While much is known about the ligament, the precise morphology and function of the thin layer of connective tissue lining its surface, termed the epiligament, have not been fully studied yet. Herein, we aimed at reviewing the recent findings on the structural and functional significance of the epiligament in both animal models and human tissue. The epiligament is made up of various connective tissue cells such as fibroblasts, fibrocytes, mast cells, and adipocytes and contains a number of neurovascular bundles. Arrangement of collagen fibers in the epiligament is rather chaotic, in multiple directions, which allows for greater mobility and resistance to stress. Differences in the collagen content and types of enzymes of the group of matrix metalloproteinases between the epiligament and the underlying ligament tissue have been reported and are reviewed herein. While the ligament tissue mainly contains collagen type I, the epiligament is also rich in collagen types III and V. As suggested by a number of studies, the epiligament plays a key role in ligament repair as a donor of cells and matrix metalloproteinases, particularly matrix metalloproteinase-2 and 9, which are essential for scar tissue remodeling. In conclusion, future studies will likely reveal additional functional aspects of the epiligament, which may allow scientists to devise more suitable treatment strategies for damaged ligaments in a world where injuries resulting from sports activities or daily routine have long merited their due attention.

Many questions regarding the morphology of the cardiovascular system are yet to be answered. In particular, elucidating the core principles of the architectonics of the myocardium is of great importance for the understanding of the exact mechanisms of the cardiac functions and the pathogenic processes which constitute a prerequisite for cardiovascular diseases. A number of contemporary studies reveal the importance of the myocardium in almost every disease -either as a primary pathophysiological unit or as the target of the pathological damage. It has to be stated that the myocardium has a remarkable diagnostic and therapeutic potential. It is comprised of various types of cells -contractile cardiomyocytes of the atria and ventricles, cells of the sinoatrial node and Purkinje fibres, the latter two being part of the conducting system of the heart. The ultrastructural components of these cells include the various structures which ensure cellular contact and communication, the specialised structures of the cellular and the sarcoplasmic membrane and the different elements of the complex cytoskeleton. Furthermore, the orientation of the cardiomyocytes plays a key role not only for the mechanical contraction but also in the electric conduction and the energy metabolism of the cardiac muscle. Studies on the size, alignment and specific characteristics of the cardiomyocytes have the potential to provide a morphological base for the diagnostics of various cardiac pathologies.

Background: The direct anterior approach (DAA) for mini-invasive hip surgery is becoming a preferred method owing to its reported benefits. The aim of the present study was to identify and describe the structures that are potentially at risk during the execution of this surgical procedure, as well as to discuss the potential advantages of using DAA in total hip arthroplasty (THA). Methods: Twenty sides' adult embalmed cadavers (12 male and 8 female) were examined at the Department of Anatomy, Histology and Embryology at the Medical University of Sofia, Bulgaria. We performed the incision of anterior approach and studied its relation to structures in proximity to the hip joint. Results: We identified the lateral femoral cutaneous nerve and the lateral femoral circumflex vessels as being potentially at risk when DAA to the hip joint is performed. We also observed and described their location and course and did not report the presence of any variations. Conclusion: This study demonstrates the location and course of the anatomical structures that may be encountered and damaged during DAA and provides important information intended to help surgeons minimize the risk of neurovascular injury.