Appendicular Skeleton - Pelvic Limb

• Hip bones refer to ilium, pubis, and ischium
• Bony pelvis refers to the ring of bone around the pelvic cavity composed of two symmetrical hip bones, sacrum, first few caudal vertebrae
• Pelvic inlet is the cranial opening into the pelvic cavity
• Pelvic outlet is the caudal opening out of the pelvic cavity
• Ilium is the largest and the most cranial part of the os coxae
• ILIUM comparative (Shape and orientation of wings):

  Oblong with a more or less saggital orientation in dog and cat. Triangular and almost vertical in horse and ruminants
• ILIUM comparative (Tuber Sacrale):

  Dorsally in smaller species, dorsomedially in large species
• ILIUM comparative (Tuber Sacrale):

  Reduced to two low (cranial and caudal dorsal) iliac spines in carnivores but is prominent in large animals in which it is close to the spinous processes of the vertebrae
• ILIUM comparative (Tuber Sacrale):

  Close to each other at the midline in ox and horse so that very little spaces separates the two
• ILIUM comparative (Tuber Sacrale):

  Widely separated in the dog (by a notch) and pig
• ILIUM comparative (Tuber Sacrale):

  Higher than the tuber coxae in the horse and about the same level in the dog and pig
• ILIUM comparative (Tuber Coxae):

  Ventrally in smaller species; ventrolaterally in larger species
• ILIUM comparative (Tuber Coxae):

  Reduced to two lown (cranial and caudal ventral) iliac spine in carnivores but is prominent in larger species (horse and ox)
• ILIUM comparative (Tuber Coxae):

  Forming the point of the tip at the dorsocaudal corner of the flank. It is also called hook in the ox, a palpable prominence on the lateral wing
• ILIUM comparative (Iliac crest/cranial border):

  Thickened and convex in carnivores and pig; thin (sharp) and concave in horse and ruminants
• ILIUM comparative (Gluteal Surface):

  Faces dorsally in horse and ox, Laterally in the pig and dog
• ILIUM comparative (Arcuate Line):

  Carries the psoas tubercle midway along it's length except in the dog. It serves for the attachment of the psoas muscle
• Pubis is the cranioventral part of the os coxae; L shaped, consists of cranial (acetabular) and caudal (symphysial) branches
• The lateral end of the cranial branch contributes to the acetabulum and is known as the body
• Cranial ramus extends from the body to the medial plane where it meets it's fellow of the opposite side to form the pubis symphysis  
• Caudal ramus passes caudally from the medial portion of the cranial ramus
• Ischium forms the most caudal part of the hipbone
• Body - the extremity of the acetabular notch that contributes to the articular cup
• ISCHIUM comparative (Ishcial Spine):

  Marked by the origin of gluteus profundus, it is relatively low in the dog and particularly high in ruminants
• ISCHIUM comparative (Ischiatic Tuberosity):

  A roughened swelling at the caudolateral corner of the plate, it is a horizontal thickening in the dog, a conspicuously triangular swelling in cattle. It is the "pin bone" in ox
• ISCHIUM comparative (Ischiatic Tuberosity):

  In most species, it is subcutaneous and it may be a visible landmark
• ISCHIUM comparative (Ischiatic Tuberosity):

  Tuber ischiadicum is represented by a thickened ridge in the horse and dog, by a caudally directed process with a lateral tubercle in the pig and by trituberculate process in the ox
• ISCHIUM comparative (Ischiatic Tuberosity):

  Are placed at a higher level than the acetabulum in the ox, at the same level in the horse, and a lower level in the dog and pig
• In horse, When the angle is less than 30 degrees, and the two tubers come close to sharing the same horizontal plane, the tail appears to be set high
• In horse, When the angle is greater than 30 degrees, the animal is said to be goose-rumped. The croup is short and the hamstring muscles are reduced in length and in the leverage they may exert
• Acetabulum is a deep articular cup (cotyloid) to which all three bones contribute
• The articular part is crescentic and is cut internally by a rough non-articular depression, the acetabular fossa
• The medial part of the rim is cut into by the acetabular notch
• PELVIC GIRDLE comparative (Pelvic Cavity):

  In dog, pelvic outlet is larger than the inlet  
• PELVIC GIRDLE comparative (Pelvic Cavity):

  In pigs, horse, and ox, pelvic inlet is larger than the outlet
• PELVIC GIRDLE comparative (Pelvic Cavity):

  Lateral wall of the pelvic cavity is formed by the broad ligament in the pig, ox, and horse, and by sacrotuberous ligament in dog
• PELVIC GIRDLE comparative (Sexual dimorphism):

  Female has a concave pubic floor and large pelvic outlet
• PELVIC GIRDLE comparative (Sexual dimorphism):

  Male has convex pubic floor and small pelvic outlet