Radiologic evaluation of congenital anomalies of anterior and posterior arch of atlas in Omani subjects

Abstract

The atlas (C1) is known to show congenital anomalies in its anterior and posterior arches. Though posterior arch anomalies are well known, the anterior arch anomalies are seldom reported in the literature [1]. Currarino et al. [1] have classified posterior arch anomalies into five types: Type A, failure of fusion of two hemi arches; Type B, defect in one side of the arch, Type C, defects on both sides of arch, Type D, absence of arch except posterior tubercle, and Type E, absence of whole arch including tubercle. Type A is the frequent type and it occurs in 5.4% of the population and 97% of all posterior arch defects. When compared to posterior arch, the occurrence of anterior arch anomalies is rare [2]. So far only few cases of anterior arch of C1 including either absence or clefts have been reported [3].Anomalies of C1 may cause atlantoaxial joint instability which necessitates the treatment with a cervical collar or surgery. Furthermore, these anomalies may increase the

Anatomical variations of the atlas arches: prevalence assessment, systematic review and proposition for an updated classification system

“…The prevalence of anatomical variations in at least one of the two arches of the atlas, as reported in previous literature, ranges between 0.074 and 5.16%, based on findings from both cadaveric and imaging studies (Senoglu et al, 2007;Hyun et al, 2018;Sanchis-Gimeno et al, 2018;Hinai et al, 2021). These statistics are in alignment with the results of the current study.…”

“…The 7 included studies were published between 1986 and 2018, and conducted in Canada ( Piatt Jr and Grissom, 2011 ), China ( Choi et al, 2011 ), India ( Currarino et al, 1994 ), South Korea ( Geist et al, 2014 ; Kim, 2015 ), Turkey ( Hinai et al, 2021 ) and the United States of America ( Martirosyan et al, 2011 ), with a total of 8 patients. All of the included records were case reports.…”

“…Fractures are typically characterized by borders with irregularity and, in the context of cervical trauma, the presence of soft tissue edema is not uncommon. This can be contrasted with congenital clefts, which generally exhibit smooth edges and lack involvement of the cortical wall or tissue edema ( Karavelioglu et al, 2014 ; Hinai et al, 2021 ).…”

“…Embryological and congenital processes are key in explaining the diverse anatomical variations observed in the atlas ( Choi et al, 2011 ; Piatt Jr and Grissom, 2011 ). These variations are multifaceted and predominantly involve alterations in the fusion of the posterior arch or its partial or complete absence, as delineated by Currarino et al (1994) , Geist et al (2014) , Kim (2015) , and Hinai et al (2021) . While deviations in the anterior arch’s structure are less frequently documented, they are equally significant in terms of structural impact ( Martirosyan et al, 2011 ; Guenkel et al, 2013 ; Karavelioglu et al, 2014 ).…”

Percutaneous full endoscopic C1 laminectomy for developmental atlantal stenosis with myelopathy: a case report of three cases and review of the literature

“…Despite its low prevalence, atlas deformity associated with spinal cord compression constitutes a potentially devastating condition, which may lead to quadriplegia and even death (1,2). In 1989, Sawada et al (3) first reported the use of C1 laminectomy (C1L) for a case of canal stenosis at the level of the atlas.…”