Deep surgical site infection following 2344 growing-rod procedures for early-onset scoliosis: Risk factors and clinical consequences

Background: Deep surgical site infection may change the course of growing-rod treatment of early-onset scoliosis. Our goal was to assess the effect of this complication on subsequent treatment. Methods: A multicenter international database was retrospectively reviewed; 379 patients treated with growing-rod surgery and followed for a minimum of two years were identified. Deep surgical site infection was defined as any infection requiring surgical intervention. Results: Forty-two patients (11.1%; twenty-five males and seventeen females) developed at least one deep surgical site infection. The mean age at the initial growing-rod surgery was 6.3 years (range, 0.6 to 13.2 years) and the mean duration of follow-up was 5.3 years (range, 2.2 to 14.3 years). The mean interval between the initial surgery and the first deep surgical site infection was 2.8 years (range, 0.02 to 7.9 years). Ten (2.6%) of the 379 patients developed deep surgical site infection before the first lengthening. Twenty-nine patients (7.7%) developed the infection during the course of the lengthening procedures, and three patients (0.8%) developed it after final fusion surgery. Thirty (13.6%) of 221 patients with stainless-steel implants had at least one deep surgical site infection compared with twelve (8%) of 150 patients with titanium implants (p < 0.05). (The remaining patients were treated with chromium-cobalt implants.) Twenty-two (52.4%) of the forty-two patients with deep surgical site infection underwent implant removal, which was complete in thirteen and partial in nine. Growing-rod treatment was terminated in two patients with partial removal and six patients with complete removal. An increased risk of deep surgical site infection was associated with stainless-steel implants (odds ratio [OR] = 5.7), non-ambulatory status (OR = 2.9), and the number of revisions before the development of deep surgical site infection (OR = 3.3). Neuromuscular etiology and non-ambulatory status increased the possibility of implant removal to treat infection (p < 0.05). Conclusions: The prevalence of deep surgical site infection associated with growing-rod surgery is higher than that associated with standard pediatric spinal fusion (historical data). Non-ambulatory status, more revisions, and stainlesssteel implants increased the risk of deep surgical site infection. After eight surgical procedures, the risk of deep surgical site infection increased to approximately 50%. When patients have implant removal, efforts should be made to retain one longitudinal implant to continue treatment. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.