Length of the sesamoids and their distance from the metatarsophalangeal joint space in feet with incipient hallux limitus.

Background: We designed this study to verify whether the sesamoids of the first metatarsal head are longer than normal in feet with incipient hallux limitus, and whether feet with incipient hallux limitus are in a more proximal than normal sesamoid position.

Methods: In a sample of 183 dorsoplantar radiographs under weightbearing conditions (115 of normal feet and 68 of feet with slightly stiff hallux), measurements were made of the length of both the medial and the lateral sesamoids and of the distance between these bones to the distal edge of the first metatarsal head. These variables were compared between the normal and the hallux limitus feet. The relationship between these variables and the hallux dorsiflexion was also studied.

Results: We found significant differences between the two types of foot in the medial and lateral sesamoid lengths, but no significant difference in the distance between the sesamoids to the distal edge of the first metatarsal. A poor-to-moderate inverse correlation was found between hallux dorsiflexion and medial sesamoid length and between hallux dorsiflexion and lateral sesamoid length.

Conclusions: The length of the sesamoid bones of the first metatarsal head could be implicated in the development of the hallux limitus deformity.