Proton Density Fat Fraction Spine MRI for Differentiation of Erosive Vertebral Endplate Degeneration and Infectious Spondylitis

Vertebral Modic type 1 (MT1) degeneration may mimic infectious disease on conventional spine magnetic resonance imaging (MRI), potentially leading to additional costly and invasive investigations. This study evaluated the diagnostic performance of the proton density fat fraction (PDFF) for distinguishing MT1 degenerative endplate changes from infectious spondylitis. A total of 31 and 22 patients with equivocal diagnosis of MT1 degeneration and infectious spondylitis, respectively, were retrospectively enrolled in this IRB-approved retrospective study and examined with a chemical-shift encoding (CSE)-based water-fat 3D six-echo modified Dixon sequence in addition to routine clinical spine MRI. Diagnostic reference standard was established according to histopathology or clinical and imaging follow-up. Intravertebral PDFF [%] and PDFFratio (i.e., vertebral endplate PDFF/normal vertebrae PDFF) were calculated voxel-wise within the single most prominent edematous bone marrow lesion per patient and examined for differences between MT1 degeneration and infectious spondylitis. Mean PDFF and PDFFratio of infectious spondylitis were significantly lower compared to MT1 degenerative changes (mean PDFF, 4.28 ± 3.12% vs. 35.29 ± 17.15% [p < 0.001]; PDFFratio, 0.09 ± 0.06 vs. 0.67 ± 0.37 [p < 0.001]). The areas under the curve (AUC) and diagnostic accuracies were 0.977 (p < 0.001) and 98.1% (cut-off at 12.9%) for PDFF and 0.971 (p < 0.001) and 98.1% (cut-off at 0.27) for PDFFratio. Our data suggest that quantitative evaluation of vertebral PDFF can provide a high diagnostic accuracy for differentiating erosive MT1 endplate changes from infectious spondylitis.

Risk Factors of Coexisting Septic Spondylitis and Arthritis: A Case-Control Study in a Tertiary Referral Hospital

Introduction: In patients under immunosuppression or severe sepsis, it is sometimes manifested as coexisting septic arthritis and spondylitis. The aim of this study is to evaluate and investigate the risk factors of infectious spondylitis associated with septic arthritis. Methods: The study retrospectively reviewed the patients diagnosed with infectious spondylitis between January 2010 and September 2018 for risk factors of coexisting major joint septic arthritis. Results: A total of 10 patients with infectious spondylitis and coexisting septic arthritis comprised the study group. Fifty matched patients with solely infectious spondylitis were selected as the control group. Major risk factors include preoperative C-reactive protein (p = 0.001), hypoalbuminemia (p = 0.011), history of total joint replacement (p < 0.001), duration of preoperative antibiotics treatment (p = 0.038) and psoas muscle abscess (p < 0.001). Conclusion: Infectious spondylitis and septic arthritis are thought of as medical emergencies due to their high mortality and morbidity. Our study evaluated 5 risk factors as significant major findings: hypoalbuminemia (<3.4 g/dL), higher preoperative CRP (>130 mg/L), psoas muscle abscess, longer preoperative antibiotics treatment (>8 days) and history of total joint replacement. Clinicians should pay attention to the patients with those five factors to detect the coexisting infections as early as possible.

Simultaneous-onset infectious spondylitis with vertebral fracture mimicking an acute osteoporotic vertebral fracture erroneously treated with balloon kyphoplasty: illustrative case

BACKGROUND Early balloon kyphoplasty (BKP) intervention for acute osteoporotic vertebral fracture (OVF) has been reported to be more effective than the conservative treatment. However, complications of early BKP intervention are still unknown. OBSERVATIONS A 71-year-old patient with OVF of L2 underwent BKP 2 weeks after symptom onset. Preoperative magnetic resonance imaging (MRI) and radiograph were compatible with new L2 OVF. Although computed tomography (CT) images revealed the atypical destruction of lower endplate of L2 as OVF, L2 BKP was planned. After BKP, his back pain improved dramatically. Two weeks after BKP, his lower back pain recurred. MRI and CT confirmed the diagnosis of infectious spondylitis with paravertebral abscess formation. With adequate antibiotic treatment and rehabilitation, he was symptom-free and completely ambulatory without signs of infection. LESSONS Signal changes on the fractured vertebral bodies during initial MRI and fractured vertebral instability on radiograph can mislead the surgeon to interpret the infection as a benign compression fracture. If the patients exhibit unusual destruction of the endplate on CT imaging, “simultaneous-onset” spondylitis with vertebral fracture should be included in the differential diagnosis. To determine the strategy for OVF, preoperative biopsy is recommended if simultaneous-onset spondylitis with vertebral fracture is suspected.

Chronic infectious lesions of the cervical spine in adults: monocentric cohort analysis and literature review

Objective. To analyze the results of surgical treatment of chronic infectious cervical spondylitis and literature data.Material and Methods. Design: retrospective monocentric cohort study for 2017–2020. The study included medical history and clinical and instrumental data of 25 patients who underwent 28 reconstructive surgeries on the suboccipital (n1 = 3) and subaxial (n2 = 25) spine. The average follow-up period was 1 year 2 months ± 4 months. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS), version 22.0.Results. The effect of the duration of the therapeutic pause (p = 0.043) and the T1 slope (T1S) (p = 0.022) on the intensity of vertebrogenic pain syndrome was established. When assessing the parameters of the sagittal balance a direct relationship between the age of patients and the value of cervical sagittal vertical axis (CSVA) (p = 0.035) was revealed, while CSVA (p = 0.514) and neck tilt angle (NTA) (p = 0.617) did not significantly affect the intensity of vertebral pain syndrome. The extent of vertebral destruction did not affect either the intensity of vertebral pain (p = 0.872) or the indices of the sagittal balance: CSVA (p = 0.116), T1S (p = 0.154), and NTA (p = 0.562). A significant predictor of postoperative complications is the level of comorbidity with an index of 7 or more (p = 0.027) according to the Charlson scale.Conclusion. The leading predictors of complications of surgical treatment of cervical infectious spondylitis are the Charlson comorbidity index (7 points or more) and the variant of anterior reconstruction (the use of a blocked extraspinal plate). The factors influencing the intensity of vertebrogenic pain syndrome in this pathology are the duration of the therapeutic pause and the magnitude of T1S compensation. Anterior reconstruction of the cervical spine in the presence of infectious spondylitis provides a correction of the sagittal balance parameters, with the possibility of long-term maintaining the achieved values.

Case Report of Infectious Spondylitis Caused by Kytococcus sedentarius

Background: Kytococcus species has not been considered a pathogen, but infections caused by this species are increasing. There are several cases of infections caused by Kytococcus sedentarius, but no case of infectious spondylitis has been reported yet. Case presentation: A 79-year-old female patient was hospitalized because of back pain for several months. She was diagnosed with infectious spondylitis, and K. sedentarius was cultured from the pus and specimen obtained during the surgical procedure. The patient recovered completely without recurrence after 6 months of treatment with ciprofloxacin alone for 8 weeks. Conclusion: This is the first case report of infectious spondylitis caused by K. sedentarius.