Foramen Magnum: A Morphological and Morphometric Study in Dried Human Skull Bones of Rajasthan Population and its Surgical Importance

Abstract

Introduction:The foramen magnum (FM) is a large opening in the base of the skull. The dimensions of FM are clinically important because many vital structure passing through it, viz., the lower end of medulla oblongata, the vertebral arteries, and spinal accessory nerves. It may endure compression such as in cases of FM herniation, FM meningiomas, and FM achondroplasia. The knowledge of FM diameter is needed to determine some malformations such as the Arnold-Chiari syndrome, which shows expansion of the transverse diameter. Materials and methods: The present study was carried out on 75 dry human skulls of unknown age and sex belonging to Rajasthan population

Anatomical Observation of Different Shapes of Foramen Magnum and Its Clinical Implications: A Study in Dry Adult Human Skulls of Indian Population

“…In the present study, pentagonal shape of foramen magnum was in 5.19% cases (18 out of 347 skulls). The finding of the present study is almost similar to the studies done by Ajay Ret al [26] (2015) in 5% cases; higher than the finding of Fathima F et al [31](2016) in 4%, Chethan P et al [5](2012) in 3.8%, Radhika PM et al [27](2014) in 2%, Sampada PK et al [ 12] (2017) in 1%, Pires LA et al [17](2016) in 1.29%, Aragão JA et al [19](2014) in 2.7%, Ilhan P et al [20](2017) in 2% and Sharma A et al [23] in 3.9% cases; lower than the finding of Radhikrishna SK et al [32](2012) in 14%, Sharma S et al [30](2015) in 8%, Devadas P et al [7](2017) in 12%, Revankar S et al [21] in 12.5% and Sharma DK et al [22] in 9.33% cases (Table 1 & 2).…”

“…In the present study, hexagonal shape of foramen magnum was in 9.22% cases (32 out of 347 skulls). The finding of the present study is almost similar to the studies done by Ganapathy A et al [28] (2014) in 9%, Riyaz ZH et al [13] (2015) in 8.19%, Sharma Set al [30](2015) in 8%, Ajay Ret al [26](2015) in 10%, Aragão JA et al [19](2014) in 9.1%, Revankar S et al [21] in 10% and Kumar A et al [16] (2015) in 8 % cases; lower than the finding of Krishna K et al [10](2016) in 11.8 %, Fathima F et al [31] (2016) in 21%, Veeramani R et al [15](2018) in 21%, Ilhan P et al [20] (2017) in 21%, Sharma DK et al [22] in 16% and Sharma A et al [23] in 45.1% cases; higher than the finding of Pires LA et al [17](2016) in 1.29% cases. (Table 1 & 2) These differences could be due to inter observer variation.…”

“…In the present study, round shape foramen magnum was found in 30.84% cases (107 out of 347 skulls). The value of this study was almost similar to the values of studies done by Riyaz ZH et al [13](2015) in 29.50% and Chandekar KS et al [24](2017) in 30.43 % cases; lower than the findings of Muthukumar N et al [25](2005) in 54% and Ajay R et al [26] (2015) in 35% cases; higher than the findings of Chethan P et al [5](2012) in 22.6%, Radhika PM et al [27] (2014) in 20%, Ganapathy A et al [28](2014) in 9%, Gopalkrishana K et al [29] (2015) in 25%, Saini K [8](2015) in 19%, Bhaskar R et al [11] (2017) in 16%, Veeramani R et al [15] (2018) in 15%, Aragão JA et al [19](2014) in 15.5%, Kumar A et al [16](2015) in 20%, Pires LA et al [17] (2016) in 24.67%, Revankar S et al [21] in 17.5%, Sharma DK et al [22] in 14.67% and Sharma A et al [23] in 3.9% cases. (Table1 & 2) This difference may be due to population variation.…”

“…In the present study, irregular shape foramen magnum was found in 6.63% cases (23 out of 347 skulls) in Indian population. This value is almost similar to the study done by Singh KC et al [14] (2017) in 8%, Aragão JA et al [19](2014) in 6.4% and Sharma A et al [23] in 5.9% cases; lower than the findings of Chethan P et al [5](2012) in 15.1%, Sampada PK et al [12](2017) in 10%, Ganapathy A et al [28] (2014) in 22%, Riyaz ZH et al [13](2015) in 11.47%, Veeramani R et al [15] (2018) in 32%, Kumar A et al [16](2015) in 16%, Pires LA et al [17](2016) in 16.88%, Ilhan P et al [20](2017) in 22%, Revankar S et al [21] in 12.5% and Sharma DK et al [22] in 10.67% cases; higher than the values of Krishna K et al [10](2016) in 2.94%, Remya K et al [9](2017) in 2% and Natsis K et al [18](2013) in 0.7% cases. (Table 1 & 2) This is because in their studies, all the foramen magnum which could not be classified into any shape was grouped as irregular shaped foramen magnum.…”

“…In the present study, egg shaped foramen magnum was in 1.44 % cases (05 out of 347 skulls). The value of the present study is lower than the finding of Chethana P et al [5](2012), in 18.6 %, Radhika PM et al [27](2014) in 10%, Sampada PK et al [12](2017) in 11%, Veeramani R et al [15](2018) in 12%, Natsis K et al [18](2013) in 21%, Ilhan P et al [20](2017) in 12%, Pires LA et al [17](2016) in 2.36%, Revankar S et al [21] in 12.5%, Sharma DK et al [22] in 12% and Sharma A et al [23] in 5.9% cases.…”