The preoccipital notch (pna) is the depression on the occipital part of the skull below the occipitofrontalis line, which is formed between the last occipital and penultimate frontal vertebrae.
This surgical intervention is performed in case of median injuries of the central nervous system (namely the spinal nerves (C1-T2)) or vertebral arteries. The preoccipital notch is performed both in emergency situations and in planned situations, or for the purpose of restorative treatment. To do this, through the front part of the surgical wound at the level of the occipital foramen, a sterile gauze cloth is brought to the pelvic diaphragm (periosteum), grasping it with two fingers. Other fingers are moved to the sides and advanced to a depth of 4-5 cm before moving to the frontal bone (os frontale). Using the index finger, move along the frontal bone 3-4 cm deep in order to find landmarks: the large anterior horns of the CCll vertebrae and the groove of the horizontal branch of the upper part of the muscle, the tension