The membrane additionally attaches posteriorly (by a soft tissue bridge which may contain muscle or tendon fibres[1]) to the recti capitis posteriores minores mucles,[4][1] and anteriorly to the dura mater.[1]
At either lateral extremity,[3]: 426, 430 the membrane is pierced by the vertebral artery[3]: 426, 430, 452 and cervical spinal nerve C1.[3]: 426 The free border of the membrane arches over the artery and nerve,[5] and is sometimes ossified (converting the passage for the vertebral artery into a foramen).[3]: 426
The membrane may be pierced with a needle at the midline superior to the arch of atlas[3]: 440 to access the cisterna magna.[2]: 894 [3]: 440
Research
In 2015, Scali et al. revisited the anatomy of the posterior atlantooccipital membrane via plastination. Their findings revealed that the PAO membrane superiorly consisted of periosteum of the occiput, whereas inferiorly it formed part of the dura at the cerebrospinal junction, terminating at the level of the third cervical vertebra (rather than attaching to the posterior arch of the atlas).[6] It is believed that this anatomical arrangement permits a superiorly located anchor point for epidural bridging structures and allows dural tensile forces to act in a summated synchronized manner. The author's hypothesize that this complex area assists with outflow of cerebrospinal fluid.[citation needed]
^Frank Scali; Matthew E Pontell; Lance G Nash; Dennis E Enix (2015). "Investigation of meningomyovertebral structures within the upper cervical epidural space: a sheet plastination study with clinical implications". The Spine Journal. 15 (11): 2417–2424. doi:10.1016/j.spinee.2015.07.438. PMID26210227.