Postoperative infections in interbody fusion for degenerative spinal disease

Scant literature exists on the treatment of infection after interbody fusion. Some authors advocate removal of the interbody grafts. Salvage of the grafts was possible in 92.3% (12 of 13) of the infections in a series of 326 consecutive patients with degenerative spinal diseases treated by three surgeons. Posterior interbody fusion and posterolateral instrumented fusion was performed in 267 patients and anterior interbody fusion was done in 59 patients. Eight infections in the first group (3%) and six in the second group (10.1%) were identified. Mean followup was 18 months (range, 12-38 months). All infections were early, presenting at a mean of 18 days (range, 11-28 months). All but one infection were in the posterior wound and deep. A high number of risk factors were present in these patients. Initial treatment included wound debridement and broad spectrum antibiotics, until culture results indicated the final antibiotic regimen. Infection recurred as osteomyelitis in one patient with multiple previous surgeries and anterior/posterior fusion. This was treated with removal of the posterior instrumentation and the interbody graft and extensive anterior/posterior reconstruction. Clinical outcomes were good in 10 patients, fair in two and poor in one using the Stauffer-Coventry scale. One pseudarthrosis was identified in a patient with anterior interbody fusion at final followup. Salvage of the interbody graft and retaining the instrumentation was safe in most cases in the presented series and did not adversely affect outcome.