Anatomical variations of the calcaneofibular ligament in human foetuses.

Ligaments anatomy often show a huge anatomy variations between species and individuals. For example calcaneofibular ligaments (CFL) characterize the great variability of morphological shape or presence of additional bands. The aim of this study was to propose first anatomical classification of CFL concerning on human fetuses. We investigated thirty spontaneously-aborted human fetuses aged 18-38 weeks of gestation at death. Sixty lower limbs (30 left and 30 right) fixed in 10% formalin solution were examined. The morphological variability of CFL was assessed. Four types of CFL morphology were observed. Type I was characterized by a band shape. This was the most common type, occurring in 53% of all cases. Based on our study we are proposing a classification based on four morphological types of CFL. Types 2 and 4 are further divided into subtypes. Present classification may be useful to better understand the anatomical development of ankle joint.