Page 127 - Anatomy and Physiology of Farm Animals, 8th Edition

112 / Anatomy and Physiology of Farm Animals

(A)
VetBooks.ir Metacarpophalangeal

(fetlock) joint

Proximal interphalangeal
(pastern) joint

Distal interphalangeal
(coffin) joint

(B)

Metacarpo-
phalangeal
(fetlock) joint

Figure 6-10. Radiographs of equine digit (a lateral projection) (A) and fetlock (a cranial‐caudal projection)
(B). DS, distal sesamoid (navicular) bone; MCIII, third metacarpal bone; P1, proximal phalanx; P2, middle
phalanx; P3, distal phalanx; PS, proximal sesamoid bones. Source: radiographs courtesy of Susan Kraft, DVM.

the adult. The articular surface of the extends from the sacrum to the tuber
sacrum is held in tight apposition to the ischiadicum. It in part forms the lateral
wing of the ilium by a number of short, wall of the pelvis and provides a broad
strong ligaments. Movement in this attachment site for some hip and caudal
joint is normally severely limited, but it thigh muscles (Fig. 6‐11).
may become more extensive just prior to The equine sacroiliac joint can be
parturition, when the ligaments stretch partially separated (a sacroiliac sublux-
under the influence of the hormone ation) by a fall or other trauma. Such an
relaxin (see Chapter 28). Other ligaments injury produces pain and muscle spasm
in this area include dorsal and ventral and often becomes a source of chronic
sacroiliac and sacrotuberous ligaments. back soreness. Sometimes visible asymme-
The latter is a strong, wide band that try in the two tubera sacrales develops,