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Original article
Submitted: 2020-06-09
Accepted: 2020-09-23
Published online: 2020-12-05
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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

G. Mbaka1, A. Osinubi2
DOI: 10.5603/FM.a2020.0144
·
Pubmed: 33330968
Affiliations
  1. Department of Anatomy, Lagos State University College of Medicine, 1-5 Oba Akinjobi Street, 234 Ikeja, Nigeria
  2. Department of Anatomy, College of Medicine of the University of Lagos, Idi-Araba, 234 Lagos,, Nigeria

open access

Ahead of Print
ORIGINAL ARTICLES
Submitted: 2020-06-09
Accepted: 2020-09-23
Published online: 2020-12-05

Abstract

Background: Sciatic nerve 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 sciatic nerve 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, sixty-six males and thirty-two females devoid of any gross pathology from Nigerian were used for the study. The cadavers were dissected to expose the sciatic nerves and the variations recorded. Anthropological measurements were taken and analysed using a Spearman’s rank-order correlation model.

Results and Conclusions: The relationships between sciatic nerve 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 sciatic nerve 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). 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 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 sciatic nerve 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, sixty-six males and thirty-two females devoid of any gross pathology from Nigerian were used for the study. The cadavers were dissected to expose the sciatic nerves and the variations recorded. Anthropological measurements were taken and analysed using a Spearman’s rank-order correlation model.

Results and Conclusions: The relationships between sciatic nerve 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 sciatic nerve 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). 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.

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Keywords

sciatic nerve, morphometry, topography, variations

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Title

Morphometric study of sciatic nerve and its topographic anatomical variations in relation to landmark structures around pelvis: a Nigerian population study

Journal

Folia Morphologica

Issue

Ahead of Print

Article type

Original article

Published online

2020-12-05

DOI

10.5603/FM.a2020.0144

Pubmed

33330968

Keywords

sciatic nerve
morphometry
topography
variations

Authors

G. Mbaka
A. Osinubi

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