Review Question - QID 3370

Previous spine surgery has not been shown to increase the risk of post-operative spinal surgery infection.

Post-operative spine surgery infections are a rare complication. The incidence has been estimated to be between 0.1-2%. Risk factors for infection include age greater than 60 years old, increased blood loss, increased operative time, more levels fused, smoking, diabetes, increased BMI, alcohol abuse, staged anterior and posterior spinal fusion under separate anesthesia, and a history of previous surgical infection. Typically, treatment involved irrigation and debridement. Usually, hardware can be retained. However, this is controversial due to biofilm formation on the implants.

Glassman et al. reviewed 858 instrumented spinal fusions. They found 22 (6.2%) had deep wound infections. Nineteen of these patients were reviewed at 1 year after surgery and they found that patients underwent and average of 2-10 I&D procedures with 7 patients having noninfectious complications. At one year no patient had a recurrent infection and overall 15 improved, 3 unchanged and 1 was worse. They concluded that surgical site drainage was the most common presenting feature and aggressive surgical management can result in adequate fusion rate and maintenance of post-operative outcomes.

Fang et al. reviewed 1629 spinal surgeries on 1095 patients and infections were found in 48 patients (4.4%). They found that most infections occurred in the early post-operative period (less than 3 months), most were monomicrobial, and the most common organism was Staph aureus. They concluded that the risk factors are age >60 years old, smoking, diabetes, previous surgical infection, increased BMI, alcohol abuse, and a staged anterior and posterior spinal fusion under separate anesthesia.

Incorrect answers:
Answers 1, 2, 3, 5: Age greater than 60, diabetes, tobacco use and a staged anterior and posterior spinal fusion under separate anesthesia is associated with an increased risk for infection.