Anatomic and radiologic appearance of several variants of the craniocervical junction.

Skull Base 02/1996; 6(2):83-94. DOI: 10.1055/s-2008-1058649
Source: PubMed

ABSTRACT Four typical manifestations of the occipital vertebra are described from both an anatomic and a radiologic point of view; the basilar process, the condylus tertius, the paracondylar process, and the isolated prebasioccipital arch. The clinical importance of the described variants is discussed.

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    ABSTRACT: Exploration of the craniocervical junction in cadavers of elderly individuals. Histologic evaluation of osseous contact zones observed between the basiocciput and anterior arch of the atlas. Previous findings of possible osseous contact zones at the anterior rim of the foramen magnum and anterior arch of the atlas suggested the existence of real joints. A total of 100 cadaver specimens were investigated using magnetic resonance imaging, computerized tomography, and median saw-cut and histologic sections. Of the specimens, 42% showed osteoarthritis-related osteophytes (primarily directed cranially) of the articular surfaces of the median atlantoaxial joint. In 5 cases, a large osteophyte of the anterior arch of the atlas touched the basiocciput. In 3 cases, a third occipital condyle touched the anterior arch of the atlas and/or tip of the dens. These osseous contact zones were histologically verified as real joints (the median atlanto-occipital or occipito-odontoid joints). Of the 8 median atlanto-occipital joints found in this study, 3 were third occipital-condyle based, and 5 osteoarthritis-based. The former were congenital in character, while the latter were acquired.
    Spine 07/2006; 31(14):E430-6. · 2.16 Impact Factor
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    ABSTRACT: A 21-year-old female presented to a chiropractic clinic with chronic neck and headache pain. She had an osseous torticollis and abnormal range of neck motion on rotation to the left. Radiographic examination revealed a unilateral paracondylar process of the occiput fusing to the lateral transverse process of the atlas. A paracondylar process is classified as an occipital vertebra. It is an enlarged bony process of the cranial base which projects caudally towards the transverse process of the atlas. She was treated with spinal manipulation below the level of fusion which resulted in a marked decrease in headache and neck pain. The embryology, frequency, radiographic appearance and clinical implications of a paracondylar process are discussed in this paper.
  • Clinical Chiropractic 01/2009; 12(4):149-153.


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