A Cadaveric Based Morphometric Analysis of the Sciatic Nerve with Clinical Implications

Background: The sciatic nerve is one of the very vital nerves of the body, which has importance not only in the field of Anatomy but also in various clinical fields such as Orthopaedics, Anaesthesia, Plastic & Reconstructive Surgery, and Neurosurgery. This study was the first attempt to analyze the different dimensions of the anatomically normal sciatic nerves at different levels, involving Malaysian cadavers.Material & Methods:The study was conducted on 78 adult, both cadaveric and disarticulated lower limb specimens belonging to both genders. The morphometric analysis was done in 64 specimens having anatomically normal sciatic nerves. The dimensions were measured by a digital Vernier caliper, a measuring tape, and thread.Results:The average width, thickness and circumference of the nerve at the lower border of piriformis muscle (PM) were 15.86 mm ± 1.47 (right) & 16.56 mm ± 1.08 (left); 4.22 mm ± 0.29 (right) & 4.10 mm ± 0.20 (left) and 27.70 mm ± 2.02 (right) & 27.72 mm ± 2.39 (left), respectively. Similarly, at the level between ischial tuberosity (IT) and greater trochanter (GT), the mean width was 11.59 mm ± 1.43 (right) & 11.50 mm ± 1.53 (left); thickness was 3.48 mm ± 0.18 (right) & 3.35 mm ± 0.17 (left) and circumference was 27.08 mm ± 2.79 (right) & 27.22 mm ± 2.87 (left). At bifurcation, the mean width was 8.66 mm ± 0.65 (right) & 8.90 mm ± 0.81 (left); thickness was 2.41 mm ± 0.12 (right) & 2.31 mm ± 0.15 (left) and circumference was 19.75 mm ± 1.44 (right) & 19.99 mm ± 1.45 (left). The average distance between IT and GT was 50.37 mm ± 4.47 (right) & 47.73 mm ± 4.24 (left); between lateral border of IT and medial border of sciatic nerve was 15.43 mm ± 1.45 (right) & 14.66 mm ± 1.37 (left); and between medial border of GT and lateral border of the nerve was 27.13 mm ± 1.38 (right) & 25.07 mm ± 1.73 (left). The average length of the nerve was 328.20 ± 26.26 (right) & 332.31 ± 21.89 (left); and that of the thigh was 412.19 ± 24.50 (right) & 407.24 ± 25.82 (left).Conclusion: This knowledge will not only aid future researchers but also will assist surgeons, orthopaedicians, anaesthetists, reconstructive surgeons, and neurosurgeons by preventing iatrogenic nerve injuries.