Pelvis.pptx

anatomy

1. T H E P E L V IS

2. INTRODUCTION The pelvis is a basin like structure which connects the spine to lower limbs. It is an important part of the skeletal system. It transmits the weight of the trunk to the legs. It takes the weight of the sitting body. It allows movements of walking and running. It protects the pelvic organs. In addition the female pelvis is adapted for childbearing with an increased width and rounded brim.

3. D E F I N I T I O N It is a skeletal ring formed by two innominate or hip bones & the sacrum & the coccyx.

4. Types of pelvic bone

5. Gynecoid Pelvis

6. The female pelvis because of its characteristics, aids in child birth. The bony pelvis in normal st anding transmits the body weight from head, trunk and the p o sture upper extremities to the lower extremities. In female it is adapted for child bearing. The obstetrical anatomy of a typical female pelvis is best considered as one unit.

7. Functions of female pelvis Th e prim ary functio n o f the pelvi c girdle is to allow mo v e m ent of the body, especially walking and running. It permits the person to sit and kneel. The women pelvis is adapted for child bearing, and because of its increased width and rounded brim women are less speedy than men. The pelvis transmits the weight of the trunk to the legs, acting as a bridge between the femur. This makes it necessary for the sacro-iliac joint to the immensely strong and virtually immobile. The pelvis also takes the weight of the sitting body on to the ischial tuberosities. The pelvis affords protection to the pelvic organs and, to a lesser extent, to the abdominal contents. The sacrum transmits the cauda equina and distribute s the n erves to the various parts of the pelvis.

8. TYPES OF PELVIC BONES There are four pelvic bones that form pelvis: T w o H i p b o n e s ( Inn o m in a t e or n a m e l e ss ) One Sacrum One Coccyx

9. 1 .T W O I NNO MI N A T E BONES innominate bone is made up of three bones Ilium ischium pubic bone

10. IL I UM The ilium is the flared out part of the hip bone. It has following parts- Iliac crest as upper border Concave border is iliac fossa Anterior superior iliac spine Anterior inferior iliac spine Posterior superior iliac spine Posterior inferior iliac spine

11. I l ium The ilium- ilium is the larger flared out part. When the hand is placed on the hip it rests on the iliac crest, which is the upper border. At the front of the iliac crest can be felt a bony prominence known as the anterior superior iliac spine . A short distance below it is the anterior inferior iliac spine. There are two similar points at the other end of the iliac crest, namely the posterior superior and the posterior inferior iliac spines. The concave anterior surface of the ilium is the iliac fossa.

12. ISCHIUM The ischium is the thick lower part of the hip bone. It has following parts- Acetabulum Ischial tuberosity Ischial spine: location in relation to fetal head, i.e. above (-), below (+) or at (zero station) Greater sciatic Notch: extends from Sacro iliac joint to ischial spine Lesser Sciatic Notch: extends from ischial spine to ischial tuberosity Obturator foramen: passage of pelvic nerve fibres

13. Ischium The ischium- ischium is the thick lower part. It has a large prominence known as the ischium tuberosity, on which the bod y r e st s when sittin g. Be hi n d and a little above the tuberosity is an inward projection, the ischial spine. in labour fetal head is estimated in relation to the the station of the ischial spines.

14. PUBI C BONE The two pubic bones form the anterior part of the hip bone. It has following parts- Inferior rami of Pubic bone (a) Superior rami of pubic bone (b) Symphysis pubis (a+b): It is formed at the junction of two pubic bones. Sub pubic angle: angle between the inferior rami of the pubic bone.

15. Pubic bone The pubic bone- this bone forms the anterior part. It has a body and two oar like projections, the superior ramus and the inferior ramus. The two pubic bones meet at the symphysis pubis and the two inferior rami from the pubic arch, merging into a similar ramus and the ischium. The space enclosed by the body of the pubic bone, the rami and the ischium is called the obturator foramen.

16. Cont . … Th e innomin a te bon e conta i n s a de e p cup to arti c u l a te with the head of the femur. This is termed as Acetabulum . all three parts of the bone contribute to the acetabulum in the following proportions: 2/5 th ilium, 2/5 th ischium and 1/5 th pubic bone. On the lower border of the innominate bone are found two curves. One extends from the posterior inferior iliac spine up to the ischial spine and is called the greater sciatic notch. It is wide and rounded. The other lies between the ischial spine and the ischial tuberosity and is the lesser sciatic notch.

17. 2 . S AC R U M It is a wedge shaped bone made up of five fused bones. It has following parts- Sacral promontory: it is prominent upper margin of first sacral vertebrae, projects inwards Sacro iliac joint Wings of Sacrum or Ala of Sacrum Hollow of the Sacrum: concave

18. Cont. Sacrum: the sacrum is a wedge shaped bone consisting of five fused vertebrae. The upper border of the first sacral vertebra juts forward and id known as the sacral promontory. The anterior surface of the sacrum is concave and is referred to as the hollow of sacrum. Laterally the sacrum extends into a wing or ala. Four pairs of holes or foramina pierce the sacrum and through these, pelv i c r ecei v e ne rv e s fr o m t h e Ca u d a Eq u i n a em e r g e to suppl y the organs. The posterior surface is roughened to attachments of muscles.

19. 3. COCC Y X It is a vestigial tail consists of four fused vertebrae forming a small triangular bone. It is articulated with the sacrum Coccyx moves backward during childbirth

20. con t . . . Coccyx: the coccyx is a vestigial tail. It consists of four fused vertebra forming a small triangular bone. With its base uppermost articulating with the lower end of the sacrum. During labour it moves backward, having more space for the delivery of the fetus this is called nodding.

21. P E LVI C J O I N TS There are four pelvic joints: T w o s ac r o ili a c j o i n t s One pubic symphysis joint One sacrococcygeal joint

22. PELVIC JOINTS

23. C o n t . … The symphysis pubis is formed at the junction of the two pubic bones, which are united by a pad of cartilage. The sacroiliac joints – these are the strongest joints in the body. They join the sacrum to the ilium and thus connect the spine to the pelvis. The sacro coccygeal joint – this joint is formed where the base of the coccyx articulate with the tip of the sacrum.

24. Con t … ⦿ In the non-pregnant state there is very little movement in these joints, but during pregnancy endocrine activity causes the ligaments to soften, which allows the joints to give. This may provide more room for the fetal head as it passes through the pelvis. The symphysis pubis may separate slightly in later pregnancy. If it widens appreciably, the degree of movement deflected permitted may give rise to pain on walking. ⦿ Th e sa c r o - c o c c y g eal jo i n t p er m i ts c o cc yx to t he backward during the birth of the head.

25. P E LVI C LIGAMENTS The pelvic bones are held together with ligaments. Sacro iliac ligament - it pass in front of and behind each sacroiliac joint. Pubic ligament - it connect the top of pubic bones. Sacro tuberous ligament - one ligament on each side , run from sacrum to the ischial tuberosity Sacro spinous ligament - one ligament on each side of the sacrum & the ischial spine. Sacro coccygeal ligament -one ligament on each side from sacrum to coccyx.

26. STRUCTURE OF PELVIS FALES PELVIS TRUE PELVIS

27. F A L S E PE L V I S It is formed by the upper flared out portion of the ilium. Laterally- iliac fossae, Posterior- fifth lumbar vertebrae, Anteriorly – the abdominal wall and inguinal ligament It protects the abdominal organs. It has no obstetrical importance except that it provides certain landmarks for external pelvimetry.

28. TRUE PELVIS The true pelvis is the bony canal through which the fetus passes during birth. It has three parts- BRIM CAVITY OUTLET

29. THE PELVIC BRIM OR INLET It is f o r me d b y the sa c rum p o s t e ri o rl y , the i l iac b o n e s laterally and the pubic bones anterior. Shape: it is almost rounded with anterio- posterior diameter being the shortest. Its boundaries are the sacral promontory and wings of the sacrum behind the iliac bones on the sides and the pubic bones in front.

30. LANDMARKS OF THE BRIM Sacral promontory Sacral ala or sacral wing Sacroiliac joint Iliopectineal line Iliopubic eminence Pectineal line Pubic tubercle Pubic Crest Symphysis pubis

31. DIAMETERS OF THE BRIM Anterio posterior Transverse Oblique

32. A NTERIO POSTERIOR (11 CM ) it is a line from the sacral promontory to the upper border of symphysis pubis. This diameter is of three types- Diagonal conjugate - distance between lower border of symphysis pubis to mid point on sacral promontory it is 12 cm. Obstetrical conjugate - it is distance between midpoint of sacral promontory to prominent bony projection in mid line of symphysis pubis. it measures 10 cm True conjugate - it extends from the sacral promontory to the top of the symphysis pubis. Its normal measurement is 11 cm or more.

33. Transverse (13cm) – it is the distance between the two farthest points on the pelvic brim over the Iliopectineal lines. Oblique (12cm) – it starts from the sacroiliac joint to the opposite iliopubic eminence.

34. TH E PE L V I C C A VIT Y The cavity extends from the brim above to the outlet below. Shape: its shape is almost rounded. It consist of Anterior border: Symphysis pubis Posterior border: Sacral hollow Lateral border: Soft tissues All diameters- measure 12cms.

35. con t .… The pelvic cavity This extends from the pelvic brim to the pelvic outlet. It forms the curve of Carus, which the fetus has to navigate in order to be born and has no specific landmarks. The pelvic outlet This is either an ovoid or diamond-shaped space; its perimeter is partially comprised of ligaments. The landmarks of the pelvic outlet are as follows: _ Lower border of the symphysis pubis _ Pubic arch _ Ischial spines and ischial tuberosities _ Sacrotuberous and sacrospinous ligaments _ Lower aspect of the sacrum and the coccyx

36. TH E PE L V I C OUTLET ANATOMICAL OUTLET: It consists of the lower border of all bones and Sacro tuberous ligament. It consists of lower border of symphysis pubis, Sacro coccygeal joint and Sacro ischial spine. Shape: it is antero – posteriorly oval.

37. OBSTETRICAL OUTLET: This outlet has greater practical significance, because it includes the narrow pelvic strait through which the fetus must pass. It is otherwise known as bony outlet. Shape: it is diamond shaped.

38. DIAMETERS OF OUTLET: Antero-posterior diameter (13cm): it Extend from lower border of symphysis pubis to the tip of coccyx. Oblique diameter (12): it extend from Rt. & Lt. Sacro spinous ligament to Obturator foramen T r a n s v e r s e di a me t e r (11cm ) : b e t w ee n t h e ischial spines.

39. TYPES OF PELVIS GYNAECOID ANTHROPOID A N D R OID P L A TY P E L L OI D

40. 1.Gynaecoid pelvis: (50%) It is commonly known as the female pelvis because that type occurs most frequently in women. Most suitable for childbirth. Wider brim. Ischial spines are blunt Sub pubic angle is 90º

41. 2.Anthropoid pelvis: (25%) It favors a posterior position of the fetus. Oval in shape T r a n s v e r s e di a me t e r i s s h o r t e r Seen in tall women with narrow shoulders

42. 3.Android pelvis: (20%) It is commonly known as male pelvis because it occurs more frequently in men. Heart shaped brim Anterior posterior diameter is shorter T r a n s v e r s e di a m e t e r is wider Childbirth is difficult

43. 4.Platypelloid (flat) pelvis: (5%) This type of pelvis is rare. Kidney shaped brim Anterior posterior diameter is smaller T r a n s v e r s e di a me t e r is wider Not conductive to vaginal delivery

44. DEFORMITIES OF PELVIS Contracted pelvis Rachitic pelvis Asymmetrical pelvis Roberts pelvis Nageles pelvis Osteomalacis / maacosteon pelvis Assimilation pelvis Others- Kyphosis, scoliosis, spondylosisthesis

45. Contracted pelvis

46. Rachitic pelvis

47. Asymmetrical pelvis

48. Roberts pelvis

49. Nageles pelvis

50. Osteomalacis / maacosteon pelvis

51. Kyphotic pelvis

52. Scoliosis pelvis

53. Sp o n d y l o s i s th e s i s