Therapeutic impact of organism isolation in management of patients with pyogenic vertebral osteomyelitis

Toshiya Tachibana, Tokuhide Moriyama, Keishi Maruo, Shinichi Inoue, Shinichi Yoshiya

In management of patients with pyogenic vertebral osteomyelitis, organism isolation by biopsy is generally considered to be of primary importance when constructing a treatment plan. In our clinical practice, however, patients can be successfully treated even without identifying the organisms. The objective of this study is to review our clinical experiences and clarify the therapeutic impact of organism isolation. Forty patients who were conservatively managed in our institution constituted the base of this study. The average follow-up period was 16.7 months. Among the study subjects, 13 patients underwent percutaneous needle biopsy and the organism was identified in 6 patients. Additionally, the organism was isolated from the sample obtained from blood and possible foci in 10 patients. In total, the causative organism was identified in 15 of the 40 patients (37.5%). Patients were divided into two groups based on whether the organism was identified by culture (Groups A and B, with and without organism isolation respectively). The duration of antibiotic therapy was not significantly different between the groups (Group A: 4.8 ± 1.6 months, Group B: 4.3 ± 2.1 months), while subsequent mortalities in Group A and B were 13.3% and 8% without significant intergroup difference. Organism isolation did not productively help select the effective antibiotics and reduce the treatment period or mortality rate in treatment of patients with pyogenic vertebral osteomyelitis. Therefore, current strategic antibiotic therapy may be effective in eradicating infection even without identification of the causative organism in treatment of patients with pyogenic vertebral osteomyelitis.