Comparative Analysis of Spontaneous Infectious Spondylitis : Pyogenic versus Tuberculous

A Comparative Factor Analysis and New Magnetic Resonance Imaging Scoring System for Differentiating Pyogenic Versus Tuberculous Spondylodiscitis

OBJECTIVE

This study aimed to compare and analyze differences in clinical and magnetic resonance imaging (MRI) findings between tuberculous spondylodiscitis (TbS) and pyogenic spondylodiscitis (PyS), and to develop and validate a simplified multiparameter MRIbased scoring system for differentiating TbS from PyS.

METHODS

We compared predisposing factors in 190 patients: 123 with TbS and 67 with PyS, confirmed by laboratory tests, culture, or pathology. Data encompassing patient demographics, clinical characteristics, laboratory results, and MRI findings were collected between 2015 and 2020. Data were analyzed using logistic regression methods, and selected coefficients were transformed into an MRI-based scoring system. Internal validation was performed using bootstrapping method.

RESULTS

Univariate analysis revealed that the significant risk factors associated with TbS included thoracic lesions, vertebral destruction > 50%, intraosseous abscess, thin-walled abscess, well-defined paravertebral abscess, subligamentous spreading, and epidural abscess. Multivariate analysis revealed that only thoracic lesions, absence of epidural phlegmon, subligamentous spreading, intraosseous abscesses, well-defined paravertebral abscesses, epidural abscesses, and absence of facet joint arthritis were independent predictive factors for TbS (all p < 0.05). These potential predictors were used to derive an MRI scoring system. Total scores ≥ 14/29 points significantly predicted the probability of TbS, with a sensitivity of 97.58%, specificity of 92.54%, and an area under the curve of 0.96 (95% confidence interval, 125.40-3,257.95).

CONCLUSION

This simplified MRI-based scoring system for differentiating TbS from PyS helps guide appropriate treatment when the causative organism is not identified.

Magnetic resonance imaging features for differentiating tuberculous from pyogenic spondylitis: a meta-analysis

OBJECTIVE

To perform a meta-analysis comparing the MRI features of tuberculous and pyogenic spondylitis, using histopathological results and/or blood culture as the standard reference.

MATERIALS AND METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched for English-language studies on the MRI features of tuberculous and pyogenic spondylitis published between January 2010 and February 2023. Risk for bias and concerns regarding applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Pooled MRI features' proportions were calculated using a bivariate random-effects model.

RESULTS

Thirty-two studies met the inclusion criteria: 21 for tuberculous spondylitis, three for pyogenic spondylitis, and eight for both. Of the nine informative MRI features comparing tuberculous spondylitis to pyogenic spondylitis, involvement of ≥ 2 vertebral bodies (92% vs. 88%, P = .004), epidural extension (77% vs. 25%, P < .001), paravertebral collection (91% vs. 84%, P < .001), subligamentous spread (93% vs. 24%, P < .001), thin and regular abscess wall (94% vs. 18%, P < .001), vertebral collapse (68% vs. 24%, P < .001), and kyphosis (39% vs. 3%, P < .01) were more suggestive of tuberculous spondylitis, while disc signal change (82% vs. 95%, P < .001) and disc height loss (22% vs. 59%, P < .001) were more suggestive of pyogenic spondylitis.

CONCLUSION

Involvement of ≥ 2 vertebral vertebral bodies, soft tissue attribution, thin and regular abscess wall, vertebral collapse, and kyphosis were MRI features more common in tuberculous spondylitis, while disc signal change and height loss were more common in pyogenic spondylitis.

Differentiation of Native Vertebral Osteomyelitis: A Comprehensive Review of Imaging Techniques and Future Applications

Native vertebral osteomyelitis, also termed spondylodiscitis, is an antibiotic-resistant disease that requires long-term treatment. Without proper treatment, NVO can lead to severe nerve damage or even death. Therefore, it is important to accurately diagnose the cause of NVO, especially in spontaneous cases. Infectious NVO is characterized by the involvement of 2 adjacent vertebrae and intervertebral discs, and common infectious agents include Staphylococcus aureus, Mycobacterium tuberculosis, Brucella abortus, and fungi. Clinical symptoms are generally nonspecific, and early diagnosis and appropriate treatment can prevent irreversible sequelae. Advances in pathologic histologic imaging have led physicians to look more forward to being able to differentiate between tuberculous and septic spinal discitis. Therefore, research in identifying and differentiating the imaging features of these 4 common NVOs is essential. Due to the diagnostic difficulties, clinical and radiologic diagnosis is the mainstay of provisional diagnosis. With the advent of the big data era and the emergence of convolutional neural network algorithms for deep learning, the application of artificial intelligence (AI) technology in orthopedic imaging diagnosis has gradually increased. AI can assist physicians in imaging review, effectively reduce the workload of physicians, and improve diagnostic accuracy. Therefore, it is necessary to present the latest clinical research on NVO and the outlook for future AI applications.

Development of a Diagnostic Model for Differentiating Tuberculous Spondylitis and Pyogenic Spondylitis With MRI: A Multicenter Retrospective Observational Study

STUDY DESIGN

Multicenter retrospective observational study.

OBJECTIVE

This study aimed to distinguish tuberculous spondylitis (TS) from pyogenic spondylitis (PS) using magnetic resonance imaging (MRI). Further, a novel diagnostic model for differential diagnosis was developed.

SUMMARY OF BACKGROUND DATA

TS and PS are the two most common spinal infections. Distinguishing between these types clinically is challenging. Delayed diagnosis can lead to deficits or kyphosis. Currently, there is a lack of radiology-based diagnostic models for TS and PS.

METHODS

We obtained radiologic images from MRI imaging of patients with TS and PS and applied the least absolute shrinkage and selection operator regression to select the optimal features for a predictive model. Predictive models were built using multiple logistic regression analysis. Clinical utility was determined using decision curve analysis, and internal validation was performed using bootstrap resampling.

RESULTS

A total of 201 patients with TS (n=105) or PS (n=96) were enrolled. We identified significant differences in MRI features between both groups. We found that noncontiguous multivertebral and single-vertebral body involvement were common in TS and PS, respectively. Vertebral bone lesions were more severe in the TS group than in the PS group (Z=-4.553, P <0.001). The patients in the TS group were also more prone to vertebral intraosseous, epidural, and paraspinal abscesses ( P <0.001). A total of 8 predictors were included in the diagnostic model. Analysis of the calibration curve and area under the receiver operating characteristic curve suggested that the model was well-calibrated with high prediction accuracy.

CONCLUSIONS

This is the largest study comparing MRI features in TS and PS and the first to develop an MRI-based nomogram, which may help clinicians distinguish between TS and PS.

Severity and Outcome of Neurologic Deficits in Patients with Pyogenic Spondylodiscitis: A Systematic Review

Patients with advanced pyogenic spondylodiscitis can present with neurologic deficits. However, the prevalence, severity, and outcome of the neurologic deficits are not well known. A systematic review was performed to improve the knowledge of this commonly encountered clinical scenario. The considerable number of severe neurologic deficits in addition to their poor recovery, even after surgical intervention, demonstrates that the early diagnosis of pyogenic spondylodiscitis is crucial. Prompt surgical intervention is likely associated with a greater chance of improvement of neurologic status than nonsurgical treatment.

Presumptive bacteriological diagnosis of spondylodiscitis in infants less than 4 years by detecting K. kingae DNA in their oropharynx: Data from a preliminar two centers study

Background and Objectives

Most cases of spondylodiscitis in children aged between 6 and 48 months old could be caused primarily by K. kingae. The present prospective study aimed to determine whether an innovative and indirect diagnosis approach - based on detection of K. kingae DNA in the oropharynx of children with suspected spondylodiscitis - provides sufficient evidence that this microorganism is responsible for the infection.

Methods

We prospectively analysed infants admitted for spondylodiscitis, considering above all the results of PCR realized in oropharyngeal swabs and in blood samples.

Results

Four of the 29 performed K. kingae-specific real-time PCR assay in blood were positive (13.8%), whereas 28 of the 32 K. kingae-specific real-time PCR assay realized on throat swabs were positive (87.5%).

Conclusions

This study demonstrates that performing oropharyngeal swab PCR is able to detect K. kingae in almost 90% of the toddlers with confirmed spondylodiscitis. That provides strong arguments for the hypothesis that K. kingae should be considered as the main aetiological pathogen to suspect in children between 6 and 48 months old with spondylodiscitis. Finally, it seems to us reasonable that oropharyngeal swab may become an early decision-making tool for the indirect identification of K. kingae in spondylodiscitis.

Spinal disorders mimicking infection

Spinal infections are very commonly encountered by radiologists in their routine clinical practice. In case of typical MRI features, the diagnosis is relatively easy to interpret, all the more so if the clinical and laboratory findings are in agreement with the radiological findings. In many cases, the radiologist is able to make the right diagnosis, thereby avoiding a disco-vertebral biopsy, which is technically challenging and associated with a risk of negative results. However, several diseases mimic similar patterns, such as degenerative changes (Modic) and crystal-induced discopathy. Differentiation between these diagnoses relies on imaging changes in endplate contours as well as in disc signal. This review sought to illustrate the imaging pattern of spinal diseases mimicking an infection and to define characteristic MRI and CT patterns allowing to distinguish between these different disco-vertebral disorders. The contribution of advanced techniques, such as DWI and dual-energy CT (DECT) is also discussed.

A disease that is difficult to diagnose and treat: evaluation of 343 spondylodiscitis cases

Objective

Spondylodiscitis is an important clinical a problem requiring serious approaches. In this study, we sought to raise awareness by examining the epidemiology and laboratory, clinical, and radiological findings of spondylodiscitis, which sometimes has a delayed diagnosis and which can be difficult to treat.

Methods

In total, 343 patients with spondylodiscitis were included in the study.

Results

The patients were classified as having as pyogenic (n = 153, 44.6%), brucellar (n = 138, 40.2%), or tuberculous (n = 52, 15.2%) spondylodiscitis. Meanwhile, 281 patients underwent magnetic resonance imaging, 71 underwent computed tomography, and 17 underwent scintigraphy for diagnosis. The rates of involvement at more than two segments and paraspinal abscess were significantly higher in tuberculous spondylodiscitis. However, disc involvement was significantly more common in brucellar and pyogenic spondylodiscitis.

Conclusion

The incidence of spondylodiscitis has increased substantially, especially in the young population. The invasive procedures and high rate of culture negativity make the diagnosis difficult. Therefore, clinical and radiological findings are useful in the diagnosis of spondylodiscitis. Despite the high rate of culture negativity, every effort should be made to identify the causative organism using invasive methods.

Assessment of diffusion tensor imaging in differentiation between pyogenic and tuberculous spondylitis

PURPOSE

to assess diffusion tensor imaging (DTI); an emerging technique for differentiation between pyogenic and tuberculous spondylitis.

PATIENTS AND METHODS

The study was carried out on 33 patients with infective spondylitis performing conventional MRI and DTI. The mean diffusivity (MD) and fractional anisotropy (FA) of the affected vertebral body were calculated by two readers.

RESULTS

The MD of pyogenic spondylitis of both readers (1.48 ± 0.09 and 1.47 ± 0.08 × 10^-3 mm²/s) were significantly higher values (P = 0.001) than tuberculous spondylitis (1.11 ± 0.15 and 1.18 ± 0.08 × 10^-3 mm²/s). The FA of pyogenic spondylitis of both readers (0.18 ± 0.09 and 0.20 ± 0.08) were significantly lower values (P = 0.001) than tuberculous spondylitis (0.30 ± 0.05 and 0.32 ± 0.03). There was a strong inter-reader agreement between both readers using MD (K = 0.963) and FA (K = 0.858). The thresholds MD and FA used for differentiating pyogenic and tuberculous spondylitis of both readers were 1.37 and 1.33 × 10^-3 mm²/s and 0.21 and 0.25 with the area under the curve (AUC) of 0.927 and 0.831 respectively. Combined MD and FA revealed increased AUC to 0.97 and 0.98 of both readers respectively.

CONCLUSION

DTI with its parameters can be considered a noninvasive beneficial quantitative method that can help in differentiation between pyogenic and tuberculous spondylitis.

Changes in the medical burden of pyogenic and tuberculous spondylitis between 2007 and 2016: A nationwide cohort study

BACKGROUND

This nationwide study aimed to compare the medical burdens of pyogenic spondylitis (PS) and tuberculous spondylitis (TS) between 2007 and 2016 in Korea.

METHODS

We used a national database managed by the National Health Insurance Service (NHIS) with data from the years 2007 and 2016. A total of 9655 newly diagnosed patients with PS or TS were correspondingly enrolled in the PS or TS group. Chi square test analyses were used to compare the PS and TS groups.

RESULTS

The overall incidence of infectious spondylitis during the study period was 9655 persons. The PS and TS groups consisted of 7305 and 2350 cases, respectively. Individual medical costs in the PS group (USD 10,049 ± 94 vs. USD 16,672 ± 17,729, P < 0.001) and the TS group (USD 4882 ± 6869 vs. USD 8531 ± 10,709, P < 0.001) both increased. The total medical cost for the PS group increased significantly between 2007 and 2016 in Korea (USD 24,428,560 vs. USD 81,044,196, P < 0.001). In contrast, the total medical cost for the TS group decreased between 2007 and 2016 in Korea (USD 8,573,038 vs. USD 4,879,520, P < 0.001).

CONCLUSION

This nationwide study shows that the total medical cost of PS has increased and that the total medical cost of TS has decreased between 2007 and 2016 in Korea.

Outcomes and risk factors for spontaneous spondylodiscitis: Case series and meta-analysis of the literature

Despite recent improvements in surgical and antimicrobial therapies, few generally applicable guidelines exist for spondylodiscitis management. We reviewed a consecutive series of patients as well as the past 18 years of the literature and analyzed outcomes for either conservative or surgical treatment. We analyzed a consecutive series of adults with spontaneous spondylodiscitis treated at our institution over the last 6 years. We analyzed predictors for neurological deficits, vertebral collapse, and surgical treatment. We also performed a meta-analysis of the literature between 2000 and 2018, stratifying the results between surgical and conservative treatment outcomes. A younger age at diagnosis, cervical location, tubercular infection, coexistence of morbidities, and vertebral collapse were predictors of surgical intervention. Cervical spondylodiscitis, vertebral collapse, and epidural collection were associated with a higher risk of developing neurological deficits, while tubercular spondylodiscitis was associated with a higher risk of vertebral collapse. Based on the current literature, conservative treatment has success rates similar to those of surgical treatment but lower complication and mortality rates. In cases without an absolute indication for surgery, a conservative approach should be considered as the first-line treatment. A closer diagnostic and clinical follow-up should be recommended in patients with cervical tract or tubercular spondylodiscitis because of the higher risk of developing bone collapse and neurological deficits.

The Value of MR Imaging in Comparative Analysis of Spinal Infection in Adults: Pyogenic Versus Tuberculous

OBJECTIVE

Differentiating pyogenic spondylitis (PS) and tuberculous spondylitis (TS) is challenging but critical in clinical practice. Accurate diagnosis and early treatment are crucial to preventing further progression of disease. Magnetic resonance imaging (MRI) is considered the best method for the diagnosis of spinal infection, but results remain imprecise; therefore, by comparing and analyzing the MRI findings of spinal infections, we intend to identify key distinguishing features between PS and TS, and with that establish a systematic scoring method to help clinicians.

METHODS

The MRI features of 70 cases of spinal infection (32 cases of PS, 38 cases of TS), confirmed by pathology or clinical diagnosis, were retrospectively analyzed. The receiver operating characteristic curve was used to analyze the diagnostic efficacy of the MRI parameter scores in PS and TS.

RESULTS

Among the 70 cases, the average age was 54.5 years, and 43 were male. Sixteen parameters were significantly different between the PS and TS groups. We hypothesized that a diagnosis of PS could be made when the number of parameters characteristic of PS exceeded the number of parameters characteristic of TS, and vice versa. We randomly selected 70% (49 patients) of the 70 patients for analysis, and then validated in the remaining 30% (21 patients) of cases. Using 0.5 as the cutoff value, of the remaining 21 patients, the correct coincidence rate was 95.23%, sensitivity was 91.67%, specificity was 100%, false-positive rate was 0%, and false-negative rate was 8.3%. The MRI parameter scores of PS and TS were analyzed with the receiver operating characteristic; area under the curve was 1.00.

CONCLUSIONS

Our systematic scoring system of MRI parameters is helpful in differentiating PS and TS.