RESUMO
STUDY DESIGN: Case-control study. OBJECTIVE: The objective of this study was to identify the best laboratory and imaging factors to predict bone biopsy culture positivity in the setting of vertebral discitis/osteomyelitis (VDO). SUMMARY OF BACKGROUND DATA: Good predictors of bone biopsy culture positivity in the setting of VDO are unknown. METHODS: Retrospective review was performed for 46 patients who underwent CT-guided bone biopsy for the evaluation of clinically confirmed VDO. Erythrocyte sedimentation rate, C-reactive protein (CRP), mean CT attenuation of the biopsied bone, and the change in the CT attenuation of the bone compared to unaffected vertebral bone (delta CT attenuation) were measured. Receiver-operator characteristic curve analyses were performed to identify the optimal threshold value for each variable. A multivariable logistic regression model was used to predict the probability of a positive bone culture using delta CT attenuation and CRPx100% fold above normal. RESULTS: For one of the 46 VDO patients, bone cultures were not obtained. Approximately 35.6% (16/45) of bone cultures were positive. The most significant predictors of bone culture positivity were CRP x100% fold above normal (Pâ=â0.011) and delta CT attenuation (Pâ=â<0.001). Optimized predictive thresholds were calculated to be CRP 4-fold above normal reference value (90.9% sensitivity, 73.7% specificity), or if the CT attenuation of the affected vertebral body was >25.9 HU lower relative to unaffected bone (93.8% sensitivity, 75.0% specificity). CONCLUSION: Delta CT attenuation, as well as CRP level over four times the upper limits of normal, were the strongest predictors for bone culture positivity in patients with VDO. LEVEL OF EVIDENCE: 3.
Assuntos
Proteína C-Reativa/metabolismo , Discite/sangue , Discite/diagnóstico por imagem , Osteomielite/sangue , Osteomielite/diagnóstico por imagem , Tomografia Computadorizada por Raios X/tendências , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Biópsia Guiada por Imagem/tendências , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Resumen:La piomiositis es una infección bacteriana primaria de músculo esquelético. Anteriormente era una enfermedad solo de pacientes de zonas de clima tropical, por lo que se conocía como piomositis tropical. No obstante, se ha dado un aumento en la aparición de casos en zonas no tropicales en especial en pacientes inmunocomprometidos. Esta condición puede asociarse a bacteremia y por ende a la aparición de focos infecciosos de diseminación hematógena. Se reporta un caso de espondilodiscitis bacteriana secundaria a bacteremia, derivada de una piomiositis de músculo iliopsoas. El paciente consulta por lumbalgia y se le diagnostica absceso en musculo psoas, el cual requirió drenaje percutáneo. No obstante, desarrolla paraplejia fláccida y se sospecha compresión medular. La tomografía espinal demuestra compresión a nivel de segmento C5-C6 secundario a espondilodiscitis, que precisó tratamiento quirúrgico y drenaje de colección.Se aisló también Staphylococcus aureus de este sitio. El caso ilustra la diseminación hematógena de una piomiositis hacia proceso vertebral con déficit neurológico, por compresión medular en un paciente inmunocompetente.
Abstract:Pyomyositis is a primary bacterial infection of skeletal muscle. Formerly, it was a disease present orly in patients in tropical climate zones, thus being known as tropical pyomyositis. Nonetheless there has been an increased incidence in non-tropical climates mainly in immunocompromised patients. This condition may be related to bacteremia and therefore to the appearance of infectious sites through hematogenous dissemination. A case of spondylodiscitis, due to bacteremia from an iliopsoas muscle pyomyositis, is reported. The patient consulted initially for severe low back pain and an abscess in the iliopsoas muscle was diagnosed and percutaneous drainage was required.Few days later, the patient suffered flaccid paralysis of both lower limbs and spinal cord compression was suspected. The spinal tomography scan showed spinal cord compression at C5-C6 level due to spondylodiscitiswhichrequired surgical treatment and drainage. A culture positive for Staphylococcus aureus was also isolated from the area.This case shows hematogenous dissemination of bacterial pyomyositis with spinal compromise and cord compression in an immunocompetent patient.