II
Uploaded byIna Irabon
PDF, PPTX30,189 views

Evaluation of the pelvis

The document discusses the anatomical evaluation of the pelvis in obstetrics, detailing the composition, planes, and shapes of the bony pelvis, as well as the anatomical features of true and false pelvises. It outlines the significant diameters and planes of the pelvic inlet, midpelvis, and pelvic outlet, providing critical measurements relevant to obstetrical significance. Additionally, references to authoritative texts on obstetrics are provided for further study.

Embed presentation

Download as PDF, PPTX
EVALUATION OF THE PELVIS Ina S. Irabon, MD, FPOGS, FPSRM, FPSGE Obstetrics and Gynecology Reproductive Endocrinology and Infertility Laparoscopy and Hysteroscopy
TO DOWNLOAD THIS LECTURE DECK: • www.slideshare.net à type “Ina Irabon” in SEARCH bar • www.wordpress.com
REFERENCE • Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS (eds).William’s Obstetrics 24th edition (20140; chapter 2 Maternal anatomy • Sumpaico WW, Ocampo-Andres IS, Blanco-Capito LR, Diamante An, Gamilla ZN. (eds). Textbook of Obstetrics 3rd edition. Chapter 23 The Passages
OUTLINE 1. Composition of the bony pelvis 2. Pelvic anatomy true pelvis false pelvis 3. Planes of the bony pelvis inlet midpelvis outlet 4. Pelvic shapes gynecoid, android, anthropoid, platypelloid 5. Soft parts of the pelvis levator ani pelvic diaphragm
COMPOSITION OF THE BONY PELVIS
COMPOSITION OF THE BONY PELVIS nctioning muscle is l layer. In e replaced muscular ntractions arian hor- ar epithe- n a sparse ying myo- fimbriated e patches. e two cell mucosa is vely more n is occu- The current of flow is y cilia and ant factor blood ves- e tubes is tion. This Anterior superior iliac spine Ilium Pubis Symphysis pubis Greater sciatic foramen Sacrospinous ligament Ischial spine Lesser sciatic foramen SacrotuberousS ligament Ischium Obturator foramen FIGURE 2-16 Sagittal view of the pelvic bones. linea terminalis serves as the superior border, whereas the pelvic outlet is the inferior margin. The posterior boundary is the anterior surface of the sacrum, and the lateral limits are formed by the inner surface of the ischial bones and the sacrosciatic notches and ligaments. In front,
PELVIC ANATOMY 1. False (Greater) pelvis • Above linea terminalis • Posterior: lumbar vertebra • Lateral: iliac fossae • Front: lower anterior abdominal wall 2. True (Lesser) Pelvis • Below linea terminalis • Superior: linea terminalis • Posterior: promontory and alae of the sacrum • Anterior: upper margin of pubic bones, ascending superior rami of the ischial bones and obturator foramina • Inferior: pelvic outlet • Lateral: inner surface of ischial bones and sacrosciatic notches and ligaments 32 Maternal Anatomy and Physiology SECTION2 TTTT APAPAPAP True Pelvis FFFaFaFaFallslslsseee PPPPellele viiv sss PPPPPPPPPososssososossososotetetetetettriiiririiirirrrorrororrorooo sasaasasaasaaasasgigigigiigggttttttttttttalalalaa Anterior sagittttttttttttttlalalalalalaaaaa FIGURE 2-17 Anteroposterior view of a normal female pelvis. Anteroposterior (AP) and transverse (T) diameters of the pelvic • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC ANATOMY 32 Maternal Anatomy and Physiology outle to ro force the d mob ver o a cas have ting squa the p obser birth ■ P TTTT APAPAPAP True Pelvis FFFaFaFaFallslslsseee PPPPellele viiv sss PPPPPPPPPososssososossososotetetetetettriiiririiirirrrorrororrorooo sasaasasaasaaasasgigigigiigggttttttttttttalalalaa Anterior sagittttttttttttttlalalalalalaaaaa
OBSTETRIC PLANES AND DIAMETERS • the pelvis is described as having four imaginary planes: • 1. plane of the pelvic inlet—the superior strait. 2. plane of the pelvic outlet—the inferior strait. 3. plane of the midpelvis—the least pelvic dimensions. 4. plane of greatest pelvic dimension—of no obstetrical significance. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
OBSTETRIC PLANES AND DIAMETERS 3 important planes: 1. Pelvic inlet 2. Midpelvis 3. Pelvic outlet • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
1. PELVIC INLET • Forms the brim of the true pelvis • Also called the superior strait • the pelvic inlet is also the superior plane of the true pelvis • Has 4 diameters: 1. Anteroposterior (AP) a) Diagonal conjugate b) True conjugate c) Obstetric conjugate 2. Transverse 3. Obliques (2) • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC INLET: ANTEROPOSTERIOR DIAMETER 1. Diagonal conjugate: • distance between lower border of symphysis pubis to midpoint of sacral promontory • measures approx 12 cm • The only AP diameter that can be measured clinically • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
VAGINAL EXAMINATION TO DETERMINE THE DIAGONAL CONJUGATE FIG det P ==
PELVIC INLET: ANTEROPOSTERIOR DIAMETER 2. True or anatomic conjugate • distance between upper margin of symphysis pubis to midpoint of sacral promontory • measures approx 11 cm • Measured indirectly by subtracting 1.2 cms from the diagonal conjugate • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3 rd edition. C hapter 23 The Passages
PELVIC INLET: ANTEROPOSTERIOR DIAMETER 3. Obstetric conjugate • distance between midpoint of inner surface of symphysis pubis to midpoint of sacral promontory • This clinically important obstetrical conjugate is the shortest distance between the sacral promontory and the symphysis pubis. • measures approx 10 cm • Measured indirectly by subtracting 1.5 to 2 cms from the diagonal conjugate • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3 rd edition. C hapter 23 The Passages
PELVIC INLET: TRANSVERSE DIAMETER • constructed at right angles to the obstetrical conjugate and represents the greatest distance between the linea terminalis on either side. • It usually intersects the obstetrical conjugate at a point approximately 5 cm in front of the promontory • Average: 13 cm • Divides the inlet into anterior and posterior segments Posterior sagittal diameter • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC INLET: OBLIQUE DIAMETERS • Extend from the sacroiliac joints to the opposite iliopubic eminence • Measures <13 cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PLANE OF THE GREATEST PELVIC DIAMETER • Corresponds to the roomiest plane of the pelvis • Posterior: 3rd to 4th sacral vertebrae • Lateral: ischial bones • Anterior: middle surface of symphysis pubis • Its AP diameter and transverse diameters average 12.5cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
MIDPELVIS • Measured at the level of the ischial spines • also called the midplane or plane of least pelvic dimensions • During labor, the degree of fetal head descent into the true pelvis may be described by station, and the midpelvis and ischial spines serve to mark zero station. • The anteroposterior diameter through the level of the ischial spines normally measures at least 11.5 cm. the true pelvis may be described by station, and the midpelvis and ischial spines serve to mark zero station. The interspinous diameter is 10 cm or slightly greater, is usually the smallest pelvicdiameter,and,incasesofobstructedlabor,isparticularly b tu in an w th tr p n ■ Th th in di se an ty de pu an an co Interspinous = 10 cmInterspinous = 10 cm Transverse of inlet = 13.5 cm Obstetrical Conj=10.5cm FIGURE 2-19 Adult female pelvis demonstrating the interspinous diameter of the midpelvis. The anteroposterior and transverse diameters of the pelvic inlet are also shown. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
2. MIDPELVIS • Extends from the lower margin of the symphysis pubis, through the level of the ischial spines, up to the tip of the sacrum • Transverse diameter: distance between the 2 ischial spines (10.5 cm)à interspinous diameter • The interspinous diameter (station 0, when the BPD of fetal head passes this diameter) is 10 cm or slightly greater, is usually the smallest pelvic diameter, is a minor elevation that marks the union site of the ilium and pubis. These oblique diameters average less than 13 cm. Midpelvis and Pelvic Outlet The midpelvis is measured at the level of the ischial spines, also called the midplane or plane of least pelvic dimensions (Fig. 2-19). During labor, the degree of fetal head descent into the true pelvis may be described by station, and the midpelvis and ischial spines serve to mark zero station. The interspinous diameter is 10 cm or slightly greater, is usually the smallest pelvic diameter, and, in cases of obstructed labor, is particularly Interspinous = 10 cmInterspinous = 10 cm Transverse of inlet = 13.5 cm Obstetrical Conj=10.5cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3 rd edition. C hapter 23 The Passages
MIDPELVIS • Suspicion of midpelvis contraction is possible with the following: 1. Prominence of the ischial spines 2. Pelvic sidewalls are convergent 3. Concavity of the sacrum is shallow 4. Bi-ischial diameter of the outlet is < 8cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
3. PELVIC OUTLET • Outlet is bounded anteriorly by the pubic arch, laterally by the ischiopubic rami, ischial tuberosity, and sacrotuberous ligament and posteriorly by the tip of the coccyx • Intertuberous (or bituberous) diameter: 11cm • AP diameter: 9.5-11.5cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC OUTLET • The pelvic outlet consists of two approximately triangular areas. • Posterior triangle • Anterior triangle • They have a common base, which is a line drawn between the two ischial tuberosities. • Clinically, three diameters of the pelvic outlet usually are described—the anteroposterior, transverse, and posterior sagittal. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC OUTLET • Intertuberous diameter may be measured by placing a closed fist against the perineum at the level of the tuberosities • Thom’s rule: when transverse diameter + PSD > 15cm (xray pelvimetry) à outlet adequate • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
CALDWELL-MOLOY ANATOMICAL CLASSIFICATION OF THE PELVIS • based on pelvic shape • its concepts aid an understanding of labor mechanisms. 34 Maternal Anatomy and Physiology SECTION2 FIGURE 2-20 The four parent pelvic types of the Caldwell–Moloy classification. A line passing through the widest transverse diameter divides the inlets into posterior (P) and anterior (A) segments. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
• the greatest transverse diameter of the inlet and its division into anterior and posterior segments are used to classify the pelvis as gynecoid, anthropoid, android, or platypelloid. • The posterior segment determines the type of pelvis, whereas the anterior segment determines the tendency. • For example: a gynecoid pelvis with an android tendency à posterior pelvis is gynecoid and the anterior pelvis is android shaped. PELVIC SHAPES (CALDWELL-MOLOY CLASSIFICATION) • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC SHAPES (CALDWELL-MOLOY CLASSIFICATION) Maternal Anatomy and Physiology Corton MM: Anatomy of the pelvis: how the pelvis is built for support. Clin FIGURE 2-20 The four parent pelvic types of the Caldwell–Moloy classification. A line passing through the widest transverse diameter divides the inlets into posterior (P) and anterior (A) segments.
CALDWELL MOLOY CLASSIFICATION • many pelves are not pure but are of mixed types. • For example, a gynecoid pelvis with an android tendency means that the posterior pelvis is gynecoid and the anterior pelvis is android shaped. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
SOFT PARTS OF THE PELVIS • Pelvic floor: muscular partition that separates pelvic cavity from perineum • 3 sets of muscles 1. Pubococcygeus (pubovisceral) 2. Iliococcygeus 3. puborectalis àCollectively known as LEVATOR ANI • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
SOFT PARTS OF THE PELVIS • Vaginal birth conveys significant risk for damage to the levator ani or to its innervation • Of these muscles, the pubococcygeus muscle is more commonly damaged • Evidence supports that these injuries may predispose women to greater risk of pelvic organ prolapse or urinary incontinence • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
SOFT PARTS OF THE PELVIS Pelvic diaphragm • Levator ani + coccygeus muscles + fascial covering • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PELVIC DIAPHRAGM 23Maternal Anatomy CHAPTER2
SOFT PARTS OF THE PELVIS • Pelvic diaphragm: 2 parts 1. Urogenital triangle (anterior) 2. Anal triangle (posterior) • Nerve supply: S4, inferior rectal nerve, perineal branch of the pudendal nerve • Supports pelvic organs • Control of external anal sphincter • Stabilize sacroiliac and sacrococcygeal joints • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
ANTERIOR TRIANGLE • Contains portions of urethra and vagina, certain portions of internal pudendal artery branches, and the compressor urethrae and urethrovaginal sphincter muscles, which comprise part of the striated urogenital sphincter complex. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
ANAL/ POSTERIOR TRIANGLE • This triangle contains the ischioanal fossae, anal canal, and anal sphincter complex, which consists of the internal anal sphincter, external anal sphincter, and puborectalis muscle. • Branches of the pudendal nerve and internal pudendal vessels are also found within this triangle. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
PUDENDAL NERVE • formed from the anterior rami of S2–4 spinal nerves. • It courses between the piriformis and coccygeus muscles and exits through the greater sciatic foramen at a location posterior to the sacrospinous ligament and just medial to the ischial spine • thus, when injecting local anesthetic for a pudendal nerve block, the ischial spine serves as an identifiable landmark • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
ANAL SPHINCTER COMPLEX: IAS • Two sphincters surround the anal canal to provide fecal continence—the external and internal anal sphincters. • Both lie proximate to the vagina, and one or both may be torn during vaginal delivery. • Internal Anal Sphincter (IAS) is a distal continuation of the rectal circular smooth muscle layer. It receives predominantly parasympathetic fibers, which pass through the pelvic splanchnic nerves. • this sphincter is supplied by the superior, middle, and inferior rectal arteries. • IAS contributes the bulk of anal canal resting pressure for fecal continence and relaxes prior to defecation. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The
ANAL SPHINCTER COMPLEX: EAS • External Anal Sphincter (EAS) is a striated muscle ring that anteriorly attaches to the perineal body and that posteriorly connects to the coccyx via the anococcygeal ligament. • EAS maintains a constant resting contraction to aid continence, provides additional squeeze pressure when continence is threatened, yet relaxes for defecation. • Receives blood supply from the inferior rectal artery, which is a branch of the internal pudendal artery. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
SUMMARY/REVIEW 1. Composition of the bony pelvis 2. Pelvic anatomy true pelvis false pelvis 3. Planes of the bony pelvis inlet midpelvis outlet 4. Pelvic shapes gynecoid, android, anthropoid, platypelloid 5. Soft parts of the pelvis levator ani pelvic diaphragm

More Related Content

PPTX
Pelvis and fetal skull.pptx
byApurvaMaheshwari11
 
PPTX
Pelvis - Obstetrical Significance
byGIMSR, Visakhapatnam, AP, India
 
PPTX
Functional Anatomy of Female Pelvis and the Fetal Skull
byBitew Mekonnen
 
PPTX
Anatomy of the female pelvis
byraj kumar
 
PPT
Female bony pelvis and fetal skull for undergraduate
byFaculty of Medicine,Zagazig University,EGYPT
 
PPTX
Fetal head, maternal pelvis & pelvimetry
byRasha Dabbagh
 
PDF
maternalpelvis-160311112407.pdf
byMeetPatel288087
 
PPT
fetus and gynaecoid pelvis
bytariggally
 
Pelvis and fetal skull.pptx
byApurvaMaheshwari11
 
Pelvis - Obstetrical Significance
byGIMSR, Visakhapatnam, AP, India
 
Functional Anatomy of Female Pelvis and the Fetal Skull
byBitew Mekonnen
 
Anatomy of the female pelvis
byraj kumar
 
Female bony pelvis and fetal skull for undergraduate
byFaculty of Medicine,Zagazig University,EGYPT
 
Fetal head, maternal pelvis & pelvimetry
byRasha Dabbagh
 
maternalpelvis-160311112407.pdf
byMeetPatel288087
 
fetus and gynaecoid pelvis
bytariggally
 

What's hot

PPTX
Previous cesarean section
byobgymgmcri
 
PPT
Pelvis and pelvimetry
byAyman Shehata
 
PDF
FIRST TRIMESTER BLEEDING
byAboubakr Elnashar
 
PPTX
Ultrasonography in pregnancy
bySharon Treesa Antony
 
PDF
WHO labour guide.pdf
bydrmonicaagrawal2
 
PPTX
BAD OBTETRIC HISTORY
byYogesh Patel
 
PPT
Lower uterine segment
byHanifullah Khan
 
PPT
Postmenopausal bleeding for undergraduate
byFaculty of Medicine,Zagazig University,EGYPT
 
PPTX
Post term pregnancy
byJoyce Mwatonoka
 
PDF
Hypertensive disorders in pregnancy
byMarwan Alhalabi
 
PPTX
Fetal biophysical profile
byJoyce Mwatonoka
 
PPTX
Molar pregnancy
byNirsuba Gurung
 
PPTX
Fibroid complicating pregnancy
byMilan Kharel
 
PPTX
MECONIUM STAINED AMNIOTIC FLUID
byNiranjan Chavan
 
PPTX
Multifetal pregnancy (Twins Pregnancy)
bynishma bajracharya
 
PPTX
Intrahepatic Cholestasis of Pregnancy (IHCP)
byPrashant Pujara
 
PPTX
Abnormal Uterine Bleeding (AUB)
byRedzwan Abdullah
 
PPTX
Pelvic organ prolapse gynaecology ppt
byTONY SCARIA
 
PPTX
Obstetric forceps and complication
bySourav Chowdhury
 
PPTX
Management of Preterm labor
bysunil kumar daha
 
Previous cesarean section
byobgymgmcri
 
Pelvis and pelvimetry
byAyman Shehata
 
FIRST TRIMESTER BLEEDING
byAboubakr Elnashar
 
Ultrasonography in pregnancy
bySharon Treesa Antony
 
WHO labour guide.pdf
bydrmonicaagrawal2
 
BAD OBTETRIC HISTORY
byYogesh Patel
 
Lower uterine segment
byHanifullah Khan
 
Postmenopausal bleeding for undergraduate
byFaculty of Medicine,Zagazig University,EGYPT
 
Post term pregnancy
byJoyce Mwatonoka
 
Hypertensive disorders in pregnancy
byMarwan Alhalabi
 
Fetal biophysical profile
byJoyce Mwatonoka
 
Molar pregnancy
byNirsuba Gurung
 
Fibroid complicating pregnancy
byMilan Kharel
 
MECONIUM STAINED AMNIOTIC FLUID
byNiranjan Chavan
 
Multifetal pregnancy (Twins Pregnancy)
bynishma bajracharya
 
Intrahepatic Cholestasis of Pregnancy (IHCP)
byPrashant Pujara
 
Abnormal Uterine Bleeding (AUB)
byRedzwan Abdullah
 
Pelvic organ prolapse gynaecology ppt
byTONY SCARIA
 
Obstetric forceps and complication
bySourav Chowdhury
 
Management of Preterm labor
bysunil kumar daha
 

Similar to Evaluation of the pelvis

PDF
evaluation-of-the-pelvis_dr-irabon (1).pdf
byhussainmahid889
 
PDF
Maternal pelvis
byArya Anish
 
PPTX
femalepelvis-201124nnnnn7777777770955bbbbbbb1).pptx
bySubi Babu
 
PPTX
Female pelvis
byPriyanka Gohil
 
PPTX
1.7 Pelvis NLHT.pptx telling more information
bykalesamrudhi167
 
PPT
Contracted pelvis
bydrmcbansal
 
PPTX
PELVIC DIAMETERS SESSION.pptxxxxxxxxxxxxx
byCHRIS ADREIN KANAKUZE
 
PPTX
Pelvic.pptx
byShinilLenin
 
PPTX
Anatomy of female pelvis and Fetal Diameters 2020.pptx
bydrmonicaagrawal2
 
PPTX
Obsteritric Anatomy overview for obs and gyn
bymoolakasiku49
 
PPTX
Presentation (2).pptx
bypugalrockzz1
 
PPTX
female pelvis.pptx
bybeminaja
 
PPT
Applied anatomy of pelvis and fetal skull
byAravind Ravi
 
PPTX
Maternal pelvis OBG SGD.pptx obs and gyn
byAkshayaGopalan
 
PPTX
anatomy of female plevis.pptx
byKalaiVani614333
 
PDF
THE_FEMALE_PELVIS_AND_ITS_SIGNIFICANCE_final.pdf
byelizadoyce1
 
PPTX
anatomy of the female bony pelvis and pelvic floor.pptx
byGaniyat4
 
PPT
Female pelvis and Fetal head Obstetrics and Gynaecology.ppt
bysthasamyam77
 
DOC
ANATOMY OF THE FEMALE REPRODUCTIVE SYSTEM.doc
byGichanaElvis
 
PPTX
THE BONY PELVIS and it's significance.pptx
byOkenyInnocent1
 
evaluation-of-the-pelvis_dr-irabon (1).pdf
byhussainmahid889
 
Maternal pelvis
byArya Anish
 
femalepelvis-201124nnnnn7777777770955bbbbbbb1).pptx
bySubi Babu
 
Female pelvis
byPriyanka Gohil
 
1.7 Pelvis NLHT.pptx telling more information
bykalesamrudhi167
 
Contracted pelvis
bydrmcbansal
 
PELVIC DIAMETERS SESSION.pptxxxxxxxxxxxxx
byCHRIS ADREIN KANAKUZE
 
Pelvic.pptx
byShinilLenin
 
Anatomy of female pelvis and Fetal Diameters 2020.pptx
bydrmonicaagrawal2
 
Obsteritric Anatomy overview for obs and gyn
bymoolakasiku49
 
Presentation (2).pptx
bypugalrockzz1
 
female pelvis.pptx
bybeminaja
 
Applied anatomy of pelvis and fetal skull
byAravind Ravi
 
Maternal pelvis OBG SGD.pptx obs and gyn
byAkshayaGopalan
 
anatomy of female plevis.pptx
byKalaiVani614333
 
THE_FEMALE_PELVIS_AND_ITS_SIGNIFICANCE_final.pdf
byelizadoyce1
 
anatomy of the female bony pelvis and pelvic floor.pptx
byGaniyat4
 
Female pelvis and Fetal head Obstetrics and Gynaecology.ppt
bysthasamyam77
 
ANATOMY OF THE FEMALE REPRODUCTIVE SYSTEM.doc
byGichanaElvis
 
THE BONY PELVIS and it's significance.pptx
byOkenyInnocent1
 

Recently uploaded

PDF
Tetracycline Class of Antibiotics: SAR, MOA and Uses
bymominzarinamdnajeeb
 
PDF
PPT Daftar Bahan Kelas Bedah Kitab Matius Khotbah di Bukit
bySABDA
 
PPTX
EYE IRRIGATION AND INSTILLATION....pptx
byAneetaSharma15
 
PDF
TỔNG HỢP 156 ĐỀ CHÍNH THỨC KỲ THI CHỌN HỌC SINH GIỎI TIẾNG ANH LỚP 12 CÁC TỈN...
byNguyen Thanh Tu Collection
 
PPTX
G5_ENGLISH_PPT_Q4_W2.pptx week 2 quarter 4
by96zn2w5tqx
 
PPTX
Saber tooth tiger.pptx (Smilodon presentation ) = Extinct Animals
byimethrandive156
 
PPTX
How to Track Employee Skill Growth with Skills Evolution Report in Odoo 18
byCeline George
 
PDF
Bones by Sadu Kassam (play) story ppt pdf
byRonnieMaeBorres
 
PPTX
How to Easily Track Appraisal Analysis Report in Odoo 18 Appraisal
byCeline George
 
PPTX
industrial arts grade 6 tle_q4_w3_melc.pptx
byadrianatillaga1
 
PPTX
A brief introduction to Minor vegetable crops.pptx
byUmeshTimilsina1
 
PDF
Unit Plan and Unit Test-pdf-Dr. Rajashekhar Shirvalkar, Principal, SMRS B.Ed ...
byRajashekhar Shirvalkar
 
PPTX
GRADE 8 - QUARTER 4 TYPES AND PARTS OF LETTER.pptx
byvillariasjazminercai
 
PDF
Chapter 05 Drugs Acting on the Central Nervous System: Anti-Depressant Drugs
bySandeshSul
 
PDF
Nursing care plan for Vomiting /B.Sc nsg
byDr. Sudhadevi Sadanandan
 
PDF
Why Projects Fail – The Need to “Do the Right Project” and “Do the Project Ri...
byAssociation for Project Management
 
PDF
RAJAT ARORA SIR PHYSICAL EDUCATION NOTES ALL CHAPTERS .pdf
bysumitkannoujiya74
 
PDF
Artificial Intelligence in Research and Academic Writing, Workshop on Researc...
byProf. Vinod Kumar Kanvaria
 
PPTX
How to Manage Closest Location in Odoo 18 Inventory
byCeline George
 
PPTX
Modeling Simple Equation using Bar Model.pptx
byshahanieabbat3
 
Tetracycline Class of Antibiotics: SAR, MOA and Uses
bymominzarinamdnajeeb
 
PPT Daftar Bahan Kelas Bedah Kitab Matius Khotbah di Bukit
bySABDA
 
EYE IRRIGATION AND INSTILLATION....pptx
byAneetaSharma15
 
TỔNG HỢP 156 ĐỀ CHÍNH THỨC KỲ THI CHỌN HỌC SINH GIỎI TIẾNG ANH LỚP 12 CÁC TỈN...
byNguyen Thanh Tu Collection
 
G5_ENGLISH_PPT_Q4_W2.pptx week 2 quarter 4
by96zn2w5tqx
 
Saber tooth tiger.pptx (Smilodon presentation ) = Extinct Animals
byimethrandive156
 
How to Track Employee Skill Growth with Skills Evolution Report in Odoo 18
byCeline George
 
Bones by Sadu Kassam (play) story ppt pdf
byRonnieMaeBorres
 
How to Easily Track Appraisal Analysis Report in Odoo 18 Appraisal
byCeline George
 
industrial arts grade 6 tle_q4_w3_melc.pptx
byadrianatillaga1
 
A brief introduction to Minor vegetable crops.pptx
byUmeshTimilsina1
 
Unit Plan and Unit Test-pdf-Dr. Rajashekhar Shirvalkar, Principal, SMRS B.Ed ...
byRajashekhar Shirvalkar
 
GRADE 8 - QUARTER 4 TYPES AND PARTS OF LETTER.pptx
byvillariasjazminercai
 
Chapter 05 Drugs Acting on the Central Nervous System: Anti-Depressant Drugs
bySandeshSul
 
Nursing care plan for Vomiting /B.Sc nsg
byDr. Sudhadevi Sadanandan
 
Why Projects Fail – The Need to “Do the Right Project” and “Do the Project Ri...
byAssociation for Project Management
 
RAJAT ARORA SIR PHYSICAL EDUCATION NOTES ALL CHAPTERS .pdf
bysumitkannoujiya74
 
Artificial Intelligence in Research and Academic Writing, Workshop on Researc...
byProf. Vinod Kumar Kanvaria
 
How to Manage Closest Location in Odoo 18 Inventory
byCeline George
 
Modeling Simple Equation using Bar Model.pptx
byshahanieabbat3
 

Evaluation of the pelvis

  • 1.
    EVALUATION OF THE PELVIS InaS. Irabon, MD, FPOGS, FPSRM, FPSGE Obstetrics and Gynecology Reproductive Endocrinology and Infertility Laparoscopy and Hysteroscopy
  • 2.
    TO DOWNLOAD THISLECTURE DECK: • www.slideshare.net à type “Ina Irabon” in SEARCH bar • www.wordpress.com
  • 3.
    REFERENCE • Cunningham FG,Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, Casey BM, Sheffield JS (eds).William’s Obstetrics 24th edition (20140; chapter 2 Maternal anatomy • Sumpaico WW, Ocampo-Andres IS, Blanco-Capito LR, Diamante An, Gamilla ZN. (eds). Textbook of Obstetrics 3rd edition. Chapter 23 The Passages
  • 4.
    OUTLINE 1. Composition ofthe bony pelvis 2. Pelvic anatomy true pelvis false pelvis 3. Planes of the bony pelvis inlet midpelvis outlet 4. Pelvic shapes gynecoid, android, anthropoid, platypelloid 5. Soft parts of the pelvis levator ani pelvic diaphragm
  • 5.
    COMPOSITION OF THEBONY PELVIS
  • 6.
    COMPOSITION OF THEBONY PELVIS nctioning muscle is l layer. In e replaced muscular ntractions arian hor- ar epithe- n a sparse ying myo- fimbriated e patches. e two cell mucosa is vely more n is occu- The current of flow is y cilia and ant factor blood ves- e tubes is tion. This Anterior superior iliac spine Ilium Pubis Symphysis pubis Greater sciatic foramen Sacrospinous ligament Ischial spine Lesser sciatic foramen SacrotuberousS ligament Ischium Obturator foramen FIGURE 2-16 Sagittal view of the pelvic bones. linea terminalis serves as the superior border, whereas the pelvic outlet is the inferior margin. The posterior boundary is the anterior surface of the sacrum, and the lateral limits are formed by the inner surface of the ischial bones and the sacrosciatic notches and ligaments. In front,
  • 7.
    PELVIC ANATOMY 1. False(Greater) pelvis • Above linea terminalis • Posterior: lumbar vertebra • Lateral: iliac fossae • Front: lower anterior abdominal wall 2. True (Lesser) Pelvis • Below linea terminalis • Superior: linea terminalis • Posterior: promontory and alae of the sacrum • Anterior: upper margin of pubic bones, ascending superior rami of the ischial bones and obturator foramina • Inferior: pelvic outlet • Lateral: inner surface of ischial bones and sacrosciatic notches and ligaments 32 Maternal Anatomy and Physiology SECTION2 TTTT APAPAPAP True Pelvis FFFaFaFaFallslslsseee PPPPellele viiv sss PPPPPPPPPososssososossososotetetetetettriiiririiirirrrorrororrorooo sasaasasaasaaasasgigigigiigggttttttttttttalalalaa Anterior sagittttttttttttttlalalalalalaaaaa FIGURE 2-17 Anteroposterior view of a normal female pelvis. Anteroposterior (AP) and transverse (T) diameters of the pelvic • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 8.
    PELVIC ANATOMY 32 MaternalAnatomy and Physiology outle to ro force the d mob ver o a cas have ting squa the p obser birth ■ P TTTT APAPAPAP True Pelvis FFFaFaFaFallslslsseee PPPPellele viiv sss PPPPPPPPPososssososossososotetetetetettriiiririiirirrrorrororrorooo sasaasasaasaaasasgigigigiigggttttttttttttalalalaa Anterior sagittttttttttttttlalalalalalaaaaa
  • 9.
    OBSTETRIC PLANES ANDDIAMETERS • the pelvis is described as having four imaginary planes: • 1. plane of the pelvic inlet—the superior strait. 2. plane of the pelvic outlet—the inferior strait. 3. plane of the midpelvis—the least pelvic dimensions. 4. plane of greatest pelvic dimension—of no obstetrical significance. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 10.
    OBSTETRIC PLANES ANDDIAMETERS 3 important planes: 1. Pelvic inlet 2. Midpelvis 3. Pelvic outlet • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 11.
    1. PELVIC INLET •Forms the brim of the true pelvis • Also called the superior strait • the pelvic inlet is also the superior plane of the true pelvis • Has 4 diameters: 1. Anteroposterior (AP) a) Diagonal conjugate b) True conjugate c) Obstetric conjugate 2. Transverse 3. Obliques (2) • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 12.
    PELVIC INLET: ANTEROPOSTERIOR DIAMETER 1.Diagonal conjugate: • distance between lower border of symphysis pubis to midpoint of sacral promontory • measures approx 12 cm • The only AP diameter that can be measured clinically • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 13.
    VAGINAL EXAMINATION TODETERMINE THE DIAGONAL CONJUGATE FIG det P ==
  • 14.
    PELVIC INLET: ANTEROPOSTERIOR DIAMETER 2.True or anatomic conjugate • distance between upper margin of symphysis pubis to midpoint of sacral promontory • measures approx 11 cm • Measured indirectly by subtracting 1.2 cms from the diagonal conjugate • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3 rd edition. C hapter 23 The Passages
  • 15.
    PELVIC INLET: ANTEROPOSTERIOR DIAMETER 3.Obstetric conjugate • distance between midpoint of inner surface of symphysis pubis to midpoint of sacral promontory • This clinically important obstetrical conjugate is the shortest distance between the sacral promontory and the symphysis pubis. • measures approx 10 cm • Measured indirectly by subtracting 1.5 to 2 cms from the diagonal conjugate • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3 rd edition. C hapter 23 The Passages
  • 16.
    PELVIC INLET: TRANSVERSE DIAMETER •constructed at right angles to the obstetrical conjugate and represents the greatest distance between the linea terminalis on either side. • It usually intersects the obstetrical conjugate at a point approximately 5 cm in front of the promontory • Average: 13 cm • Divides the inlet into anterior and posterior segments Posterior sagittal diameter • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 17.
    PELVIC INLET: OBLIQUE DIAMETERS •Extend from the sacroiliac joints to the opposite iliopubic eminence • Measures <13 cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 18.
    PLANE OF THEGREATEST PELVIC DIAMETER • Corresponds to the roomiest plane of the pelvis • Posterior: 3rd to 4th sacral vertebrae • Lateral: ischial bones • Anterior: middle surface of symphysis pubis • Its AP diameter and transverse diameters average 12.5cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 19.
    MIDPELVIS • Measured atthe level of the ischial spines • also called the midplane or plane of least pelvic dimensions • During labor, the degree of fetal head descent into the true pelvis may be described by station, and the midpelvis and ischial spines serve to mark zero station. • The anteroposterior diameter through the level of the ischial spines normally measures at least 11.5 cm. the true pelvis may be described by station, and the midpelvis and ischial spines serve to mark zero station. The interspinous diameter is 10 cm or slightly greater, is usually the smallest pelvicdiameter,and,incasesofobstructedlabor,isparticularly b tu in an w th tr p n ■ Th th in di se an ty de pu an an co Interspinous = 10 cmInterspinous = 10 cm Transverse of inlet = 13.5 cm Obstetrical Conj=10.5cm FIGURE 2-19 Adult female pelvis demonstrating the interspinous diameter of the midpelvis. The anteroposterior and transverse diameters of the pelvic inlet are also shown. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 20.
    2. MIDPELVIS • Extendsfrom the lower margin of the symphysis pubis, through the level of the ischial spines, up to the tip of the sacrum • Transverse diameter: distance between the 2 ischial spines (10.5 cm)à interspinous diameter • The interspinous diameter (station 0, when the BPD of fetal head passes this diameter) is 10 cm or slightly greater, is usually the smallest pelvic diameter, is a minor elevation that marks the union site of the ilium and pubis. These oblique diameters average less than 13 cm. Midpelvis and Pelvic Outlet The midpelvis is measured at the level of the ischial spines, also called the midplane or plane of least pelvic dimensions (Fig. 2-19). During labor, the degree of fetal head descent into the true pelvis may be described by station, and the midpelvis and ischial spines serve to mark zero station. The interspinous diameter is 10 cm or slightly greater, is usually the smallest pelvic diameter, and, in cases of obstructed labor, is particularly Interspinous = 10 cmInterspinous = 10 cm Transverse of inlet = 13.5 cm Obstetrical Conj=10.5cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3 rd edition. C hapter 23 The Passages
  • 21.
    MIDPELVIS • Suspicion ofmidpelvis contraction is possible with the following: 1. Prominence of the ischial spines 2. Pelvic sidewalls are convergent 3. Concavity of the sacrum is shallow 4. Bi-ischial diameter of the outlet is < 8cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 22.
    3. PELVIC OUTLET •Outlet is bounded anteriorly by the pubic arch, laterally by the ischiopubic rami, ischial tuberosity, and sacrotuberous ligament and posteriorly by the tip of the coccyx • Intertuberous (or bituberous) diameter: 11cm • AP diameter: 9.5-11.5cm • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 23.
    PELVIC OUTLET • Thepelvic outlet consists of two approximately triangular areas. • Posterior triangle • Anterior triangle • They have a common base, which is a line drawn between the two ischial tuberosities. • Clinically, three diameters of the pelvic outlet usually are described—the anteroposterior, transverse, and posterior sagittal. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 24.
    PELVIC OUTLET • Intertuberousdiameter may be measured by placing a closed fist against the perineum at the level of the tuberosities • Thom’s rule: when transverse diameter + PSD > 15cm (xray pelvimetry) à outlet adequate • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 25.
    CALDWELL-MOLOY ANATOMICAL CLASSIFICATION OFTHE PELVIS • based on pelvic shape • its concepts aid an understanding of labor mechanisms. 34 Maternal Anatomy and Physiology SECTION2 FIGURE 2-20 The four parent pelvic types of the Caldwell–Moloy classification. A line passing through the widest transverse diameter divides the inlets into posterior (P) and anterior (A) segments. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 26.
    • the greatesttransverse diameter of the inlet and its division into anterior and posterior segments are used to classify the pelvis as gynecoid, anthropoid, android, or platypelloid. • The posterior segment determines the type of pelvis, whereas the anterior segment determines the tendency. • For example: a gynecoid pelvis with an android tendency à posterior pelvis is gynecoid and the anterior pelvis is android shaped. PELVIC SHAPES (CALDWELL-MOLOY CLASSIFICATION) • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 27.
    PELVIC SHAPES (CALDWELL-MOLOY CLASSIFICATION) MaternalAnatomy and Physiology Corton MM: Anatomy of the pelvis: how the pelvis is built for support. Clin FIGURE 2-20 The four parent pelvic types of the Caldwell–Moloy classification. A line passing through the widest transverse diameter divides the inlets into posterior (P) and anterior (A) segments.
  • 30.
    CALDWELL MOLOY CLASSIFICATION •many pelves are not pure but are of mixed types. • For example, a gynecoid pelvis with an android tendency means that the posterior pelvis is gynecoid and the anterior pelvis is android shaped. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 31.
    SOFT PARTS OFTHE PELVIS • Pelvic floor: muscular partition that separates pelvic cavity from perineum • 3 sets of muscles 1. Pubococcygeus (pubovisceral) 2. Iliococcygeus 3. puborectalis àCollectively known as LEVATOR ANI • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 32.
    SOFT PARTS OFTHE PELVIS • Vaginal birth conveys significant risk for damage to the levator ani or to its innervation • Of these muscles, the pubococcygeus muscle is more commonly damaged • Evidence supports that these injuries may predispose women to greater risk of pelvic organ prolapse or urinary incontinence • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 33.
    SOFT PARTS OFTHE PELVIS Pelvic diaphragm • Levator ani + coccygeus muscles + fascial covering • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 34.
  • 35.
    SOFT PARTS OFTHE PELVIS • Pelvic diaphragm: 2 parts 1. Urogenital triangle (anterior) 2. Anal triangle (posterior) • Nerve supply: S4, inferior rectal nerve, perineal branch of the pudendal nerve • Supports pelvic organs • Control of external anal sphincter • Stabilize sacroiliac and sacrococcygeal joints • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 36.
    ANTERIOR TRIANGLE • Containsportions of urethra and vagina, certain portions of internal pudendal artery branches, and the compressor urethrae and urethrovaginal sphincter muscles, which comprise part of the striated urogenital sphincter complex. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 37.
    ANAL/ POSTERIOR TRIANGLE •This triangle contains the ischioanal fossae, anal canal, and anal sphincter complex, which consists of the internal anal sphincter, external anal sphincter, and puborectalis muscle. • Branches of the pudendal nerve and internal pudendal vessels are also found within this triangle. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 38.
    PUDENDAL NERVE • formedfrom the anterior rami of S2–4 spinal nerves. • It courses between the piriformis and coccygeus muscles and exits through the greater sciatic foramen at a location posterior to the sacrospinous ligament and just medial to the ischial spine • thus, when injecting local anesthetic for a pudendal nerve block, the ischial spine serves as an identifiable landmark • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 39.
    ANAL SPHINCTER COMPLEX:IAS • Two sphincters surround the anal canal to provide fecal continence—the external and internal anal sphincters. • Both lie proximate to the vagina, and one or both may be torn during vaginal delivery. • Internal Anal Sphincter (IAS) is a distal continuation of the rectal circular smooth muscle layer. It receives predominantly parasympathetic fibers, which pass through the pelvic splanchnic nerves. • this sphincter is supplied by the superior, middle, and inferior rectal arteries. • IAS contributes the bulk of anal canal resting pressure for fecal continence and relaxes prior to defecation. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The
  • 40.
    ANAL SPHINCTER COMPLEX:EAS • External Anal Sphincter (EAS) is a striated muscle ring that anteriorly attaches to the perineal body and that posteriorly connects to the coccyx via the anococcygeal ligament. • EAS maintains a constant resting contraction to aid continence, provides additional squeeze pressure when continence is threatened, yet relaxes for defecation. • Receives blood supply from the inferior rectal artery, which is a branch of the internal pudendal artery. • C unningham FG , Leveno KJ, Bloom SL, Spong C Y, D ashe JS, Hoffm an BL, C asey BM , Sheffield JS (eds).W illiam ’s O bstetrics 24 th edition (20140; chapter 2 M aternal anatom y • Sum paico W W , O cam po-Andres IS, Blanco-C apito LR, D iam ante An, G am illa ZN. (eds). Textbook of O bstetrics 3rd edition. C hapter 23 The Passages
  • 41.
    SUMMARY/REVIEW 1. Composition ofthe bony pelvis 2. Pelvic anatomy true pelvis false pelvis 3. Planes of the bony pelvis inlet midpelvis outlet 4. Pelvic shapes gynecoid, android, anthropoid, platypelloid 5. Soft parts of the pelvis levator ani pelvic diaphragm