Spondylodiscitis (disc space infection) associated with negative microbiological tests: comparison of outcome of suspected disc space infections to documented non-tuberculous pyogenic discitis

Spondylodiscitis: A Diagnostic and Management Dilemma

Aims Spondylodiscitis (SpD), a debilitating infective condition of the spine, mandates early diagnosis and institution of appropriate therapy, for which accurate microbiology and histological evaluation of the affected tissue is vital. The objectives of the study were to assess the correlation between clinical and magnetic resonance imaging (MRI) findings with histopathology (HPE) and microbiology (MB) in clinically diagnosed spondylodiscitis. Settings and design This was a prospective study of 34 consecutive patients reporting at the outpatient department of a tertiary hospital with clinical and imaging features of SpD, who underwent image-guided/surgical biopsy of lesions. Methods and material The provisional diagnosis of SpD in all patients was made on the combined basis of clinical profile and MRI Spine findings. Tissue samples in all patients, obtained by either open surgery or CT-guided biopsy, were subjected to HPE and MB analysis.  Results SpD has a bimodal age distribution with the majority of patients being males in the fourth to fifth decades. Only raised erythrocyte sedimentation rate (ESR) was consistently seen amongst laboratory parameters, with leucocytosis being added pointer towards pyogenic etiology. MRI remained the imaging modality of choice for SpD but was not dependable for etiologic differentiation. On HPE and MB evaluations, 24 patients (71%) had findings consistent with infective SpD, while combined results augmented etiologic confirmation for 28 patients (82.4%). HPE was more sensitive than traditional MB methods to determine etiology in SpD, but the addition of the GeneXpert (Cepheid, Sunnyvale, California, United States) technique improved the MB positivity rate, especially in patients with tubercular SpD. Six patients (17.6%) with both negative HPE and MB results were categorized as 'Non-specific' SpD. Conclusions SpD poses a challenge to determine the etiology for the administration of specific antimicrobial therapy. A stratified standard institutional approach needs adoption to systematically evaluate SpD patients by having a high index of clinical suspicion, early imaging, followed by tissue biopsy for HPE and MB. Despite efforts to reach a diagnosis, a subset of patients without conclusive etiologic agent identification would remain as 'Non-specific', needing empiric antibiotic treatment based on clinico-radiologic profile.

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.

Outcome of one-stage percutaneous endoscopic debridement and lavage combined with percutaneous pedicle screw fixation for lumbar pyogenic spondylodiscitis

BACKGROUND

This study assessed the therapeutic effect of one-stage percutaneous endoscopic debridement and lavage (PEDL) combined with percutaneous pedicle screw fixation (PPSF) in the treatment of lumbar pyogenic spondylodiscitis.

METHODS

From March 2017 to October 2019, 51 patients diagnosed with pyogenic spondylodiscitis underwent PPSF followed by PEDL in our department. Biopsy specimens were examined for microorganisms and evaluated histopathologically. Clinical outcomes were assessed by physical examination, routine serological testing, visual analogue scale (VAS), Oswestry Disability Index (ODI) and imaging studies.

RESULTS

Of the enrolled patients, the operation time ranged from 90 min to 114 min every level with an average of 102 min, and the average drainage time ranged from 6 days to 10 days with an average of 7.4 days. All patients who complained of lower back pain symptoms were more relieved than before surgery. Causative pathogens were identified in 20 of 51 biopsy specimens; Staphylococcus aureus was the most prevalent. However, there were eight patients with postoperative complications. The mean follow-up was 25.0 ± 3.8 (range: 20-32) months. Inflammatory markers showed that infection was controlled. The VAS and ODI improved significantly. At the last follow-up, magnetic resonance imaging showed that the infected lesions had disappeared.

CONCLUSION

PEDL supplementing PPSF may be useful for patients with single-level lumbar pyogenic spondylodiscitis, as it is minimally invasive, especially for patients who cannot undergo conventional open surgery due to poor health or advanced age.

The Induced Immune Response in Patients With Infectious Spondylodiscitis: A Prospective Observational Cohort Study

Introduction

Infectious spondylodiscitis is a rare infection of the intervertebral disc and the adjacent vertebral bodies that often disseminates and requires long-term antibiotic therapy. Immunologic profiling of patients with infectious spondylodiscitis could allow for a personalized medicine strategy. We aimed to examine the induced immune response in patients with infectious spondylodiscitis during and after antibiotic therapy. Furthermore, we explored potential differences in the induced immune response depending on the causative pathogen and the dissemination of the disease.

Methods

This was a prospective observational cohort study that enrolled patients with infectious spondylodiscitis between February 2018 and August 2020. A blood sample was collected at baseline, after four to six weeks of antibiotic therapy (during antibiotic therapy), and three to seven months after end of antibiotic therapy (post-infection). The induced immune response was assessed using the standardized functional immune assay TruCulture^®. We used a panel of three immune cell stimuli (lipopolysaccharide, Resiquimod and polyinosinic:polycytodylic acid) and an unstimulated control. For each stimulus, the induced immune response was assessed by measuring the released concentration of Interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12p40, IL-17A, Interferon-γ (IFN-γ) and Tumor necrosis factor-α (TNF-α) in pg/mL.

Results

In total, 49 patients with infectious spondylodiscitis were included. The induced immune responses were generally lower than references at baseline, but the cytokine release increased in patients after treatment with antibiotic therapy. Post-infection, most of the released cytokine concentrations were within the reference range. No significant differences in the induced immune responses based on stratification according to the causative pathogen or dissemination of disease were found.

Conclusion

We found lower induced immune responses in patients with infectious spondylodiscitis at baseline. However, post-infection, the immune function normalized, indicating that an underlying immune deficiency is not a prominent factor for spondylodiscitis. We did not find evidence to support the use of induced immune responses as a tool for prediction of the causative pathogen or disease dissemination, and other methods should be explored to guide optimal treatment of patients with infectious spondylodiscitis.

Treatment Guideline for Patients with Native Culture-negative Pyogenic Vertebral Osteomyelitis

BACKGROUND

With the development of evidence-based guidelines for the diagnosis and antibiotic treatment of patients with pyogenic vertebral osteomyelitis, various nonsurgical and surgical treatment strategies have achieved favorable results. However, sufficient administration of appropriate antibiotics is a prerequisite for treatment success, which cannot be guaranteed in patients with culture-negative pyogenic vertebral osteomyelitis. Unfortunately, previous studies on culture-negative pyogenic vertebral osteomyelitis were limited by small patient groups, short follow-up periods, varied treatment protocols, and inconsistently defined clinical endpoints.

QUESTIONS/PURPOSES

Among patients treated according to our center's treatment protocol for culture-negative pyogenic vertebral osteomyelitis, which included patients treated without surgery, with surgery but without spinal instrumentation, as well as patients treated with instrumented surgery, (1) what proportion of patients in each treatment group experienced recurrence (or persistence) of infection, complications of treatment, and death; and (2) what factors were independently associated with recurrent or persistent infection after treatment under this algorithm?

METHODS

This was a retrospective evaluation of a treatment protocol in use at one center from 2008 to 2020. During that time, we treated 183 patients for culture-negative pyogenic vertebral osteomyelitis. The diagnosis was based on clinical, laboratory, and radiological features excluding disease that presents similar features to pyogenic vertebral osteomyelitis. For those patients, our protocol included three possible approaches: nonsurgical treatment, including the use of empirical antibiotics (nonoperative group, n = 82); spinal decompression without instrumentation (noninstrumented group, n = 41); and spinal decompression with instrumentation (instrumented group, n = 60). The indications for each treatment during the period remained relatively consistent. Nonsurgical treatment including empirical antibiotics was applied to all patients according to the specified antibiotic protocol. Spinal decompression without instrumentation was employed when a patient presented substantial or aggravating neurologic deficits or intractable pain from an abscess. Instrumentation was added in patients with mechanical instability before or after spinal decompression. Minimum follow-up to be included in this study was 1 year, and 91% (252 of 277) of patients were accounted for at that time, with no differential loss to follow-up among the study groups (12, five, and four patients missing from the three groups, respectively, at 1 year). Chart review was performed to ascertain the proportion of patients in each group who experienced recurrence, complications, and death. Factors associated with recurrence were assessed across the entire cohort using a multivariable logistic model. We analyzed 1-year recurrence and mortality rates using the Kaplan-Meier method, and their 95% confidence intervals were calculated using the method by Hosmer and Lemeshow.

RESULTS

At 1 year, the recurrence-free survival rate was 87% (95% confidence interval 78% to 93%) in the nonoperative group, 87% (95% CI 72% to 94%) in the noninstrumented group, and 91% (95% CI 80% to 96%) in the instrumented group. The proportion of patients who experienced a major medical complication in each group was 12% (10 of 82), 10% (4 of 41), and 8% (5 of 60), respectively. At 1 year, the survival rate with patient death as the endpoint was 95% (95% CI 88% to 98%) in the nonoperative group, 95% (95% CI 82% to 99%) in the noninstrumented group, and 97% (95% CI 87% to 99%) in the instrumented group. After controlling for potentially confounding variables including age, medical comorbidities, and anatomical involvement of infection, the following factors were independently associated with increased odds of infection recurrence or persistence: higher Charlson Comorbidity Index (CCI) score (odds ratio 1.6 per point on the CCI [95% CI 1.2 to 2.1]; p = 0.004) and the presence of a psoas abscess (OR 4.7 [95% CI 1.6 to 13.9]; p = 0.005).

CONCLUSION

Among patients with negative initial nonoperative culture results, spinal decompression and abscess drainage can be used in those with substantial or aggravating neurological deficits or intractable pain caused by an abscess, while additional early spinal instrumentation can be applied upon consideration of their medical comorbidities and the presence of a psoas abscess when mechanical instability is present before or after the spinal decompression. Reasonable clinical results can be expected, regardless of the results from subsequent operative cultures. However, our study results should be replicated by other centers, and further studies that consider individual differences such as bone mineral density and include patients with previous spinal instrumentation or recurrent infection should be performed to establish a more comprehensive treatment protocol.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Involvement of L5-S1 level as an independent risk factor for adverse outcomes after surgical treatment of lumbar pyogenic spondylitis: A multivariate analysis

PURPOSE

To identify the independent risk factors for adverse outcomes and determine the effect of L5-S1 involvement on the outcome of surgical treatment of lumbar pyogenic spondylitis (PS).

METHODS

A retrospective analysis was performed for all consecutive patients who underwent surgery for lumbar PS between November 2004 and June 2020 at a single institution. The patients were divided into two groups based on the outcomes: good and adverse (treatment failure, relapse, or death). Treatment failure was defined as persistent or worsening pain with C-reactive protein (CRP) reduction less than 25% from preoperative measurement or requiring additional debridement. Relapse was defined as the reappearance of symptoms and signs with an elevated white blood cell count, erythrocyte sedimentation rate, and CRP after the first period of treatment. Binary logistic regression analyses were performed to identify the independent risk factors for adverse outcomes.

RESULTS

Twenty-four (21.2%) of the 113 patients were classified as having adverse outcomes: treatment failure, relapse, and death occurred in 15, 7, and 2 patients, respectively. The involvement of L5-S1 (adjusted odds ratio [aOR] = 6.561, P = 0.004), Methicillin-resistant Staphylococcus aureus (MRSA) infection (aOR = 6.870, P = 0.008), polymicrobial infection (aOR = 12.210, P = 0.022), and Charlson comorbidity index (CCI; P = 0.005) were identified as significant risk factors for adverse outcomes.

CONCLUSION

Involvement of L5-S1, MRSA, polymicrobial infection, and CCI were identified as independent risk factors for adverse outcomes after surgical treatment of lumbar PS. Because L5-S1 is anatomically demanding to access anteriorly, judicious access and thorough debridement are recommended in patients requiring anterior debridement of L5-S1.

Antimicrobial therapy and assessing therapeutic response in culture-negative pyogenic vertebral osteomyelitis: a retrospective comparative study with culture-positive pyogenic vertebral osteomyelitis

Background

There are still controversies regarding the treatment and outcomes in culture-negative pyogenic vertebral osteomyelitis (PVO). The purpose of this study is to investigate the antimicrobial therapy, assessment of therapeutic response, and outcome of culture-negative PVO compared to culture-positive PVO.

Methods

A retrospective study was performed with non-surgical lumbar PVO patients. The patients were divided into two groups based on the causative bacterial identification (CN group with culture-negative PVO and CP group with culture-positive PVO). The clinical features, use of antibiotics, laboratory data, and outcomes were compared between the two groups.

Results

Seventy-three patients with 41 (56.2%) of the CN group and 32 (43.8%) of the CP group were enrolled. The CN group showed a shorter duration of parenteral antibiotics (45.88 ± 16.14 vs. 57.31 ± 24.39, p = 0.019) but a tendency of prolonged duration of total (parenteral + oral) antibiotics (101.17 ± 52.84 vs. 84.19 ± 50.29 days, p = 0.168). When parenteral antibiotics were discontinued or switched to oral antibiotics, the mean erythrocyte segmentation rate (ESR, normal range: < 25 mm/h), C-reactive protein (CRP, normal range: < 0.5 mg/dL) level, and visual analog scale (VAS) score of back pain were 42.86 ± 24.05 mm/h, 0.91 ± 1.18 mg/dL, and 4.05 ± 1.07, respectively, with no significant differences between the two groups. The recurrence rates of CN and CP groups were 7.3% (3/41) and 6.3% (2/32), respectively (p = 1.000). The presence of epidural abscess was the most significant factor for the identification of causative bacteria (p = 0.002), and there was no significant relationship between the use of empirical antibiotics before tissue culture and the causative bacterial identification (p = 0.194).

Conclusions

The CN group required a shorter duration of parenteral antibiotics than the CP group. Discontinuation of parenteral antibiotics or changing the administration route can be considered based on the values of ESR, CRP, and VAS score of back pain. The presence of epidural abscess was the most significant factor for the identification of causative bacteria.

[Which factors influence the inpatient course for patients with spondylodiscitis?]

BACKGROUND

Spondylodiscitis is a rare disease with an increasing incidence.

METHODS

In this retrospective study 112 patients with spondylodiscitis surgically treated from 1 January 2005 to 31 December 2012 in a level I spine center were investigated with respect to potential prognostic criteria. The time period covered by the investigation was the duration of hospitalization. The parameters analyzed were mortality, age, localization of the spondylodiscitis, detection of abscesses and pathogens, neurological status and body mass index (BMI).

RESULTS

The average age of the patients was 68.3 years (±12.9 years). The mortality rate during hospitalization was 10.7% (N = 12). Older patients had a significantly higher in-hospital mortality rate (p = 0.008). Abscess formation was found in 49.1% of the patients and was associated with a significantly longer hospital stay (p = 0.001) and in the intensive care unit (ICU, p = 0.001) as well as a higher risk of revision surgery (p = 0.018). In addition, obese patients had a significantly higher occurrence of abscesses (p = 0.034). Pathogen detection was successful in 60.7 % of the cases with Staphylococcus aureus as the most frequent pathogen. Detection of pathogens was associated with a longer hospital stay (p = 0.006) and a greater need of intensive care monitoring (p = 0.017). Patients with a nephropathy had a significantly increased mortality, longer duration of hospitalization and a more frequent occurrence of multilevel afflictions.

CONCLUSION

Old age, abscess formation, positive detection of pathogens and renal failure can be used as prognostic criteria. Risk factors for formation of abscesses include a lumbar localization of spondylodiscitis, nephropathy as well as detection of a pathogen and obesity.

Spondylodiscitis: experience of surgical management of complicated cases after failed antibiotic treatment

INTRODUCTION

The term Spondylodiscitis (SD) involves infection of the vertebra (Spondylitis), infection of the intervertebral disc (Discitis), or both (Spondylodiscitis). SD represents a diagnostic and therapeutic challenge to any spine surgeon. Any delay in its diagnosis or management may cause serious long-term morbidity or even lead to mortality. In this study, we report the experience of our Institution in the management of severe and complicated cases of SD.

METHODS

Over a period of 1 year, 39 patients with the diagnosis of SD were surgically treated in Assiut University Hospital, Assiut, Egypt. The management processes were tailored according to the clinical condition, radiological and lab studies of each case; and patients were then prospectively followed-up until they were cured (for a minimum of 6 months). The outcomes were analyzed, to be able to give recommendations while aiming to improve the overall outcome of such dangerous health issue.

RESULTS

In this series, patients were managed surgically by drainage and debridement of the infection site with/without instrumented fusion. Results included: satisfactory fusion was achieved in 97.3% of patients (confidence interval [CI] = 0.6856-1.3421). Neurological Improvement Rate (NIR) was 71.5% (Statistically significant improvement P-value = 0.014) and reoperation rate was 5% (CI = 0.00621-0.18525). Mortality rate was 7.7% (CI = 0.016-0.209). Several aspects were analyzed in each case.

CONCLUSION

Surgical management of severe and complicated cases of SD allows for effective debridement and rapid cure of inflammation, earlier patient mobilization and significantly shorter duration of antibiotic usage.

Clinical Characteristics and Outcomes of Patients with Culture-Negative Pyogenic Spondylitis according to Empiric Glycopeptide Use

Background

The optimal choice of antibiotics is challenging in culture-negative pyogenic spondylitis (PS). The empiric use of glycopeptides is suggested depending on various risk factors, although clinical data are sparse. This study aimed to analyze the clinical characteristics and outcomes of patients with culture-negative PS and evaluate the effect of empiric glycopeptide use on clinical outcomes in these patients.

Materials and Methods

Data on the characteristics, treatment, and outcomes of 175 patients diagnosed with PS were retrospectively obtained from the electronic database of a tertiary referral hospital from 2009 to 2016. Patients with negative culture results were grouped by the duration of glycopeptide treatment: glycopeptide therapy <28 days (Group A) and glycopeptide therapy ≥28 days (Group B).

Results

Of 89 patients with negative culture results, 78 were included in the analysis (Group A, n = 66; Group B, n = 12). The mean age of patients with negative culture results was 65.5 years, and 52.6% were male. The median follow-up duration was 573 (interquartile range [IQR], 83 – 1,037) days. The duration of intravenous glycopeptide therapy was 0.0 (IQR, 0.0 – 0.0) days and 55.5 (IQR, 37.0 – 75.7) days for Groups A and B, respectively. Patients who used glycopeptide longer empirically (Group B) had more commonly undergone a previous spinal procedure, including surgery (P = 0.024). The length of hospitalization, erythrocyte sedimentation rate, and C-reactive protein level were significantly higher in Group B compared with those in Group A (P <0.001, P <0.001, and P = 0.006, respectively). Regarding treatment modalities, patients in Group B underwent surgery more frequently (P = 0.017). The duration of parenteral antibiotic treatment was longer in Group B (P <0.001). Recurrence was noted in 7 patients (9.0%), and the recurrence rate was not significantly different between the 2 groups (Group A, 5/66 [7.6%]; Group B, 2/12 [16.7%]; P = 0.293).

Conclusion

The recurrence rate among patients with culture-negative PS was not different based on the duration of empiric glycopeptide use. However, considering the small sample size and heterogeneity of our study population, we suggest that it is reasonable to administer glycopeptide antibiotics in these patients depending on clinical risk factors. Further large-scale prospective studies are needed to obtain more evidence for appropriate antibiotic treatment.

Treatment Strategy and Outcomes in Patients with Hematogenous Culture-Negative Pyogenic Vertebral Osteomyelitis

Study Design

Retrospective case series.

Purpose

The aim of this study was to analyze functional and radiological outcomes in patients with culture-negative pyogenic vertebral osteomyelitis (PVO).

Overview of Literature

There were only few literature available for these group of patients.

Methods

Patients with biopsy-positive but culture-negative PVO were included. We analyzed records for data on demography, comorbidities, coexisting infections, neurological status, prior antibiotic therapy, pre- and postoperative erythrocyte sedimentation rate, C-reactive protein levels, and Oswestry Disability Index, and Japanese Orthopedics Association scores.

Results

Sixty-one patients were included, of which data of 45 patients were available for follow-up. The patients were predominantly males (71%), with a mean age of 53.2 years. Seventy-seven percent patients had comorbidities. Echocardiography, blood culture, and urine culture were performed on 8%, 24%, and 18% of patients, respectively. Thirty-one percent patients had neurological deficits. Computed tomography-guided biopsy was performed on 67% patients. Fifty-two percent patients were treated surgically, and 48% were treated non-surgically. Nineteen percent patients were treated according to the results of cultures from other foci, and the rest were treated empirically. For the initial 2 weeks, all patients were treated with intravenous antibiotics empirically or based on culture from other foci. This treatment was followed by 10 weeks of oral cloxacillin/cephalexin for gram-positive organisms or ciprofloxacin for gram-negative organisms. The mean follow-up time was 18 months (range, 12–120 months). All patients had improvement in Japanese Orthopedics Association, Oswestry Disability Index, and Visual Analog Scale scores (p<0.001).

Conclusions

Treatment with empirical antibiotics for 12 weeks with watchful clinical and radiological follow-up yields good resolution of the disease. Further multicenter clinical research needs to be performed for obtaining an algorithmic treatment plan for these patients.

Diagnostic yield of repeat CT-guided biopsy for suspected infectious spondylodiscitis

OBJECTIVE

The purpose of this study was to examine the yield of repeat CT-guided biopsy in patients with suspected infectious spondylodiscitis following an initial biopsy with negative microbiology, and to identify factors associated with successful pathogen isolation.

MATERIALS AND METHODS

In this retrospective study, 21 patients (12 men, 9 women; mean age, 52, range, 12-84) were identified with clinically and radiologically suspected infectious spondylodiscitis who underwent repeat biopsy following negative cultures from an initial biopsy. The microbe yield as well as demographic, clinical, and laboratory findings were reviewed and statistical analysis was performed.

RESULTS

Repeat CT-guided biopsy isolated a causative microbe in 3/21 patients (14.3%). Younger age (p = 0.021) was significantly associated with successful microbe isolation. All three cases of successful microbe isolation occurred in patients not exposed to antibiotics (3/9 patients) whereas no successful microbe isolation occurred in patients who received antibiotics (0/12 patients); however, this difference did not reach statistical significance (p = 0.062). Gender, duration of symptoms, white blood cell count, biopsy interval, and biopsy site were not significantly associated with microbe isolation.

CONCLUSIONS

Overall microbiologic yield of repeat CT-guided biopsy for patients with suspected infectious spondylodiscitis was low at 14.3%; however, a higher yield was identified in patients who were younger in age and not exposed to pre-biopsy antibiotics.

Acute Lumbar Back Pain

BACKGROUND

Back pain has many causes. In Germany, about 70% of adults have at least one episode of back pain per year.

METHODS

This review is based on a selective literature search and on the German National Disease Management Guideline for Low Back Pain.

RESULTS

The physician taking the history from a patient with back pain should ask about the nature, onset, course, localization, and radiation of the pain and its dependence on physical activity and/or emotional stress. In the differential diagnosis, neurologic deficits and any "red flags" suggesting dangerous conditions such as spinal fracture, bacterial infection, and tumors must be ruled out. If no specific cause of the pain can be identified, no imaging studies are indicated on initial presentation. The treatment of acute, nonspecific low back pain focuses on pain relief and functional improvement. Adequate patient education and counseling are essential. Exercise therapy is no more effective than the continuation of normal daily activities. Restriction of activity, including bed rest, is of no benefit and merely prolongs recovery and the resumption of normal activity. Further diagnostic testing is indicated if there is any suspicion of a fracture, infection, or tumor.

CONCLUSION

After dangerous conditions have been ruled out, low back pain can be pragmatically classified as either nonspecific or specific. More research is needed so that the diagnostic assessment and individualized treatment of acute lower back pain can be further refined.

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.

Comparison of characteristics of culture-negative pyogenic spondylitis and tuberculous spondylitis: a retrospective study

Background

Differences between the characteristics of culture positive pyogenic spondylitis (CPPS) and tuberculous spondylitis (TS) are well known. However, differences between the characteristics of culture negative pyogenic spondylitis (CNPS) and TS have not been reported; these would be more helpful in clinical practice especially when initial microbiologic examination of blood and/or biopsy tissue did not reveal the causative bacteria in patients with infectious spondylitis.

Methods

We performed a retrospective review of the medical records of patients with CNPS and TS. We compared the characteristics of 71 patients with CNPS with those of 94 patients with TS.

Results

Patients with TS had more previous histories of tuberculosis (9.9 vs 22.3 %, p = 0.034), simultaneous tuberculosis other than of the spine (0 vs 47.9 %, p < 0.001), and positive results in the interferon-gamma release assay (27.6 vs 79.2 %, p < 0.001). Fever (15.5 vs. 31.8 %, p = 0.018), psoas abscesses (15.5 vs 33.0 %, p = 0.011), and paravertebral abscesses (49.3 vs. 74.5 %, p = 0.011) were also more prevalent in TS than CNPS.

Conclusions

Different from or contrary to the previous comparisons between CPPS and TS, fever, psoas abscesses, and paravertebral abscesses are more common in patients with TS than in those with CNPS.

Diagnostic yield of computed tomography-guided bone biopsy and clinical outcomes of tuberculous and pyogenic spondylitis

BACKGROUND/AIMS

This study aimed to evaluate the efficacy of computed tomography (CT)-guided bone biopsy for the diagnosis of spinal infection and compared the clinical outcomes between tuberculous and pyogenic spinal infections.

METHODS

The retrospective cohort study included patients who received CT-guided bone biopsy at a tertiary hospital over the 13 years.

RESULTS

Among 100 patients, 67 had pyogenic spondylitis and 33 had tuberculous spondylitis. Pathogens were isolated from bone specimens obtained by CT-guided biopsy in 42 cases, with diagnostic yields of 61% (20/33) for tuberculous spondylitis and 33% (22/67) for pyogenic spondylitis. For 36 culture-proven pyogenic cases, Staphylococcus aureus was the most commonly isolated organism. Patients with pyogenic spondylitis more frequently presented with fever accompanied by an increase in inflammatory markers than did those with tuberculosis. Among all patients who underwent surgery, the incidence of late surgery performed one month after diagnosis was higher in patients with tuberculous infection (56.3%) than in those with pyogenic disease (23.3%, p = 0.026).

CONCLUSIONS

Results obtained by CT-guided bone biopsy contributed to prompt diagnoses of spinal infections, especially those caused by tuberculosis. Despite administration of anti-tuberculous agents, patients with tuberculous spondylitis showed an increased tendency to undergo late surgery.

Does Pathogen Identification Influence the Clinical Outcomes in Patients With Pyogenic Spinal Infections?

STUDY DESIGN

Retrospective study.

OBJECTIVE

To study the clinical outcomes of patients suffering from pyogenic spinal infections (PSI), by comparing the outcomes of patients with an identified microbiological agent with those of patients without an identified pathogen.

SUMMARY OF BACKGROUND DATA

PSI is associated with significant risks for morbidity and mortality. Specific antibiotic treatment has been considered a key to successful medical treatment; however, clinicians frequently treat patients with PSI without an identified agent. A paucity of data is available comparing the clinical outcomes of patients with or without an identified pathogen.

MATERIALS AND METHODS

The records of 97 consecutive patients discharged from a University Hospital with the diagnosis of PSI during a 14-year period were retrospectively reviewed. Patients' demographics, etiological agent, comorbidities, site of infection, white blood cell count, erythrocyte sedimentation rate, C-reactive protein at the time of presentation, neurological impairment, length of hospital stay, and mortality were registered to compare the clinical outcomes of patients with an identified pathogen with those of patients without an identified agent.

RESULTS

The causative organism was identified in 74 patients (76.3%). Patients with microbiological diagnosis were younger, and a larger percentage of them exhibited elevated C-reactive protein value; however, they were not different from those without an identified agent in terms of sex, site of infection, comorbidities, and the presence of a concomitant infection. Our study could not demonstrate different neurological outcomes, length of stay, or mortality rates among the 2 groups.

CONCLUSIONS

In a large series of patients with PSI, we did not demonstrate differences in clinical outcomes using empirical antibiotics in patients without an identified pathogen compared with patients with an identified microbiological agent receiving specific antibiotics. Future prospective multicenter studies should be conducted to obtain an answer to this important clinical question.

Differential diagnosis between tuberculous spondylodiscitis and pyogenic spontaneous spondylodiscitis: a multicenter descriptive and comparative study

BACKGROUND CONTEXT

Although tuberculous and pyogenic spondylodiscitis are common causes of spinal infections, their protean manifestation complicates differential diagnosis.

PURPOSE

The clinical, laboratory, and radiologic characteristics of tuberculous and pyogenic spontaneous spondylodiscitis were compared in this study.

STUDY DESIGN

This multicenter retrospective study was conducted in 11 teaching hospitals in the Republic of Korea from January 2011 to December 2013.

PATIENT SAMPLE

Study subjects included adult patients (≥18 years) diagnosed with tuberculous (n=60) or pyogenic (n=117) spontaneous spondylodiscitis.

OUTCOME MEASURES

Risk factors for tuberculous spondylodiscitis were determined, and their predictive performance was evaluated.

METHODS

Multivariate logistic regression analysis was performed to determine predictors independently associated with tuberculous spondylodiscitis. Receiver-operating characteristic curve analysis using the presence or absence of risk factors was used to generate a risk index to identify patients with increased probability of tuberculous spondylodiscitis.

RESULTS

Of 177 patients, multivariate logistic regression analysis showed that patients with tuberculous spondylodiscitis (n=60) were more frequently women, with increased nonlumbar spinal involvement and associated non-spinal lesions, delayed diagnosis, higher serum albumin levels, reduced white blood cell counts, and lower C-reactive protein and procalcitonin levels. Among 117 patients with pyogenic spondylodiscitis, the most frequent causative microorganism was Staphylococcus aureus (64.1%). The mean diagnostic delay was significantly shorter, which may reflect higher clinical expression leading to earlier diagnosis. A combination of clinical data and biomarkers had better predictive value for differential diagnosis compared with biomarkers alone, with an area under the curve of 0.93, and sensitivity, specificity, and positive and negative predictive values of 95.0%, 79.5%, 70.4%, and 96.9%, respectively.

CONCLUSIONS

This study provides guidance for clinicians to predict the causative organisms of spondylodiscitis in uncertain situations and before culture or pathologic examinations. Clinical data and single biomarkers combined can be useful for differential diagnoses between tuberculous and pyogenic spondylodiscitis.

Which tissues are best for microbiological diagnosis in patients with pyogenic vertebral osteomyelitis undergoing needle biopsy?

Identification of the causative microorganism is important in the management of pyogenic vertebral osteomyelitis (PVO). The aim of this study was to investigate whether culture positive rates differ between needle biopsy sites in patients with PVO, and which tissues are best for microbiological diagnosis. Between January 2005 and December 2013, we conducted a retrospective cohort study of PVO patients who had soft-tissue abscesses (paraspinal or psoas abscesses) and who received needle biopsy for microbiological diagnosis. Needle biopsy sites were classified into two anatomical categories: vertebral bodies, or soft tissues (intervertebral discs, paraspinal abscesses, or psoas abscesses). A generalized estimating equation model was developed to identify factors associated with tissue-culture positivity. During the study period a total of 136 tissues were obtained by needle biopsy from 128 PVO patients with soft-tissue abscesses. The culture positive rates of vertebral bodies and soft tissues were 39.7% (29/73), and 63.5% (40/63), respectively (p < 0.05). In a multivariate analysis, male gender (adjusted odds ratio (aOR) 2.24, 95% CI 1.00-5.02), higher C-reactive protein (aOR 1.07, 95% CI 1.01-1.15), positive blood culture (aOR 2.57, 95% CI 1.01-6.59), and soft tissues as biopsy site compared with vertebral bodies (aOR 2.28, 95% CI 1.08-4.78) were independent factors associated with tissue culture positivity. Soft tissues were the best sites for microbiological diagnosis in PVO patients undergoing needle biopsy.

Successful use of tigecycline for treatment of culture-negative pyogenic vertebral osteomyelitis

BACKGROUND

Pyogenic vertebral osteomyelitis (PVO) is a severe infection that requires prolonged antimicrobial therapy and/or surgical interventions. Limited data are available on the safety and clinical efficacy of tigecycline in PVO. The objective of this study was to describe the clinical outcomes of patients treated with tigecycline for culture-negative PVO that was unresponsive to empirical antibiotic therapy including intravenous ampicillin-sulbactam plus ciprofloxacin or ampicillin-sulbactam alone.

METHODS

We retrospectively reviewed 15 patients with culture-negative PVO from 2009 through 2014. The patients received tigecycline as secondary empirical therapy, after not responding to the first empirical therapy. Clinical success was defined as recovery from symptoms and normalization of laboratory parameters at the end of therapy. Continued clinical success at 24 weeks after the end of the therapy was defined as sustained clinical success.

RESULTS

Tigecycline treatment was completed in 14 patients and discontinued in 1 due to severe nausea and vomiting. The mean age of the patients was 67.7 years (range 58-77 years), and 57.1% (8/14) were women. In all, 78.6% (11/14) of patients had risk factors for probable resistant staphylococcal and gram-negative infections such as diabetes mellitus, presence of hemodialysis catheters, and prior antibiotic usage. The average duration of tigecycline treatment was 8.3 weeks (range 6-11 weeks). Sustained clinical success was obtained in all patients.

CONCLUSIONS

Tigecycline should be considered as an alternative agent for the treatment of PVO in selected patients due to microbiological activity against resistant gram-positive and gram-negative bacteria.

Factors influencing culture positivity in pyogenic vertebral osteomyelitis patients with prior antibiotic exposure

We conducted a retrospective cohort study to evaluate factors influencing tissue culture positivity in patients with pyogenic vertebral osteomyelitis exposed to antibiotics before diagnosis. Tissue culture was positive in 48.3% (28/58) of the patients, and the median antibiotic-free period was 1.5 days (range, 0.7 to 5.7 days). In a multivariate analysis, a higher C-reactive protein (CRP) level (adjusted odds ratio [aOR], 1.18; 95% confidence interval, 1.07 to 1.29) and open surgical biopsy (aOR, 6.33; 95% confidence interval, 1.12 to 35.86) were associated with tissue culture positivity.

Microbiology and epidemiology of infectious spinal disease

Objective

Infectious spinal disease is regarded as an infection by a specific organism that affects the vertebral body, intervertebral disc and adjacent perivertebral soft tissue. Its incidence seems to be increasing as a result of larger proportion of the older patients with chronic debilitating disease, the rise of intravenous drug abuser, and the increase in spinal procedure and surgery. In Korea, studies assessing infectious spinal disease are rare and have not been addressed in recent times. The objectives of this study are to describe the epidemiology of all kind of spinal infectious disease and their clinical and microbiological characteristics as well as to assess the diagnostic methodology and the parameters related to the outcomes.

Methods

A retrospective study was performed in all infectious spinal disease cases presenting from January 2005 to April 2010 to three tertiary teaching hospitals within a city of 1.5 million in Korea. Patient demographics, risk factors, clinical features, and outcomes were assessed. Risk factors entailed the presence of diabetes, chronic renal failure, liver cirrhosis, immunosuppressants, remote infection, underlying malignancy and previous spinal surgery or procedure. We comparatively analyzed the results between the groups of pyogenic and tuberculous spinal infection. SPSS version 14 statistical software was used to perform the analyses of the data. The threshold for statistical significance was established at p<0.05.

Results

Ninety-two cases fulfilled the inclusion criteria and were reviewed. Overall, patients of tuberculous spinal infection (TSI) and pyogenic spinal infection (PSI) entailed 20 (21.7%) and 72 (78.3%) cases, respectively. A previous spinal surgery or procedure was the most commonly noted risk factor (39.1%), followed by diabetes (15.2%). The occurrence of both pyogenic and tuberculous spondylitis was predominant in the lumbar spine. Discs are more easily invaded in PSI. At initial presentation, white cell blood count and C-reactive protein levels were higher in PSI compared to TSI (p<0.05). Etiological agents were identified in 53.3%, and the most effective method for identification of etiological agents was tissue culture (50.0%). Staphyococcus aureus was the most commonly isolated infective agent associated with pyogenic spondylitis, followed by E. coli. Surgical treatment was performed in 31.5% of pyogenic spondylitis and in 35.0% of tuberculous spondylitis cases.

Conclusion

Many previous studies in Korea usually reported that tuberculous spondylitis is the predominant infection. However, in our study, the number of pyogenic infection was 3 times greater than that of tuberculous spinal disease. Etiological agents were identified in a half of all infectious spinal disease. For better outcomes, we should try to identify the causative microorganism before antibiotic therapy and make every effort to improve the result of culture and biopsy.

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.

Microbiologically and clinically diagnosed vertebral osteomyelitis: impact of prior antibiotic exposure

We retrospectively reviewed medical records to identify the factors that affect the results of culture in patients with pyogenic vertebral osteomyelitis. In multivariate analysis, the presence of paravertebral abscess was associated with positive results of microbiologic culture. Prior antibiotic exposure, especially of longer duration, was strongly associated with negative results.

Spondylodiscitis associated with multiple level involvement and negative microbiological tests: an unusual case

STUDY DESIGN

A case report.

OBJECTIVE

To report an unusual case of spondylodiscitis with multiple level involvement.

SUMMARY OF BACKGROUND DATA

Spondylodiscitis, an infection of the intervertebral disc space, vertebral bodies, or the paraspinal epidural space can be a serious disease because of diagnostic delay and inadequate treatment.

METHODS

A previously healthy, 52-year-old man was presented to our outpatient clinic with a complaint of acute, atraumatic onset of severe back pain for more than 1 month. Initially, he was misdiagnosed at another clinic as myofascial pain and treated with nonsteroidal anti-inflammatories and physical therapy, which he did not benefit from. He never complained of fever; however, laboratory tests revealed raised erythrocyte sedimentation values, increased C-reactive protein values but normal leukocyte count. Thoracal and lumbal plain radiographs were nonspecific. Magnetic resonance imaging demonstrated increased signal intensity in vertebral bodies and intervertebral disc space through T12-L4 and in the paravertebral musculature at L2-L3 with contrast enhancement. Blood cultures and computed tomography-guided needle biopsy and cultures were negative.

RESULTS

The patient was treated with oral amoxicillin and clavulanate and responded very well clinically; however, imaging examinations were repeated up to 6 months because of multilevel involvement. Follow-up magnetic resonance imaging findings at 3 months and 6 months showed decreased signal intensity, and luckily, there was no evidence of vertebral destruction.

CONCLUSION

Diagnosis of spondylodiscitis could be challenging and commonly missed; however, it should always be included in the differential diagnoses of back pain in the middle aged and healthy population.

Pyogenic vertebral osteomyelitis: identification of microorganism and laboratory markers used to predict clinical outcome

The aim of this study is to determine the predictive values of laboratory indicators of pyogenic vertebral osteomyelitis (PVO) and a potential cure if the microorganism cannot be identified. Forty-five consecutive patients with PVO were enrolled. Antibiotic therapy with or without surgery was performed according to microorganism. In the negative-culture (NC) group, cefazolin was administered in cases of hematogenous PVO, and vancomycin was administered in cases of postoperative or procedure-related PVO. The clinical, laboratory, and radiological findings were followed up with regard to an appropriate response to antimicrobial therapy. Nine patients were treated with antibiotics alone. We were able to identify the microorganism in 34 cases (75.6%). Ten cases in NC group were cured without recurrence, but one was not. Identification of the microorganisms did not have any significant influence on the treatment outcome, duration of antibiotic administration or normalization of laboratory profiles. For erythrocyte sedimentation rate (ESR) values over 55 mm/h and C-reactive protein (CRP) values of 2.75 mg/dL at fourth week after antibiotic administration by means of ROC curve analysis, we expect significantly high rates of treatment failure by Pearson chi(2) test (chi(2) = 4.344, Odds ratio = 5.15, p = 0.037, 95% CI 1.004-26.597). Even in patients with negative culture findings, it is expected that a good outcome will be achieved by the administration of cefazolin or vancomycin for about 6 weeks. It is concluded that antibiotics selected according to the etiological setting can be initiated without the need to start empirical antibiotics. In every instance at fourth week after the initiation of antibiotic therapy, the values of CRP and ESR can provide meaningful information regarding whether clinicians need to reevaluate the effectiveness of antibiotics by performing follow-up imaging studies and monitoring the patient's clinical manifestations.