Tarsal bones

Ox

The tarsal bone is composed of five short bones in Ox

Tibial tarsal (astragalus)

• It has six surfaces.
• The proximal and the dorsal face continuous and form a trochlea with vertical ridges for the tibia and the lateral malleolus.
• Distal face articulates with the fused central and 4th tarsal.
• The plantar face responds to fibular tarsal. A narrow elongated area on the medial aspect of the lower part of this face for the planter prolongation of the fused central and 4th tarsal.
• The lateral face is more depressed and shows two facets for the fibular tarsal.

Fibular tarsal (os calcis)

• It is  the largest tarsal, is placed behind and lateral to tibial tarsal.
• It has body and medial process -the sustentaculum tali.
• The lateral face of the body is flat and rough while the medial face presents two facets for the tibial tarsal.
• The process the sustentaculum tali-projects medially and presents a facet dorsally for tibial tarsal. The body is prolonged above to form the tuber calcis.

Fused central and fourth tarsal (scapho-cuboid)

• The proximal face presents two concave areas for the tibial tarsal, a projection postero-medially for the narrow medial facet on the distal face of the tibial tarsal and a narrow facet on its lateral aspect for fibular tarsal.
• The distal face is uneven. The medial half is higher in level and presents a large facet in front for second and third tarsal and a small facet behind for the first tarsal. The lateral half presents two facets separated by a transverse groove and articulates with the large metatarsal bone.

First tarsal (cuneiform parvum)

• It is a small round piece of bone situated at the postero-medial aspect of the tarsus.
• The proximal face articulates with the fused central and 4th tarsal.
• The distal face with the large metatarsal and the dorsal face with the fused second and third tarsal.

Fused 2nd and 3rd tarsal (cuneiform magnum)

• It is placed beneath the fused central and 4th tarsal on its medial aspect.
• The proximal face is concavo-convex from before backward and articulates with the fused central and 4th tarsal.
• The distal face articulates with the large metatarsal.
• The plantar face has a facet for the first tarsal.
• The dorsal and medial faces are continuous, convex and rough.

Sheep and Goat

Tarsal bones of sheep and goat are Similar to ox

Horse

Horse has six tarsal bones

1. In the tibial tarsal, the ridges of the trochlea curve obliquely downward and outward. The lateral face has no facets for the fibular tarsal.
2. The fibular tarsal is short and thick. It does not articulate with the lateral malleolus. The medial process is larger.
3. The central tarsal (scaphoid) is not fused to the fourth tarsal (cuboid). It is flat and irregularly quadrilateral. The proximal face is concave and articulates with the tibial tarsal. The distal face is convex and articulates with the third tarsal and the fused 1st and 2nd tarsal. The dorsal and the medial borders are continuous and rough. The lateral border is oblique and has two faces for the cuboid.
4. The fused 1st and 2nd tarsal (cuneiform parvum) is irregular in shape. The medial face is convex. The lateral face is concave. The proximal face is concave and has two facets for the central tarsal. The distal face articulates with the large and the medial small metatarsals. The plantar end is prolonged downward into a nodular projection.
5. The third tarsal (cuneiform magnum) is triangular in outline. The proximal face is concave and articulates with central tarsal. The distal face is convex and is for the large metatarsal. The medial border has no facet for the fused 1st and 2nd tarsal and the lateral has two facets for the fourth tarsal.
6. The fourth tarsal (cuboid) has six surfaces. It is not fused to the central tarsal. The proximal face is convex transversely and is for the fibular tarsal and the tibial tarsal. The distal face presents two facets separated by a sagittal ridge for the lateral small metatarsal bones. The medial face has facets for the central and the third tarsal. The dorsal, lateral and the plantar surfaces are convex and rough

Pig

Pig has seven Tarsal bones

Dog

Dog has seven Tarsal bones

Rabbit

Rabbit has six Tarsal bones

Fowl

• The tarsal bone is absent as such in the adult fowl.
• In the proximal row the embryonic elements fuse with the tibia and in the distal row with the metatarsus.