Distribution of Underlying Causative Organisms, Patient Age, and Survival in Spontaneous spondylodiscitis with Special Focus on Elderly Patients

spondylodiscitis is becoming a more frequently encountered diagnosis in our clinical practice. Multimorbid and especially older patients build up a relevant portion of cases. The goal of our study was to evaluate our clinical data and to reveal specifics concerning elderly patients with spontaneous spondylodiscitis.

We retrospectively analyzed clinical data for the years from 2012 to 2014. The search was conducted on the basis of the International Classification of Diseases, 10th Revision (ICD-10) diagnoses for spondylodiscitis. Postoperative infections were not included in this study. All cases were evaluated in terms of infectious agents (in blood culture and/or computerized tomography [CT]-guided or surgical biopsy), age, and overall survival.

Fifty-one patients with spontaneous spondylodiscitis were identified. The most frequent pathogen was methicillin-sensitive Staphylococcus aureus (MSSA; n = 21; 41.17%). Escherichia coli and S. epidermidis were each found in four patients each (7.84%). Methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, and S. hominis were found in three cases (5.88%). Other bacteria were found in one case (each 1.96 %). In 12 cases, there was no bacteria growth (23.53%). One of these patients revealed to have a tuberculosis infection, diagnosed after the study period (in 2015). Two-thirds of the patients were ≥65 years old (n = 34). All three patients with MRSA were >65 years old. Three of seven patients <50 years had IV drug abuse (42.86%). In these patients, rather rare infectious agents for spondylodiscitis were found (P. aeruginosa, S. hominis, Citrobacter). Mortality was 7.84% (n = 4). All of these patients were ≥67 years old, three of four (75%) were ≥75 years old.

Our study of spontaneous spondylodiscitis showed a stronger representation of older patients (>65 years). Lethal outcome exclusively concerned the older age group. S. aureus was the most frequent pathogen as shown previously. MRSA infections might be more common in the older age group. Rare causative organisms mainly occurred in patients with iv drug abuse. Further evaluation through randomized multicenter studies focusing on the different subgroups and comorbidities in larger populations and correlation with appropriate treatment options is necessary.