Induction of cervical disc degeneration and discogenic pain by low concentration Propionibacterium acnes infection: an in vivo animal study.

BACKGROUND: Although cervical intervertebral disc (IVD) degeneration is closely associated with neck pain, its cause remains unclear. In this study, an animal model of cervical disc degeneration and discogenic neck pain induced by a low concentration of Propionibacterium acnes (P. acnes-L) is investigated to explore the possible mechanisms of cervical discogenic pain. METHODS: Cervical IVD degeneration and discitis was induced in 8-week-old male rats in C3-C6 IVDs through the anterior intervertebral puncture with intradiscal injections of low and high concentrations of P. acnes (P. acnes-L, n = 20 and P. acnes-H, n = 15) or Staphylococcus aureus (S. aureus, n = 15), compared to control (injection with PBS, n = 20). The structural changes in the cervical IVD using micro-CT, histological evaluation, and gene expression assays after MRI scans at 2 and 6 weeks post-modeling. The P. acnes-L induced IVD degeneration model was assessed for cervical spine MRI, histological degeneration, pain-like behaviors (guarding behavior and forepaw von Frey), nerve fiber growth in the IVD endplate region, and DRG TNF-α and CGRP. RESULTS: IVD injection with P. acnes-L induced IVD degeneration with decreased IVD height and MRI T2 values. IVD injection with P. acnes-H and S. aureus both lead to discitis-like changes on T2-weighted MRI, trabecular bone remodeling on micro-CT, and osseous fusion after damage in the cartilage endplate adjacent to the injected IVD. Eventually, rats in the P. acnes-L group exhibited significant nociceptive hypersensitivity, nerve fiber ingrowth was observed in the IVD endplate region, inflammatory activity in the DRG was significantly increased compared to the control group, and the expression of the pain neurotransmitter CGRP was significantly upregulated. CONCLUSION: P. acnes-L was validated to induce cervical IVD degeneration and discogenic pain phenotype, while P. acnes-H induced was identified to resemble septic discitis comparable to those caused by S. aureus infection.

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.

Clinical features of septic discitis in the UK: a retrospective case ascertainment study and review of management recommendations.

Septic discitis is a rare but important cause of spinal pain caused by intervertebral disc infection. This retrospective observational case series analysis will examine the clinical features and management of septic discitis in 23 patients and compare with a similar 2001 study. We will also review the evidence behind management recommendations to identify areas for future research. The incidence of septic discitis was 2 per 100,000 per year. Patients presented with spinal pain (96 %), fever (70 %) and raised inflammatory markers. All patients had blood cultures and 52 % had targeted microbiological analysis. Staphylococcus aureus was the most common causative organism (39 %). Treatment was most often with intravenous flucloxacillin or ceftriaxone. CT-guided sampling for culture before commencing antibiotics increased organism detection from 33 to 67 %, and organism identification reduced the antibiotic course from an average of 142 days to 77 days. An increased number of significant co-morbid conditions were associated with worse outcomes. Results broadly resembled the 2001 study. Key differences were increased use and yield of magnetic resonance imaging and computerised tomography (CT) scanning and more frequent use of intravenous antibiotics. Comparisons between the studies suggest that improvements in the consistency of management have been slow. We suggest this due to the large spectrum of disease and the lack of guidelines in the UK. It is widely recommended to perform blood cultures and CT-guided biopsies before starting antibiotics, but it is unclear how long to withhold antibiotics if cultures remain negative. Six weeks of intravenous followed by 6 weeks of oral therapy is often suggested as treatment, whereas some recommend using inflammatory markers to guide antibiotic duration. Larger studies addressing these specific questions are required to provide more definitive guidance for these clinical decisions.

Espondilodiscite séptica: série de casos / Septic spondylodiscitis: a case series

Introdução: Objetivamos avaliar os principais aspectos clínico-epidemiológicos relacionados à espondilodiscite séptica, infecção do corpo vertebral e espaço discal, em uma série de casos. Métodos: Estudo transversal dos casos de espondilodiscite séptica no período de dez anos (2002 - 2012). Resultados: Foram identificados 12 pacientes com espondilodiscite séptica, sendo 58% homens e a idade média de 64 anos. Quanto aos sintomas, todos os pacientes apresentaram dor nas costas, 25% febre e 25% parestesias e paresia nos membros inferiores. Patologias associadas foram diabetes mellitus e neoplasias, ambas em 25% dos casos. O micro-organismo predominante foi Staphylococcus aureus, em 54% dos pacientes. Conclusão: Os achados desta série de casos corroboram os dados apresentados na literatura médica. O diagnóstico de espondilodiscite séptica deve ser considerado em todo o paciente com dor nas costas associada à febre e marcadores laboratoriais de inflamação. O diagnóstico precoce permite o pronto início de antibioticoterapia,proporcionando melhores desfechos.

Introduction: We aimed to evaluate the main clinical and epidemiological aspects related to septic discitis, infection of the vertebral body and discal space in a series of cases. Methods: Cross-sectional study of cases of septic spondylodiscitis treated at Hospital Santa Cruz in the 2002-2012 period. Results: Twelve patients with septic discitis were identified, 58% of whom males, with mean age of 64 years. As for symptoms, all patients had back pain, 25% had fever and 25% paresthesia and weakness in lower limbs. Associated pathologies were diabetes mellitus and cancer, both in 25% of cases. The predominant micro-organism was Staphylococcus aureusin 54% of patients. Conclusion: The findings of this series of cases corroborate the data reported in the medical literature. The diagnosis of septic spondylodiscitis should be considered in every patient with back pain associated with fever and laboratory markers of inflammation. Early diagnosis allows prompt initiation of antibiotic therapy, leading to better outcomes.