The L3 Flexion Angle Predicts Failure of Non-Operative Management in Patients with Tandem Spondylolithesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Determine impact of standard/novel spinopelvic parameters on global sagittal imbalance, health-related quality of life (HRQoL) scores, and clinical outcomes in patients with multi-level, tandem degenerative spondylolisthesis (TDS). METHODS: Single institution analysis; 49 patients with TDS. Demographics, PROMIS and ODI scores collected. Radiographic measurements-sagittal vertical axis (SVA), pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, sagittal L3 flexion angle (L3FA) and L3 sagittal distance (L3SD). Stepwise linear multivariate regression performed using full length cassettes to identify demographic and radiographic factors predictive of aberrant SVA (≥5 cm). Receiver operative curve (ROC) analysis used to identify cutoffs for lumbar radiographic values independently predictive of SVA ≥5 cm. Univariate comparisons of patient demographics, (HRQoL) scores and surgical indication were performed around this cutoff using two-way Student's t-tests and Fisher's exact test for continuous and categorical variables, respectively. RESULTS: Patients with increased L3FA had worse ODI (P = .006) and increased rate of failing non-operative management (P = .02). L3FA (OR 1.4, 95% CI) independently predicted of SVA ≥5 cm (sensitivity and specifity of 93% and 92%). Patients with SVA ≥5 cm had lower LL (48.7 ± 19.5 vs 63.3 ± 6.9 mm, P < .021), higher L3SD (49.3 ± 12.9 vs 28.8 ± 9.2, P < .001) and L3FA (11.6 ± 7.9 vs -3.2 ± 6.1, P < .001) compared to patients with SVA ≤5 cm. CONCLUSIONS: Increased flexion of L3, which is easily measured by the novel lumbar parameter L3FA, predicts global sagittal imbalance in TDS patients. Increased L3FA is associated with worse performance on ODI, and failure of non-operative management in patients with TDS.

Cervical Spine Fractures: Who Really Needs CT Angiography?

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Compare a novel two-step algorithm for indicating a computed tomography angiography (CTA) in the setting of a cervical spine fracture with established gold standard criteria. SUMMARY OF BACKGROUND DATA: As CTA permits the rapid detection of blunt cerebrovascular injuries (BCVI), screening criteria for its use have broadened. However, more recent work warns of the potential for the overdiagnosis of BCVI, which must be considered with the adoption of broad criteria. METHODS: A novel two-step metric for indicating CTA screening was compared with the American College of Surgeons guidelines and the expanded Denver Criteria using patients who presented with cervical spine fractures to a tertiary-level 1 trauma center from January 1, 2012 to January 1, 2016. The ability for each metric to identify BCVI and posterior circulation strokes that occurred during this period was assessed. RESULTS: A total of 721 patients with cervical fractures were included, of whom 417 underwent CTAs (57.8%). Sixty-eight BCVIs and seven strokes were diagnosed in this cohort. All algorithms detected an equivalent number of BCVIs (52 with the novel metric, 54 with the ACS and Denver Criteria, P = 0.84) and strokes (7/7, 100% with the novel metric, 6/7, 85.7% with the ACS and Denver Criteria, P = 1.0). However, 63% fewer scans would have been needed with the proposed screening algorithm compared with the ACS or Denver Criteria (261/721, 36.2% of all patients with our criteria vs. 413/721, 57.3% with the ACS standard and 417/721, 57.8%) with the Denver Criteria, P < 0.0002 for each). CONCLUSION: A two-step criterion based on mechanism of injury and patient factors is a potentially useful guide for identifying patients at risk of BCVI and stroke after cervical spine fractures. Further prospective analyses are required prior to widespread clinical adoption. LEVEL OF EVIDENCE: 4.