Inferoplantar longitudinal ligament
The inferoplantar longitudinal ligament is one of three components of the spring ligament complex, which stabilizes the longitudinal arch of the foot and supports the head of the talus .
Gross anatomy
The inferoplantar longitudinal ligament connects the lateral part of the coronoid fossa of the calcaneus with the inferolateral aspect of the navicular bone and runs lateral to the medioplantar oblique ligament .
Attachments
The origin of the inferoplantar longitudinal ligament is located in the lateral part of the coronoid fossa between the anterior and middle facets at the superomedial aspect of the anterior process of the calcaneus .
The navicular insertion is located lateral to the insertion of the medioplantar oblique ligament at the inferior proximal aspect or beak of the navicular bone .
Radiographic features
Like the medioplantar oblique ligament, the inferoplantar longitudinal ligament is inconsistently visualized on ultrasound but can be seen on MRI .
MRI
On MRI the inferoplantar longitudinal ligament can be visualized in 91% on axial and sagittal images lateral to the medioplantar oblique ligament, it is usually the thickest ligament and also displays a striated appearance .