Validation of the SmartPlan Balance* mobile application to measure sagittal parameters of the spine

Objective. To assess the inter- and intra-expert reliability of measurements of spinopelvic parameters using the SmartPlan Balance mobile application.

Material and Methods. The following spinopelvic parameters were measured on postural radiographs of patients with degenerative spine diseases: pelvic index (PI), pelvic tilt (PT), sacral slope (SS), total lumbar lordosis (LL), and lower lordosis L4–S1 (LowLL). The measurements were performed by three experts using the SmartPlan Balance mobile application and the Radiant DICOM Viewer desktop program. The values obtained by the mobile application and by the computer program were compared. The inter-rater reliability of the measurements obtained using SmartPlan Balance was calculated. After repeated measurements of parameters using the SmartPlan Balance, the intra-rater reliability was calculated for each expert.

Results. No statistically significant differences were found when comparing consecutive measurements of all experts for each parameter with each tool (Radiant DICOM Viewer and SmartPlan Balance); p > 0.05. The Pearson correlation coefficient ranged from 0.83 to 0.95 (PI: r = 0.956; PT: r = 0.912; SS: r = 0.865; GLL: r = 0.943; LowLL: r = 0.839) regardless of the specific expert or method. The inter- and intra-rater reliability of measurements by the SmartPlan Balance application had excellent or good reliability: the most stable and highest value of the intra- and interclass correlation index (ICC) was determined for the LowLL parameter (0.85–0.92), and the lowest ICC consistency values were found for the PT parameter (0.75–0.81).

Conclusion. Measurements of spinopelvic parameters using SmartPlan Balance demonstrate high reliability and reproducibility, comparable to the standard desktop program. The use of the SmartPlan Balance mobile application is recommended in the daily practice of each spine surgeon, particularly in surgical planning, intraoperative parameter measurements, and analysis of non-digital radiographs.

* The application is available on the Android platform via the QR code provided at the end of the article.

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