Impact of causative organism identification on clinical outcomes after minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: multicenter retrospective cohort study.

PURPOSE: This study aimed to evaluate the difference in treatment duration and unplanned additional surgeries between patients with unidentified causative organisms on empiric antibiotics and those with identified organisms on selective antibiotics in treating thoracolumbar pyogenic spondylitis with minimally invasive posterior fixation. METHODS: This multicenter retrospective cohort study included patients with thoracolumbar pyogenic spondylitis refractory to conservative treatment who underwent minimally invasive posterior fixation. Patients were divided into the identified (known causative organism) and unidentified groups (unknown causative organism). We analyzed data on demographics, antibiotic use, surgical outcomes, and infection control indicators. RESULTS: We included 74 patients, with 52 (70%) and 22 (30%) in the identified and unidentified groups, respectively. On admission, the identified group had higher C-reactive protein (CRP) levels and more iliopsoas abscesses. The duration to postoperative CRP negative was similar in the identified and unidentified groups (7.13 vs. 6.48 weeks, p = 0.74). Only the identified group had unplanned additional surgeries due to poor infection control, affecting 6 of 52 patients (12%). Advanced age and causative organism identification increased the additional surgery odds (odds ratio [OR], 8.25; p = 0.033 and OR, 6.83; p = 0.034, respectively). CONCLUSION: The use of empiric antibiotics in minimally invasive posterior fixation was effective without identifying the causative organism and did not prolong treatment duration. In patients with identified organisms, 12% required unplanned additional surgery, indicating a more challenging infection control. Causative organism identification was associated with the need for additional surgery, suggesting a more cautious treatment strategy for these patients.

Pyogenic Spondylitis Four Years After an Injection Into the Paraspinal Muscles.

In the context of local injection techniques, there are infectious complications such as epidural abscesses and pyogenic spondylitis. An 83-year-old female who received an injection into the paraspinal muscles for lower back pain four years ago developed a paraspinal muscle abscess accompanied bymethicillin-susceptible Staphylococcus aureus bacteremia and multiple sites of pyogenic spondylitis. Non-surgical treatment was followed with 73 days of antibiotic therapy by cefazoline. We noted an improvement in inflammatory response in blood tests and findings of inflammation on imaging tests. Instances of delayed-onset infectious complications several years after simple local injection techniques are rare.

Thoracic Pyogenic Spondylitis Misdiagnosed As Osteoporotic Compression Fracture Status Post Vertebral Augmentation With Resultant Paraplegia: A Case Report.

This paper describes a case of serious complications following vertebral augmentation resulting from a misdiagnosis of pyogenic spondylitis as osteoporotic compression fracture (OCF). A 56-year-old female with systemic lupus erythematosus underwent vertebral augmentation following a diagnosis of T10 OCF based on plain film analysis. Note that preoperative computed tomography (CT) and magnetic resonance imaging (MRI) were not performed. One day after vertebral augmentation, the patient experienced a recurrence of low back pain with fever and paraplegia. MRI findings revealed paravertebral and epidural soft tissue over T9 and T10 with cord compression. Subsequent laminectomy of T9 and T10 revealed devitalized lamina, epidural abscess, and granulation tissue. Pathological analysis indicated a combination of acute and chronic inflammation. A pus culture identified Staphylococcus aureus, indicative of pre-existing pyogenic spondylitis. Further revision surgery was performed at another hospital. The patient remained in a paraplegic state one year after surgery. Infectious spondylitis often manifests with nonspecific symptoms similar to those of compression fracture, and plain radiographs are insufficient to differentiate between the two, often leading to misdiagnosis and mistreatment. Nonetheless, many practitioners base preoperative planning solely on plain film imaging. We advocate the routine usage of CT and/or MRI for patients diagnosed with compression fractures, particularly for immunocompromised individuals.

Clinical characteristics and outcomes of persistent bacteremia in patients with head and neck cancer in a tertiary care hospital.

Introduction: Compared to other cancers, research on bloodstream infection in head and neck cancer is scarce, lacking comparative studies on persistent versus transient bacteremia outcomes. Methods: This retrospective survey examined patients with head and neck cancer undergoing blood culture at our center from June 2009 to May 2023. Blood culture-positive cases suspected of infection were divided into persistent bacteremia and transient bacteremia groups. We investigated their clinical, epidemiological, and microbiological features, including risk factors for persistent bacteremia and mortality. The primary outcome was 90-day mortality. Results: In this 97-patient cohort, 14 (14%) cases were assigned to the persistent bacteremia group. Catheter-related bloodstream infections were the leading cause of infection in both groups, consistently contributing to a high proportion of overall bloodstream infections. The mortality rate was generally higher in the persistent bacteremia group than in the transient bacteremia group (odds ratio [OR], 2.6; 95% confidence interval [CI], 0.6-11.1), particularly in the non-clearance subgroup (OR, 9; 95% CI, 0.5-155.2). Pyogenic spondylitis was a key risk factor for persistent bacteremia, while hypoalbuminemia increased mortality. Conclusion: In patients with bacteremia and head and neck cancer, persistent bacteremia was associated with higher mortality than was transient bacteremia. Adittionally, bacteremia clearance in persistent bacteremia is thus crucial for prognostic improvement.

Comparative analysis of different treatment strategies for septic spondylitis: a retrospective study of one hundred and twelve patients.

PURPOSE: To compare the clinical efficacy and prognosis differences between conservative treatment and surgical treatment in patients with non-serious neurologically intact pyogenic spondylitis (Nsi-Nsni-PS), and to provide theoretical reference for the clinical treatment of Nsi-Nsni-PS patients. METHODS: A retrospective analysis was conducted on 112 cases of Nsi-Nsni-PS patients treated in our hospital from June 2016 to June 2021. According to different treatment methods, they were divided into conservative treatment group (53 cases) and surgical treatment group (59 cases). The general data, laboratory tests, imaging examinations, length of hospital stay, duration of antibiotic use, VAS for pain before and after treatment, ODI, local kyphotic angle correction of diseased vertebrae, and recurrence rate were collected and analyzed in both groups. SPSS 26.0 statistical software was used for analysis. Measurement data were expressed as mean ± standard deviation, and independent sample t-test or rank sum test was used for comparison between groups, while variance analysis was used for intra-group comparison. Count data were expressed as number (%) and compared between groups using chi-square test or Fisher's exact test. Mann-Whitney U test was used to evaluate the changes in local kyphotic angle between the two groups. A p value < 0.05 was considered statistically significant. RESULTS: There were no significant differences in general data and imaging characteristics between the two groups (P > 0.05); there were no statistically significant differences in the positive culture rate of pathogens, length of hospital stay, duration of antibiotic use, treatment complications, WBC, CRP, ESR levels at admission and discharge, VAS and ODI at admission and last follow-up between the two groups (P > 0.05). The WBC and CRP levels of patients in the conservative group at discharge were lower than those in the surgical group (P < 0.05), and there was no significant difference in the decrease in inflammatory indicators (WBC, CRP, ESR) between the two groups (P > 0.05). By the last follow-up, the neurological function of patients in both groups had significantly improved compared to admission (P < 0.05), with 12 out of 15 ASIA grade D patients in the conservative group recovering to grade E, and 21 out of 25 grade D patients in the surgical group recovering to grade E, with no worsening of neurological function in either group. The differences in VAS and ODI scores at the last follow-up compared to before treatment were statistically significant in both groups (P < 0.05), and all patients regained normal activity. Compared with before treatment, the correction degree of local kyphotic angle in the surgical group at the last follow-up was 0.93 ± 4.94°, slightly higher than that in the conservative group (-0.83 ± 3.37°), and the difference was statistically significant(P < 0.05). CONCLUSIONS: During our follow-up, we found that both conservative and surgical treatments achieved satisfactory clinical outcomes in patients with Nsi-Nsni-PS. Compared to conservative treatment, surgical intervention did not demonstrate significant advantages in reducing hospitalization time and antibiotic usage duration, increasing pathogen culture positivity rate, lowering treatment complications, or controlling recurrence. However, surgical intervention showed superiority in correcting the local kyphotic angle of spinal lesions, albeit with relatively increased surgical trauma, risks, and treatment costs. At the last follow-up, the surgical group did not exhibit better long-term efficacy. Therefore, when formulating clinical treatment strategies for patients with Nsi-Nsni-PS, it may be preferable to prioritize conservative treatment, supplemented by the use of sensitive or empiric antibiotics for infection management, to improve patient prognosis.

A rare case of acute obstructive suppurative pancreatic ductitis (AOSPD) which developed pyogenic spondylitis.

Acute obstructive suppurative pancreatic ductitis (AOSPD) is an acute suppuration of the pancreatic duct. Endoscopic retrograde cholangiopancreatography (ERCP) drainage and intravenous antibiotics treatment is the mainstay of therapy. Herein we describe an extremely rare case of AOSPD leading to pyogenic spondylitis. A 61-year-old male with a past medical history of chronic pancreatitis and diabetes mellitus presented to our hospital with abdominal and dorsal pain, fever, and shock status. Laboratory data showed severe inflammation, disseminated intravascular coagulation, and normal pancreatic enzymes. Computed tomography showed dilated main pancreatic duct and surrounding pancreatic abscesses. Spinal abnormalities were not detected at this point. He was initially diagnosed as infected pancreatic pseudocyst, but did not respond well to conservative intravenous antibiotic treatment. ERCP performed one week later revealed purulent pancreatic juice and the diagnosis was changed to AOSPD. Upon ERCP, we experienced technical difficulty in passing obstructing calculi. However, successful pancreatic drainage was achieved using new dilation and penetration devices. The patient responded quickly to drainage, but later developed pyogenic spondylitis. Our case highlights the difficulty of diagnosing AOSPD, the usefulness of new devices in urgent endoscopic drainage, and underscores the possibility of progression of pyogenic spondylitis even after adequate treatment.

Pedicle screw insertion into infected vertebrae reduces operative time and range of fixation in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: a multicenter retrospective cohort study.

BACKGROUND: Minimally invasive posterior fixation surgery for pyogenic spondylitis is known to reduce invasiveness and complication rates; however, the outcomes of concomitant insertion of pedicle screws (PS) into the infected vertebrae via the posterior approach are undetermined. This study aimed to assess the safety and efficacy of PS insertion into infected vertebrae in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis. METHODS: This multicenter retrospective cohort study included 70 patients undergoing minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis across nine institutions. Patients were categorized into insertion and skip groups based on PS insertion into infected vertebrae, and surgical data and postoperative outcomes, particularly unplanned reoperations due to complications, were compared. RESULTS: The mean age of the 70 patients was 72.8 years. The insertion group (n = 36) had shorter operative times (146 versus 195 min, p = 0.032) and a reduced range of fixation (5.4 versus 6.9 vertebrae, p = 0.0009) compared to the skip group (n = 34). Unplanned reoperations occurred in 24% (n = 17) due to surgical site infections (SSI) or implant failure; the incidence was comparable between the groups. Poor infection control necessitating additional anterior surgery was reported in four patients in the skip group. CONCLUSIONS: PS insertion into infected vertebrae during minimally invasive posterior fixation reduces the operative time and range of fixation without increasing the occurrence of unplanned reoperations due to SSI or implant failure. Judicious PS insertion in patients with minimal bone destruction in thoracolumbar pyogenic spondylitis can minimize surgical invasiveness.

Bacteroides fragilis spondylitis after suspected oral ulcer: a clinical case and comprehensive literature review.

This paper reports a case of Bacteroides fragilis induced spondylitis. Diagnosis was confirmed through blood culture and metagenomic sequencing of pus for pathogen detection. Due to persistent lumbar pain, surgical intervention became imperative, resulting in favorable postoperative outcomes. A detailed patient history revealed a severe episode of oral ulceration two weeks before symptom onset, although a direct link to the infection remained elusive. Leveraging insights from this case, we conducted a comprehensive literature review on B. fragilis spondylitis, elucidating clinical manifestations, diagnostic methodologies, and therapeutic strategies.

[Pyogenic spondylitis after Corynebacterium striatum blood stream infection following allogeneic hematopoietic stem cell transplantation for malignant lymphoma].

Patient 1 was a 70-year-old woman with refractory diffuse large B-cell lymphoma who received allogeneic peripheral blood stem cell transplantation from an HLA-haploidentical related donor. Upper back pain appeared on day63, and Th8-Th9 pyogenic spondylitis was diagnosed based on magnetic resonance imaging (MRI). Blood culture on day14 identified Corynebacterium striatum as the causative bacteria of blood stream infection (BSI). The pyogenic spondylitis resolved after treatment with daptomycin for 2 months. Patient 2 was a 65-year-old man with relapsed angioimmunoblastic T-cell lymphoma who received bone marrow transplantation from an HLA-DR single-antigen-mismatched unrelated donor. Lower back pain appeared on day30, and L4-L5 pyogenic spondylitis was diagnosed based on MRI. Blood culture was negative. Daptomycin and clindamycin were selected for treatment based on the drug susceptibility of bacteria that had caused pre-engraftment BSI (Escherichia coli on day3 and Corynebacterium striatum on day9), and the pyogenic spondylitis resolved after 6 months of this treatment. Pyogenic spondylitis should be considered in the differential diagnosis of back pain accompanied by BSI before engraftment in allogeneic hematopoietic stem cell transplant recipients.

Two-Stage Cervical and Thoracic-Lumbar-Sacral Circumferential Fixation for Pyogenic Spondylitis: A Case Report.

Pyogenic spondylitis is a rare life-threatening condition. Conservative treatment with antibiotics is indicated; however, surgery can be considered in refractory cases. The surgical strategy varies, as pyogenic spondylosis can occur from the cervical to sacral regions. To our knowledge, although there is less invasiveness as an advantage in the following management, cervical and thoracic-lumbar-sacral circumferential fixations in two sessions for pyogenic spondylitis have not been previously described. An 84-year-old man complained of ambulation disturbances and pain in the neck and upper and lower extremities (the Japan Orthopaedic Association cervical myelopathy evaluation questionnaire score of 5/17). Magnetic resonance imaging revealed pyogenic spondylitis of the cervical, thoracic, and lumbar regions. Epidural abscesses and spondylodiscitis were concurrently diagnosed with multi-level skipping lesions from the cervical to the sacral regions. As these lesions were resistant to antibiotic treatment and the neurological symptoms worsened, surgical treatment was planned. Anterior cervical discectomy and fusion, and posterior cervical fixation were followed by oblique and posterior lumbar intervertebral fusions with long-level fixation from T12 to the ilium using percutaneous pedicle screws. The surgeries were performed in two sessions to avoid the invasiveness of surgeries in a single session. The patient's condition improved after a second surgery. The patient was discharged on postoperative day 116. No recurrence was observed for six months, and the patient was able to ambulate independently. Two-stage cervical and thoracic-lumbar-sacral circumferential fixation for pyogenic spondylitis contributed to a favorable outcome (the Japan Orthopaedic Association cervical myelopathy evaluation questionnaire score of 13/17).

Diagnostic and Management Challenges of Esophageal Rupture with Concomitant Cervical Abscess in Chronic High Cervical Tetraplegia.

A 65-year-old with a history of spinal cord injury and previous cervical surgery presented with persistent fever despite antibiotic treatment. MRI scans revealed an abscess in the neck extending from C3 to C6, with associated osteomyelitis. After an initial discharge following antibiotic therapy, the patient was readmitted due to recurrent systemic infection symptoms and another abscess. A subsequent endoscopy showed esophageal rupture with protruding cervical fusion metal. Due to operative risks, a percutaneous endoscopic gastrostomy was performed without further infection recurrence. The absence of typical imaging signs of esophageal rupture made diagnosis difficult. The infection spread through the cervical fascia from superficial to deep cervical areas. Esophageal rupture, a rare complication of cervical surgery, presents with varying symptoms depending on its location and was particularly challenging to diagnose in this patient due to high cervical tetraplegia, which masked typical pain responses. Therefore, this case highlights the need to consider esophageal rupture in differential diagnoses for chronic ACDF patients, even when typical symptoms are absent.

Vertical Subluxation Caused by Infection Around the Odontoid Process: A Case Report.

Introduction: There are few reports of cases with vertical subluxation. We report our experience of a vertical subluxation of the atlantoaxial joint caused by infection. Case Report: A 63-year-old man had a 5-month history of neck pain. He was treated for rheumatoid arthritis by a local doctor. At admission to our hospital, he had neck pain and complained of dysphagia and hoarseness. His white blood cell count and C-reactive protein were 7200/mm3 and 4.86 mg/dL. Cervical X-ray showed atlantoaxial subluxation. Computed tomography showed osteolysis around the odontoid process, including the atlantooccipital and atlantoaxial joints, causing vertical subluxation. Magnetic resonance imaging showed spinal cord and brainstem compression and the presence of fluid. Gadolinium-enhanced magnetic resonance imaging showed enhancement around the odontoid process. We performed occipital-cervical spine fixation and C1 laminectomy. Following surgery, his symptoms completely resolved. Bone fusion was confirmed 6 months after surgery. Conclusion: If subluxation of the upper cervical spine occurs rapidly, infection should be considered.

MRI-based interpretable radiomics nomogram for discrimination between Brucella spondylitis and Pyogenic spondylitis.

Background: Pyogenic spondylitis (PS) and Brucella spondylitis (BS) are commonly seen spinal infectious diseases. Both types can lead to vertebral destruction, kyphosis, and long-term neurological deficits if not promptly diagnosed and treated. Therefore, accurately diagnosis is crucial for personalized therapy. Distinguishing between PS and BS in everyday clinical settings is challenging due to the similarity of their clinical symptoms and imaging features. Hence, this study aims to evaluate the effectiveness of a radiomics nomogram using magnetic resonance imaging (MRI) to accurately differentiate between the two types of spondylitis. Methods: Clinical and MRI data from 133 patients (2017-2022) with pathologically confirmed PS and BS (68 and 65 patients, respectively) were collected. We have divided patients into training and testing cohorts. In order to develop a clinical diagnostic model, logistic regression was utilized to fit a conventional clinical model (M1). Radiomics features were extracted from sagittal fat-suppressed T2-weighted imaging (FS-T2WI) sequence. The radiomics features were preprocessed, including scaling using Z-score and undergoing univariate analysis to eliminate redundant features. Furthermore, the Least Absolute Shrinkage and Selection Operator (LASSO) was employed to develop a radiomics score (M2). A composite model (M3) was created by combining M1 and M2. Subsequently, calibration and decision curves were generated to evaluate the nomogram's performance in both training and testing groups. The diagnostic performance of each model and the indication was assessed using the receiver operating curve (ROC) with its area under the curve (AUC). Finally, we used the SHapley Additive exPlanations (SHAP) model explanations technique to interpret the model result. Results: We have finally selected 9 significant features from sagittal FS-T2WI sequences. In the differential diagnosis of PS and BS, the AUC values of M1, M2, and M3 in the testing set were 0.795, 0.859, and 0.868. The composite model exhibited a high degree of concurrence with the ideal outcomes, as evidenced by the calibration curves. The nomogram's possible clinical application values were indicated by the decision curve analysis. By using SHAP values to represent prediction outcomes, our model's prediction results are more understandable. Conclusions: The implementation of a nomogram that integrates MRI and clinical data has the potential to significantly enhance the accuracy of discriminating between PS and BS within clinical settings.

Factors associated with the time required for CRP normalization in pyogenic spondylitis: A retrospective observational study.

Background: Treatment for pyogenic spondylitis tends to be prolonged; however, few studies have examined the factors associated with the time required for infection control. Therefore, we analyzed a consecutive cohort of patients to identify factors associated with the time required to control infection in pyogenic spondylitis. This study aimed to clarify the factors linked to the duration necessary for achieving infection control in cases of pyogenic spondylitis, using C-reactive protein (CRP) normalization as an indicator. Methods: In this retrospective observational study, we investigated 108 patients diagnosed with pyogenic spondylitis. We evaluated the number of days from the first visit to CRP normalization; for cases wherein CRP did not normalize, the number of days to the date of final blood sampling was evaluated. In the present study, infection control in pyogenic spondylitis was defined as a CRP falling within the normal range (≤0.14 mg/dL). We performed univariate and multivariate Cox regression analyses to identify various factors associated with the time required for CRP normalization in pyogenic spondylitis. Results: The mean time required for CRP normalization was 148 days. Univariate Cox regression analysis showed that the serum creatinine level, estimated glomerular filtration rate (eGFR), lymphocyte percentage, neutrophil percentage, CRP level, CRP-albumin ratio, and neutrophil-to-lymphocyte ratio were significantly associated with the time required to control infection. Multivariate Cox regression analysis showed that a higher neutrophil percentage, diabetes mellitus, and a lower eGFR were the independent factors associated with a longer infection control time. Conclusions: We found that a higher neutrophil percentage, diabetes mellitus, and a lower eGFR were significantly associated with a longer time for CRP normalization in pyogenic spondylitis. These findings may help identify patients with pyogenic spondylitis who are at a high risk for an extended infection control period.

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.

Pyogenic Spondylitis Caused by Parvimonas micra: A Case Report.

Parvimonas micra (P. micra) is a gram-positive anaerobic coccus endemic to the oral cavity and intestinal tract. We report a case of pyogenic spondylitis caused by P. micra and summarize the clinical features of previous case reports. An 81-year-old man with a history of lumbar vertebral compression fracture two years previously presented to the emergency department with low back pain. He was clinically diagnosed with pyogenic spondylitis due to difficulty in moving his body, spinal tapping pain, and signs of inflammation. He was hospitalized, and aerobic and anaerobic blood culture samples were collected, but the results were negative. Computed tomography and magnetic resonance imaging revealed inflammation in the second and third lumbar vertebrae and L2/3 and L3/4 intervertebral discs, and culture of the infected disc biopsy showed P. micra growth. After six weeks of treatment with ampicillin-sulbactam and ampicillin, the patient's symptoms improved, and he was discharged. During hospitalization, he was diagnosed with periodontitis and type 2 diabetes; his dentures were adjusted, and he was started on an oral hypoglycemic agent. Pyogenic spondylitis caused by P. micra tends to be associated with oral infections. This case illustrates the importance of appropriate detection and treatment of the source of infection to prevent recurrence.

The Potential of a CT-Based Machine Learning Radiomics Analysis to Differentiate Brucella and Pyogenic Spondylitis.

Background: Pyogenic spondylitis (PS) and Brucella spondylitis (BS) are common spinal infections with similar manifestations, making their differentiation challenging. This study aimed to explore the potential of CT-based radiomics features combined with machine learning algorithms to differentiate PS from BS. Methods: This retrospective study involved the collection of clinical and radiological information from 138 patients diagnosed with either PS or BS in our hospital between January 2017 and December 2022, based on histopathology examination and/or germ isolations. The region of interest (ROI) was defined by two radiologists using a 3D Slicer open-source platform, utilizing blind analysis of sagittal CT images against histopathological examination results. PyRadiomics, a Python package, was utilized to extract ROI features. Several methods were performed to reduce the dimensionality of the extracted features. Machine learning algorithms were trained and evaluated using techniques like the area under the receiver operating characteristic curve (AUC; confusion matrix-related metrics, calibration plot, and decision curve analysis to assess their ability to differentiate PS from BS. Additionally, permutation feature importance (PFI; local interpretable model-agnostic explanations (LIME; and Shapley additive explanation (SHAP) techniques were utilized to gain insights into the interpretabilities of the models that are otherwise considered opaque black-boxes. Results: A total of 15 radiomics features were screened during the analysis. The AUC value and Brier score of best the model were 0.88 and 0.13, respectively. The calibration plot and decision curve analysis displayed higher clinical efficiency in the differential diagnosis. According to the interpretation results, the most impactful features on the model output were wavelet LHL small dependence low gray-level emphasis (GLDN). Conclusion: The CT-based radiomics models that we developed have proven to be useful in reliably differentiating between PS and BS at an early stage and can provide a reliable explanation for the classification results.

Predictors of conversion surgery after conservative treatment for pyogenic spondylitis.

BACKGROUND: Patient demographic and clinical characteristics may be factors associated with the success of conservative treatment for pyogenic spondylitis. The ability of imaging findings at initial diagnosis to predict patient outcomes remains unclear. The aim of this study was to investigate the risk factors associated with conversion surgery after conservative treatment for pyogenic spondylitis, with a special focus on the initial computed tomography (CT) findings. METHODS: This study enrolled 35 patients with pyogenic spondylitis who underwent CT and magnetic resonance imaging (MRI) at diagnosis and were followed-up for more than 6 months. Patients were diagnosed by MRI, and the degree of bone destruction was assessed on CT cross-sectional images. Vertebral body destruction was classified as grades 0 (almost normal), 1 (endplate irregularity), 2 (vertebral body destruction not involving the posterior wall), and 3 (destruction involving the posterior wall). Patients were divided into four groups based on grade of bone destruction and their clinical characteristics were compared. RESULTS: 1, 11, 11, and 12 patients were classified as grades 0, 1, 2, and 3, respectively. Univariate analysis showed no significant differences in the demographic and clinical characteristics of the four groups. Eighteen (51.4 %) patients had been treated surgically, with the rate of surgical treatment being significantly higher in patients with grade 3 (83.3 %) than in those with grades 0 + 1 (25 %) and grade 2 (45.5 %) (P < 0.05). Multivariate analysis showed that epidural abscess on MRI (odds ratio [OR] 10.8, 95 % confidence interval [CI] 1.68-69.7), grade 3 bone destruction on CT (OR 3.97, 95 % CI 1.21-13.0), and C-reactive protein (CRP) improvement rate after 1 week of treatment (OR 0.95, 95 % CI 0.91-0.99) were risk factors for surgery. CONCLUSIONS: Early surgical treatment should be considered for patients with pyogenic spondylitis who present with an epidural abscess on MRI and bone destruction extending to the posterior wall on CT at the time of diagnosis.

Spinal epidural abscess as predicting factor for the necessity of early surgical intervention in patients with pyogenic spondylitis.

BACKGROUND: Pyogenic spondylitis is a condition with low incidence that can lead to neurological sequelae and even life-threatening conditions. While conservative methods, including antibiotics and bracing, are considered the first-line treatment option for pyogenic spondylitis, it is important to identify patients who require early surgical intervention to prevent progressive neurologic deficits or deterioration of the systemic condition. Surgical treatment should be considered in patients with progressive neurologic deficits or deteriorating systemic condition. However, currently, there is a lack of treatment guidelines, particularly with respect to whether surgical treatment is necessary for pyogenic spondylitis. This study aims to analyze the radiological epidural abscess on MRI and clinical factors to predict the need for early surgical intervention in patients with pyogenic spondylitis and provide comprehensive insight into the necessity of early surgical intervention in these patients. METHODS: This study retrospectively reviewed 47 patients with pyogenic spondylitis including spondylodiscitis, vertebral osteomyelitis, epidural abscess, and/or psoas abscess. All patients received plain radiographs, and a gadolinium-enhanced magnetic resonance imaging (MRI) scan. All patients have either tissue biopsies and/or blood cultures for the diagnosis of a pathogen. Demographic data, laboratory tests, and clinical predisposing factors including comorbidities and concurrent other infections were analyzed. RESULTS: We analyzed 47 patients, 25 of whom were female, with a mean age of 70,7 years. MRI revealed that 26 of 47 patients had epidural abscesses. The surgical group had a significantly higher incidence of epidural abscess than the non-surgical group (p = 0.001). In addition, both CRP and initial body temperature (BT) were substantially higher in the surgical group compared to the non-surgical group. There was no significant difference between the surgical group and the non-surgical group in terms of age, gender, comorbidities, and concurrent infectious disorders, as well as the number of affected segments and affected spine levels. However, the surgical group had lengthier hospital stays and received more antibiotics. CONCLUSION: The presence of an epidural abscess on MRI should be regarded crucial in the decision-making process for early surgical treatment in patients with pyogenic spondylitis in order to improve clinical outcomes.

Recurrence rate after posterior percutaneous screw fixation without anterior debridement for pyogenic spondylitis compared with conservative treatment: a propensity score-matched analysis.

PURPOSE: Previous studies have shown that percutaneous pedicle screw (PPS) posterior fixation without anterior debridement for pyogenic spondylitis can improve patient quality of life compared with conservative treatment. However, data on the risk of recurrence after PPS posterior fixation compared with conservative treatment is lacking. The aim of this study was to compare the recurrence rate of pyogenic spondylitis after PPS posterior fixation without anterior debridement and conservative treatment. METHODS: The study was conducted under a retrospective cohort design in patients hospitalized for pyogenic spondylitis between January 2016 and December 2020 at 10 affiliated institutions. We used propensity score matching to adjust for confounding factors, including patient demographics, radiographic findings, and isolated microorganisms. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence of pyogenic spondylitis during the follow-up period in the matched cohort. RESULTS: 148 patients (41 in the PPS group and 107 in the conservative group) were included. After propensity score matching, 37 patients were retained in each group. PPS posterior fixation without anterior debridement was not associated with an increased risk of recurrence compared with conservative treatment with orthosis (HR, 0.80; 95% CI, 0.18-3.59; P = 0.77). CONCLUSIONS: In this multi-center retrospective cohort study of adults hospitalized for pyogenic spondylitis, we found no association in the incidence of recurrence between PPS posterior fixation without anterior debridement and conservative treatment.