Assessment of the position of the navicular by three-dimensional magnetic resonance imaging in infant foot deformities.

As the navicular is unossified in infants with foot deformities, until 5 years old (boys) and 3 years old (girls), it is difficult to give the exact position of hindfoot bones. Magnetic resonance imaging associated with three-dimensional reconstruction allows the visualization of the cartilaginous volume of the bones and the measurement of the relationships of the navicular with the talus. In normal feet, we noted that in the coronal plane the navicular was laterally situated (75%) relative to the talus. In club feet (17 patients), the navicular and the cuboid had a large medial displacement (77%) with a slight pronation movement in the sagittal plane. In suspected skewfoot (seven feet) we noted three cases with a lateral subluxation of the navicular. This objective technique of measurement may be of value for diagnosis and treatment of foot deformities.