The so-called hock-joint, like the knee, is formed of a number of articulations, by which the various bones are enabled to move one upon the other. The extent of movement between the different pieces varies from a slight gliding action to a great range of flexion and extension.

In the tibio - tarsal articulation, or the "true hock-joint", seven ligaments are engaged, viz., two external lateral, three internal lateral, and an anterior and posterior.

Both external lateral ligaments are attached above to the tuberosity (outer malleolus) on the lower and outer part of the tibia. The superficial one, the longer and stronger of the two, passes down the outer side of the hock, and in its course becomes united with the astragalus, calcaneus, cuboides, and finally with the large and outer small metatarsal bones. The External Deep Ligament, on leaving the outer tuberosity of the tibia, inclines backward, and becomes attached to the astragalus and the calcaneus.

Posterior View of Stifle joint.

Fig. 360. - Posterior View of Stifle-joint.

1, Femur. 2, Tibia. 3, Fibula. 4, External condyle. 5, Internal condyle. 6, Internal lateral ligament. 7, Posterior crucial ligament. 8, Internal inter-articular cartilage. 9, Posterior ligament of cartilage. 10, External lateral ligament.