Year: 2023
Type: article
Abstract: Different types of classification of formation of AF were given by the authors over time.Cederberg et al., designated four grades of ossification to classify the AF-(1) No calcification, (2) less than half calcified, (3) At least half calcified, and (4) Complete calcification.9 Santhi et al., described the AF formation as posterior, lateral, and posterolateral.This was given on the basis of the direction of bony bridge formed on the vertebral groove.10 Hasan et al., described the arcuate foramina into six classes-(1) Class 1-If an impression for the vertebral artery was noticeable on the posterior arch, (2) Class 2-The impression for the artery was deeper, (3) Class 3-If a partial posterior ponticulus or a bony spicule was present, (4) Class 4-If a complete posterior ponticulus was found, (5) Class 5-When a bridge extends from the lateral mass to the transverse process of atlas, and (6) Class 6-Where a relatively more extensive posterolateral tunnel was found.11 IntroductIonAtlas, cervical vertebra 1 (C1) is the superior most cervical vertebra, which gives support to the skull and spinal cord.It also gives attachment to the muscles of neck.It is named atlas due to its unique position, where it holds the skull at the top of the vertebral column. 1 Unlike most cervical vertebrae, the ring-shaped atlas has no vertebral body and spinous process.It consists of two articulating lateral masses, which are connected by short anterior and posterior arches and two transverse processes.The centrum of atlas is fused with the axis to form the odontoid process or dens of the axis.The anterior arch articulates with the dens of axis vertebra (C2) and form a pivot type of synovial median atlantoaxial joint.Each lateral mass consists upper kidney-shaped and lower circular articular facets.Upper facet articulates with the occipital condyles and forms atlantooccipital joint.Lower facet articulates with the corresponding facet of axis to form lateral atlantoaxial joint.Transverse processes surround the transversarium foramen through which vertebral artery and vein pass.Just behind the lateral mass, the upper surface of posterior arch of atlas represents a wide groove on both sides for the lodgement of first cervical spinal nerve and third part of vertebral artery. 2 The arcuate foramen (AF), an anatomical variation of atlas, is formed by the presence of a bony bridge due to ossification of posterior atlantooccipital membrane over the passage of the vertebral artery.3 It is known by many names such as foramen arcuate atlantis, ponticulus posticus (PP) or posterior ponticle, or Kimmerle's anomaly.4 This anomaly is reported to be present in approximately 3-15% of the population.5,6 AF is found more common in females than in males, 7 while some authors reported no difference in prevalence on the basis of sex and age.
Source: Journal of Medical Academics
Institution: Indian Army
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4382583496