P113. Pedicle morphology of the lumbar spine in a diverse population

BACKGROUND CONTEXT Recent literature underscores the importance of understanding diverse pedicle isthmus morphology to perform successful transpedicular procedures. These studies suggest that more detailed and reliable measurements of pedicles should be undertaken. However, none of the current literature comprehensively compares average pedicle diameters (PDs), estimated pedicle screw lengths (EPSLs) or transverse pedicle angle (TPA) between diverse racial populations with a standardized study design. PURPOSE We sought to determine how height, weight and race correlated with PD, EPSL and TPA in the lumbar spine between various races: 'Asian', 'Black', 'White' and 'Hispanic/Other.' These data could aid in perioperative planning during instrumented spinal fusion. STUDY DESIGN/SETTING Retrospective chart review. PATIENT SAMPLE CT scans of the abdomen and pelvis performed over a 2-week period (between July 1, 2016 to July 14, 2016) at seven hospitals within a single health system was performed. Data was collected and categorized on the basis of patient-reported racial information, race was categorized as ‘Asian’, ‘Black’, ‘White’, and ‘Hispanic/Other.’ Patients were excluded if they had prior lumbo-sacral laminectomy or fusion, CT imaging that did not allow for visualization of all five lumbar segments, scoliosis involving the lumbar vertebrae with Cobb measurement angle greater than 20°, and patients with spondylolisthesis having greater than 25% slippage. OUTCOME MEASURES N/A METHODS Analysis of over 5,060 lumbar pedicles from randomly selected CT scans on patients who underwent imaging over a two-week period for non-back pain related complaints was conducted. Outer cortical PD (as measured through the isthmus), EPSL (measuring the posterior entry point at the longest distance, which perpendicularly transected the measured isthmic diameter to the anterior cortex) and TPA (midline bisecting vertebral body to the mid-axis of the pedicle bilaterally) were determined. Data was collected and categorized on the basis of patient reported race, height and weight. To determine the significance, we used a mixed analysis of variance and a post hoc analysis. RESULTS Height and weight significantly correlated with PD, whereas BMI did not. The Asian cohort consistently had significantly smaller PD at L1–L5 than Blacks or Whites (p CONCLUSIONS Pedicle anatomy is variable. There are significant differences among races, heights and weights. We suggest using preoperative CT for pedicle screw templating as a safe method for maximizing pullout strength given the variability of pedicles among a diverse population. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.