Does the Embryologic Limb Rotation Modify the Distribution of Dermal Collagen and Elastic Fibers in Different Planes of Human Extremities?

Background: The collagen and the elastic fiber content of the dermis is known to show the asymmetric distribution across the planes of the body region. During the period of limb development, the upper and lower limbs rotate 90 degrees laterally and medially respectively. Objectives: The study aims to check if the limb bud rotation during embryonic development favors the unequal distribution of the dermal connective tissue fiber content distribution. Methods: A total of 240 skin samples from the forearm and thigh regions of adult human cadavers were collected in horizontal and vertical directions from the anatomical and oblique planes. The tissues were processed with tissue-quant analysis. The data were analyzed statistically using SPSS. Results: There were no significant differences in the pattern of distribution of the collagen and elastic fiber contents in the tissues of horizontal and vertical directions from the two planes of forearm and thigh regions. However significant Spearman's correlation was observed in both elements in the thigh region but only the collagen content in the forearm region. Conclusion: The pattern of distribution of connective tissue fibers in the dermis is regulated by the mechanical communications between the cells and their extracellular matrices. Hence, the significant role of embryologic limb rotation in the event of unequal distribution of dermal collagen and elastic fibers in the limb region is to be ruled out.