Comparison of gram-negative and gram-positive hematogenous pyogenic spondylodiscitis: clinical characteristics and outcomes of treatment

Abstract

Background: To the best of our knowledge, no study has compared gram-negative bacillary hematogenous pyogenic spondylodiscitis (GNB-HPS) with gram-positive coccal hematogenous pyogenic spondylodiscitis (GPC-HPS) regarding their clinical characteristics and outcomes.

Methods: From January 2003 to January 2013, 54 patients who underwent combined antibiotic and surgical therapy in the treatment of hematogenous pyogenic spondylodiscitis were included.

Results: Compared with 37 GPC-HPS patients, the 17 GNB-HPS patients were more often found to be older individuals, a history of cancer, and a previous history of symptomatic urinary tract infection. They also had a less incidence of epidural abscess formation compared with GPC-HPS patients from findings on magnetic resonance imaging (MRI). Constitutional symptoms were the primary reasons for initial physician visits in GNB-HPS patients whereas pain in the affected spinal region was the most common manifestation in GPC-HPS patients at initial visit. The clinical outcomes of GNB-HPS patients under combined surgical and antibiotic treatment were not different from those of GPC-HPS patients. In multivariate analysis, independent predicting risk factors for GNB-HPS included a malignant history and constitutional symptoms and that for GPC-HPS was epidural abscess.

Conclusions: The clinical manifestations and MRI presentations of GNB-HPS were distinguishable from those of GPC-HPS.

Keywords: Gram-negative infection; Gram-positive infection; Hematogenous pyogenic spondylodiscitis.

Fig. 1

Escherichia coli infectious spondylodiscitis of L3-4 in a patient with a past history of colon cancer (a). Disc space was narrowing with nearby destructed endplates on L3-4 level; b Osteomyelitis in L3-4 vertebral bodies, discitis and psoas abscess without epidural abscess were found in gadolinium-enhanced magnetic resonance imaging; c Anterior and posterior spinal surgery was noticed in the immediate postoperative X-ray.; d and e Solid bone fusion was noticed at the 2-year follow-up

Fig. 2

Hematogenous Pyogenic Spondylodiscitis of L4-5 due to methicillin-resistant Staphylococcus aureus infections (a). Narrowing disc space with endplate erosion with pigtail catheter placement for drainage of paravertebral abscess was noticed on L4-5 level; b Abscess formation was found in ventral epidural space, bilateral psoas and back muscles; c Supplementary posterior spinal instrumentation was performed 6 weeks after anterior debridement and a tricortical iliac strut bone graft for intervertebral fusion; d and e Solid bone fusion on L4-5 was noticed at the 1-year follow-up

Fig. 3

Elucidation of epidural abscess and muscle abscess in contrast-enhanced magnetic resonance imaging with fat suppression among 9 g-positive pyogenic spondylodiscitis (a–c). The spinal epidural abscess was defined as an epidural mass with iso-or hypointensity on T1-weighted images, which was surrounded by linear enhancement (ring sign) on magnetic resonance imaging. Abscess formation in psoas muscle or back muscle was defined as an asymmetrical enlarged mass of the involved muscle with ring sign on magnetic resonance imaging. d–f Ventral epidural abscess was noticed on sagittal gadolinium-enhanced fat-suppressed T1-weighted magnetic resonance