SpineOS
Try the demo Get the app

Free clinician calculator

Spinopelvic parameters calculator

Enter PI, PT, SS, LL, and SVA from a standing lateral radiograph. The calculator derives PI-LL mismatch, checks PI ~= PT + SS, and grades the SRS-Schwab sagittal modifiers using the same domain interpretation used in SpineOS.

Overall profile -- Enter measurements

Measurements

Use degrees for PI, PT, SS, and LL. Use millimeters for SVA; anterior offset is positive.

Thresholds used

The SRS-Schwab sagittal modifiers use PI-LL <= 10 degrees, SVA <= 40 mm, and PT <= 20 degrees as aligned. Moderate and marked bands follow the SpineOS domain interpretation helper.

Measure these directly on the radiograph

Use the free SpineOS measurement page to place landmarks on an image, then bring the values back here or book a demo for the guided clinician workspace.

Open the measurement tool Book a demo