Risk stratification for early postoperative infection in Pediatric spinal deformity correction: development and validation of the Pediatric scoliosis infection risk score (PSIR score).

Background Context: Postoperative infection after spinal deformity correction in pediatric patients is associated with significant costs. Identifying risk factors associated with postoperative infection would help surgeons identify high-risk patients that may require interventions to minimize infection risk.

Purpose: To investigate risk factors associated with 30-day postoperative infection in pediatric patients who have received posterior arthrodesis for spinal deformity correction.

Study Design/setting: Retrospective review of prospectively collected data.

Patient Sample: The National Surgical Quality Improvement Program Pediatric database for years 2016-2021 was used for this study. Patients were included if they received posterior arthrodesis for scoliosis or kyphosis correction (CPT 22,800, 22,802, 22,804). Anterior only approaches were excluded.

Outcome Measures: TThe outcome of interest was 30-day postoperative infection.

Methods: Patient demographics and outcomes were analyzed using descriptive statistics. Multivariable logistic regression analysis using likelihood ratio backward selection method was used to identify significant risk factors for 30-day infection to create the Pediatric Scoliosis Infection Risk Score (PSIR Score). ROC curve analysis, predicted probabilities, and Hosmer Lemeshow goodness-of-fit test were done to assess the scoring system on a validation cohort.

Results: A total of 31,742 patients were included in the study. The mean age was 13.8 years and 68.7% were female. The 30-day infection rate was 2.2%. Reoperation rate in patients who had a post-operative infection was 59.4%. Patients who had post-operative infection had a higher likelihood of non-home discharge (X2 = 124.8, p < 0.001). In our multivariable regression analysis, high BMI (OR = 1.01, p < 0.001), presence of open wound (OR = 3.18, p < 0.001), presence of ostomy (OR = 1.51, p < 0.001), neuromuscular etiology (OR = 1.56, p = 0.009), previous operation (OR = 1.74, p < 0.001), increasing ASA class (OR = 1.43, p < 0.001), increasing operation time in hours (OR = 1.11, p < 0.001), and use of only minimally invasive techniques (OR = 4.26, p < 0.001) were associated with increased risk of 30-day post-operative infection. Idiopathic etiology (OR = 0.53, p < 0.001) and intraoperative topical antibiotic use (B = 0.71, p = 0.003) were associated with reduced risk of 30-day postoperative infection. The area under the curve was 0.780 and 0.740 for the derivation cohort and validation cohort, respectively.

Conclusions: To our knowledge, this is the largest study of risk factors for infection in pediatric spinal deformity surgery. We found 5 patient factors (BMI, ASA, osteotomy, etiology, and previous surgery, and 3 surgeon-controlled factors (surgical time, antibiotics, MIS) associated with risk. The Pediatric Scoliosis Infection Risk Score (PSIR) Score can be applied for risk stratification and to investigate implementation of novel protocols to reduce infection rates in high-risk patients.