Keilbeins

Keilbeins, in human anatomy, are the cuneiform bones, a trio of wedge-shaped tarsal bones in the foot. The group consists of the medial, intermediate, and lateral cuneiforms (os cuneiforme mediale, intermedium, and laterale). They lie in the distal row of the tarsus between the navicular bone proximally and the bases of the first through third metatarsals distally; the lateral cuneiform also forms a joint with the cuboid.

Each bone is slender and wedge-shaped, with articular facets on its surfaces for articulations with neighboring bones. The medial cuneiform is the largest and forms key joints with the navicular proximally and the base of the first metatarsal distally; the intermediate cuneiform sits between the medial and lateral, articulating with the navicular and the bases of the second and third metatarsals; the lateral cuneiform contacts the navicular and the cuboid and bases of the third metatarsal.

Functionally, the cuneiforms contribute to the transverse arch of the foot and help stabilize the midfoot while enabling flexion and abduction movements. They also serve as attachment points for ligaments and small foot muscles.

In clinical practice, fractures of the Keilbeins are uncommon but can occur in high-energy injuries or crush injuries to the foot; diagnosis is by radiography, and treatment ranges from immobilization to surgical fixation if there is displacement or instability.

The term Keilbein is German for wedge bone; in English anatomy these bones are called the cuneiforms.