A case of monolateral duplication of the Achilles tendon due to an anomaly of the medial gastrocnemius muscle.

: The authors describe the chance finding of a congenital morphological anomaly in the Achilles tendon, characterized by monolateral duplication as a result of anomalous differentiation of the medial gastrocnemius muscle. This may be added to the previous congenital deformities described in the literature (shortness of the Achilles tendon, its duplication as a result of the lack of fusion of the aponeurosis of the soleus and of the gastrocnemii, the presence of a supplementary medial gastrocnemius).