Morphometric Study and Anatomical Variations of the Medial Ligament of the Talocrural Joint Estudio Morfométrico y Variaciones Anatómicas del Ligamento Medial de la Articulación Talocrural

The aim of this study was to perform a descriptive study of the morphology, anatomical variations and morphometry of medial talocrural (or deltoid) ligament. We dissected 27 lower limbs obtained from amputations without histories of age, sex or disease. The measurements were made with a caliper, compass and ruler, expressing the results in millimeters. We described the superficial layer morphology of the medial ligament, measuring the size and ligament’s thickness. For the deep layer we described and measured the length (l), width (w) and thickness (t). Results: Superficial layer: trapezoid form=66.7% (anterior margin=30.5 mm; posterior margin=27.6 mm; top margin=22.6 mm; bottom margin=50.5 mm), rectangular form=19% (anterior margin=19.3 mm; posterior margin=27.2 mm; top margin=24.4 mm; bottom margin=29.8 mm), triangular form=14.3% (anterior margin=37 mm; posterior margin=37.8 mm; bottom margin=48.3 mm). The average thickness of the superficial layer was 3.6 mm. Deep layer of the medial ligament: l=6.9 mm, w=11 mm, t=5.7 mm; presented rectangular form in 100%. In 76.2% of the specimens, the deep layer was covered completely by the superficial layer; however, in 23.8% the coverage is incomplete, showing the deep layer by posterior angle. The literature is contradictory regarding the anatomy and variations of the medial ligament of the ankle. There are important differences in morphology, attachments, subdivisions and relationships between the two layers of the deltoid ligament. Conclusions: We found significant anatomical variations in the morphology and the relationship between the superficial and deep layers of the deltoid ligament.