Correlation of postoperative infection with the etiology of the disease in spinal surgery with instrumentation

Objective: To evaluate the epidemiological characteristics of postoperative infection in surgeries of the spine with instrumentation in our service, and whether there is a correlation between the rate of postoperative infection and the etiology of the indication for the primary surgical procedure. Methodology: A retrospective search through medical records of patients who underwent spinal surgery with instrumentation in our hospital between 2015 and 2019 was performed, and the ones that evolved with acute or chronic postoperative infection with need for surgical cleaning to resolve it were selected. Cases of non-instrumented surgery, primary infection of the spine (osteomyelitis and spondylodiscitis) and superficial infection of the surgical wound without the need for surgical cleaning were excluded. Results: The rate of postoperative infection was 11.6%. In this group of patients who evolved with this complication, most were submitted to surgery primarily for trauma (38.9%), followed by degenerative disease (30.8%), neoplasm (19.2%), and deformity (15, 4%). However, when we analyzed these patients comparing them with the total number of cases of spinal surgery with instrumentation performed in the period, we obtained a higher prevalence of infection in patients operated for deformity (17.6%), followed by degenerative disease (13%), neoplasm (11.4%) and trauma (9.9%). This difference did not prove to be statistically significant (p = 0.79), nor the correlation with sex and age. Conclusion: In our study, proportionally, there was a difference in the prevalence of postoperative infection according to the etiological indication, being higher in cases operated for deformity, mainly due to neuromuscular disease. Level of evidence IV; A case series therapeutic study.