Page 45 - Adams and Stashak's Lameness in Horses, 7th Edition

Functional Anatomy of the Equine Musculoskeletal System 11

VetBooks.ir Suspensory ligament

Cruciate sesamoidean
ligaments
Lateral collateral
sesamoidean
ligament

Proximal 1
scutum
1

2 2 Extensor branch
of suspensory
ligament
Superficial Collateral
and middle sesamoidean
distal ligament
sesamoidean
ligaments
Lateral palmar
ligament of
Short sesamoidean Elastic ligament
ligaments pastern joint 3 to cartilage of
3 distal phalanx
4
Fibrocartilaginous plate
(middle scutum)

Distal digital annular ligament

Figure 1.11. Sesamoidean ligaments. Dashed lines indicate of (1) palmar annular ligament, (2) proximal digital annular ligament,
positions of the proximal sesamoid bones embedded in the (3) superficial digital flexor, and (4) deep digital flexor tendon.
metacarpointersesamoidean ligament. Numbers indicate cut stumps

inserts lateral to the common digital extensor tendon on ment on the middle phalanx. The abaxial palmar liga­
the proximal dorsal surface of the proximal phalanx. ments pass from the lateral aspects of the proximal
The proximal interphalangeal (pastern) joint is phalanx to the palmar surface of the middle phalanx.
formed by the condyle on the distal end of the proximal The axial ligaments blend somewhat with the branches
phalanx and two corresponding concave articular of the SDFT and the straight sesamoidean ligament, and
foveae on the proximal end of the middle phalanx. Two they may be difficult to discern as individual entities.
short collateral ligaments and four palmar ligaments The joint capsule of the pastern joint blends with
stabilize these bones. The collateral ligaments are ori­ the deep surface of the common digital extensor ten­
ented vertically between the eminences on the bones don dorsally where it is accessible for arthrocentesis
rather than parallel to the axis of the digit. The axial (Figure 1.10). It also blends with the collateral ligaments
pair of palmar ligaments extends from the ridges on the of the joint. The palmar aspect of the capsule extends
palmar side of the proximal phalanx to the region on slightly proximad, compressed between the middle pha­
each side of the straight sesamoidean ligaments’ attach­ lanx and the terminal branches of the SDFT and the