.93, 95% CI 1.59-15.30), ESR ≤92 mm/hr (OR 4.07, 95% CI 1.24-13.36) and presence of paraspinal abscess in MRI (OR 10.25, 95% CI 3.17-33.13), with an area under the curve of 0.921. The scoring system stratified the probability of TS into three categories: low, moderate, and high with a TS prevalence of 8.1%, 29.6%, and 82.2%, respectively.

CONCLUSIONS

This prediction model incorporating WBC, neutrophil fraction counts, ESR and presence of paraspinal abscess accurately predicted the causative pathogens. The scoring scheme with combination of these biomarkers and radiologic features can be useful to differentiate TS from PS.

Bilateral Percutaneous Transpedicular Drainage under Local Anesthesia for Thoracic Tuberculous Spondylitis

Tuberculous spondylitis is a common spinal infection. If surgical intervention is necessary, anterior debridement and anterior fixation are typically performed. However, a minimally invasive surgical strategy under local anesthesia seems rarely implemented. A 68-year-old man presented with severe pain in the left flank. Whole spinal magnetic resonance imaging revealed abnormal intensity of vertebral bodies from T6-9. A bilateral paravertebral abscess extending from T4-10 was suspected. The T7/T8 intervertebral disc was destroyed, but severe vertebral deformity or spinal cord compression was not observed. Bilateral percutaneous transpedicular drainage under local anesthesia was planned. The patient was set in the prone position. Under the guide of a biplanar angiographic system, the bilateral drainage tubes were placed paravertebrally in the abscess cavity. The left flank pain improved after the procedure. Laboratory culture of the pus specimen confirmed a diagnosis of tuberculosis. A chemotherapy regimen for tuberculosis was soon initiated. The patient was discharged during postoperative week 2, with continuation of chemotherapy for tuberculosis. Percutaneous transpedicular drainage under local anesthesia can be effective in the management of thoracic tuberculous spondylitis without severe vertebral deformity or compression of the spinal cord by an abscess.

Diagnostic Sensitivity of Blood Culture, Intraoperative Specimen, and Computed Tomography-Guided Biopsy in Patients with Spondylodiscitis and Isolated Spinal Epidural Empyema Requiring Surgical Treatment

BACKGROUND

the successful treatment of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) depends on early detection of causative pathogens, which is commonly performed either via blood cultures, intraoperative specimens, and/or image-guided biopsies. We evaluated the diagnostic sensitivity of these three procedures and assessed how it is influenced by antibiotics.

METHODS

we retrospectively analyzed data from patients with SD and ISEE treated surgically at a neurosurgery university center in Germany between 2002 and 2021.

RESULTS

we included 208 patients (68 [23-90] years, 34.6% females, 68% SD). Pathogens were identified in 192 cases (92.3%), including 187 (97.4%) pyogenic and five (2.6%) non-pyogenic infections, with Gram-positive bacteria accounting for 86.6% (162 cases) and Gram-negative for 13.4% (25 cases) of the pyogenic infections. The diagnostic sensitivity was highest for intraoperative specimens at 77.9% (162/208, p = 0.012) and lowest for blood cultures at 57.2% (119/208) and computed tomography (CT)-guided biopsies at 55.7% (39/70). Blood cultures displayed the highest sensitivity in SD patients (SD: 91/142, 64.1% vs. ISEE: 28/66, 42.4%, p = 0.004), while intraoperative specimens were the most sensitive procedure in ISEE (SD: 102/142, 71.8% vs. ISEE: 59/66, 89.4%, p = 0.007). The diagnostic sensitivity was lower in SD patients with ongoing empiric antibiotic therapy (EAT) than in patients treated postoperatively with targeted antibiotic therapy (TAT) (EAT: 77/89, 86.5% vs. TAT: 53/53, 100%, p = 0.004), whereas no effect was observed in patients with ISEE (EAT: 47/51, 92.2% vs. TAT: 15/15, 100%, p = 0.567).

CONCLUSIONS

in our cohort, intraoperative specimens displayed the highest diagnostic sensitivity especially for ISEE, whereas blood cultures appear to be the most sensitive for SD. The sensitivity of these tests seems modifiable by preoperative EAT in patients with SD, but not in those with ISEE, underscoring the distinct differences between both pathologies.

Application of metagenomic next-generation sequencing in the detection of pathogens in spinal infections

BACKGROUND CONTEXT

The precise diagnosis and treatment of spinal infections (SI) remains challenging for spine surgeons. Identifying the pathogens of SI through metagenomic next-generation sequencing (mNGS) may be a key approach to addressing this challenge.

PURPOSE

To evaluate the accuracy and applicability of mNGS in determining the etiology of SI.

STUDY DESIGN

Diagnostic test study.

PATIENT SAMPLE

Twenty-five patients who had a clinical suspicion of SI and underwent mNGS testing.

OUTCOME MEASURES

The specificity, sensitivity, and time cost of mNGS and bacterial culture were compared. Clinical outcomes were assessed using the numeric rating scale (NRS) score, Oswestry Disability Index (ODI), and the Japanese Orthopedic Association (JOA) score. Demographic data and laboratory results (blood cell count (WBC), erythrocyte sedimentation rate (ESR), neutrophil percentage (NEUT%), and C-reactive protein level (CRP) were also evaluated.

METHODS

In this retrospective study, samples were obtained from 25 eligible patients via surgery or CT-guided puncture and subjected to histopathological examination, bacterial culture, and mNGS. The sensitivity and specificity of the bacterial cultures and mNGS were calculated with respect to the histopathological results as a reference. Postoperative antibiotics or antituberculosis drugs were administered on the basis of mNGS results, combined with clinical manifestations, imaging examination, and histopathology. The changes of clinical outcomes and laboratory results after treatment were observed.

RESULTS

Of the 25 patients, 21 had a positive pathology, of which 10 showed a tuberculous pathology, and the remaining 11 showed a nontuberculous inflammatory pathology. The sensitivity of mNGS was higher than that of the bacterial culture. However, the difference in specificity between bacterial culture and mNGS was not significant. Moreover, the time needed to perform mNGS was significantly lower than that of bacterial culture and pathology. All patients were followed up for more than three months, and CRP and NEUT% significantly decreased by three months after treatment. There was no significant difference in WBC and ESR. The ODI, NRS and JOA scores were significantly improved after treatment.

CONCLUSION

Metagenomic next-generation sequencing technology can play an important role in the detection of pathogens in SI and should be further investigated and applied in future studies.

Intramedullary Spinal Cord Abscess with Concomitant Spinal Degenerative Diseases: A Case Report and Systematic Literature Review

Intramedullary spinal cord abscess (ISCA) is a rare clinical pathology of the central nervous system that usually accompanies other underlying comorbidities. Traditionally it has been associated with significant mortality and neurological morbidities because it is often difficult to diagnose promptly, owing to its nonspecific clinical and neuroimaging features. The mortality rate and the outcome of these infections have been improved by the introduction into clinical practice of antibiotics, advanced neuroimaging modalities, and immediate surgery. We report the case of a 65-year-old male patient who presented with a progressive spastic gait and lumbar pain, predominantly in the left leg. An MRI image revealed an expansile intramedullary cystic mass in the thoracic spinal cord, which was initially diagnosed as a spinal tumor. He underwent laminectomy and myelotomy, and eventually the pus was drained from the abscess. The follow-up MRI showed improvement, but the patient’s paraplegia persisted. In light of his persistent hypoesthesia and paraplegic gait with developing neuropathic pain, he was readmitted, and an MRI of his lumbar spine revealed multilevel degenerative disease and tethered spinal cord syndrome with compression of the medulla at the L2–L3 level. The patient underwent central flavectomy with bilateral foraminotomy at the L2–L3 level, and the medulla was decompressed. Postoperatively, his neurological symptoms were significantly improved, and he was discharged from hospital on the third day after admission. In support of our case, we systematically reviewed the recent literature and analyzed cases published between 1949 and May 2022, including clinical features, mechanisms of infection, predisposing factors, radiological investigations, microbial etiologies, therapies and their duration, follow-ups, and outcomes. Initial clinical presentation can be misleading, and the diagnosis can be challenging, because this condition is rare and coexists with other spinal diseases. Hence, a high index of suspicion for making an accurate diagnosis and timely intervention is required to preclude mortality and unfavorable outcomes. Our case is a clear example thereof. Long-term follow-up is also essential to monitor for abscess recurrences.

C-arm Fluoroscopy-Guided Percutaneous Needle Biopsy for the Diagnosis of Spinal Infection: A Study of 203 Consecutive Patients

C-arm fluoroscopy-guided percutaneous needle biopsy (PNB) is a commonly used biopsy method, which shows similar diagnostic outcomes to CT-guided biopsy. This study aimed to evaluate the diagnostic value of C-arm fluoroscopy-guided percutaneous needle biopsy (PNB) for spinal infection. A total of 30 male and 73 female patients with suspected spinal infection were enrolled. Among enrolled patients, the spinal lesion was mainly located in the thoracic (T3-T12, 48.28%) and lumbar vertebra (L1-L5, 46.80%), and T12 was the most frequently involved site. C-arm fluoroscopy-guided PNB was performed for the isolation of biopsy samples in these patients. The overall detection rate of pathological changes in bone tissues was 94.1% (191/203), including 92 granulomata with caseous necrosis, 81 inflammatory tissues, 18 tumor tissues, and 12 bone tissues without visible pathological changes. After excluding the tumors, the detection rate of pathogenic microorganisms in liquid tissues was 50.27% (93/185), including 68 Mycobacterium tuberculosis, and 25 other microorganisms. Spinal tuberculosis was diagnosed in 118 (58%) cases, and nonspecific spinal infection with microorganisms other than Mycobacterium tuberculosis was diagnosed in 25 (12.7%) cases. Definite diagnosis was not determined in the left 42 (20.5%) patients with neither positive pathological nor pathogenic results. C-arm fluoroscopy-guided PNB is effective in the detection of pathological changes and pathogenic microorganisms, which is a practical approach for the diagnosis of spinal infection with high accuracy.

Gas within the Intervertebral Disc Does Not Rule Out Spinal Infection-A Case Series of 135 Patients with Spontaneous Spondylodiscitis

Gas in the intervertebral disc is mainly associated with degenerative disc diseases and experts generally assume that it is unlikely in spinal infection. However, large-scale studies supporting this notion are lacking, which is why our study's aim was to analyze the prevalence of and factors associated with the occurrence of gas in patients with spontaneous spondylodiscitis. Patients presenting with spontaneous spondylodiscitis from 2006 to 2020 were included retrospectively. Exclusion criteria were previous interventions in the same spinal segment and missing imaging data. Clinical data were retrieved from electronic medical reports. Computed tomography (CT) scans were evaluated for the presence of intervertebral gas. Causative pathogens were identified from CT-guided biopsy, open biopsy, intraoperative tissue samples, and/or blood cultures. 135 patients with a mean age of 66.0 ± 13.7 years were included. In 93 patients (68.9%), a causative pathogen was found. Intervertebral gas was found in 31 patients (23.0%) in total and in 19 patients (20.4%) with positive microbiology. Patients with gas presented with significantly higher body temperatures (37.2 ± 1.1 vs. 36.8 ± 0.7 °C, p = 0.044) and CRP levels (134.2 ± 127.1 vs. 89.8 ± 97.3 mg/L, p = 0.040) on admission. As a considerable number of patients with spondylodiscitis showed intervertebral gas formation, the detection of intervertebral gas is not suited to ruling out spondylodiscitis but must be interpreted in the context of other imaging and clinical findings, especially in elderly patients.

PMMA-Cement-PLIF Is Safe and Effective as a Single-Stage Posterior Procedure in Treating Pyogenic Erosive Lumbar Spondylodiscitis—A Single-Center Retrospective Study of 73 Cases

Background: Surgical treatment for erosive pyogenic spondylodiscitis of the lumbar spine is challenging as, following debridement of the intervertebral and bony abscess, a large and irregular defect is created. Sufficient defect reconstruction with conventional implants using a posterior approach is often impossible. Therefore, we developed the “Cement-PLIF”, a single-stage posterior lumbar procedure, combining posterior lumbar interbody fusion (PLIF) with defect-filling using antibiotic-loaded polymethylmethacrylate (PMMA). This study first describes and evaluates the procedure’s efficacy, safety, and infection eradication rate. Radiological implant stability, bone-regeneration, sagittal profile reconstruction, procedure-related complications, and pre-existing comorbidities were further analyzed. Methods: A retrospective cohort study analyzing 73 consecutive patients with a minimum of a one-year follow-up from 2000–2017. Patient-reported pain levels and improvement in infectious serological parameters evaluated the clinical outcome. Sagittal profile reconstruction, anterior bone-regeneration, and posterior fusion were analyzed in a.p. and lateral radiographs. A Kaplan–Meier analysis was used to determine the impact of pre-existing comorbidities on mortality. Pre-existing comorbidities were quantified using the Charlson-Comorbidity Index (CCI). Results: Mean follow-up was 3.3 (range: 1–16; ±3.2) years. There was no evidence of infection persistence in all patients at the one-year follow-up. One patient underwent revision surgery for early local infection recurrence (1.4%). Five (6.9%) patients required an early secondary intervention at the same level due to minor complications. Radiological follow-up revealed implant stability in 70/73 (95.9%) cases. Successful sagittal reconstruction was demonstrated in all patients (p < 0.001). There was a significant correlation between Kaplan–Meier survival and the number of pre-existing comorbidities (24-months-survival: CCI ≤ 3: 100%; CCI ≥ 3: 84.6%; p = 0.005). Conclusions: The Cement-PLIF procedure for pyogenic erosive spondylodiscitis is an effective and safe treatment as evaluated by infection elimination, clinical outcome, restoration, and maintenance of stability and sagittal alignment.

Non-specific spondylodiscitis: a new perspective for surgical treatment

PURPOSE

Pyogenic spondylodiscitis is a relatively rare spinal disease; non-specific spondylodiscitis (NSS) cases are increasing. This study aims to identify if changes of inflammatory markers under antibiotic therapy can be used to determine which NSS patients can benefit from surgical indication earlier than others.

METHODS

Two groups of patients with NSS were examined. Group A underwent surgery, while Group B was treated conservatively. Group B was also subdivided in patients undergoing antibiotic therapy for > 6 weeks (B1) and < 6 weeks (B2). Groups were compared for age, gender, BMI, blood levels of ESR and CRP and VAS scale.

RESULTS

There were no differences (P = 0.06) in reduction in ESR at 4 weeks between two main groups. A reduction in CRP, with < 2.7 mg/dl at 4 weeks, was observed in Group A (P = 0.01). Comparing Group B1 to B2, a reduction (P = 0.0001) in VAS, ESR and CRP at 4 weeks was observed in Group B2. It was possible to isolate the pathogen in 52.8% of Group B, without any differences on VAS, ESR and CRP values and on length of the antibiotic therapy.

CONCLUSIONS

The surgical treatment should be considered for patients who, after 4 weeks of conservative therapy, do not show a reduction in the ESR < 50 mm/h and of the CRP < 2.7 g/dl. The comparison between groups underwent surgically and those treated conservatively showed a reduction in the CRP at 4 weeks and better VAS for pain at 3 months in Group A.

The first rare and fatal case of invasive aspergillosis of spinal cord due to Aspergillus nidulans in an Iranian child with chronic granulomatosis disease: review of literature

Background and Purpose:

Invasive aspergillosis (IA) of the central nervous system (CNS) is a devastating complication which is rarely reported in immunocompromised children.

In this case presentation, we reported a rare and fatal IA with spinal cord involvement in a 10-year-old child with X-linked chronic granulomatosis disease (CGD).

Case report:

The child had a previous history of pulmonary tuberculosis. A cervical spine X-ray revealed the involvement of cervical vertebrae (T4/T5) and ribs causing spinal cord compression and epidural abscess. The patient underwent a decompressive laminectomy and mass removal. The histopathology and culture results suggested IA. Despite the aggressive and prolonged therapy, he died within one year. Aspergillus nidulans was identified as the causative agent based on morphological and molecular studies.

Conclusion:

This synopsis represents the aggressive behavior of infection caused by A. nidulans in the CGD patient.

Spinal Infections: An Update

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. The most common route for spinal infection is through hematogenous spread of the microorganism from a distant infected area. Most patients with spinal infections diagnosed in 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. In either case, close monitoring of the patients with spinal infection with serial neurological examinations and imaging studies is necessary.

Recent Increase in the Rate of Spinal Infections May be Related to Growing Substance-use Disorder in the State of Washington: Wide Population-based Analysis of the Comprehensive Hospital Abstract Reporting System (CHARS) Database

STUDY DESIGN

Epidemiological study.

OBJECTIVE

The aim of this study was to evaluate trends in the incidence of spinal infections (SI) and the possible role of substance use disorder (SUD) as a key associated factor.

SUMMARY OF BACKGROUND DATA

SI pose major diagnostic and therapeutic challenge in developed countries, resulting in substantial morbidity and mortality. With an estimated incidence of up to 1:20,000, recent clinical experiences suggest that this rate may be rising.

METHODS

To evaluate a possible change in trend in the proportion of SI, we searched the Washington state Comprehensive Hospital Abstract Reporting System (CHARS) data during a period of 15 years. We retrieved ICD-9 and 10 codes, searching for all conditions that are regarded as SI (discitis, osteomyelitis, and intraspinal abscess), as well as major known SI-related risk factors.

RESULTS

We found that the proportion of SI among discharged patients had increased by around 40% during the past 6 years, starting at 2012 and increasing steadily thereafter. Analysis of SI-related risk factors within the group of SI revealed that proportion of SUD and malnutrition had undergone the most substantial change, with the former increasing >3-fold during the same period.

CONCLUSION

Growing rates of drug abuse, drug dependence, and malnutrition throughout the State of Washington may trigger a substantial increase in the incidence of spinal infections in discharged patients. These findings may provide important insights in planning prevention strategies on a broader level.

LEVEL OF EVIDENCE

4.

Management of spinal infection: a review of the literature

Spinal infection (SI) is defined as an infectious disease affecting the vertebral body, the intervertebral disc, and/or adjacent paraspinal tissue and represents 2–7% of all musculoskeletal infections. There are numerous factors, which may facilitate the development of SI including not only advanced patient age and comorbidities but also spinal surgery. Due to the low specificity of signs, the delay in diagnosis of SI remains an important issue and poor outcome is frequently seen. Diagnosis should always be supported by clinical, laboratory, and imaging findings, magnetic resonance imaging (MRI) remaining the most reliable method. Management of SI depends on the location of the infection (i.e., intraspinal, intervertebral, paraspinal), on the disease progression, and of course on the patient’s general condition, considering age and comorbidities. Conservative treatment mostly is reasonable in early stages with no or minor neurologic deficits and in case of severe comorbidities, which limit surgical options. Nevertheless, solely medical treatment often fails. Therefore, in case of doubt, surgical treatment should be considered. The final result in conservative as well as in surgical treatment always is bony fusion. Furthermore, both options require a concomitant antimicrobial therapy, initially applied intravenously and administered orally thereafter. The optimal duration of antibiotic therapy remains controversial, but should never undercut 6 weeks. Due to a heterogeneous and often comorbid patient population and the wide variety of treatment options, no generally applicable guidelines for SI exist and management remains a challenge. Thus, future prospective randomized trials are necessary to substantiate treatment strategies.

A Case of Cervical Tuberculous Spondylitis: An Uncommon Cause of Neck Pain

Neck pain is a common presentation to the emergency department. We report a case of cervical tuberculous spondylitis in an old lady with neck pain. She re-attended the emergency department because of progressive nocturnal pain and stiffness. X-ray of the cervical spine showed blurred endplate and prevertebral soft tissue swelling. CT cervical spine showed evidence of infective discitis. Surgical intervention and anti-tuberculosis therapy were given. The patient became bed-ridden and died of pneumonia two months later. Alarming clinical features and serial assessment of X-ray changes would help to look for potentially fatal differential diagnoses of neck pain.

Spondylodiscitis revisited

Spondylodiscitis may involve the vertebral bodies, intervertebral discs, paravertebral structures and spinal canal, with potentially high morbidity and mortality rates.

A rise in the susceptible population and improved diagnosis have increased the reported incidence of the disease in recent years.

Blood cultures, appropriate imaging and biopsy are essential for diagnosis and treatment.

Most patients are successfully treated by conservative means; however, some patients may require surgical treatment.

Surgical indications include doubtful diagnosis, progressive neurological deficits, progressive spinal deformity, failure to respond to treatment, and unresolved pain.

Cite this article: EFORT Open Rev 2017;2:447–461. DOI: 10.1302/2058-5241.2.160062

Long-term prognosis of hematogenous vertebral osteomyelitis: Mortality, quality of life, and pain

BACKGROUND

Hematogenous vertebral osteomyelitis (HVO) has a generally favorable prognosis if appropriate treatment is initiated in its early phase; however, some intractable cases with HVO can develop neurological impairment as well as spinal deformity during the course of treatment and these sequelae may lead to impaired quality of life (QOL). In this study, we aimed to evaluate the long-term relapse rate, mortality, and QOL of patients with HVO.

METHODS

In this retrospective case series study, medical records of 60 patients with HVO with a mean follow-up period of 8 years (5-23 years) were reviewed to assess demographic data, details of infection, and clinical course. Mortality rate was assessed using a Kaplan-Meier plot. QOL was measured using the EuroQol 5 Dimension (EQ-5D) questionnaire and residual pain using a numeric rating scale (NRS).

RESULTS

HVO relapsed in 4 of 60 patients (7%). Overall 5-year survival rate in 60 patients with HVO was 85%. The factors associated with increased mortality were malignant tumor, diabetes mellitus, chronic use of glucocorticoids, and drug-resistant strains of staphylococcus. Female-to-male ratio, NRS, prevalence of neurological impairment were significantly higher in patients with low EQ-5D score (poor health) compared to those with high EQ-5D score (good health).

CONCLUSIONS

Patients with HVO have shorter life expectancy if they have malignancy, diabetes mellitus, chronic use of glucocorticoids, and a history of drug-resistant strains of staphylococcus infection. Female gender, residual neurological defects and persistent back pain are associated with impaired QOL in patients with HVO.

Minimally invasive spine surgery in lumbar spondylodiscitis: a retrospective single-center analysis of 67 cases

BACKGROUND

Minimally invasive surgical techniques have been developed to minimize tissue damage, reduce narcotic requirements, decrease blood loss, and, therefore, potentially avoid prolonged immobilization. Thus, the purpose of the present retrospective study was to assess the safety and efficacy of a minimally invasive posterior approach with transforaminal lumbar interbody debridement and fusion plus pedicle screw fixation in lumbar spondylodiscitis in comparison to an open surgical approach. Furthermore, treatment decisions based on the patient´s preoperative condition were analyzed.

METHODS

67 patients with lumbar spondylodiscitis treated at our department were included in this retrospective analysis. The patients were categorized into two groups based on the surgical procedure: group (MIS) minimally invasive lumbar spinal fusion (n = 19); group (OPEN) open lumbar spinal fusion (n = 48). Evaluation included radiological parameters on magnetic resonance imaging (MRI), laboratory values, and clinical outcome.

RESULTS

Preoperative MRI showed higher rates of paraspinal abscess (35.5 vs. 5.6%; p = 0.016) and multilocular location in the OPEN group (20 vs. 0%, p = 0.014). Overall pain at discharge was less in the MIS group: NRS 2.4 ± 1 vs. NRS 1.6 ± 1 (p = 0.036). The duration of hospital stay was longer in the OPEN than the MIS group (19.1 ± 12 days vs. 13.7 ± 5 days, p = 0.018).

CONCLUSION

The open technique is effective in all varieties of spondylodiscitis inclusive in epidural abscess formation. MIS can be applied safely and effectively as well in selected cases, even with epidural abscess.

Pedicle Screw Fluid Sign: An Indication on Magnetic Resonance Imaging of a Deep Infection After Posterior Spinal Instrumentation

STUDY DESIGN

A single-center case-referent study.

OBJECTIVE

To assess whether the "pedicle screw (PS) fluid sign" on magnetic resonance imaging (MRI) can be used to diagnose deep surgical site infection (SSI) after posterior spinal instrumentation (PSI).

SUMMARY OF BACKGROUND DATA

MRI is a useful tool for the early diagnosis of a deep SSI. However, the diagnosis is frequently difficult with feverish patients with clear wounds after PSI because of artifacts from the metallic implants. There are no reports on MRI findings that are specific to a deep SSI after PSI. We found that fluid collection outside the head of the PS on an axial MRI scan (PS fluid sign) strongly suggested the possibility of an abscess.

METHODS

The SSI group comprised 17 patients with a deep SSI after posterior lumbar spinal instrumentation who had undergone an MRI examination at the onset of the SSI. The non-SSI group comprised 64 patients who had undergone posterior lumbar spinal instrumentation who did not develop an SSI and had an MRI examination within 4 weeks after surgery. The frequency of a positive PS fluid sign was compared between both groups.

RESULTS

The PS fluid sign had a sensitivity of 88.2%, specificity of 89.1%, positive predictive value of 68.1%, and negative predictive value of 96.6%. The 2 patients with a false-negative PS fluid sign in the SSI group had an infection at the disk into which the interbody cage had been inserted. Three of the 7 patients with a false-positive PS fluid sign in the non-SSI group had a dural tear during surgery.

CONCLUSIONS

The PS fluid sign is a valuable tool for the early diagnosis of a deep SSI. The PS fluid sign is especially useful for diagnosing a deep SSI in difficult cases, such as feverish patients without wound discharge.

Pathogen Identification in Suspected Cases of Pyogenic Spondylodiscitis

Pyogenic spinal infection continues to represent a worldwide problem. In approximately one-third of patients with pyogenic spondylodiscitis, the infectious agent is never identified. Of the cases that lead to organismal identification, bacteria are more commonly isolated from the spine rather than fungi and parasites. This study applied universal prokaryotic 16S rRNA PCR as a rapid diagnostic tool for the detection of bacterial agents in specimens from patients suspected of pyogenic spondylodiscitis. Gram and Ziehl-Neelsen staining were used as a preliminary screening measure for microbiologic evaluation of patient samples. PCR amplification targeting 16S rRNA gene was performed on DNA extracted from 57 cases including specimens from epidural abscesses, vertebral, and disc biopsies. Positive samples were directly sequenced. MRI findings demonstrated that disc destruction and inflammation were the major imaging features of suspected pyogenic spondylodiscitis cases, as 44 cases showed such features. The most common site of infection was the lumbar spine (66.7%), followed by thoracic spine (19%), the sacroiliac joint (9.5%), and lumbar-thoracic spine (4.8%) regions. A total of 21 samples amplified the 16S rRNA-PCR product. Sanger sequencing of the PCR products identified the following bacteriological agents: Mycobacterium tuberculosis (n = 9; 42.9%), Staphylococcus aureus (n = 6; 28.5%), Mycobacterium abscessus (n = 5; 23.8%), and Mycobacterium chelonae (n = 1; 4.8%). 36 samples displayed no visible 16S rRNA PCR signal, which suggested that non-bacterial infectious agents (e.g., fungi) or non-infectious processes (e.g., inflammatory, or neoplastic) may be responsible for some of these cases. The L3–L4 site (23.8%) was the most frequent site of infection. Single disc/vertebral infection were observed in 9 patients (42.85%), while 12 patients (57.15%) had 2 infected adjacent vertebrae. Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) inflammatory markers were noted in majority of the patients. In conclusion, microbiological methods and MRI findings are vital components for the proper diagnosis of pyogenic spondylodiscitis. Our findings suggest that molecular methods such as clinical application of 16S rRNA PCR and sequencing may be useful as adjunctive diagnostic tools for pyogenic spondylodiscitis. The rapid turnaround time of 16S rRNA PCR and sequencing submission and results can potentially decrease the time to diagnosis and improve the therapeutic management and outcome of these infections. Although S. aureus and M. tuberculosis were the most common causes of pyogenic spinal infections in this study, other infectious agents and non-infectious etiologies should be considered. Based on study results, we advise that antibiotic therapy should be initiated after a definitive etiological diagnosis.

Primary acquired spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery: a single-center retrospective study of 159 cases

Spondylodiscitis may arise primarily via hematogenous spread or direct inoculation of virulent organisms during spine surgery. To date, no comparative data investigating the differences between primary and postoperative spondylodiscitis is available. Thus, the purpose of this retrospective study was to investigate differences between these two etiologies. One hundred fifty-nine patients that were treated at our department were included in the retrospective analysis. The patients were categorized into two groups based on the etiology of spondylodiscitis: group NS, primary spondylodiscitis without prior spinal surgery; group S, spondylodiscitis following spinal surgery. Evaluation included magnetic resonance imaging (MRI), laboratory values, clinical outcome, and operative or conservative management. Preoperative MRI showed higher rates of epidural and paraspinal abscess in patients with primary spondylodiscitis (p < 0.005). Vertebral bone destruction was more severe in group NS (p < 0.05). Survival rate in group S (98.2%) was higher than in group NS (87.5%, p = 0.024). The extent of the operative procedure in patients who were surgically treated (n = 116) differed between the two groups (p < 0.005). In conclusion, spondylodiscitis is a life-threatening and serious disease and requires long-term treatment. Primary spondylodiscitis is frequently associated with epidural and paraspinal abscess, vertebral bone destruction and has a higher mortality rate than postoperative spondylodiscitis. Therefore, primary spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery.

Lymphopenia at 4 Days Postoperatively Is the Most Significant Laboratory Marker for Early Detection of Surgical Site Infection Following Posterior Lumbar Instrumentation Surgery

Study Design

Case control study.

Purpose

To identify the most significant laboratory marker for early detection of surgical site infection (SSI) using multiple logistic regression analysis.

Overview of Literature

SSI is a serious complication of spinal instrumentation surgery. Early diagnosis and treatment are crucial.

Methods

We retrospectively reviewed the laboratory data of patients who underwent posterior lumbar instrumentation surgery for degenerative spinal disease from January 2003 to December 2014. Six laboratory markers for early SSI detection were considered: renewed elevation of the white blood cell count, higher at 7 than 4 days postoperatively; renewed elevation of the C-reactive protein (CRP) level, higher at 7 than 4 days postoperatively; CRP level of >10 mg/dL at 4 days postoperatively; neutrophil percentage of >75% at 4 days postoperatively; lymphocyte percentage of <10% at 4 days postoperatively; and lymphocyte count of <1,000/µL at 4 days postoperatively.

Results

Ninety patients were enrolled; five developed deep SSI. Multivariate regression analysis showed that a lymphocyte count of <1,000/µL at 4 days postoperatively was the sole significant independent laboratory marker for early detection of SSI (p=0.037; odds ratio, 11.9; 95% confidence interval, 1.2–122.7).

Conclusions

A lymphocyte count of <1,000/µL at 4 days postoperatively is the most significant laboratory marker for early detection of SSI.

Removing Outer Gloves as a Method to Reduce Spinal Surgery Infection

STUDY DESIGN

A retrospective cohort study was performed to analyze the effect of a specifically timed glove change on infection rates in lumbar spinal fusion.

OBJECTIVES

Postoperative infection is a frequent and taxing complication following posterior lumbar spine fusion with instrumentation. This procedure is associated with infection rates up to 9%. The most common organism responsible for infection is Staphylococcus aureus which, along with many of the other common causative organisms, is often part human skin flora. This implicates the surgeon's gloves as the mode of transfer for these organisms from the patient's skin to the wound. The authors conducted a retrospective study to determine if a simple glove change before handling instrumentation could significantly reduce the rate of postoperative infection for this procedure.

MATERIALS AND METHODS

A total of 389 patients requiring lumbar spine fusion were enrolled retrospectively and divided into 2 groups: a control group of 179 patients treated with standard protocol for the procedure (group A) and a treatment group of 210 patients in whom, after initially double gloving, the outer pair of gloves was removed before handling the instrumentation. Infection rates were compared up to 1 year postoperatively.

RESULTS

There was a statistically significant reduction of infection rate from 3.35% in group A (control) to 0.48% in group B (P=0.0369).

CONCLUSION

This study shows that the removal of an outer pair of gloves before handling instrumentation may be a simple, cost-effective, and practical way to reduce the burden of postoperative infection following lumbar spinal fusion.

Positron emission tomography in spinal infections

Magnetic resonance imaging is the imaging method of choice for diagnosing infection of the spine in unoperated cases. 2-[(18)F]-fluoro-2deoxy-d-glucose positron emission tomography/computed tomography study is recommended to distinguish between spinal infection and common Modic change in patients with metallic implants and prosthetic replacements and for differentiating tuberculous from pyogenic spondylitis in ambiguous cases, reflecting the activity of the infection. Also, it seems to have a strong clinical impact in more than half of patients with infectious spondylitis, while it is superior to other imaging techniques in revealing residual disease after treatment and early response to therapy. New tracers as well as new hybrid modalities are under investigation.

Role of 18F-fluoro-D-deoxyglucose PET/CT in diagnosing surgical site infection after spine surgery with instrumentation

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To investigate the effectiveness of positron emission tomography/computed tomography (PET/CT) in diagnosing surgical site infection (SSI) after spinal surgery with instrumentation.

SUMMARY OF BACKGROUND DATA

Several reports have indicated the usefulness of F-fluoro-D-deoxyglucose (F-18 FDG) PET in detecting sites of infection including spinal infection sites. However, no report has documented the efficacy of PET/CT in detecting SSI after spinal surgery with instrumentation.

METHODS

A total of 811 consecutive case patients who underwent minimally invasive posterior lumbar interbody fusion surgery with instrumentation from December 2008 to February 2012 were enrolled. Of these, for all case patients clinically suspected as having SSI by laboratory data and clinical symptoms, PET/CT was performed. Six patients with no apparent sign of SSI served as a control group. Image data were evaluated by 2 nuclear medicine physicians blinded to the clinical and pathological results. The data were quantitatively analyzed by the maximum standardized uptake value as an index of F-18 FDG uptake.

RESULTS

Visual assessment by PET/CT revealed that all 8 patients with suspected SSI were positive for infection whereas all 6 controls without apparent infection were negative for infection. There was a statistically significant difference in the maximum standardized uptake values (mean and range) between the SSI and control groups (9.0 and 5.5-14.7 vs. 3.3 and 2.0-4.3, respectively; P = 0.003). All 8 patients underwent surgical debridement with selective implant removal and achieved a good clinical course.

CONCLUSION

PET/CT was effective in diagnosing SSI and identifying infection sites despite the presence of spinal instruments. Although further studies with a larger number of patients are required, PET/CT presents a good candidate for detecting early-phase SSI after instrumented spinal surgery.

The utility of image-guided percutaneous needle aspiration biopsy for the diagnosis of spontaneous vertebral osteomyelitis: a systematic review and meta-analysis

BACKGROUND CONTEXT

Spontaneous vertebral osteomyelitis (SVOM) is mostly acquired via hematogenous seeding. Diagnosis of SVOM is often delayed because of the insidious nature and rarity of this disease. The microbiological yield of image-guided needle biopsy varies between 36% and 91%. The utility and accuracy of this procedure have not been systematically reviewed.

PURPOSE

To systematically review and assess the diagnostic accuracy of image-guided spinal biopsy for SVOM in adults when compared with combined reference standards.

STUDY DESIGN

A systematic review and meta-analysis.

SAMPLE

Seven retrospective studies involving 482 patients with clinical and/or radiologic suspicion of SVOM who underwent image-guided spinal biopsy were included.

OUTCOME MEASURES

The primary outcome measure was diagnostic odds ratio (DOR). Other outcomes included likelihood ratio of a positive test (LRP), likelihood ratio of a negative test (LRN), sensitivity, and specificity.

METHODS

We searched in six medical databases through September 1, 2013 for studies evaluating the performance of image-guided spinal biopsy for SVOM with no limits on language or publication date. Combined reference standards, which included histopathologic findings consistent with vertebral osteomyelitis, identifications of pathogens from open surgery and/or blood cultures, and/or evidence of clinical and radiologic improvement after empiric antimicrobial therapy, were used for comparison. The random-effect model was used for meta-analysis. Two reviewers independently selected the studies.

RESULTS

Three hundred fifty-eight potentially relevant studies were identified. Seven studies were included in our analysis. Two studies that used only single reference standard were excluded in the sensitivity analysis, and five studies involving 352 patients were pooled. Image-guided spinal biopsy had a DOR of 45.50 (95% confidence interval [CI], 13.66-151.56), an LRP of 16.76 (95% CI, 5.51-50.95), an LRN of 0.39 (95% CI, 0.24-0.64), a sensitivity of 52.2% (95% CI, 45.8-58.5), and a specificity of 99.9% (95% CI, 94.5-100). This is based on the assumption that combined reference standards are a valid standard for comparison.

CONCLUSIONS

Image-guided spinal biopsy is highly specific and performs well in predicting SVOM, but has a moderate accuracy for ruling out this diagnosis. This procedure should be considered in the diagnostic work-up of adults suspected with SVOM.

Spondylodiscitis by drug-multiresistant bacteria: a single-center experience of 25 cases

BACKGROUND CONTEXT

Although the incidence of pyogenic spinal infections is increasing, the ideal treatment of spondylodiscitis is still a controversially discussed issue. Furthermore, the proportion of multiresistant bacteria in spondylodiscitis is increasing, and treatment recommendations or reported results are missing for this especially difficult subset of patients.

PURPOSE

The aim of this study is to evaluate the surgical outcome and the postoperative antibacterial treatment regime.

STUDY DESIGN

Retrospective case series.

PATIENT SAMPLE

Patients treated for a spondylodiscitis from multiresistant bacteria at our department between 2006 and 2011.

METHODS

Data were gathered through review of patients' case notes, relevant imaging, and electronic records. Magnetic resonance imaging of the whole spine including gadolinium (Gd)-enhanced T1 sequences and computed tomography scans of the affected regions were obtained in all cases.

OUTCOME MEASURES

C-reactive protein (CRP) and complete blood cell count were analyzed in all cases using routine laboratory techniques. Neurologic deficits were classified according to the American Spinal Injury Association (ASIA) impairment scale.

RESULTS

Twenty-five patients were identified (15 gram-positive and 10 gram-negative drug-multiresistant bacteria). The mean age at presentation was 66 years, and 14 patients were male (56%). All patients presented with pain, and a neurologic deficit was present in 11 (44%) cases. An epidural abscess was found in 11 (44%) cases. At admission, CRP was elevated in all cases with a mean of 13±9.2 mg/dL. The main source of infection was previous spine surgery (36%). All patients in this series underwent surgical debridement of the infection and instrumentation of the spine. Postoperative intravenous antibiotics were administered for 19±8.6 days followed by 3±0.3 months of oral antibiotic therapy. Eradication of the infection was achieved ultimately in all surviving patients. Out of 11 patients with neurologic deficits, 4 had a full recovery, 4 improved incompletely, and 3 remained unchanged after surgery.

CONCLUSIONS

Staged surgical immobilization and instrumentation and optimal debridement at the interdiscal space and spinal canal is a reliable approach to achieve complete healing of spinal infection with multiresistant bacteria. A period of intravenous antibiotic therapy of 2 to 3 weeks followed by a 3-month oral antibiotic therapy seems appropriate for most cases.

Comparison of pyogenic spondylitis and tuberculous spondylitis

Pyogenic spondylitis and tuberculous spondylitis are common causes of spinal infection. It is difficult to differentiate tuberculous spondylitis and pyogenic spondylitis clinically and radiologically. Recently magnetic resonance imaging has been reported to be beneficial for early diagnosis and differential diagnosis of the spondylitis, and is being used extensively for diagnosis. However, the diagnosis must be considered in combination with corresponding changes in clinical manifestations, radiological findings, blood and tissue cultures and histopathological findings. Conservative treatments, including antimicrobial medications, are started initially. Surgical treatments, which include anterior or posterior approach, single-stage or two-stage surgery, with or without instrumentation, may be performed as indicated.

[Indications for magnetic resonance imaging for low back pain in adults]

INTRODUCTION

Low back pain is a common disorder that generates many medical consultations. Magnetic Resonance Imaging (MRI) is commonly used in the clinical management of some of these patients. However, the cost of inappropriate MRI use is high, so there is a need to develop guidelines to help physicians make correct decisions and optimize available resources.

OBJECTIVE

To determine the main clinical indications for MRI scanning in adults with low back pain.

MATERIAL AND METHODS

The RAND/UCLA appropriateness method was used: After a systematic review (May 2012), a list of the clinical indications for MRI scanning in patients with low back pain was prepared. A multidisciplinary expert panel scored each indication from 1, «totally inappropriate» to 9, «totally appropriate». A first on-line round, an in-person panel meeting, where results of the first round were discussed, and a final second on-line round were arranged. A clinical indication was considered appropriate if the median score was 6.5 or higher, and there was agreement between experts (IPRAS index was used).

RESULTS

An MRI test is considered appropriate if cancer, spinal infection or a fracture, even with a negative X-ray test is suspected.; if there is inflammatory back pain; severe/progressive neurological deficit; severe and progressive low back pain; subacute or chronic low back pain with radicular involvement unresponsive to conservative therapy.

CONCLUSIONS

Clinical indications for a MRI scanning are based on the suspicion of a secondary serious pathology. This methodology helps to set clinical indications for MRI, and may be of great value for both clinicians and health managers.

Spinal infection: state of the art and management algorithm

INTRODUCTION

Spinal infection is a rare pathology although a concerning rising incidence has been observed in recent years. This increase might reflect a progressively more susceptible population but also the availability of increased diagnostic accuracy. Yet, even with improved diagnosis tools and procedures, the delay in diagnosis remains an important issue. This review aims to highlight the importance of a methodological attitude towards accurate and prompt diagnosis using an algorithm to aid on spinal infection management.

METHODS

Appropriate literature on spinal infection was selected using databases from the US National Library of Medicine and the National Institutes of Health.

RESULTS

Literature reveals that histopathological analysis of infected tissues is a paramount for diagnosis and must be performed routinely. Antibiotic therapy is transversal to both conservative and surgical approaches and must be initiated after etiological diagnosis. Indications for surgical treatment include neurological deficits or sepsis, spine instability and/or deformity, presence of epidural abscess and upon failure of conservative treatment.

CONCLUSIONS

A methodological assessment could lead to diagnosis effectiveness of spinal infection. Towards this, we present a management algorithm based on literature findings.

The management gram-negative bacterial haematogenous vertebral osteomyelitis: a case series of diagnosis, treatment and therapeutic outcomes

PURPOSE

The incidence of gram-negative bacterial haematogenous vertebral osteomyelitis (GNB HVO) is increasing. We performed a retrospective cohort study of patients with this type of infection in an effort to gain an improved understanding of the current clinical presentation, management and outcome.

METHODS

Between May 2007 and May 2010, all patients, over the age of 18 years, suffering from GNB HVO were identified and their microbiological diagnoses were evaluated.

RESULTS

This study identified seventy-nine patients with haematogenous vertebral osteomyelitis (HVO). Of these seventy-nine patients, 10 patients (12.66%) had Gram-negative organisms isolated. These organisms included Escherichia coli (4), Pseudomonas aeruginosa (3), Klebsiella pneumonia (1), Haemophilus influenza (1) and Enterobacter cloacae (1). Eight patients were successfully treated with antibiotics and/or surgery. Of the eight patients whose HVO was cured, five had Ciprofloxacin as part of their definitive antibiotic regime.

CONCLUSION

The treatment of GNB HVO is often challenging because of unpredictable resistance patterns and limited published data on effective treatment regimens. Our study has highlighted the need for prompt microbiological sampling and initiation of early appropriate antibiotic regime. The most effective treatment for GNB HVO was with oral Ciprofloxacin over a period of 6-8 weeks.

[Pyogenic spondylodiscitis: therapy algorithm and a new classification for therapeutic decision-making]

The incidence of pyogenic spondylodiscitis is low but has been steadily increasing in recent years. To date there has been no consensus concerning selection of the appropriate treatment, management and strategies and the recommendations for an operative strategy are still a highly controversial issue. In the literature a few statements have been published concerning therapeutic decision-making in pyogenic spondylodiscitis. The classification given in this article is based on clinical experience and retrospective data analysis considering the degree of segmental bony destruction, grade of kyphosis and instability, epidural involvement of the disease and neurological deficits, which are pivotal for therapeutic decision-making. The therapeutic procedure can be defined based on this classification.

Hematogenous pyogenic spinal infection: current perceptions

As a result of reading this article, physicians should be able to:1.Understand the importance of early diagnosis and treatment of spinal infection in an effort to avoid devastating and crippling complications such as paralysis, painful deformity, and death.2.Understand current perceptions in the ongoing debate of whether operative or conventional treatment should be preferred and in which cases.3.Understand the latest advances in the surgical treatment of spinal infection, their indications, and their effectiveness.4.Understand the change in the traditionally held belief that in the presence of infection, the use of metal implants or grafts is not indicated. Controversy exists regarding optimal treatment for pyogenic spinal infection. The authors systematically reviewed peer-reviewed published clinical trials in the English language through 2009 on the clinical presentation, complications, and conservative and operative treatments of pyogenic spinal infection. The cornerstone of therapy for uncomplicated spondylodiskitis is intravenous antibiotics followed by oral antibiotics and bracing. Surgery is effective in complicated cases and improves sagittal balance, restores neurological impairment, and relieves severe pain. In cases of delayed diagnosis or surgery, potential early devastating and late crippling complications may occur. To the authors' knowledge, no Level I studies compare operative vs conservative treatment of pyogenic spinal infection.

Infections in spinal instrumentation

Surgical-site infection (SSI) in the spine is a serious postoperative complication. Factors such as posterior surgical approach, arthrodesis, use of spinal instrumentation, age, obesity, diabetes, tobacco use, operating-room environment and estimated blood loss are well established in the literature to affect the risk of infection. Infection after spine surgery with instrumentation is becoming a common pathology. The reported infection rates range from 0.7% to 11.9%, depending on the diagnosis and complexity of the procedure. Besides operative factors, patient characteristics could also account for increased infection rates. These infections after instrumented spinal fusion are particularly difficult to manage due to the implanted, and possibly infected, instrumentation. Because the medical, economic and social costs of SSI after spinal instrumentation are enormous, any significant reduction in risks will pay dividends. The goal of this literature review was to analyse risk factors, causative organisms, diagnostic elements (both clinical and biological), different treatment options and their efficiency and consequences and the means of SSI prevention.

Treatment of spondylodiscitis

PURPOSE

Pyogenic infections of the spine are relatively rare with an incidence between 1:100,000 and 1:250,000 per year, but the incidence is increasing due to increases in average life-expectancy, risk factors, and medical comorbidities. The mean time in hospital varies from 30 to 57 days and the hospital mortality is reported to be 2-17%. This article presents the relevant literature and our experience of conservative and surgical treatment of pyogenic spondylodiscitis.

METHOD

We have performed a review of the relevant literature and report the results of our own research in the diagnosis and treatment of pyogenic spondylodiscitis. We present a sequential algorithm for identification of the pathogen with blood cultures, CT-guided biopsies and intraoperative tissue samples. Basic treatment principles and indications for surgery and our surgical strategies are discussed.

RESULTS

Recent efforts have been directed toward early mobilisation of patients using primary stable surgical techniques that lead to a further reduction of the mortality. Currently our hospital mortality in patients with spondylodiscitis is around 2%. With modern surgical and antibiotic treatment, a relapse of spondylodiscitis is unlikely to occur. In literature the relapse rate of 0-7% has been recorded. Overall the quality of life seems to be more favourable in patients following surgical treatment of spondylodiscitis.

CONCLUSION

With close clinical and radiological monitoring of patients with spondylodiscitis, conservative and surgical therapies have become more successful. When indicated, surgical stabilisation of the infected segments is mandatory for control of the disease and immediate mobilisation of the patients.

Vertebral osteomyelitis: eight years' experience of 100 cases

To evaluate the etiology and characteristics of vertebral osteomyelitis cases in our country, patients with vertebral osteomyelitis between January 2000 and December 2007 were included in this study. Clinical and laboratory data of the patients were collected from the medical records retrospectively. Of these 100 patients, 44 had pyogenic, 24 had brucellar, and 32 had tuberculous spondylodiscitis. The age of the patients ranged from 13 to 82 years, with a mean of (SD±) 55 ± 15.6 years. Within the pyogenic group, 10 (22.7%) patients had a spinal surgery history, and in 18 patients of the pyogenic group, an etiological agent was isolated. Ten (56%) of these 18 were methicillin-sensitive Staphylococcus aureus. While all of the patients included in this study suffered from pain, 49 of these had fever. Sixty-nine percent of the patients had lumbar involvement. The etiological distribution may differ according to geographical areas. Although brucella and tuberculosis (TB) are endemic in our country, pyogenic vertebral osteomyelitis was more frequent. The most common involved area in our patients was the lumbar vertebrae. Although thoracic involvement may be more predominant in tuberculous vertebral osteomyelitis, it does not strongly suggest TB. Magnetic resonance imaging may exclude some disorders mimicking vertebral osteomyelitis and may delineate the degree of the involvement. Microbiological and/or histopathological examination of computerized tomography-guided fine-needle aspiration biopsies are the mainstays for the diagnosis. Suspicion and early diagnosis seem critical for preventing sequelae development.

The safety and efficacy of cadaveric allografts and titanium cage as a fusion substitutes in pyogenic osteomyelitis

OBJECTIVE

The safety and efficacy of various fusion substitutes in pyogenic osteomyelitis has not been investigated. We evaluated and compared the cadaveric allograft and titanium cages used to reconstruct, maintain alignment and achieve fusion in the management of pyogenic spinal infection.

METHODS

There were 33 patients with pyogenic osteomyelitis underwent fusion in this study. Fifteen of the 33 patients were operated on by fusion with allografts (cadaveric patella bones) and 18 of those were operated with titanium mesh cages filled with autologous cancellous iliac bone. After the affected disc and vertebral body resection with pus drainage, cadaveric allograft or titanium cages were inserted into the resected space. Posterior transpedicular screw fixation and rod compression in resected space, where cadaveric allograft or titanium cages were inserted, was performed to prevent the malposition in all patients except in 1 case. Recurrent infection was identified by serial erythrocyte sedimentation rate and cross reactive protein follow-up. Osseous union and recurred infection available at a minimum of 2 years following operation was identified. The amount of kyphosis correction and the subsidence were measured radiographically.

RESULTS

Spinal fusion was achieved in 29 of 33 patients. In the cadaveric allograft group, 93.3% of patient (14 of 15) showed the osseous union while 83.3% of patient (15 of 18) in the titanium cage group showed union. Subsidence was noted in 12 of the patients. Twelve patients (36.3%) showed unsettling amounts of subsidence postoperatively whereas 46.6% of patients in the cadaveric allograft group and 37.7% of patients in the titanium cage group showed similar subsidence, respectively. There were statistical difference in the fusion rate (p=0.397) and subsidence rate (p=0.276) between the two groups. There was significant statistical difference in the postoperative improvement of segmental kyphosis between the two groups (p=0.022), that is the improvement in sagittal alignment was greater in the titanium cage group than in the cadaveric allograft group. There was no case of recurred infection.

CONCLUSION

The cadaveric allograft and titanium cages are effective and safe in restoring and maintaining sagittal plane alignment without increased incidence in infection recurrence in pyogenic osteomyelitis. The postoperative improvement of segmental kyphosis was better in the cage group.

Magnetic resonance imaging for diagnosing lumbar spinal pathology in adult patients with low back pain or sciatica: a diagnostic systematic review

PURPOSE

In about 5% of all cases LBP is associated with serious underlying pathology requiring diagnostic confirmation and directed treatment. Magnetic resonance imaging (MRI) is often used for this diagnostic purpose yet its role remains controversial. Consequently, this review aimed to summarize the available evidence on the diagnostic accuracy of MRI for identifying lumbar spinal pathology in adult low back pain (LPB) or sciatica patients.

METHODS

MEDLINE, EMBASE and CINAHL were searched (until December 2009) for observational studies assessing the diagnostic accuracy of MRI compared to a reference test for the identification of lumbar spinal pathology. Two reviewers independently selected studies for inclusion, extracted data and assessed methodological quality. Pooled summary estimates of sensitivity and specificity with 95% confidence intervals were calculated for homogenous subsets of studies.

RESULTS

Eight studies were included in this review. Strata were defined for separate pathologies i.e. lumbar disc herniation (HNP) and spinal stenosis. Five studies comparing MRI to findings at the surgery for identifying HNP were included in a meta-analysis. Pooled analysis resulted in a summary estimate of sensitivity of 75% (95% CI 65-83%) and specificity of 77% (95% CI 61-88%). For spinal stenosis pooling was not possible.

CONCLUSIONS

The results suggest that a considerable proportion of patients may be classified incorrectly by MRI for HNP and spinal stenosis. However, the evidence for the diagnostic accuracy of MRI found by this review is not conclusive, since the results could be distorted due to the limited number of studies and large heterogeneity.

Treatment of infections of the spine

Spinal infection may involve the vertebrae, the intervertebral discs, and the adjacent intraspinal and paraspinal soft tissues. It often starts with subtle and insidious clinical signs and symptoms and may development to a debilitating and even life threatening disease. Spinal infections occur with increasing incidence and are nowadays a disease of everyday's practice for physicians treating spinal disorders. Traditionally, conservative treatment consisting of antibiosis and immobilisation is considered the first tier therapy. However, due to a considerably high rate of vertebral column instability or neurological impairment caused by the infected tissue, comprehensive experience with surgical measures have been acquired over the last decades. Thanks to tremendous improvements of surgical implants and techniques, surgical treatment has already begun to challenge conservative treatment to eventually become the first tier therapy for spinal infections in the future. This review seeks to give an overview of epidemiology, pathogenesis, diagnostic evaluation, and current nonsurgical and surgical therapy of spinal infections on the basis of the existing literature, which consists largely of retrospectively acquired data of single-centre experience with sample sizes of less than 100 patients treated with individually defined indications and treatment algorithms, and followed with various outcome parameters.

Clinical impact of (18)F-FDG PET/CT on the management and diagnosis of infectious spondylitis

OBJECTIVE

The aim of this study was to evaluate the impact of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) on the management of patients with infectious spondylitis.

MATERIALS AND METHODS

Twenty-nine patients with infectious spondylitis (9 with tuberculous spondylitis and 20 with pyogenic spondylitis) who had undergone an (18)F-FDG PET/CT examination were retrospectively evaluated; 42 lesions were detected. A useful impact on the clinical management of infection therapy (start or longer duration of antibiotic therapy, or surgical intervention, etc) was defined as a strong impact, whereas gaining new information not affecting the clinical management of infection therapy from (18)F-FDG PET/CT was defined as a weak impact. No impact was defined as not obtaining any new information influencing infection therapy.

RESULTS

(18)F-FDG PET/CT had a strong impact on the clinical management of 52% (15 of 29) of the patients. (18)F-FDG PET/CT detected 10 cases of spondylitis and one artificial graft infection that the clinician had not recognized, and the therapeutic period was extended in these patients. In five patients with tuberculous spondylitis, the (18)F-FDG PET/CT images were used to decide the biopsy sites in three patients and to determine which lesions required surgery in two patients.

CONCLUSION

(18)F-FDG PET/CT is useful for detecting infectious spondylitis.

A comparative study of pyogenic and tuberculous spondylodiscitis

STUDY DESIGN

We performed a retrospective review of 126 cases of infectious spondylodiscitis over a 4-year period.

OBJECTIVE

Differentiation between pyogenic spondylodiscitis (PS) and tuberculous spondylodiscitis (TS) is essential for deciding on the appropriate therapeutic regimen. The aim of this study was to compare the characteristics of the 2 forms of spondylodiscitis.

SUMMARY OF BACKGROUND DATA

There has been much effort to distinguish the radiologic findings in PS versus TS, but classification based on radiologic findings alone had limitations yet.

METHODS

We compared the predisposing factors or associated illnesses, clinical, radiologic, and laboratory features of microbiologically confirmed cases of PS and TS in 2 university hospitals.

RESULTS

Of 126 patients, 79 had PS and 47 TS. PS was more frequently associated with the followings: previous invasive spinal procedures (PS vs. TS: 32.9% vs. 8.5%), preceding bacteremia (13.9% vs. 0%), chronic renal failure (12.7% vs. 0%), liver cirrhosis (13.9% vs. 0%), fever (temperature >38°C) (48.1% vs. 17.0%), white blood cell counts over 10,000/mm (41.8% vs. 19.1%), fraction of neutrophils >75% (49.4% vs. 27.7%), C-reactive protein levels over 5 mg/dL (58.2% vs. 27.7%), erythrocyte sedimentation rate levels over 40 mm/h (84.4% vs. 66.0%), and ALP levels over 120 IU/L (45.6% vs. 17.0%). TS was frequently associated with active tuberculosis of other organs (0% vs. 31.9%), longer diagnostic delay (47.6 vs. 106.3 days), involvement of thoracic spines (21.5% vs. 38.3%), and involvement of ≥3 spinal levels (11.4% vs. 36.2%).

CONCLUSION

Previous invasive spinal procedures, preceding bacteremia, fever, higher white blood cell counts, C-reactive protein, ALP, and higher fraction of neutrophils are suggestive of PS. Concurrent active tuberculosis, more indolent course and involvement of thoracic spines are suggestive of TS. When the causative organism is not identified despite all efforts at diagnosis, combination of the clinical, radiologic, and laboratory characteristics of the patient is helpful.