[Is MRI useful in the follow-up of pyogenic vertebral osteomyelitis?]

[A vertebral polymicrobial osteomyelitis with atypicial microorganisms: A case report]

Vertebral Osteomyelitis (VO) is a rare disease, which has seen a gradual increase in its incidence over the past years. Here, we report a case, showing how difficult it can be to diagnose and manage a therapy in case of atypical microorganism. A 68-year-old man was hospitalized for a VO documented by blood cultures at Bacteroides fragilis. He first progressed favorably, but an increase in lumbar pain prompted, after an IRM, a percutaneous needle biopsy (PNB) that documented a recurrent VO at Corynebacterium striatum. In the face of this multi-microbial VO with atypicals microorganisms, a first PNB could have been discussed despite the positive blood cultures. This case report illustrates the complexity of management of VO, and its evolution according to the latest recommendations (interest of RMI during the follow-up, place of the TEP-scan, terms and conditions of immobilization, antibiotic administration methods).

Interest of Follow-Up Radiological Imaging in Patients with Pyogenic Vertebral Osteomyelitis

No recommendations are established for monitoring pyogenic vertebral osteomyelitis (PVO). Thus, the realization of systematic follow-up radiological imaging is controversial. The objective of this study was to evaluate the interest in follow-up radiological imaging in patients with PVO. We conducted a retrospective cohort analysis of patients with PVO who had both baseline and follow-up radiological imaging. We classified the follow-up images into two groups, improvement/stability, and deterioration, compared with the baseline data. For each patient, we compared their radiological imaging follow-up to their clinical-biological condition assessed at the same time. Eighty-six patients were included. The mean age was 68 years (±13). A total of 99 radiological imaging examinations at diagnosis and at follow-up were analyzed, 69 Magnetic Resonance Imaging (MRI), and 30 Computerized Tomography (CT scans). The mean delay between the follow-up radiological imaging and clinical evaluation was 2.8 +/- 2.1 months. Of the 36 patients with clinical and biological recovery, 24 patients (67%) had improved radiological imaging and 12 patients (34%) had radiological worsening (new abscesses (n = 4), extension of soft tissue infiltration (n = 2) and/or epiduritis (n = 2) or appearance of new locations (n = 1)). Among the 50 patients considered as unhealed, on the contrary, radiological imaging showed an improvement in imaging in 39 patients (78%) and a worsening in 11 patients (22%). Our study showed that there was no correlation between the clinical condition of patients and their follow-up radiological imaging in the context of PVO.

Culture yield of repeat percutaneous image-guided biopsy after a negative initial biopsy in suspected spondylodiscitis: a systematic review

OBJECTIVE

To systematically review the published data on the culture yield of a repeat (second) percutaneous image-guided biopsy after negative initial biopsy in suspected spondylodiscitis.

MATERIALS AND METHODS

A systematic search was performed of the PubMed/Medline and Embase databases. The methodological quality of the studies included was assessed. The proportions of positive cultures among all initial biopsies and second biopsies (after a negative initial biopsy) were calculated for each study and assessed for heterogeneity (defined as I² > 50%).

RESULTS

Eight studies, comprising a total of 107 patients who underwent a second percutaneous image-guided biopsy after a culture-negative initial biopsy in suspected spondylodiscitis, were included. All eight studies were at risk of bias and were concerning with regard to applicability, particularly patient selection, flow of patients through the study, and timing of the biopsy. The proportions of positive cultures among all initial biopsies ranged from 10.3 to 52.5%, and were subject to heterogeneity (I² = 73.7%). The proportions of positive cultures among all second biopsies after negative initial biopsy ranged from 0 to 60.0%, and were not subject to heterogeneity (I² = 38.7%).

CONCLUSION

Although a second percutaneous image-guided biopsy may have some value in patients with suspected spondylodiscitis, its exact value remains unclear, given the available poor-quality evidence. Future well-designed studies are needed to determine the role of a second percutaneous image-guided biopsy in this setting. Such studies should clearly describe the spectrum of patients that was selected for a second percutaneous image-guided biopsy, the method of biopsy, and differences compared with the first biopsy, if any.