Morphologic evaluation of dorsal surface of sacrum

Öz

Purpose: The aim of this study was to examine the macroscopic variations of certain anatomical structures in the dorsal surface of the sacral bone. Method: A number of twenty dry sacrum with undetermined gender, from the collection of Anatomy Department Mersin University Faculty of Medicine, were evaluated. Sacral canal, posterior sacral foramina, sacral hiatus, sacral cornu and superior articular processes located in the dorsal surface of the sacrum were examined. Results: There were 3 individual sacralization case and a case of complete agenesis of dorsal bony wall among the assessed bones. The level of maximum curvature of sacrum was detected in S3 level as at 60% and S4 level as at 25% whereas there was no curvature in 15% of the cases. Upper aperture of sacral canal was in “U” (26%) and “V” (74%) shapes. Articular surfaces of superior articular processes were detected as bilateral flat (35%) and concave (55%); and unilateral concave (10%). Some of the sacrums were found to be united with the 5th lumbar vertebra (10%) and with coccyx (20%). Accordingly, it was determined that the numbers of posterior sacral foramina varied. Shape differences were also observed in these foramina. In general, the foramina were observed at the S1 level as oval in vertical direction and those at the S4-5 level as oval in horizontal direction. The shape of sacral hiatus was observed as “inverted U" (%28), "dumbbell" (28%), “inverted V" (%17), "M" (17%) and “irregular” (12%). Sacral cornu was detected in 78% sacrums. In 22% of sacrums, sacral cornu and coccygeal cornu were united. Apex of sacral hiatus was detected at S4 (42%), between S3-S4 (%32), at S3 (%16), between S2 - S3 (%5) and at S5 (5%) levels. Base of sacral hiatus was located at S4 (32%) and S5 (68%) levels. Conclusion: In the light of the data obtained from the study, it was thought that this diversity in sacral structures may affect the method in the interventional procedures performed in the sacral region or may be important in terms of being a reference point.

Anahtar Kelimeler

• Sacrum, morphology
• variation
• sacral hiatus
• posterior sacral foramina

Os sacrum’un facies dorsalis’inin morfolojik incelenmesi

Öz

Amaç: Bu çalışmanın amacı, os sacrum’un facies dorsalis’inde yer alan belirli anatomik yapıların makroskopik olarak varyasyonlarını incelemektir. Yöntem: Mersin Üniversitesi Tıp Fakültesi Anatomi Anabilim Dalı laboratuvarında bulunan, cinsiyeti belirlenemeyen ve kemik aşınmaları bulunmayan 20 adet os sacrum kullanıldı. Os sacrum’un facies dorsalis’inde yer alan canalis sacralis, foramina sacralia posteriora, hiatus sacralis, cornu sacrale ve processus articularis superior gözlemsel olarak değerlendirildi. Bulgular: Os sacrum’ların 3’ünde sakralizasyon ve 1’inde canalis sacralis arka duvar komplet agenezisi tespit edildi. Os sacrum’ların %60’ında konveksite S3 seviyesinde, %25’inde S4 seviyesinde iken, %15’inde konveksite yoktu. Canalis sacralis üst açıklığının “U” (%26) ve “V” (%74) şeklinde olduğu gözlendi. Processus articularis superior’ların eklem yüzeyleri, bilateral düz (%35), bilateral konkav (%55) ve unilateral konkav (%10) şeklinde gözlendi. Os sacrum’ların %10’u 5. lumbar vertebra ile %20’si os coccygis ile birleşmişti. Buna bağlı olarak foramina sacralia posteriora sayılarının değişkenlik gösterdiği belirlendi. Bu deliklerde şekil farklılıkları da gözlendi. Sıklıkla S1 seviyesindeki delikler vertikal yönde oval ve S4-5 seviyesindekiler yatay yönde oval olarak bulunuyordu. Hiatus sacralis’in şekli, “ters U” (%28), “halter” (%28), “ters V” (%17), “M” (%17),ve irregular (%12) şeklinde gözlendi. Cornu sacrale %78 oranında bulunuyordu. Cornu sacrale ile cornu coccygeum %22 oranında birleşiyordu. Hiatus sacralis’in tepesi S4 (%42), S3-S4 arasında (%32), S3 (%16), S2-S3 arasında (%5) ve S5 (%5) seviyelerinde; hiatus sacralis’in tabanı ise S4 (%32) ve S5 (%68) seviyelerinde yer alıyordu. Sonuç: Çalışmadan elde edilen veriler ışığında os sacrum’un kemik yapılarındaki bu çeşitliliğin sakral bölgede yapılan girişimsel işlemlerde işlem metodunu etkileyebileceği veya referans noktası olmaları bakımından önem teşkil edebileceği düşünüldü.

Anahtar Kelimeler

• foramina sacralia posteriora
• hiatus sacralis
• morfoloji
• Os sacrum
• varyasyon

Kaynakça

1. Kaynaklar 1. Nastoulis E, Karakasi MV, Pavlidis P, Thomaidis V, Fiska A. Anatomy and clinical significance of sacral variations: a systematic review. Folia Morphol (Warsz). 2019;78(4):651-667.
2. 2. Sekiguchi M, Yabuki S, Satoh K, Kikuchi S. An anatomic study of the sacral hiatus: a basis for successful caudal epidural block. Clin J Pain. 2004;20(1):51-54.
3. 3. Bagheri H, Govsa F. Anatomy of the sacral hiatus and its clinical relevance in caudal epidural block. Surg Radiol Anat. 2017;39(9):943-951.
4. 4. Wu LP, Li YK, Li YM, Zhang YQ, Zhong SZ. Variable morphology of the sacrum in a Chinese population. Clin Anat. 2009;22(5):619-626.
5. 5. Cheng JS, Song, J. K. Anatomy of the sacrum. Neurosurgical Focus. 2003;15(2), 1-4.
6. 6. Seema Singh M, Mahajan, A. An Anatomical Study of Variations of Sacral Hiatus in Sacra of North Indian Origin and Its Clinical Significance. Int J Morphol. 2013;31(1),110-114.
7. 7. Singh R. Classification, causes and clinical implications of sacral spina bifida occulta in Indians. Basic Sci Med, 2013;2(1),14-20.
8. 8. Singh R. Classification and analysis of fifth pair of sacral foramina in indian dry sacra. Int J Morphol. 2014; 32(1):125–130.

9. 9. Singh R. Anatomical variations of sacral hiatus and associated clinical relevance-A review. Int J Anat Var. 2017, 4(10), 96-98.
10. 10. Singh A, Gupta R, Singh A. Morphological and Morphometrical Study of Sacral Hiatus of Human Sacrum. Natl J Integr Res Med. 2018; 9(4):65-73.
11. 11. Chen CP, Tang SF, Hsu TC ve ark. Ultrasound guidance in caudal epidural needle placement. Anesthesiology. 2004;101(1):181-184.
12. 12. Liguoro D, Viejo-Fuertes D, Midy D, Guerin J. The posterior sacral foramina: an anatomical study. J Anat. 1999;195 (Pt 2) (Pt 2):301-304.
13. 13. Aggarwal A, Aggarwal A, Harjeet, Sahni D Morphometry of sacral hiatus and its clinical relevance in caudal epidural block. Surg Radiol Anat. 2009;31(10):793–800.
14. 14. Povo A, Arantes M, Matzel KE ve ark. Surface anatomical landmarks for the location of posterior sacral foramina in sacral nerve stimulation. Tech Coloproctol. 2016; 20(12), 859-864.
15. 15. McGrath MC, Stringer MD. Bony landmarks in the sacral region: the posterior superior iliac spine and the second dorsal sacral foramina: a potential guide for sonography. Surg Radiol Anat. 2011;33(3):279-286.
16. 16. Senoglu N, Senoglu M, Oksuz H ve ark. Landmarks of the sacral hiatus for caudal epidural block: an anatomical study. Br J Anaesth. 2005;95(5):692-695.
17. 17. Bron JL, van Royen BJ, Wuisman PI. The clinical significance of lumbosacral transitional anomalies. Acta Orthop Belg. 2007;73(6): 687–695.
18. 18. Gray H. Gray’s Anatomy: The anatomical basis of clinical practice. 40th Edition Standring, S. (Ed.). London: Elsevier;2008.
19. 19. Nagar SK. A study of sacral hiatus in dry human sacra. J Anat Soc India. 2004; 53(2):18–21.
20. 20. Polat SÖ, Kabakcı AG, Öksüzler FY, Öksüzler M, Yücel AH. Sağlıklı Türk yetişkinlerinde os sacrum’un ve hiatus sacralis’ in klinik anatomisi ve morfometrik analizi. Cukurova Med J. 2020;45(2), 672-679.
21. 21. Nadeem G. Importance of knowing the level of sacral hiatus for caudal epidural anesthesia. J Morphol Sci. 2014;31(1):9–13.
22. 22. Kumar V, Nayak SR, Potu BK, Pulakunta T. Sacral hiatus in relation to low back pain in south Indian population. Kumar Bratisl Lek Listy. 2009;110(7):436–441.