Page 379 - Canine Lameness

20.2 Normal Anatomy 351

(A) (C)

(B) (D)

Figure 20.2 Normal anatomy of the hip region: (A) ventrodorsal and (B) lateral radiographic views of a
normal immature dog; (C) ventrodorsal and (D) lateral radiographic views of a normal adult dog. The arrows
indicate the (white arrow) physis of greater trochanter; (black arrow) capital physis; (red arrow) pubic
symphysis; (a) pelvis; (b) femur; (c) obturator foramen; (d) ilial body; (e) L7; (f) sacrum; (g) pubis; (h) ischium;
(i) ischiatic tuberosity; (j) acetabulum; (k) sacroiliac joint; (l) greater trochanter; (m) femoral head; (n) lesser
trochanter; (o) tuber coxae; and (p) tuber sacrale.
with the middle gluteal tendon. The superficial gluteal extends the pelvic limb as well as HIP REGION
contributing to abduction; its origin is the lateral border of the sacrum and Cd1 and the sacrotuber-
ous ligament extending distal to insert on the third trochanter. The sacrotuberous ligament runs
from the transverse process of S3 and Cd1 to the lateral angle of the ischiatic tuberosity. As a group,
the gluteal muscles are innervated by the cranial and caudal branches of the gluteal nerve.
The quadratus femoris, gemelli, and the internal and external obturator muscles make up the
caudal hip muscles. This group of muscles is innervated by the sciatic nerve and primarily allows
rotation of the femur as the stifle turns outward (creating a supination-like effect). They also
antagonize the middle gluteal muscle, which tends to pronate the femur (i.e. moves the stifle
inward).
The adductor muscle is the primary adductor of the pelvic limb originating on the entire pelvic
symphysis, ischiatic arch, and ventral pubis and ischium. It also has a large insertion area covering
the entire lateral lip of the caudal surface of the femur. Also originating from the pubis at the
iliopubic eminence of the pubic tubercle is the pectineus, inserting on the distal end of the medial
lip of the caudal face of the femur. Along with the adductor, the pectineus contributes to hip
adduction. They are both innervated by the obturator nerve.
The iliopsoas muscle is comprised of the psoas major and iliacus muscle and is innervated by the
femoral nerve. The psoas major originates from the transverse processes of L2 and L3 and the bod-
ies of L4 through L7. The iliacus originates on the ventral surface of the ilium. They combine to