BONES OF THE PELVIC LIMB 



205 



The tarsus comprises seven bones. The tibial tarsal consists of a body, neck, 

 and head, like the bone in man. The body presents a proximal trochlea for articula- 

 tion with the tibia and fibula. The plantar surface has three facets for articulation 

 with the fibular tarsal bone. The head is directed a little inward and articulates 

 with the central. The fibular tarsal has a long anterior process or "beak," but 

 the sustentaculum is short. The tuber calcis presents a sagittal groove. The 

 central has a concave proximal surface adapted to the head of the tibial tarsal. 

 Its distal surface articulates with the first, second, and third tarsals. It bears two 

 plantar tubercles. The first tarsal is flattened and irregularly quadrangular; its 

 proximal surface articulates with the central and the distal with the first metatarsal. 



Sulciis muscu- 

 laris 



Head of fibula 



Tuberosity 



Spine 



Medial -^.^.j^ 

 condyle T *S*i 



Medial con- 

 dyle 



■ Lateral 

 condyle 



■ Head of fibula 



Interosseous ■ 

 space 

 Shaft of fibula . — L 



■ Crest of tibia 



Shaft of tibia - 



- Shaft of tibia 



Interosseous space 



Lateral 

 malleolus ' 



Medial 

 ' malleolus 



Medial . 

 malleolus 



Lateral malleolus 



Fig. 



226. — Right Tibia and Fibula of Dog; Ante- 

 rior "S'lEW. 



Fig. 227. — Right Tibia and Fibula of Dog; Poste- 

 rior "V'lEW. 



The second tarsal is the smallest and is wedge-shaped; it articulates distally with 

 the second metatarsal bone. The third tarsal is also wedge-shaped, the base being 

 in front; it articulates with the third metatarsal distally. The fourth tarsal is 

 remarkably high, and resembles a quadrangular prism; its proximal surface 

 a,rticulates with the fibular tarsal, its distal with the fourth and fifth metatarsal, 

 and the medial with the central and third tarsal bones. A groove for the tendon of 

 the peroneus longus crosses its lateral and plantar surface, and above it are one or 

 two tubercles. The tuber calcis fuses with the body of the bone at fourteen or 

 fifteen months. 



Five metatarsal bones are present. The first is commonly very small and has 

 the form of a blunt cone, somewhat compressed laterally. It articulates with the 



