Figure 1

Guided freehand procedure. Top: A single image is taken from the distal part of the nail in arbitrary C-arm orientation. Guiding landmarks are calculated from the hole contours and projected into the image. A skin incision is performed at the incision landmark. Middle: Targeting jig and drill are inserted through the incision onto the bone surface. Under fluoroscopic control the jig is translated until the projection of the small ring coincides with the small targeting ellipse. Bottom: The jig is rotated until alignment of the projection of the large ring and the large targeting ellipse is achieved for drilling the hole