The tibialis anterior muscle is known as the strongest extensor of the foot and ankle. Its tendon inserts at the base of the os cuneiforme mediale and the os metatarsale I but it is known that variations at the insertion exist.
The aim of this study is a precise analysis of the dimensions, shapes, and variations of the insertional footprints of the tibialis anterior tendon at the base of the os cuneiforme mediale and os metatarsale I. Forty-one formalin-fixed human cadaveric specimens were dissected. After preparation of the footprint of the tibialis anterior tendon, standardized photographs were made and the following parameters were evaluated: the footprint length, width, area of insertion, dorsoplantar location, shape, and additional tendon slips.
Twenty feet (48.8%) showed an equal insertion at the base of the os cuneiforme mediale and os metatarsale I, another 20 feet (48.8%) had a wide insertion at the os cuneiforme mediale and a narrow insertion at the os metatarsale I, and 1 foot (2.4%) demonstrated a narrow insertion at the os cuneiforme mediale and a wide insertion at the os metatarsale I. Additional tendon slips inserting at the metatarsal shaft were found in two feet (4.8%). Regarding the dorsoplantar orientation, the footprints were located medial in 29 feet (70.7%) and medioplantar in 12 feet (29.3%). The most common shape at the base of the os metatarsale I was the crescent type (75.6%) and the oval type at the os cuneiforme mediale (58.5%).
The present study provided more detailed data on the dimensions and morphologic types of the tibialis anterior tendon footprint. The established anatomical data may allow for a safer surgical preparation and a more anatomical reconstruction.