Page 128 - Anatomy and Physiology of Farm Animals, 8th Edition

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(A) (B)
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(C)

Figure 6-11. Ligaments of the pelvis, left lateral view. Sacrotuberous ligament red, dorsal iliosacral
ligaments blue. (A) Porcine. (B) Bovine. (C) Equine.

with the subluxated side displaced muscles, tendons, and ligaments effectively
upward. This sign is commonly called limit the normal range of motion to exten-
hunter’s bump. sion and flexion.
The coxofemoral (hip) joint is the best The stifle joint corresponds to the
example of a spheroid (ball and socket) human knee (Figs. 6‐12 and 6‐13). It com-
joint. The head of the femur is about two‐ prises the condyles of the distal femur, the
thirds of a sphere that is partially covered patella, and the proximal tibia. The femo-
by the acetabulum of the os coxae. The ral condyles are partially separated from
margin of the acetabulum is reinforced the proximal tibia by two intra‐articular
and deepened by a marginal cartilage menisci. Each meniscus is a half‐moon‐
(cartilaginous labrum). shaped disk that conforms to the surface of
The joint capsule of the hip joint is the proximal tibia and is concave on the
extensive, but not so extensive as that of upper surface to fit the respective condyle
the shoulder. The ligament of the femoral of the femur. These menisci help keep the
head (formerly round ligament) connects joint congruent and absorb shock. The stifle
the head of the femur with a nonarticular is stabilized by medial and lateral collat-
area within the acetabulum. The hip joint eral ligaments and by two intracapsular
of the horse is reinforced by an accessory cruciate ligaments that form an X as they
ligament that extends from the prepubic cross from the tibia to the femur in the
tendon to the head of the femur. It is pre- middle of the joint.
sumed to prevent significant abduction of The patella (kneecap) is a sesamoid
the pelvic limb. Movements in nearly all bone (the largest one of the body) embed-
directions are theoretically possible in ded in the tendon of insertion of the large
the hip joint, but as in the shoulder joint, cranial muscles of the thigh. This muscle