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Morphometric study of sciatic nerve and its topographic anatomical variations in relation to landmark structures around pelvis: a Nigerian population study
- Department of Anatomy, Lagos State University College of Medicine, Ikeja, Nigeria
- Department of Anatomy, College of Medicine of the University of Lagos, Idi-Araba, Lagos, Nigeria
open access
Abstract
Background: Sciatic nerve (SN) presents significant variations that pertain to its topography and divisions. The topographic variation shows sex effect due to differences in the dimension of pelvis that makes for the adaptability of female pelvis for pregnancy and childbirth. The objective therefore was to evaluate the SN morphology and its topographical variations in relation to landmark structures in the pelvis of both sexes.
Materials and methods: Ninety-eight lower limb adult cadavers, 66 males and 32 females devoid of any gross pathology from Nigerians were used for the study. The cadavers were dissected to expose the SNs and the variations recorded. Anthropological measurements were taken and analysed using a Spearman’s rank-order correlation model.
Results: The relationships between SN and the piriformis muscle shows five varied types with the typical type comprising 83.0%. The largest thickness of SN in males and females were 18.5 cm and 17.3 cm, respectively while the smallest thickness were 8.6 cm and 11.9 cm, respectively. The dimensions between posterior superior iliac spine and greater trochanter (PSIS-GT) and between lateral edges of SN intersection with piriformis to the tip of greater trochanter (LESN-GT) shows inverse correlation relationship between the two sexes. In males, there was a weak positive correlation (rs = 0.165) between LESN-GT (4.75 ± 1.52) and PSIS-GT (15.3 ± 2.90) which was not statistically significant at 0.01 level (p = 0.989). In females, the relationship between LESN-GT (6.39 ± 0.59) and PSIS-GT (12.2 ± 3.70) shows moderate negative correlation (rs = –0.476) which was not statistically significant at 0.01 level (p = 0.195).
Conclusions: The dimension of LESN-GT which was observed to be longer in females was deemed to account for the deviation of sciatic nerve of females from the males’ topographic anatomical relations.
Abstract
Background: Sciatic nerve (SN) presents significant variations that pertain to its topography and divisions. The topographic variation shows sex effect due to differences in the dimension of pelvis that makes for the adaptability of female pelvis for pregnancy and childbirth. The objective therefore was to evaluate the SN morphology and its topographical variations in relation to landmark structures in the pelvis of both sexes.
Materials and methods: Ninety-eight lower limb adult cadavers, 66 males and 32 females devoid of any gross pathology from Nigerians were used for the study. The cadavers were dissected to expose the SNs and the variations recorded. Anthropological measurements were taken and analysed using a Spearman’s rank-order correlation model.
Results: The relationships between SN and the piriformis muscle shows five varied types with the typical type comprising 83.0%. The largest thickness of SN in males and females were 18.5 cm and 17.3 cm, respectively while the smallest thickness were 8.6 cm and 11.9 cm, respectively. The dimensions between posterior superior iliac spine and greater trochanter (PSIS-GT) and between lateral edges of SN intersection with piriformis to the tip of greater trochanter (LESN-GT) shows inverse correlation relationship between the two sexes. In males, there was a weak positive correlation (rs = 0.165) between LESN-GT (4.75 ± 1.52) and PSIS-GT (15.3 ± 2.90) which was not statistically significant at 0.01 level (p = 0.989). In females, the relationship between LESN-GT (6.39 ± 0.59) and PSIS-GT (12.2 ± 3.70) shows moderate negative correlation (rs = –0.476) which was not statistically significant at 0.01 level (p = 0.195).
Conclusions: The dimension of LESN-GT which was observed to be longer in females was deemed to account for the deviation of sciatic nerve of females from the males’ topographic anatomical relations.
Keywords
sciatic nerve, morphometry, topography, variations
Title
Morphometric study of sciatic nerve and its topographic anatomical variations in relation to landmark structures around pelvis: a Nigerian population study
Journal
Issue
Article type
Original article
Pages
44-51
Published online
2020-12-05
Page views
5895
Article views/downloads
1557
DOI
Pubmed
Bibliographic record
Folia Morphol 2022;81(1):44-51.
Keywords
sciatic nerve
morphometry
topography
variations
Authors
G. Mbaka
A. Osinubi
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