| Abstract [eng] |
Aim of the study: To identify the formation variations and frequency of the sural nerve by examining cadaveric specimens, and to assess the morphometric parameters of the sural nerve and its contributing structures. Methods: A pilot cross-sectional cadaveric study was conducted on nine formalin-fixed adult human cadavers at the Department of Anatomy, Histology, and Anthropology, Faculty of Medicine, Vilnius University. Standard dissection techniques were employed to examine the formation and course of the sural nerve. Morphometric parameters, such as nerve diameter and length, were measured using an RS PTO digital caliper with a precision of 0.01 mm. Variations in sural nerve formation were classified according to the system proposed by P.K. Ramakrishnan et al. Statistical analysis was performed using SPSS 26.0 and RStudio software, with the significance level set at p ≤ 0.05. Results: The distribution of sural nerve formation types among all 18 dissected limbs was as follows: type 1A in 4 limbs (22.2%), type 1B in 1 limb (5.6%), type 2 in 3 limbs (16.7%), type 3A in 6 limbs (33.3%), type 3B in 2 limbs (11.1%), type 4 in 1 limb (5.6%), and type 5 in 1 limb (5.6%). No instances of type 6 were observed. Symmetrical formation of the sural nerve in both lower limbs was observed in 5 out of 9 cadavers (55.6%). The average length of the sural nerve was 21.99 ± 6.27 cm, and the average diameter was 2.48 ± 0.68 mm. The sural nerve was significantly thicker in cases where it formed through the convergence of two branches (3.17 mm), compared to when it was a continuation of a single branch (1.93 mm, p = 0.001). Additionally, the nerve was significantly longer in two-contributor formations (25.80 cm) than in single-contributor formations (18.96 cm, p = 0.016). No statistically significant differences in nerve morphology were found between left and right limbs. The average distance from the nerve to the lateral malleolus was 1.3 ± 0.5 cm, and to its distal tip—1.5 ± 0.4 cm. The formation site was most frequently located in the middle portion of the leg—specifically, in the second (7/18 limbs, 38.8%) and third (9/18 limbs, 50%) quartiles of the leg length. Conclusions: The most common sural nerve formation variation in the Lithuanian population was type 3, observed in 8 out of 18 limbs (44.4%). Symmetrical nerve formation was found in 5 out of 9 cadavers (55.6%). The nerve formed by the fusion of two components was significantly thicker (3.17 mm) than the one formed as a continuation of a single branch (1.93 mm, p = 0.001), and also significantly longer (25.80 cm vs. 18.96 cm, p = 0.016). Keywords: sural nerve, anatomical variations, cadaveric study. |
