🎯 Facet Joint Injection Diagnostic Block Simulator (3D)

This 3D companion drives the same diagnostic logic as the 2D version — intra-articular injection versus medial branch block, the comparative dual-block paradigm that controls for the ~25-40% single-block placebo/false-positive rate, and contrast-confirmed needle placement — but renders it as a real, orbitable WebGL scene instead of a flat canvas. The lumbar vertebrae L3-S1 are built as genuine 3D geometry with the SAP-TP junction and posterior-inferior joint recess placed at their real relative positions; the C-arm beam and the needle's approach line both rotate together around the spine's long axis when you move the "Fluoroscope Oblique Angle" slider, reproducing the actual "gun-barrel" (tunnel-vision) technique fluoroscopists use to line up the needle with the image before advancing it — a spatial relationship the 2D top-down view could only imply.