Surgeon and SterEOS agreement of spinal sagittal plane parameters in patients with adolescent idiopathic scoliosis.

Purpose: To compare agreement between surgeons and sterEOS sagittal plane measurements.

Methods: EOS radiographs of 74 patients with adolescent idiopathic scoliosis were reviewed. The measurements were generated by two surgeons and compared to sterEOS. Intraclass correlations (ICC) were calculated. Agreement was also analyzed for the following subgroups: Cobb angle < 70° vs ≥ 70°, lumbar modifier A vs B/C, and BMI of < 24.5 kg/m vs ≥ 24.5 kg/m. Agreement was poor if the ICC was < 0.5, moderate if 0.5-0.75, good if 0.75-0.9, and excellent if > 0.9. Paired t tests were performed to compare the surgeon's and sterEOS means.

Results: For the surgeons, agreement was good (0.75-0.89) except for pelvic tilt (PT) and sacral slope (SS), which were excellent (0.91-0.92). Agreement between the surgeons and sterEOS were good (0.78-0.9) except PT and SS, which were excellent (0.91-0.93). Agreement was negatively affected for T4-T12 kyphosis, PI, and SS in the ≥ 70°group, LL when BMI was ≥ 24.5 kg/m, and LL, PI, and SS in the lumbar modifier B/C group. The ICCs overlapped with the 95% confidence intervals (95% CI). Paired t-test showed a significant difference for T4-T12 kyphosis (p < 0.001). This was also true in the < 70° group (p < 0.001), the ≥ 70° group (p = 0.04), and the BMI < 24.5 kg/m group. PT was significantly different for the ≥ 70° group.

Conclusions: There was good to excellent agreement between the surgeons and surgeons and sterEOS. Some variables may affect agreement. The surgeons overestimated T4-T12 kyphosis.