12. Late spinal infections are more common among pediatric vs adult spinal deformity patients

Abstract

<h3>BACKGROUND CONTEXT</h3> Late-onset postoperative infections after surgical correction of spinal deformity represent an uncommon, but significant complication of spine surgery. The incidence of late infection following posterior spinal fusion (PSF) in pediatric patients with AIS has been reported to be up to 7.5%. However, there is limited literature on late infections following ASD surgery suggesting that this phenomenon may be less frequent in adults. <h3>PURPOSE</h3> The objective of this study is to characterize the incidence, timing, and pathogenic etiology of late spinal infections after instrumentation for spinal arthrodesis in both age groups who present with spinal deformity. <h3>STUDY DESIGN/SETTING</h3> Retrospective review, single institution <h3>PATIENT SAMPLE</h3> Institutional data was retrospectively queried from 2000 to 2015 to identify patients who underwent instrumented PSF. Patients with more than 12 months follow-up, spinal arthrodesis spanning greater than 5 levels, and idiopathic or degenerative spinal pathology were selected for inclusion. A total of 1113 patients met inclusion criteria<b>:</b> 607 pediatric AIS patients and 506 adult spinal deformity patients. Within the pediatric AIS cohort, 76.1% (462/607) were female compared to 70.9% (359/506) within the ASD cohort. Mean follow-up was 3.9 ± 2.86 years for the AIS patients vs 4.6 ± 3.16 years for the ASD patients. <h3>OUTCOME MEASURES</h3> The following outcomes were assessed and were compared by age cohort of less than 21 vs greater than or equal to 21 years: rate of late-onset spinal infection, timing of late-onset spinal infection, and causative microorganism(s) associated with late-onset spinal infections. Demographic and surgical data were also compared between the two cohorts. <h3>METHODS</h3> The individual charts of all patients were personally reviewed by study team members to identify those who went on to develop late spinal infections. We classified late-onset as spinal infections occurring beyond 6 months (180 days) from the index operation. Diagnosis was established on the basis of return to the operating room for intraoperative bacterial cultures and sensitivities, and irrigation and debridement. <h3>RESULTS</h3> A total of 26 (4.29%) AIS patients and 2 (0.4%) ASD patients developed a late postoperative spinal infection (p = 0.01). Average onset of infection was 4.2 years (1.0-11.6) in the AIS group and 4.0 years (0.6-7.3) in the ASD group. There were significant differences in number of levels fused and reported blood loss between the two groups (p <0.001). After controlling for these intraoperative factors, age remained a significantly correlated with onset of late spinal infection (p < 0.001). Cutibacerium acnes and coagulase-negative Staphylococci were the most commonly detected microorganisms for both groups. <h3>CONCLUSIONS</h3> Pediatric patients are at significantly increased risk for late-onset postoperative spinal infections compared to adults. Skin and indolent organisms are the primary identifiable causative agents in both cohorts. Further research on these differences in infection patterns among adolescents and adults may help tailor personalized management protocols. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.