Posteroperative seroma

Patient Positioning:

The patient is placed in a prone position with the heels rotated laterally and a cushion pillow is used as an iliac wedge to facilitate the exposure.

Probe Positioning:

To identify the correct level, start with a saggital plane of the spinous processes. Then rotate the probe by 90 ° to show the spinous process and adjacent structures (lamina of the vertebral arch, facet joint,
accessory process, and mamillary process).