1. PELVIMETRY

2. The bony structures of the pelvis is comprised of
Sacrum
First to third coccygeal vertebra, and
The two os coxae, each formed by the
Ilium
Ischium, and
Pubis.

3. Sacrum
In cow, sacrum is formed by the fusion of five vertebrae.
In older cow, horse and pig, the first coccygeal vertebra may fuse with the sacrum.
Ilium
Irregularly triangular in shape.
Broad, flat, dorsal part of the ilium is referred to as the Wing.
The external portion of the wing of the ilium is referred to as the tuber coxae, hip bone, or “HOOK” bone.

5. Ischium
Forms the caudal part of the ventral floor of the pelvis.
Caudal lateral portion of these bones are referred to as tuber ischii or “PIN” bones.
In pig, tuber ischii are largely cartilaginous and complete ankylosis of the symphysis does not occur until 6-7 years of age.
In sow and cow, ischiatic spines are prominent.
Pelvic symphysis is formed by the medial fusion of ischial and pubic bones.
In cow and ewe, the portion of the pelvic floor formed by the two ischial is deeply concave from side to side.

7. Pubis
Smallest bone of the os coxae and forms the cranial portion of the pelvic floor.
Pelvic surface is smooth
In females: concave
In males: convex
In young cows, on the cranial portion of the pubic symphysis, occasionally a sharp tuberosity projects and may rarely result in contusion or laceration of the birth canal during dystocia.
Acetabulum
Formed by the fusion of ilium, ischium and pubis.
These bones form a cotyloid cavity for lodging the head of the femur.

8. Form the non-bony part of the pelvis.
PELVIC LIGAMENTS
Form the non-bony part of the pelvis.
To maintain the relationship of the pelvis to the spinal
column, there are three, single or paired, pelvic ligaments.
1. Dorsal and lateral sacroiliac ligaments – attached to the medial wing of the ilium and lateral portion of the sacrum and the summits of the sacral spines

9. 2. SACROSCIATIC LIGAMENTS
An extensive quadrilateral ligamentous sheet that completes the
lateral wall of the pelvic cavity.
Extends from the lateral border of the sacrum and the transverse
processes of the first coccygeal vertebrae to the ischiatic spine
and tuber ischii.
Provides attachment for large gluteal muscles and the vulva.
In dog, this ligament is referred to as sacro-tuberous ligament.

10. 3. Prepubic tendon is essentially the tendon of insertion of recti abdominis muscle and others, except the transverse abdominis muscle. It is attached strongly to the cranial medial border of the pubic bones.
Significance: Fixing the sacro-iliac articulation and maintaining the bony pelvis in proper position.

11. SHAPE AND BIOMETRY OF BONY PELVIS
PELVIC CAVITY
Cone shaped with the base of the cone located cranially.
Base is formed by bony pelvis.
Size of the pelvic inlet varies greatly within species due to
breed, age and size.
SHAPE AND BIOMETRY OF BONY PELVIS
Species
Shape of pelvic inlet
Sacro-pubic
(Cm)
Bisiliac
Cow
Elliptical
19.0 – 24.1
14.6 – 19.0
Mare
Round
20.3 – 25.4
Sheep
7.6 – 10.8
5.7 – 8.9
Sow
9.5 – 15.2
6.3 – 10.2
Bitch
3.3 – 6.3
2.8 – 5.7

12. Pelvices of domestic animals

13. PELVIMETRY
Is the technique of measuring the dimensions of the osseous pelvis from which the approximate pelvic area is calculated.

14. INTRODUCTION part of the prenatal management
In human obstetrics, pelvimetry has been a routine
part of the prenatal management
Little attention in veterinary obstetrics until the last
decade.
In the recent years there is a great deal of interest
shown in this area and the information gained will
help one to reduce the incidence of dystocia.

15. INDICATIONS
To select heifers at the time of joining breeding programme.
Pregnancy testing for dystocia-free calving.
To predict a possible dystocia due to feto-pelvic disproportion. 

16. METHODS
External or indirect pelvimetry is carried out by calculating the pelvic diameter based on measurements taken between the angles of the ilia, the distance between the ischia and the height from the hip joint to highest point of the croup. In general, this method has been shown to be inaccurate and is no longer used.
Internal or direct pelvimetry refers to the measurement of the interior of the pelvis through the rectum with a pelvimeter.

17. MATERIALS AND RESTRAINT
A hinged or sliding graduated pelvic caliper.
Obstetrical lubricant or non-irritant soap, bucket of clean water with disinfectant.
Full arm rubber or disposable gloves.
Paper and pen for recording the observations.
Restraint
Animal should be restrained in a trevis or chute to prevent sideways movement.

18. Designed by DR.S.BALASUBRAMANIAN Dr. D.KATHIRESAN Dr.S.A.ASOKAN

19. EXTERNAL PELVIMETRY
This is arrived at by determining the diameters of pelvis from certain body measurements.
The following external pelvic measurements are taken
Distance between the external angle of the ilium (cm)
: A
Distance between the ischial tuberosity (cm)
: B
Distance between the summit of the croup and the hip joint (cm)
: C

20. Distance between the external angle of the ilium (cm) : A

21. Distance between the ischial tuberosity (cm) : B

22. Distance between the summit of the croup and the hip joint (cm) : C

23. Based on the measurements the pelvic area is calculated as follows
S.No.
Measurement
Formula 1.
Transverse diameter of pelvic outlet :
¼ (A+B) 2.
Vertical diameter of pelvic outlet
¾ x C 3.
Transverse diameter of pelvic inlet
12.2/10 x (Transverse diameter of pelvic outlet) 4.
Vertical diameter of pelvic inlet
13/10 x (vertical diameter of pelvic outlet).

24. INTERNAL PELVIMETRY
This is done by direct manual examination of the interior of pelvis on rectal and vaginal examination.
The distances between various parts of the pelvis can be approximately determined by calibrating the palm.

25. RICE PELVIMETER

26. GENERAL PROCEDURE Restrain the animal in a chute with light squeeze.
A comfortable normal standing position is best.
Feces should be removed from the rectum and the caliper carefully carried into the rectum with the hand and arm to the pelvic inlet.
The width of the pelvic inlet is obtained at its widest point between the right and left shafts of the ilium. This is the horizontal (bisiliac) diameter of the pelvis.
The height of the pelvic inlet is obtained by measuring the distance between the dorsal pubic tubercle on the floor of the pelvic and the sacrum, dorsal. This is the vertical (sacro-pubic) diameter of the pelvis.

27. CALCULATION The two measurements are read in centimeters and are
multiplied to give the pelvic area in square centimeters.
Alternatively, an adjustment can be made for the elliptical
shape of the anterior pelvic opening using
the formula: V x Tx π /4.
Either method gives a relative figure which, when
correctly interpreted, may provide useful information.

28. PELVIC INLET

29. RICE PELVIMETER
VERTICAL DIAMETER

30. RICE PELVIMETER
HORIZONTAL DIAMETER

31. krautmann PELVIMETER
VERTICAL DIAMETER

32. krautmann PELVIMETER
HORIZONTAL DIAMETER