Skin-to-spine distance as a risk factor for surgical site infection in pediatric scoliosis surgery

Introduction: Surgical Site Infection (SSI) is a rare but serious complication following Posterior Spinal Fusion (PSF) for pediatric scoliosis. Several studies have identified patient risk factors for SSI following PSF, including high Body Mass Index (BMI). The purpose of this study was to determine whether Radiographic Skin-to-spine Distance (RSD) can be used as a surrogate for BMI when evaluating the pediatric patient's risk of developing a SSI after PSF. Methods: This study was performed retrospectively and included patients ages 0-18 who underwent PSF for scoliosis over a four-year period. RSD, defined as the distance from the L5 spinous process to the skin, was measured using preoperative lateral radiographs. Results: Of the 176 included patients, we identified eight (4.5%) who suffered from surgical site infection following PSF. Logistic regression analysis revealed no statistically significant predictors for SSI. However, there was a strong, statistically significant linear regression prediction between RSD and BMI (r = 0.71, p=0.001). Discussion: RSD was not shown to be predictive of SSI in this patient cohort. However, the strong correlation found between RSD and BMI suggests that when assessing risk of SSI, RSD may be useful as a substitute for BMI when BMI cannot be easily ascertained