Cuneiform (anatomy)

As cuneiform (Latin for " sphenoid ", plural cuneiform bones ) or Os are three tarsal bone called that are a part of the tarsus of the foot. They lie between the scaphoid ( navicular ) and the 1st to the 3rd metatarsal.

Designations

The German -language name cuneiform bones indicates the wedge shape of the bones, which can lead ( sphenoid bone ) to confusion with the sphenoid bone of the skull. The cuneiform bones are numbered from the inner ( medial ) edge of the foot toward the outer ( lateral ) margin of the foot with the numbers 1 to 3 ( → metatarsal ). As an alternative to the numbering can be the wedge legs also give the following names:

• The first sphenoid is also referred to as the inner sphenoid bone, medial cuneiform or Os tarsal primum and is the largest of the three bones.
• The third sphenoid is also referred to as the outer sphenoid, lateral cuneiform or Os tarsal tertium.

Joint surfaces

The forward-facing ( distal) side of the cuneiform bones have articular surfaces on the 1st to 3rd metatarsal. The joints formed with the metatarsal bones are called tarsometatarsal joints ( articulationes tarsometatarsales ) and are an integral part of the Lisfranc joint line. To the rear ( proximal) the cuneiform bones have articular surfaces of the scaphoid. The joints formed here are referred to in the singular as articulation cuneonavicularis and numbered according to the cuneiform bones.

Cuneiform bones and transverse arch

The dorsum of the foot to ( dorsum of the foot ) located towards sides of the wedge legs are wider than the sole of the foot ( sole of the foot ) situated pages. This gives the wedge legs have a wedge shape. Through this form, they form as the stones of a brick arch bridge the transverse arch of the foot. The wedge shape is also found in the bases of the metatarsal bones again.

• Bones of the lower extremity