• Ilium. - waist bonen
• Ischium - sitbone
• Pubis - sexbone

• HIP BONE; COXAL BONE; PELVIC BONE
  • Acetabulum
    • Acetabular margin
    • Acetabular fossa
    • Acetabular notch
    • Lunate surface
  • Ischiopubic ramus
  • Obturator foramen
  • Greater sciatic notch
  • Ilium
    • Body of ilium
      • Supra-acetabular groove
    • Ala of ilium; wing of ilium
      • Arcuate line
      • Iliac crest
      • Outer lip
        • Tuberculum of iliac crest
        • Intermediate zone
        • Inner lip
        • Anterior superior iliac spine
        • Anteriror inferior iliac spine
        • Posterior superior iliac spine
        • Posterior inferior iliac spine
      • Iliac fossa
      • Gluteal surface
        • Anterior gluteal line
        • Posterior gluteal line
        • Inferior gluteal line
      • Sacropelvic surface
        • Auricular surface
        • Iliac tuberosity
• Ischium
  • Body
    • Ramus
      • Ischial tuberosity
    • Ischial spine
    • Lesser sciatic notch
• Pubis
  • Body
    • Pubic tubercle
    • Symphysial surface
    • Pubic crest
  • Superior pubic ramus
    • Iliopubic ramus
    • Pecten pubis; pectineal line
    • Obturator crest
    • Obturator groove
    • Anterior obturator tubercle
    • (Posterior obturator tubercle)
  • Inferior pubic ramus

The hip bone [Figs. 13.1, 13.2] is made up of three bones—the ilium, ischium, and pubis.

The ilium is large, flat, slightly curved, and directed upwards. The pubis and ischium lie inferiorly, the pubis more anteromedially, and the ischium more posterolaterally. The obturator foramen is a large aperture in the hip bone between the pubis and ischium. The ilium, ischium, and pubis meet at a narrow, thick central part which has the acetabular fossa for articulation with the head of the femur. The pubis and ischium are fused together by a bar of bone, inferior to the obturator foramen. This is the ischiopubic ramus and is formed by the union of the inferior ramus of the pubis and the ramus of the ischium. In the region of the acetabulum, the ilium fuses with the superior ramus of the pubis at the iliopubic eminence, and with the ischium at the rough ridge on the posterior surface of the acetabulum.

The greater sciatic notch is a deep, curved depression, or notch, on the posterior margin of the ilium, immediately above the acetabulum. The medial aspect of the ischium has a shallow lesser sciatic notch, separated from the greater sciatic notch by the spine of the ischium. Immediately inferior to the lesser sciatic notch, the ischium expands to form the ischial tuberosity.

The body of the pubis articulates with its fellow of the opposite side through a median fibrous joint—the pubic symphysis. The pubic symphysis may be felt at the lower end of the abdominal wall. Draw your finger laterally from the pubic symphysis on the anterosuperior surface of the body of the pubis. This surface is the pubic crest which ends in a small, blunt prominence—the pubic tubercle—laterally. The tubercle is less easily felt in the male, because it is covered by the spermatic cord. Lateral to the pubic tubercle, a resilient band can be felt in the inguinal groove between the anterior surface of the thigh and the abdomen. This is the inguinal ligament. On the bone, note a sharp ridge which curves posterolaterally on the superior ramus of the pubis from the pubic tubercle to the iliopubic eminence. This is the pecten pubis. Fibres of the inguinal ligament stretch posteriorly to the pecten and form the lacunar ligament. Below and behind the pubic symphysis, the two inferior pubic rami diverge to form the pubic arch. Each inferior pubic ramus unites with the corresponding ramus of the ischium to form the ischiopubic ramus. The ischiopubic ramus forms the boundary between the thigh and perineum, and is palpable through its length.

Find the iliac crest at the lower margin of the waist. Trace it forwards. It slopes downwards and slightly medially to end in a rounded knob—the anterior superior iliac spine. This may be grasped between the finger and thumb in a thin individual. The inguinal ligament stretches from this spine to the pubic tubercle. On the bone, a

• 1 The acetabulum is directed laterally.
• 2 The flat, expanded ilium forms the upper part of the bone, that lies above the acetabulum.
• 3 The obturator foramen lies below the acetabulum. It is bounded anteriorly by the thin pubis, and posteriorly by the thick and strong ischium.

• 1 The pubic tubercle and anterior superior iliac spine lie in the same coronal plane.
• 2 The pelvic surface of the body of the pubis is directed backwards and upwards.
• 3 The symphyseal surface of the body of the pubis lies in the median plane.

The ilium or flank forms the upper expanded p late-like part of the hip bone. Its lower part forms the upper two-fifths of the acetabulum. The ilium has the following:

• 1 An upper end which is called the iliac crest.
• 2 A lower end which is smaller, and is fused with the pubis and the ischium at the acetabulum. The ilium forms the upper two-fifths of the acetabulum.
• 3 Three borders-anterior, poste:rior and medial.
• 4 Three surfaces-gluteal surface, iliac surface or iliac fossa, and a sacropelvic surface.

The iliac crest (Fig. 2.1) is a broad convex ridge forming the upper end of the ilium. It can be felt in the living at the lower limit of the flank. Curvatures: Vertically it is convex upwards, anteroposteriorly it is concave inwards in front and concave outwards behind (Fig. 2.1). The highest point of the iliac crest is situated a little behind the midpoint of the crest. It lies at the level of the interval between the spines of vertebrae L3 and L4. Ends: The anterior end of the iliac crest is called the anterior superior iliac spine (A.SIS). This is a prominent landmark that is easily felt in the living. The posterior end of the crest is called the posterior superior iliac spine. Its position on the surface of the body is marked by a dimple 5 cm lateral of the second sacral spine (S2)

Hip/ innominate bone is a large irregular bone. It is made up of three parts. These are the iliac (Latin loin) superiorly, the pubis (Latin genital area) anteroinferiorly, and the isc/1i11111 (Greek hip joint) posteroinferiorly. The three parts are joined to each other at a cup-shaped hollow, called the acetab11l11111 (Latin vinegar cup). The pubis and ischium are separated by a large oval opening called the obturntor fornmen. The acetabulum articulates with the head of the femur to form the lzip joint. The pubic parts of the two hip bones meet anteriorly to form the pubic symphysis. The two hip bones form the pelvic or hip girdle. The bony pelvis is formed by the two hip bones along with the sacrum and coccyx.

Side Determination

• 1 The acetabulum is directed laterally.
• 2 The flat, expanded ilium forms the upper part of the bone, that lies above the acetabulum.
• 3 The obturator foramen lies below the acetabulum. It is bounded anteriorly by the thin pubis, and posteriorly by the thick and strong ischium.

Anatomical Position

• 1 The pubic tubercle and anterior superior iliac spine lie in the same coronal plane.
• 2 The pelvic surface of the body of the pubis is directed backwards and upwards.
• 3 The symphyseal surface of the body of the pubis lies in the median plane.

The ilium or flank forms the upper expanded p late-like part of the hip bone. Its lower part forms the upper two-fifths of the acetabulum. The ilium has the following:

• 1 An upper end which is called the iliac crest.
• 2 A lower end which is smaller, and is fused with the pubis and the ischium at the acetabulum. The ilium forms the upper two-fifths of the acetabulum.
• 3 Three borders-anterior, poste:rior and medial.
• 4 Three surfaces-gluteal surface, iliac surface or iliac fossa, and a sacropelvic surface.

The iliac crest is a broad convex ridge forming the upper end of the ilium. It can be felt in the living at the lower limit of the flank. Curvatures: Vertically it is convex upwards, anteroposteriorly it is concave inwards in front and concave outwards behind (Fig. 2.1). The highest point of the iliac crest is situated a little behind the midpoint of the crest. It lies at the level of the interval between the spines of vertebrae L3 and L4. Ends: The anterior end of the iliac crest is called th.e anterior superior iliac spine (A.SIS). This is a prominent landmark that is easily felt in the living. The posterior end of the crest is called the posterior superior iliac spine. Its position on the surface of the body is marked by a dimple 5 cm lateral of the second sacral spine (S2).

Morphological divisions: Morphologically, the iliac crest is divided into a long ventral segment and a short dorsal segment. The ventral segment forms more than the anterior two-thirds of the crest. It has an outer lip, an inner lip, and an intermediate area. The tubercle of the iliac crest is an elevation that lies on the outer lip about 5 cm behind the anterior superior iliac spine . The dorsal segme nt forms less than the posterior onethird of the crest. It has a lateral and a medial slope separated by a ridge.

Anterior Border of Ilium

Anterior border s tarts at the anterior superior iliac spine and runs downwards to the acetabulum. The upper part of the border presents a notch, w hile its lower part shows an e levated area ca lled th e anterior inferior iliac spine. The lower half of this spine is large, triangular and rough.

Posterior Border of Ilium

Posterior border ex tends from the posterior superior iliac spi ne to the upper e nd of th e posterior border of the ischium. A few centimetres below the posterior superior iliac s pine it presents another prominence called the posterior inferior il iac spine. Still lower down the posterior border is marked by a large deep notch called the greater sciatic notch (Fig. 2.1).

Medial Border

Medial border extends on the inner or pelvic surface of the ilium from the iliac cr est to the iliopubic eminence. It separates the iliac fos sa from the s acropelvic s urface. Its lower rounded part forms the iliac parts of the arcuate lin e or inlet of pelvis.

Gluteal Surface

Gluteal surface is the outer surface of the ilium, w hich is convex in front and concave behind, like the iliac crest. It is divided into four areas by three gluteal lines (Fig. 2.1). The posterior gluteal line, the shortest, begins 5 cm in front of the posterior superior iliac spine, and runs downwards to end at upper part of greater sciatic notch. The anterior gluteal line, the longest, begins about 4 cm behind the anterior s uperi or iliac spine, runs backwards and then downwards to end a t the middle of the upper border of the greater scia tic notch. The inferior gluteal line, the most ill-defined, begins a little above and behind the anterior inferior spine, runs backwards and downwards to end near the apex of the greater sciatic notch.

Iliac Fossa

Iliac fossa is the large concave area on the inner surface of the ilium, situated in front of its medial border. lt forms the lateral wall of the false pelvis (Fig. 2.2).

Sacropelvic Surface

Sacropclvic surface is the uneven area on the inner surface of the ilium, situated behind its medial border. It is subdivided into three parts; the iliac tuberosity, the auricular surface and the pel vie surface. The iliac tuberosity is the upper, large, roughened area, lying just below the dorsal segment of the iliac crest. It is raised in the middle and depressed both above and below (Fig. 2.2). The auricular surface is articular but pitted. It lies anteroinferior to the iliac tuberosity. It articulates with the sacrwn to form the sacroiliac joint. The pelvic surface is smooth and lies anteroinferior to the auricular surface. It forms a part of the lateral wall of the true pelvis. Along the upper border of the greater sciatic notch, this surface is marked by the preauricular sulcus. This sulcus its deeper in females than in males.

• 1 The anterior superior iliac spine gives attachment to the lateral end of the inguinal ligament. It also gives origin to the sartorius muscle; the origin extends onto the upper half of the notch below the spine
• (Figs 2.3 and 2.5).
• 2 The outer lip of the iliac crest provides:
  • a. Attachment to the fascia lata in its whole extent.
  • b. Origin to the tensor fasciae /atae in front of the tubercle.
  • c. Insertion to the extemnl oblique muscle in its anterior two-thirds.
  • d. Origin to /atissi11111s don,i just behind highest point of the crest. Tubercle of crest gives attachment to the iliotibial trnct (see Fig. 3.8).
• 3 The intermediate area of the iliac crest gives origin to the i11ternal oblique muscle in its anterior two-thirds.
• 4 The inner lip of the iliac crest provides:
  • a. Origin to the trm1sversus abdominis in its anterior two-thirds (Figs 2.4 and 2.5).
  • b. Attachment to the fascia transversalis and to the fascia iliaca in its anterior two-thirds, deep to the attachment of the transver:sus abdominis.
  • c. Origin to the quadmtus lumbomm in its posterior one-third (Fig. 2.4).
  • d. Attachment to the thoraco/umbar fascia around the attachment of the quadrahJS lumborum.
• 5 The attachments on the dorsal segment of the iliac crest are as follows.
  • a. The lateral slope gives origin to the gluteus 111axi11111s (Fig. 2.5).
  • b. The medial slope gives origin to the erector spi11ae.
  • c. The 111terosseo11s and dorsal sacroiliac ligaments are a ttached to the medial margin d eep to the attachment of the erector spinae (fig. 2.4).
• 6 The upper half of the anterior inferior iliac spine gives origin to the straight head of the rcctus femoris. The rough lower part of this spine gives attachment to the iliofemnral ligament (Fig. 2.14).
• 7 The posterior border of the ilium provides:
  • a. Attachment to upper fibres of the sacrot11berous ligame11/ above the greater sciatic notch.
  • b. Origin to few fibres of the piriforrnis from upper margin of the greater sciatic notch (Fig. 2.3).
• 8 The attachments on the gluteal surface are as follows.
  • a. The area behind the posterior gluteal line gives origin to upper fibres of the gluteus maximus.
  • b. The gluteus medius arises from the area between the anterior and posterior gluteal lines (Fig. 2.3).
  • c. The gluteus mi11i11111s arises from the area between the anterior and inferior gluteal lines (Fig. 2.3).
  • d. Below the inferior gluteal line, the reflected head of the rectusfemoris arises from the groove above the acetabulum (Fig. 2.3).
  • e. The cap:;11/ar ligament of the hip jomt is attache along the margin of acetabulum.
• 9 The iliac fossa gives origin to the iliacus from its upper two-thirds (Fig. 2.4). The lower grooved part of the fossa is covered by the iliac bursa.
• 10 The iliac tuberosity provides attachment to:
  • a. The interosseous sacroiliac ligament in its greater part (Fig. 2.4).
  • b. The dorsal sacroiliac ligament posteriorly.
  • c. The iliolw11/Jar ligament superiorly.
• 11 The convex margin of the auriwlar surface gives attachment to ventral sacroiliac ligament.
• 12 The attachments on the pelvic surface are as follows.
  • a. The preauricular sulcus provides attachment to the lower fibres of the ventral sacroiliac ligament.
  • b. The part of the pelvic s urfa ce la teral to the preauricular sulcus gives origin to a few fibres of the pirifor111is.
  • c. The rest of the pelvic surface gives origin to the upper half of the obturator intenws

It forms the anteroinferior part of the hip bone and the anterior one-fifth of the acetabulum, forms the anterior boundary of the obturator foramen. It has:

• a. A body anteriorly.
• b. A superior ramus superola terally.
• c. An inferior ramus inferolaterally (Figs 2.1 and 2.2).

Body of Pubis

This is flattened from before backwards, and has:

• 1 A superior border called the pubic crest.
• 2 A pubic tubercle at the lateral end of the pubic crest.
• 3 Three surfaces, viz. anterior, posterior and medial.

• The pubic tubercle is the lateral end of the pubic crest, forming an important landmark (Fig. 2.1).
• The anterior surface is directed downwa rds, forwards and slightly laterally. It is rough superomedially and smooth elsewhere.
• The posterior or pelvic surface is smooth. It is directed upwards and backwards. It forms the anterior wall of the true pelvis, and is related to the urinary bladder.
• The medial or symphyseal surface articulates with the opposite pubis to form the pubic symphysis.

Superior Ramus

It extends from the body of the p ubis to the acetabulum, above the obturator foramen. It has three borders and three surfaces.

• The superior border is called the pectineal line or pecten pubis. It is a sharp crest extending &om just behind the pubic tubercle to the posterior part of the iliopubic eminence. With the pubic crest it forms the p ubic part of the arcuate line (Fig. 2.1).
• The anterior border is called the obturator crest. The border is a row1ded ridge, extending from the pubic tubercle to the acetabular notch.
• The inferior border is sharp and forms the upper margin of the obturator foramen.
• The pectineal surface is a triangul ar area between the anterior and superior borders, extending from the p ubic tubercle to the iliopubic eminence.
• The pelvic surface lies between the superior and inferior borders. It is smooth and is continuous with the pelvic surface of the body of the pubis (Fig. 2.2).
• The obturator surface lies between the anterior and inferior borders. It presents the obturator groove.

Inferior Ramus

It extends from the body of the pubis to the ramus of the ischium, medial to the obturator fora men. It mutes with the ramus of the ischium to form the conjoined ischiopubic rami. For convenience of description, the conjoined rami will be considered together at the end .

• 1 The pubic tubercle provides attachment to the medial end of the i11g11inal ligament (see Fig. 3.2) and to ascending loops of the cremnster muscle (see Fig. 16.17). In males, the tubercle is crossed by the spermatic cord (see Fig. 16.13).
• 2 The medial part of the pubic crest is crossed by the medial head of the rectus abdominis. The lateral part of the crest gives origin to the lateral head of the rectus abdominis, and to the pyramidalis (Fig. 2.3).
• 3 The anterior surface o f the body of the pubis provides:
  • a. Attachment to the anterior pubic ligament medially.
  • b. Origin to the adductor /ongus in the angle between the crest and the symphysis (Fig. 2.3).
  • c. Origin to the gracilis, from the margin ofsymphysis, and from the inferior ramus.
  • d. Origin to the adductor brevis lateral to the origin of the gracilis (Fig. 2.3).
  • e. Origin to the obturator extemus near the margin of the obturator foramen (Fig. 2.3).
• 4 The posterior surface of the body of the pubis provides:
  • a. Origin to the /evator ani from its middle part
  • (Fig. 2.4).
  • b. Origin to the obturator intemus laterally (Fig. 2.4).
  • c. A ttachment to the puboprostatic/pubovesical ligaments medial to the attachment of the levator ani.
• 5 The pectineal line provides attachment to:
  • a. The conjoint tendon at the medial end.
  • b. The lacunar ligament at the medial end, in front of the attachment of the conjoint tendon.
  • c. The pecltineal ligament of Cooper along the whole length of the line lateral to the attachment of the lacunar ligament .
  • d. The peclrineus muscle which arises from the wholelength of the line (Fig. 2.3).
  • e. The fascia covering the pectineus.
  • f. The psoas minor, which is inserted here when present.
• 6.The upper part of the pectineal surface gives origin to the pectineus (Fig. 2.3).
• 7. The pelvic surface is crossed by round ligament of the uterus in females and by the ductus deferens in males .
• 8. The obturator groove (Fig. 2.2) transmits the obturator vessels and nerve.

The ischium forms the posteroinferior part of the hip bone, and the adjoining two-fifths of the acetabulum. It forms the posterior boundary of the obturator foramen. The ischium has a body and a ram us (Figs 2.1 to 2.4).

Body of the lschium

This is a thick and massive mass of bone that lies below and behind the acetabulum. It has: Two ends–upper and lower; Three borders-anterior, posterior and lateral; Three surfaces-femoral, dorsal and pelvic.

Two Ends

• 1 The upper end forms the posteroinferior two-fifths of the acetabulum. The ischium, ilium and pubis fuse with each other in the acetabulum.
• 2 The lower end forms the isc'1ia1 tuberosihJ. It gives off the ramus of the ischium which forms an acute angle with the body.

Three Borders

• 1 The anterior border forms the posterior margin of the obturator foramen.
• 2 The posterior border is continuous above with the posterior border of the ilium. Below, it ends at the upper encl of the ischial tuberosity. lt also forms part of the lower border of the greater sciatic notch. Below the notch the posterior margin shows a projection
• called the ischial spine. Below the spine the posterior border shows a concavity called the lesser sciatic notch.
• 3 The lateral border forms the lateral margin of the ischial tuberosity, except at the upper end where it is rounded.