Postoperative infections after posterior spondylodesis of thoracic and lumbal spine. Surgical spine infections.

BACKGROUND: Postoperative infection after posterior spondylodesis of thoracic and lumbal spine is the most common complication, and a reason for revision surgery. Aim of this work is to analyze rate of postoperative spine infections at our institution, and to determine eventual risk factors.

SUBJECTS AND METHODS: In our paper we analyze incidence of deep surgical infections after posterior spondylodesis, performed on our Spine department during last 5 years (September 1, 2008 - September 1, 2013). Including criteria were: posterior spondylodesis with transpedicular screws from Th1 to S2 due to different spine indications (injuries, degenerations, deformities, tumors), absence of local or general infection prior the index surgery, surgery performed by the same surgeon (MB). Excluding criteria were: needle procedures (kypho/vertebro-plasties, nerve root and faset blocades), anterior spine surgeries, cervical spine surgeries, and decompresive surgeries.

RESULTS: One hundred sixty five patients with 183 surgeries have been included in this study. Early surgical infection (within a month after the surgery) has appeared at five patients (2.7%). There have been no late surgical infections. Analyzing patients' charts, we have found that Meticillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA) have caused infections in two patients, while Clebisiela pneumoniae ESBL has caused infection in one patient. Those five patients with infections have had further risk factors: long preoperative hospitalization at four patients, polytrauma, diabetes and advanced age at one patient, each. Three patients with postoperative infection had completely non-titanium surface of implants, and other two had about 20% of non-titanium implant surface, although vast majority of surgeries have been performed by implants whose surface was completely titanium alloy. Infections have appeared between 10-30 postoperative days. In two patients where revision surgeries (debridement, drainage, antibiotic according the species) had been performed in two weeks after appearance of infection, infections have been cured. In three patients where revisions had been postponed for longer than two weeks, additional surgeries (removal of implants) were necessary for curing the infections.

CONCLUSIONS: This study presented that rate of infection, microbiological species and risk factors are similar to the other orthopedics procedures and other institutions. Early revision is preferable, since it effectively avoids implant removal.