Posterior and lateral ponticles of atlas: An osteological study at Fatima Jinnah Medical University, Lahore

2020 ◽  
Vol 14 (2) ◽  
pp. 91-96
Author(s):  
Saira Munawar ◽  
Farhana Jafri ◽  
Ahmad Farzad Qureshi ◽  
Darab Fatima ◽  
Aliya Zahid

Background: Among the cervical vertebrae, atlas is known to have many variations, posterior ponticle being the commonest. It may completely or incompletely covers the groove of vertebral artery leading to ischemia of posterior circulation. Therefore, vertebral artery is at greater risk of injury during neurological and spinal surgeries. Prevalence of posterior ponticles varies widely among different populations, for instance in Turkish population it was 10.8%, in American 22.1%, Kenyan 14.7%, Brazilian and Indian 16.7%. The prevalence of lateral ponticle in Kenyan population was reported to be 3.9% and in Indians it was 2%. However, the data regarding the prevalence of these ponticles is largely lacking in Pakistan. Therefore, this research was designed to determine the prevalence of posterior and lateral ponticle in atlas vertebrae of Pakistani population. Materials and methods: A total of 47 human atlas vertebrae of unknown age and gender from bone bank of Department of Anatomy Fatima Jinnah Medical University, Lahore were studied for the presence of complete and incomplete posterior and lateral ponticles. The bones studied were completely intact and did not have any pathology. Results: Total incidence of ponticles was 38 % in this study, of which 36% were posterior ponticles and 2% were lateral ponticles. Bilateral incomplete posterior ponticles/were found in 8 (17%) atlas vertebrae whereas bilateral complete posterior ponticles/foramen arcuale were found in only 1 (2%) atlas vertebrae. Unilateral incomplete posterior ponticle was identified on right side in 5 (11%) and left side in 2 (4%) atlas vertebrae. Unilateral complete posterior ponticle was found in only 1 (2%) atlas on the left side whereas no such finding was identified on right side in any vertebra. Unilateral complete lateral ponticle was found in only 1 (2%) atlas on the right side but not on left side. No bilateral complete lateral ponticle and incomplete unilateral or bilateral lateral ponticles were identified in this study. Conclusion: Presence of posterior and lateral ponticles pose a risk of vertebrobasilar vascular insufficiency and may cause variety of symptoms. Vertebral artery may be at risk during neurosurgical procedures when having a foramen arculae and may give a false impression of much wider posterior arch of atlas. Knowing the prevalence of this can help neurosurgeons, general surgeons, radiologists, and chiropractors in management of the patients.

Author(s):  
Handan Soysal ◽  
Niyazi Acer ◽  
Meltem Özdemir ◽  
Önder Eraslan

Abstract Objective The aim of this study is to measure the average corpus callosum (CC) volume of healthy Turkish humans and to analyze the effects of gender and age on volumes, including the genu, truncus, and splenium parts of the CC. Patients and Methods Magnetic resonance imaging brain scans were obtained from 301 healthy male and female subjects, aged 11 to 84 years. The median age was 42 years (min–max: 11–82) in females and 49 years (min–max: 12–84) in males. Corpus callosum and its parts were calculated by using MRICloud. CC volumes of each subject were compared with those of the age and gender groups. Results All volumes of the CC were significantly higher in males than females. All left volumes except BCC were significantly higher than the right volumes in both males and females. The oldest two age groups (50–69 and 70–84 years) were found to have higher bilateral CC volumes, and bilateral BCC volumes were also higher than in the other two age groups (11–29 and 30–49 years). Conclusion The results suggest that compared with females/males, females have a faster decline in the volume of all volumes of the CC. We think that quantitative structural magnetic resonance data of the brain is vital in understanding human brain function and development.


2015 ◽  
Vol 05 (02) ◽  
pp. 080-083 ◽  
Author(s):  
Qudusia Sultana ◽  
Ramakrishna Avadhani ◽  
Varalakshmi KL ◽  
Shariff MH ◽  

Abstract Introduction: The second part of the vertebral artery along with vertebral venous plexus and sympathetic plexus traverses through vicinity of foramen transversarium of atlas. Derangement of these structures in their course may be seen due to deformities, narrowing and presence of osteophytes in foramen transversarium. Methods: Two hundred foramen transversarium of 100 atlas vertebrae were grossly studied for their variations. Results: Out of hundred atlas vertebrae examined, we found that all the vertebrae had foramina transversaria. Absence of costal element was noticed in five atlas vertebrae. 2 of the vertebrae showed incomplete unilateral foramen transversarium, 3 vertebrae showed bilateral incomplete foramen, In 1 vertebra along with normal foramen transversarium, complete retroarticular foramen was observed on the left side and incomplete retroarticular foramen observed on the right side of the posterior arch.4 vertebrae showed incomplete retroarticular foramen. Conclusion: The increasing incidence of neck injuries and related syndromes necessitates the study of bony variations of the atlas vertebra and its transverse foramina. Due to the incomplete formation of the foramen transversarium the second part of vertebral artery is prone to be damaged easily during posterior cervical injuries and Surgeries. The bony bridges embracing the vertebral artery may be responsible for vertigo and cerebrovascular accidents hence the knowledge of such variations is important for Physicians, Otirhinolaryngologists, neurologists ,Orthopaedicians and Radiologists.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Santosh Kaur Sangari ◽  
Paul-Michel Dossous ◽  
Thomas Heineman ◽  
Estomih Phillip Mtui

The study was conducted on random sample of seventy-one dried, typical cervical vertebrae (C3–C6). The data on the age, sex, and built was not available. Using vernier calipers with 0.01 mm accuracy, the anteroposterior and transverse diameters of transverse foramina and their distance from the medial margin of the uncinate process were measured bilaterally. The mean diameter of the right/left transverse foramen varied from 2.54 mm to 7.79 mm (mean = 5.55 ± 0.87 mm) and from 2.65 mm to 7.35 mm (mean = 5.48 ± 0.77 mm), respectively. The transverse foramen was less than 3.5 mm in three vertebrae on the right and two on the left. The osteocytes observed in 21.3% of specimens and the narrow transverse foramen may place patients at risk for vertebrobasilar insufficiency or thrombus formation. The mean distance of the transverse foramen from the medial margin of uncinate process is an important landmark to avoid vertebral artery laceration and was 5.0 ± 0.87 mm (range: 3.5–7.9 mm) on the right and 5.0 ± 1.0 mm (range: 3.2–7.7 mm) on the left side. No statistically significant difference was observed between the right and left sides. The accessory transverse foramina seen in 24% of vertebrae suggest duplications or fenestrations in the vertebral artery.


2008 ◽  
Vol 9 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Satoshi Yamaguchi ◽  
Kuniki Eguchi ◽  
Yoshihiro Kiura ◽  
Masaaki Takeda ◽  
Kaoru Kurisu

Object The vertebral artery (VA) often takes a protrusive course posterolaterally over the posterior arch of the atlas. In this study, the authors attempted to quantify this posterolateral protrusion of the VA. Methods Three-dimensional CT angiography images obtained for various cranial or cervical diseases in 140 patients were reviewed and evaluated. Seven patients were excluded for various reasons. To quantify the protrusive course of the VA, the diameter of the VA and 4 parameters were measured in images of the C1–VA complex obtained in the remaining 133 patients. The authors also checked for anomalies and anatomical variations. Results When there was no dominant side, mean distances from the most protrusive part of the VA to the posterior arch of the atlas were 6.73 ± 2.35 mm (right) and 6.8 ± 2.15 mm (left). When the left side of the VA was dominant, the distance on the left side (8.46 ± 2.00 mm) was significantly larger than that of the right side (6.64 ± 2.0 mm). When compared by age group (≤ 30 years, 31–60 years, and ≥ 61 years), there were no significant differences in the extent of the protrusion. When there was no dominant side, the mean distances from the most protrusive part of the VA to the midline were 30.73 ± 2.51 mm (right side) and 30.79 ± 2.47 mm (left side). When the left side of the VA was dominant, the distance on the left side (32.68 ± 2.03 mm) was significantly larger than that on the right side (29.87 ± 2.53 mm). The distance from the midline to the intersection of the VA and inner cortex of the posterior arch of the atlas was ~ 12 mm, irrespective of the side of VA dominance. The distance from the midline to the intersection of the VA and outer cortex of the posterior arch was ~ 20 mm on both sides. Anatomical variations and anomalies were found as follows: bony bridge formation over the groove for the VA on the posterior arch of C-1 (9.3%), an extracranial origin of the posterior inferior cerebellar artery (8.2%), and a VA passing beneath the posterior arch of the atlas (1.8%). Conclusions There may be significant variation in the location and branches of the VA that may place the vessel at risk during surgical intervention. If concern is noted about the vulnerability of the VA or its branches during surgery, preoperative evaluation by CT angiography should be considered.


Author(s):  
Selda Aksoy ◽  
Bulent Yalcin

Abstract Background Atlantoaxial instability is an important disorder that causes serious symptoms such as difficulties in walking, limited neck mobility, sensory deficits, etc. Atlantal lateral mass screw fixation is a surgical technique that has gained important recognition and popularity. Because accurate drilling area for screw placement is of utmost importance for a successful surgery, we aimed to investigate morphometry of especially the posterior part of C1. Methods One hundred and fifty-eight human adult C1 dried vertebrae were obtained. Measurements were performed directly on dry atlas vertebrae, and all parameters were measured by using a digital caliper accurate to 0.01 mm for linear measurements. Results The mean distance between the tip of the posterior arch and the medial inner edge of the groove was found to be 10.59 ± 2.26 and 10.49 ± 2.20 mm on the right and left, respectively. The mean distance between the tip of the posterior arch and the anterolateral outer edge of the groove was 21.27 ± 2.28 mm (right: 20.96 ± 2.22 mm; left: 21.32 ± 2.27 mm). The mean height of the screw entry zone on the right and left sides, respectively, were 3.86 ± 0.81 and 3.84 ± 0.77 mm. The mean width of the screw entry zone on both sides was 13.15 ± 1.17 and 13.25 ± 1.3 mm. Conclusion Our result provided the literature with a detailed database for the morphometry of C1, especially in relation to the vertebral artery groove. We believe that the data in the present study can help surgeons to adopt a more accurate approach in terms of accurate lateral mass screw placement in atlantoaxial instability.


2017 ◽  
Vol 26 (6) ◽  
pp. 679-683 ◽  
Author(s):  
Marc Moisi ◽  
Christian Fisahn ◽  
Lara Tkachenko ◽  
Shiveindra Jeyamohan ◽  
Stephen Reintjes ◽  
...  

OBJECTIVEPosterior atlantoaxial stabilization and fusion using C-1 lateral mass screw fixation has become commonly used in the treatment of instability and for reconstructive indications since its introduction by Goel and Laheri in 1994 and modification by Harms in 2001. Placement of such lateral mass screws can be challenging because of the proximity to the spinal cord, vertebral artery, an extensive venous plexus, and the C-2 nerve root, which overlies the designated starting point on the posterior center of the lateral mass. An alternative posterior access point starting on the posterior arch of C-1 could provide a C-2 nerve root–sparing starting point for screw placement, with the potential benefit of greater directional control and simpler trajectory. The authors present a cadaveric study comparing an alternative strategy (i.e., a C-1 screw with a posterior arch starting point) to the conventional strategy (i.e., using the lower lateral mass entry site), specifically assessing the safety of screw placement to preserve the C-2 nerve root.METHODSFive US-trained spine fellows instrumented 17 fresh human cadaveric heads using the Goel/Harms C-1 lateral mass (GHLM) technique on the left and the posterior arch lateral mass (PALM) technique on the right, under fluoroscopic guidance. After screw placement, a CT scan was obtained on each specimen to assess for radiographic screw placement accuracy. Four faculty spine surgeons, blinded to the surgeon who instrumented the cadaver, independently graded the quality of screw placement using a modified Upendra classification.RESULTSOf the 17 specimens, the C-2 nerve root was anatomically impinged in 13 (76.5%) of the specimens. The GHLM technique was graded Type 1 or 2, which is considered “acceptable,” in 12 specimens (70.6%), and graded Type 3 or 4 (“unacceptable”) in 5 specimens (29.4%). In contrast, the PALM technique had 17 (100%) of 17 graded Type 1 or 2 (p = 0.015). There were no vertebral artery injuries found in either technique. All screw violations occurred in the medial direction.CONCLUSIONSThe PALM technique showed statistically fewer medial penetrations than the GHLM technique in this study. The reason for this is not clear, but may stem from a more angulated ”up-and-in” screw direction necessary with a lower starting point.


2017 ◽  
Vol 78 (01) ◽  
pp. e37-e39
Author(s):  
Christian Fisahn ◽  
Brittni Burgess ◽  
Joe Iwanaga ◽  
Fernando Alonso ◽  
Jens Chapman ◽  
...  

Introduction Several arterial variants have been reported to occur around the posterior arch of the atlas. Understanding the various anomalies and diagnosing them preoperatively can dramatically reduce the risk of surgical insult during neurosurgical procedures. Herein we report a case of an arterial variant found just below the posterior arch of C1. Case Report During the routine dissection of the suboccipital region via a posterior approach, an unusual bulge was identified just inferior to the inferior capitis oblique muscle. With further dissection, the structure was identified as a tortuous internal carotid artery. Conclusion Arterial variants around the posterior arch of C1 are surgically significant and can result in catastrophic injuries if unappreciated. Most of these variants will be related to the vertebral artery. To our knowledge, an arterial variant of the internal carotid artery in this location, as reported herein, has not been previously reported.


2002 ◽  
Vol 97 (6) ◽  
pp. 1456-1459 ◽  
Author(s):  
Teiji Tominaga ◽  
Toshiyuki Takahashi ◽  
Hiroaki Shimizu ◽  
Takashi Yoshimoto

✓ Vertebral artery (VA) occlusion by rotation of the head is uncommon, but can result from mechanical compression of the artery, trauma, or atlantoaxial instability. Occipital bone anomalies rarely cause rotational VA occlusion, and patients with nontraumatic intermittent occlusion of the VA usually present with compromised vertebrobasilar flow. A 34-year-old man suffered three embolic strokes in the vertebrobasilar system within 2 months. Magnetic resonance imaging demonstrated multiple infarcts in the vertebrobasilar territory. Angiography performed immediately after the third attack displayed an embolus in the right posterior cerebral artery. Radiographic and three-dimensional computerized tomography bone images exhibited an anomalous osseous process of the occipital bone projecting to the posterior arch of the atlas. Dynamic angiography indicated complete occlusion of the left VA between the osseous process and the posterior arch while the patient's head was turned to the right. Surgical decompression of the VA resulted in complete resolution of rotational occlusion of the artery. An occipital bone anomaly can cause rotational VA occlusion at the craniovertebral junction in patients who present with repeated embolic strokes resulting from injury to the arterial wall.


2019 ◽  
Vol 08 (03) ◽  
pp. 106-111
Author(s):  
Monika Lalit ◽  
Anupama Mahajan ◽  
Sanjay Piplani ◽  
Jagdev S. Kullar

Abstract Background and Aims Arcuate foramina (AF), the atlas bridges formed by a delicate bony spicule over the posterior arch of atlas, have been implicated in the compression of the vertebral artery during extreme rotation of head and neck movements. Reduction in the size of arcuate foramina as compared with foramen transversarium (FT) is also an important cause for the compression of vertebral artery. Aim of the present study was to determine the morphometric differences between complete AF and ipsilateral foramina transversaria. Materials and Methods Eighty dry adult human atlas vertebrae were obtained in the Department of Anatomy, Government Medical College and Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India. Measurements were taken of the maximum dimensions of AF and ipsilateral FT and cross-sectional area was also calculated. Results The following results were obtained.The AF were seen in total 11 (13.75%) vertebrae, 3 (3.75%) on the right side, 6 (7.5%) on left side, and 2 (2.5%) bilateral.• The mean ventrodorsal (AFL) and superoinferior (AFH) diameter of AF was 8.79 mm and 5.98 mm, and 8.11 mm and 5.54 mm on the right and left sides, respectively, and the difference was found to be highly significant.• The mean ventrodorsal (FTL) and mediolateral (FTW) diameter of the FT 8.19 mm and 6.56 mm, and 7.31 mm and 6.86 mm on the right and left sides, respectively, with significant difference on the right side.• The mean cross-sectional area of AF was 41.32 mm2 and 35.38 mm2, and FT was 42.53 mm2 and 39.71 mm2 on the right and left sides, respectively, and AF has smaller area than ipsilateral FT. Conclusions Knowledge about the dimensions and cross-sectional area of the AF and ipsilateral foramina transversaria of the atlas vertebra can improve the success rate of surgeries, thus preventing damage to the adjoining vital structures.


2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Julius Ogeng’o ◽  
Beda Olabu ◽  
Rankeet Sinkeet ◽  
Nafula M. Ogeng’o ◽  
Hemedi Elbusaid

This study examined the characteristics of vertebral artery hypoplasia in 346 arteries of adult black Kenyans. The circumference was measured on haematoxylin/eosin stained microscopic sections of the distal one-third of the intracranial vertebral arteries using scion image analyser. Internal diameter was calculated in millimetre. Data were analysed using SPSS version 16.0. Vertebral artery hypoplasia (diameter < 2.0 mm) occurred in 100 (28.9%) arteries. Sixty of these (17.3%) were on the left and 40 (11.6%) on the right. Sixty (17.3%) were in females while 40 (11.6%) were in males. The side and gender differences were statistically significant at confidence interval of 95%. Frequency of vertebral artery hypoplasia was higher than in most other populations studied. The condition differs from that in other populations because it is more common on the left side and in females. We recommend ultrasound, angio-CT, or angio-MRI evaluation of vertebral arterial system before diagnostic or interventional procedures on posterior circulation.


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