Age-specific variations of the sciatic nerve in the paediatric hip: an MRI study

Christina Byun1, Nalini Pather2, Sarah Morris3

1Department of Anatomy, University of New South Wales, Sydney, Australia
2Faculty of Medicine, University of Queensland, Brisbane, Australia
3Department of Medical Imaging, Sydney Children’s Hospital, Sydney, Australia

Objective: In paediatric patients, sciatic nerve is one of the most commonly blocked peripheral nerve during surgical procedures of the lower limb. The success of the nerve blockade is determined by the accurate identification of the sciatic nerve, relative to surrounding anatomical landmarks. However, reports have demonstrated lack of understanding of the variations of the sciatic nerve in the gluteal region, especially in the growing children. Previously, an imaging study demonstrated the variation of the sciatic nerve branches in the popliteal region of the paediatric knee. This clinical imaging study aimed to analyse the morphometric variation of the sciatic nerve in the paediatric hip.
Methods: From a dataset of 132 magnetic resonance imaging scans, 84 were selected based on patient age (0 – 16 years), resolution, and presence of pathology. Morphometric parameters of the sciatic nerve were measured in relation to surrounding bony landmarks across six different levels.
Results: Sciatic nerve was found 5.4cm medial to the most lateral point of the greater trochanter at the levels of the ischial spine and the coccyx. Strong correlations were found between age and morphometric parameters, and stature. To predict the location of the sciatic nerve in the gluteal region, regression formulae using patient age was created.
Conclusion: This study is the first to report the morphometric changes of the sciatic nerve in the gluteal region in different age groups of children. The findings have implications for the posterior approach of the sciatic nerve blockade in paediatric patients aged 0 – 16 years.

Keywords: anatomy; child; hip; magnetic resonance imaging; sciatic nerve

Ethical statement: Ethical approval was obtained from the Sydney Children’s Hospital (LNR/16/SCHN/387)

Funding statement: -