Safety of instrumentation in patients with spinal infection

Treatment of spine infection remains a challenge for spine surgeons, with the most effective method still being a matter of debate. Most surgeons agree that in early stages of infection, antibiotic treatment should be pursued; under certain circumstances, however, surgery is recommended. The goals of surgery include radical debridement of the infective focus. In some cases, when surgery causes mechanical spinal instability, the question arises whether the risk of recurrent infection outweighs the benefits of spinal instrumentation and stabilization. The authors report their series of cases in which instrumentation was placed in actively infected sites and review the relevant literature.

The authors performed a retrospective analysis of all cases of spinal infection that were surgically treated with debridement and placement of instrumentation at their institution between 2000 and 2006. Patient presentation, risk factor, infective organism, surgical indication, level of involvement, type of procedure, and ultimate outcome were reviewed. Improved outcome was based on improvement of initial American Spinal Injury Association Impairment Score.

Forty-seven patients (32 men, 15 women) were treated with instrumented surgery for spinal infection. Their average age at presentation was 54 years (range 37-78 years). Indications for placement of instrumentation included instability, pain after failure of conservative therapy, or both. Patients underwent surgery within an average of 12 days (range 1 day to 5 months) after their presentation to the authors' institution. The average length of hospital stay was 25 days (range 9-78 days). Follow-up averaged 22 months (range 1-80 months). Eight patients died; causes of death included sepsis (4 patients), cardiac arrest (2), and malignancy (2). Only 3 patients were lost to follow-up. Using American Spinal Injury Association scoring as the criterion, the patients' conditions improved in 34 cases and remained the same in 5. Complications included hematoma (2 cases), the need for hardware revision (1), and recurrent infection (2). Hardware replacement was required in 1 of the 2 patients with recurrent infection.

Instrumentation of the spine is safe and has an important role in stabilization of the infected spine. Despite the presence of active infection, we believe that instrumentation after radical debridement will not increase the risk of recurrent infection. In fact, greater benefit can be achieved through spinal stabilization, which can even promote accelerated healing.