OS COXAE.pptx

anatomy of os coxae in domestic animals

1. VETERINARY COLLEGE HASSAN VETERINARY ANATOMY SUBMITTED TO: Dr.Rajashailesh N M HOD Dept. of Veterinary Anatomy SUBMITTED BY: Swaroop R Jr.MVSc Dept. of VSR COMPARATIVE ANATOMY OF OS COXAE

2. OS  COXAE The  os coxae  or  hip  bone  consists of three flat bones,  ilium ,  ischium  and  pubis , which fuse together to form the  acetabulum . The ilium extends from the  acetabulum  upwards forming the lateral wall of the pelvic cavity. The pubis and ischium extend medially and backward respectively and their medial borders fuse with those of the opposite side to form the  pelvic/ ischio -pubic symphysis. The pubis and ischium form the anterior and posterior parts respectively of the floor of the bony pelvis and enclose between them on each side, a large  obturator foramen.

3. Ilium The  ilium  is the largest of the three parts. It is irregularly triangular being wide above narrow and prismatic at the middle and slightly expanded below. It presents  two surfaces, three borders and three angles . The  lateral  or  gluteal surface   is directed dorso -laterally and backward. The inferior third of this surface presents rough lines for the origin of the  gluteus profundus .   This surface is traversed by the gluteal line running nearly parallel to the cotyloid edge from a little below the tuber coxae to become continuous with the ischiatic spine. This surface serves for the origin of the  gluteus medius .

4. The  medial  or  pelvic surface  presents a rough triangular medial part-the  sacral surface   and a smooth quadrilateral part -the  iliac surface . The former presents an irregular facet, the articular surface for the  sacrum . The iliac surface is directed forward and is covered by  iliacus . The  ilio-pectineal  line , which separates these two surfaces, begins below the articular surface and joins the anterior border of the pubis and forms the lateral boundary of the pelvic inlet. It bears about the middle the  psoas tubercle   for the  psoas minor.

5. The  cotyloid border   leads to the  acetabulum , little above and infront of which are two depressions (the lateral one is faint) for the origin of the  rectus femoris . The  ischiatic border  is concave and forms the  greater isciatic notch The notch forms the greater ischiatic foramen which is covered by the sacro -sciatic ligament in life and serves for the passage of gluteal nerves and anterior gluteal vessels . In its lower part, it is convex, rough and is continuous with the ischiatic spine, which gives attachment to the sacro -sciatic ligament at its free edge and to the  gluteus profundus   on its lateral aspect. The  dorsal border  or  the crest  of the ilium is concave thick and rough for the attachment of the muscles of the loin.

6. The  medial angle  or  tuber sacrale   is separated from its fellow and forms with it and the sacrale spines, the  point of the croup. The  lateral angle  or  tuber coxae   is large and prominent, wide in the middle and smaller at either end and serves for the attachment of the iliacus   obliquus abdominis internus tensor fasciae latae gluteus medius   etc. The  inferior  or  acetabular angle  is thick and meets the other two parts at the  acetabulum .

7. Ishium smaller than ilium. irregularly quadrilateral and placed behind the ilium and the pubis. two surfaces   dorsal pelvic surface - slightly concave transversely and forms posterior part of pelvic floor. ventral surface   presents about its middle a rough ridge for the  biceps femoris.  It is roughened for the origin of the  adductor  muscles of the thigh.

8. four borders anterior border is concave and forms posterior boundary of obturator foramen. posterior border   slopes forward and downward and meets same borders of its fellow to form ischial arch   medial border   with its fellow form   ischiatic symphysis presents ventrally a ridge which gives attachment to suspensory ligament of penis in male and udder in female   lateral border   is concave and forms the  lesser isciatic notch   and is continuous with ischiatic spine.

9. antero-lateral angle joins ilium and pubis at   acetabulum .   postero lateral angle- tuber ischii  is trifid process serves for origin of   biceps femoris, semitendinosus and semimembranosus.

10. Pubis S mallest of three I rregularly triangular Two surfaces   dorsal  or  pelvic surface  forms anterior part of pelvic floor urinary bladder rests on it  ventral surface  is rough for muscular attachment.  

11.   T hree borders A nterior border is thick Laterally it bears ilio-pectineal eminence and curves for the attachment of the prepubic tendon.  Posterior border forms - anterior margin of obturator foramen. M edial border meets same border of its fellow at the pubic symphysis. Acetabular angle joins the ilium and the ischium at the  acetabulum . Medial borders of pubis and ischium meet corresponding borders of their fellows to form   pelvic symphysis  / Ischio -pubic symphysis 

12. Acetabulum C otyloid cavity on ventro -lateral aspect by meeting of its three components Articular part nearly circular and articulates with head of femur rim of the cavity on its postero -medial aspect - acetabular notch , which transmits round ligament of   hip joint N on-articular part acetabular fossa   is situated in depth of   acetabulum Another small notch may be seen antero-medially, though sometimes it is replaced by a foramen or is absent.

13. Obturator foramen It is a large, elliptical opening on the floor of pelvis and is circumscribed by ischium and pubis. C overed by obturator muscles.

14. Sexual differences The ischial arch is wider and the outlet is larger in the female than in the male. The conjugate (vertical) and transverse diameters are greater in the female so that the cavity is roomier. The pubis and the ischium of the opposite sides meet at a more open angle in the female than in the male.

15. Sheep and Goat The long  axis  of the ilium is almost in straight line with that of ischium. Greater ischiatic spine is low and everted. Ischial symphysis is not ossified even in old animals. Acetabulum  is large and deep. The pelvic brim is elliptical in outline.

16. Horse The gluteal line is very faint. The tuber coxae is large and compounded four tuberosities arranged in pairs. The pelvic surface of the ischium is less concave and meets its fellow at a more open angle. The ischial arch is wide and shallow. The ridge on the inferior face of the ischium is absent. The symphyseal ridge is also absent.

17. The tuber ischii is not trifid and its lower border forms the ventral ischiatic spine. The ventral face of the pubis crossed near the anterior border by the pubic groove which leads to the acetabular notch which transmits the pubo -femoral or the accessory and round ligaments of the hip to  femur The acetabular notch is on the medial part of the rim.

18. Pig Os coxae is long and narrow. The ilium and ischium are almost in line with each other. The gluteal surface is divided into two fossa by a ridge which is continuous with the greater ischiatic spine behind. The iliac crest forms the highest point of the  bone There is a crest or tubercle on the ventral surface of the ischium. The ilio-pectineal line is prominent and the psoas tubercle is well marked. Pelvic inlet is elliptical in outline.

19. Dog The ilium is nearly in a vertical plane. The gluteal surface is concave. The crest of the ilium is strongly convex . The ischium has a twisted appearance . The lesser ischiatic notch is absent. The  acetabulum  is deep. The symphyseal part of pubis is thick and fuses late with the opposite  bone .

20. Fowl The  ilium  is elongated and extends over the entire length of the hipbone. It is firmly fused to the transverse processes of the lumbo-sacral mass. The pelvic face is concave for the lodgment of kidney . The lateral border is free in its anterior half but is fused with the ischium behind. The  ischium  is smaller and lies below and lateral to the posterior part of the ilium is triangular. The sciatic foramen is formed by the adjacent borders of the ischium and ilium behind the  acetabulum The ventral border forms the obturator foramen with the pubis. The  pubis  is a long and slender rod running along the ventral border of the ischium. The anterior end has a muscular process. The  acetabulum  is large and perforated and presents at its supero -posterior part process -  anti-trochanter  for articulation with the great trochanter of the  femur .

21. Clinical aspect Pelvic radiographs are used in: Cases of trauma Evaluation of lameness Evaluation of congenital disorders ( eg , hip dysplasia).

22. Norberg angle (NA) is a measurement of femoral head displacement from the acetabulum. NA is calculated by drawing a line connecting the centers of the femoral heads and one from the center of each femoral head to the craniolateral acetabular rim on the same side. NA ≥105 degrees is considered normal by one source. This dog’s Nas of 96 degrees and 93 degrees on left and right hips, respectively, are consistent with increased hip laxity.

23. The distraction index is the measurement of maximal femoral head displacement from the acetabulum when the legs are placed in a neutral position and a distractive force is applied. The distraction index is calculated by dividing the distance between the geometric center of the femoral head and the geometric center of the acetabulum by the radius of the femoral head. Risk of osteoarthritis increases as the distraction idex exceeds 0.3

24. The distraction device is placed between the hind legs of the patient The knee joints are pressed towards one another in a 90° angle Distraction device

25. Percentage of femoral head coverage (% FHC) is a measurement of femoral head displacement from the acetabulum. Normal FHC (i.e., good hip joint congruity) is defined as ≥50% coverage

26. VENTRO DORSAL VIEW