Comparison of pyogenic spondylitis and tuberculous spondylitis

Tuberculous Spondylitis: A Report of Different Clinical Scenarios and Literature Update

Tuberculosis is still one of the most important health problems in the world. In developed countries, the proportion of extrapulmonary tuberculosis cases is increasing. Nowadays tuberculous spondylitis, also known as Pott disease, is a rare clinical condition but can cause severe vertebral and neurological sequelae that can be prevented with an early correct diagnosis. The aim of this paper is to increase awareness of tuberculous spondylitis in modern times, describing three different cases and discussing its best diagnostic and therapeutic approach based on the current literature.

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

Extrapulmonary involvement in pediatric tuberculosis

Tuberculosis in childhood is clinically challenging, but it is a preventable and treatable disease. Risk factors depend on age and immunity status. The most common form of pediatric tuberculosis is pulmonary disease, which comprises more than half of the cases. Other forms make up the extrapulmonary tuberculosis that involves infection of the lymph nodes, central nervous system, gastrointestinal system, hepatobiliary tree, and renal and musculoskeletal systems. Knowledge of the imaging characteristics of pediatric tuberculosis provides clues to diagnosis. This article aims to review the imaging characteristics of common sites for extrapulmonary tuberculous involvement in children.

Magnetic resonance imaging of bacterial and tuberculous spondylodiscitis with associated complications and non-infectious spinal pathology mimicking infections: a pictorial review

Magnetic resonance (MR) imaging plays an important role in the evaluation of bacterial and tuberculous spondylodiscitis and associated complications. Owing to its high sensitivity and specificity, it is a powerful diagnostic tool in the early diagnosis of ongoing infections, and thus provides help in prompt initiation of appropriate, therapy which may be medical or surgical, by defining the extent of involvement and detection of complications such as epidural and paraspinal abscesses. More specifically, MR imaging helps in differentiating bacterial from tuberculous infections and enables follow up of progression or resolution after appropriate treatment. However, other non-infectious pathology can demonstrate similar MR imaging appearances and one should be aware of these potential mimickers when interpreting MR images. Radiologists and other clinicians need to be aware of these potential mimics, which include such pathologies as Modic type I degenerative changes, trauma, metastatic disease and amyloidosis. In this pictorial review, we will describe and illustrate imaging findings of bacterial and tuberculous spondylodiscitis, their complications and non-infectious pathologies that mimic these spinal infections.

A 6500-year-old Middle Neolithic child from Pollera Cave (Liguria, Italy) with probable multifocal osteoarticular tuberculosis

Clear skeletal evidence of prehistoric tuberculosis (TB) is rare, especially in children. We describe and differentially diagnose the pathological changes displayed by a five-year-old child, Pollera 21 (PO21) dated to the Middle Neolithic of Liguria (Italy), or 5740±30 BP (Beta-409341; 6635-6453cal BP, 2σ, OxCal 4.2). PO21 shows a number of osteoarticular lesions, mainly of a lytic nature with very little bone proliferation: the vertebral column, the shoulder and pelvic girdles, and the ribcage are involved. Given the nature and pattern of the lesions, we propose a diagnosis of multifocal (or multiple) bone TB. Attempts to detect TB aDNA through molecular analysis gave negative results, but this alone is not sufficient to prove that PO21 was not infected with TB. The lesions observed in PO21 share similarities with other published evidence, such as spinal and joint involvement, and disseminated cyst-like lesions. Conversely, PO21 does not show diffuse bone deposition, such as hypertrophic osteoarthropathy (HOA) or endocranial modifications such as serpens endocrania symmetrica (SES). PO21 adds to our knowledge of patterns of TB manifestation in archaeological skeletal remains, which is especially important considering the variability in types and patterns of osteoarticular lesions seen today in people with TB.

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.

Magnetic Resonance Imaging in Differentatial Diagnosis of Pyogenic Spondylodiscitis and Tuberculous Spondylodiscitis

BACKGROUND

Infectious spondylodiscitis is characterized by the involvement of two adjacent vertebrae and the intervening disc. Incidence rate of the disease is estimated at 0.4-2 cases per 100000 per year. Staphylococcus aureus is the most common infectious agent causing pyogenic spondylodiscitis. Non-pyogenic infections of the spine are most frequently caused by Mycobacterium tuberculosis, and fungi. Clinical symptoms are nonspecific. Early diagnosis and appropriate treatment can prevent unfavorable irreversible sequela for the patient. Significant developments in techniques of imaging of pathological tissues raised expectations among the clinicians regarding possibility to distinguish between tuberculous spondylodiscitis and pyogenic spondylodiscitis on MR images. The aim of this study was to identify and differentiate between features of tuberculous and pyogenic spondylodiscitis on MR images.

MATERIAL/METHODS

We performed retrospective analysis of MR images obtained from 34 patients with confirmed spondylodiscitis (18 with pyogenic spondylodiscitis, and 16 with tuberculous spondylodiscitis). Data acquisition was performed using 1.5 T MRI scanners where images were obtained using similar protocols. T2 TIRM and T1-weighted images with and without contrast enhancement were subject to assessment in coronal, axial and sagittal planes.

RESULTS

Characteristic features of pyogenic spondylodiscitis include: involvement of the lumbar spine, ill-defined paraspinal abnormal contrast enhancement, diffuse/homogeneous contrast enhancement of vertebral bodies, low-grade destruction of vertebral bodies, hyperintense/homogeneous signal from the vertebral bodies on T2 TIRM images. Prevailing features of tuberculous spondylodiscitis included: involvement of the thoracic spine, involvement of 2 or more adjacent vertebral bodies, severe destruction of the vertebral body, focal/heterogeneous contrast enhancement of vertebral bodies, heterogeneous signal from the vertebral bodies on T2 TIRM images, well-defined paraspinal abnormal contrast enhancement, paraspinal and epidural abscesses, meningeal enhancement at the affected spine level.

CONCLUSIONS

Comparison of MR images of patients diagnosed with pyogenic spondylodiscitis and tuberculous spondylodiscitis allowed identification of individual characteristics for preliminary differentiation between TB and infectious spondylodiscitis and thereby enabling proper treatment.

Comparison of Tuberculous and Brucellar Spondylitis on Magnetic Resonance Images

STUDY DESIGN

Retrospective cross-sectional study.

OBJECTIVE

To investigate the differences between tuberculous spondylitis (TS) and brucellar spondylitis (BS) on magnetic resonance images (MRI).

SUMMARY OF BACKGROUND DATA

Both TS and BS are common spinal affections and can cause deformities and permanent neurologic deficiencies without prompt diagnosis and treatment. However, differentiating the types of spondylitis clinically and radiographically is challenging. Despite the diagnosis studies on spine infection throughout the literature, the outcome has not been established. Our study about the different characteristics between TS and BS on MRI may be helpful.

METHODS

Eighteen patients with TS and 26 with BS were included in this study. MRI images were obtained and analyzed. For statistical analysis, the χ test was performed. Statistical significance was defined as P < 0.05.

RESULTS

There were statistically significant differences between TS and BS on the MRI images: (i) subligamentous spread to three or more vertebral levels [TS 54% (7/13) vs. BS 8% (1/12)]; (ii) subligamentous spread to fewer than three vertebral levels [23% (3/13) vs. 58% (7/12)]; (iii) thoracic spine involvement [50% (9/18) vs. 4% (1/26)]; and lumbar spine involvement [22% (4/18) vs. 77% (20/26)]; (iv) abnormal signal from the vertebral disc on T2-weighted images [33% (7/21) vs. 85% (30/35)]; (v) focal or fan-shaped hyperintense signals on middle sagittal fat-suppressed weighted images [14% (7/50) vs. 50% (31/62)] and especially fan-shaped hyperintense signal [0% (0/50) vs. 23% (14/62)]; (vi) spinal kyphosis [22% (11/50) vs. 3% (2/62)]; (vii) vertebral collapse [42% (21/50) vs. 2% (1/62)]; (viii) peridiscal bone destruction [22% (11/50) vs. 44% (27/62)]; and (ix) psoas abscesses [6% (3/50) vs. 0% (0/62)].

CONCLUSION

MRI is a sensitive imaging technique and can clearly define the different features between TS and BS, so it should be the first choice for imaging in the diagnosis of spondylodiscitis.

LEVEL OF EVIDENCE

4.

Imaging in extrapulmonary tuberculosis

Tuberculosis (TB) remains a major global public health problem, with 1.5 million deaths annually worldwide. One in five cases of TB present as extrapulmonary TB (EPTB), posing major diagnostic and management challenges. Mycobacterium tuberculosis adapts to a quiescent physiological state and is notable for its complex interaction with the host, producing poorly understood disease states ranging from latent infection to active clinical disease. New tools in the diagnostic armamentarium are urgently required for the rapid diagnosis of TB and monitoring of TB treatments, and to gain new insights into pathogenesis. The typical and atypical imaging features of EPTB are reviewed herein, and the roles of several imaging modalities for the diagnosis and management of EPTB are discussed.

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.

Infectious Spondylodiscitis by Uncommon Pathogens: A Pitfall of Empirical Antibiotics

Objective

The goal of this study is to evaluate the prevalence of spondylodiscitis (SD) caused by uncommon pathogens and review the efficacy of the treatment strategy including the coverage by usual empirical broad-spectrum antibiotic therapy.

Methods

Ninety-nine consecutive patients diagnosed and treated for infectious SD between January 2007 to May 2015 were reviewed retrospectively. The prevalence of uncommon SD, predisposing factors, antibiotics sensitivity, and clinical outcome were analyzed in comparison with that of common SD.

Results

Among 99 patients, 68 patients were culture positive. Out of 68 patients with positive culture results, 54 of them(79.4%) were common pathogen and 14 (20.6%) were uncommon pathogen. Postoperative SDs were significantly prevalent in uncommon SD(42.9%) than common SD(27.8%). Recurrence rate was higher in uncommon pathogen SD(14.3%) than common SD group (2.3%), and it showed statistically significant difference (p=0.025). Empirical antibiotics of vancomycin and 3rd or 4th generation cephalosporin covered 100% of nontuberculous common SD and 14.3% of uncommon SD.

Conclusion

In our study, the prevalence of uncommon SD was relatively high uncommon (20.5% of culture positive SD and 14.1% of total cases) and the coverage rate of empirical antibiotics for them were only 14.3%. In particular, the possibility of SD with fun gal, polymicrobial, or multiple drug resistant organism should be considered in SD unresponsive to broad spectrum antibiotics therapy.

Clinical case report: discitis osteomyelitis complicated by inferior vena cava venous thrombosis and septic pulmonary emboli

Viridans group streptococcus is an infrequent cause of osteomyelitis that is found in association with infective endocarditis. Only a few studies report viridans osteomyelitis in the absence of endocarditis. Vertebral pyogenic osteomyelitis can sometimes be complicated by psoas or paraspinal abscesses. These intra-abdominal and/or pelvic collections can very rarely result in venous thrombosis. A paraspinal abscess resulting in inferior vena cava (IVC) thrombosis has only been reported once in the literature. We report a case of a young female with a history of polysubstance abuse and chronic back pain, who was found to have extensive vertebral osteomyelitis and discitis with epidural, paraspinal, and psoas abscesses caused by viridans streptococci. These abscesses compressed on the IVC causing IVC thrombophlebitis extending to the iliac veins distally. Imaging also demonstrated multifocal bilateral septic pulmonary emboli and pleural effusions secondary to septic IVC thrombus; a transesophageal echocardiogram showed no evidence of infective endocarditis.

Impact on Neurological Recovery of Transforaminal Debridement and Interbody Fusion versus Transpedicular Decompression in Combination with Pedicle Screw Instrumentation for Treating Thoracic and Lumbar Spinal Tuberculosis

Study Design

Retrospective study.

Purpose

To compare the neurological outcome of transforaminal debridement and interbody fusion with transpedicular decompression for treatment of thoracic and lumbar spinal tuberculosis.

Overview of Literature

Few articles have addressed the impact of neurological recovery in patients with tuberculosis who were treated by two different operative methods via the posterior-only approach.

Methods

Clinical and radiographic results of one-stage posterior instrumented spinal fusion for treatment of tuberculous spondylodiscitis with neurological deficits were reviewed and analyzed from 2009 to 2013. The extensive (E) group consisted of patients who received transforaminal debridement and interbody fusion, whereas transpedicular decompression was performed on limited (L) group. Rapid recovery was improvement of at least one Frankel grade within 6 weeks after operation. Otherwise, it was slow recovery.

Results

All 39 patients had improved neurological signs. The median follow-up period was 24 months. Proportionately younger patients (under 65 years of age) received extensive surgery (15 of 18, 83.3% vs. 11 of 21, 52.4%; p=0.04). The mean operative time and blood loss in the group E were higher than in the group L (both p<0.01). With regard to type of procedure, especially at thoracic and thoracolumbar spine, patients who underwent extensive surgery had rapid neurological recovery significantly different from those of limited surgery (p=0.01; Relative Risk, 3.06; 95% Confidence Interval, 1.13 to 8.29).

Conclusions

Transforaminal debridement and interbody fusion provides more rapid neurological recovery in patients with thoracic and thoracolumbar spinal tuberculosis compared to transpedicular decompression.

Multifocal Skeletal Tuberculosis Mimicking Langerhans Cell Histiocytosis in a Child: a Case Report With a Long-Term Follow-Up

Introduction:

Multifocal skeletal tuberculosis is a rare condition that may masquerade as Langerhans cell histiocytosis, especially in children.

Case Presentation:

We report a case of multifocal osseous tuberculosis in a 5-year-old female patient admitted to our hospital with a complaint of low back pain but no history of respiratory symptoms or malaise. Radiological findings included vertebra plana and multiple lytic lesions in both the frontal and pelvic bones. An initial diagnosis of Langerhans cell histiocytosis was made based on imaging findings; however, the patient underwent further evaluation for Mycobacterium tuberculosis, and histopathologic findings confirmed the diagnosis of tuberculosis. The patient showed a nearly complete response after receiving a course of anti-tuberculosis drugs.

Conclusions:

A high index of suspicion is required for the early diagnosis and prompt treatment of patients with osseous tuberculosis. Given the high prevalence of tuberculosis in developing countries, tuberculosis should be considered in the differential diagnosis of multifocal lytic lesions and vertebra plana, especially in children.

Role of Magnetic Resonance Imaging in Differentiating Spondylitis from Vertebral Metastasis

Study Design

Observational analytic design with a cross-sectional approach.

Purpose

To analyze the suitability of magnetic resonance imaging (MRI) in distinguishing radiology images with a corresponding delineation of spondylitis and vertebral metastasis confirmed by histology results.

Overview of Literature

MRI is an accurate modality for assessing vertebrae and their disorders. Infections and metastasis are most commonly found in the vertebrae. It is difficult to differentiate between these two disorders both clinically and radiographically, particularly in atypical cases.

Methods

McNemar statistical test was used to analyze the data. Samples were chosen using the consecutive method. There were 35 samples (14 males and 21 females), consisting of 22 samples of spondylitis and 13 samples of metastasis confirmed on histology examination.

Results

Nineteen (86%) out of the 22 samples of histological spondylitis were diagnosed as having spondylitis on MRI, whereas all 13 samples of metastasis were 100% accurately diagnosed on MRI.

Conclusions

There was no statistically significant difference between diagnostic radiology using MRI and histological diagnosis with a p=0.250 (p>0.05). In this respect, MRI was more precise in diagnosing metastasis. Typical MRI description of spondylitis was the involvement of anterior vertebrae and components of intervertebral discs, stiffening of discs, paravertebral abscess, and involvement of the vertebral segment sequence. Typical MRI delineation of metastasis was involvement of the anterior posterior vertebral component, paravertebral mass, and skip lesions.

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.

When and how to operate on spondylodiscitis: a report of 13 patients

PURPOSE

Conflicting reports exist regarding the surgical indications, timing, approach, staged or not operation, and spinal instrumentation for patients with spondylodiscitis. Therefore, we performed this study to evaluate the outcome of a series of patients with spondylodiscitis aiming to answer when and how to operate on these patients.

MATERIALS AND METHODS

We retrospectively studied the files of 153 patients with spondylodiscitis treated at our institution from 2002 to 2012. The approach included MR imaging of the infected spine, isolation of the pathogen with blood cultures and/or biopsy, and further conservative or surgical treatment. The mean follow-up was 6 years (range 1-13 years). We evaluated the indications, timing (when), and methods (how) for surgical treatment, and the clinical outcome of these patients.

RESULTS

Orthopedic surgical treatment was necessary for 13 of the 153 patients (8.5 %). These were patients with low access to healthcare systems because of low socioeconomic status, third-country migrants, prisoners or intravenous drug use, patients in whom a bacterial isolate documentation was necessary, and patients with previous spinal operations. The most common pathogen was Mycobacterium tuberculosis. The surgical indications included deterioration of the neurological status (11 patients), need for bacterial isolate (10 patients), septicemia due to no response to antibiotics (five patients), and/or spinal instability (three patients). An anterior vertebral approach was more commonly used. Nine of the 13 patients had spinal instrumentation in the same setting. Improvement or recovery of the neurological status was observed postoperatively in all patients with preoperative neurological deficits. Postoperatively, two patients deceased from pulmonary infection and septicemia, and heart infarction. At the last follow-up, patients who were alive were asymptomatic; ten patients were neurologically intact, and one patient experienced paraparesis. Imaging showed spinal fusion, without evidence of recurrent spondylodiscitis. Complications related to the spinal instrumentation were not observed in the respective patients.

CONCLUSIONS

Conservative treatment is the standard for spondylodiscitis. Physicians should be alert for Mycobacterium tuberculosis spondylitis because of the low access to healthcare systems of patients with low social and economic status. Surgical indications include obtaining tissue sample for diagnosis, occurrence or progression of neurological symptoms, failure of conservative treatment, large anterior abscesses, and very extensive disease. Thorough debridement of infected tissue and spinal stability is paramount. The anterior approach provides direct access and improved exposure to the most commonly affected part of the spine. Spinal instrumentation is generally recommended for optimum spinal stability and fusion, without any implant-related complications.