HIP BONE
Hip/innominate bone is a large irregular bone. It is
made up of three parts. These are the ilium (Latin loin) superiorly, the pubis (Latin genital area)
anteroinferiorly, and the ischium (Greek hip joint) posteroinferiorly. The three parts are joined to
each other at a cup-shaped hollow, called the acetabulum (Latin vinegar cup). The pubis and
ischium are separated by a large oval opening
called the obturator foramen.The acetabulum articulates with the head of the femur to form the
hip 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.Page 1
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.
ILIUM :
The ilium or flank forms the upper expanded plate-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, posterior and medial.
4) Three surfaces-gluteal surface, iliac surface or iliac fossa, and a sacropelvic surface.
ILIAC CREST :
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, antero-posteriorly it is concave inwards in front and
concave outwards behind.
• 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 (ASIS). 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).Page 1
• 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 cmbehind the anterior superior
iliac spine.
The dorsal segment forms less than the posterior one-third of the crest. It has a lateral and a
medial slope separated by a ridge.
ANTERIOR BORDER OF ILIUM :
Anterior border starts at the anterior superior iliac spine and runs downwards to the acetabulum.
The upper part of the border presents a notch, while its lower part shows an elevated area
called the anterior inferior iliac spine. The lower half of this spine is large, triangular and rough.
POSTERIOR BORDER OF ILIUM :
Posterior border extends from the posterior superior iliac spine to the upper end of the posterior
border of the ischium. A few centimetres below the posterior superior iliac spine it presents
another prominence called the posterior inferior iliac spine. Still lower down the posterior border
is marked by a large deep notch called the greater sciatic notch.
MEDIAL BORDER :
Medial border extends on the inner or pelvic surface of the ilium from the iliac crest to the
iliopubic eminence. It separates the iliac fossa from the sacropelvic surface. Its lower rounded
part forms the iliac parts of the arcuate line or inlet of pelvis.
GLUTEAL SURFACE :
Gluteal surface is the outer surface of the ilium, which is convex in front and concave behind,
like the iliac crest. It is divided into four areas by three gluteal lines.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
superior iliac spine, runs backwards and then
Hip/innominate bone is a large irregular bone. It is
made up of three parts. These are the ilium (Latin loin) superiorly, the pubis (Latin genital area)
anteroinferiorly, and the ischium (Greek hip joint) posteroinferiorly. The three parts are joined to
each other at a cup-shaped hollow, called the acetabulum (Latin vinegar cup). The pubis and
ischium are separated by a large oval opening
called the obturator foramen.The acetabulum articulates with the head of the femur to form the
hip 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.Page 1
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.
ILIUM :
The ilium or flank forms the upper expanded plate-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, posterior and medial.
4) Three surfaces-gluteal surface, iliac surface or iliac fossa, and a sacropelvic surface.
ILIAC CREST :
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, antero-posteriorly it is concave inwards in front and
concave outwards behind.
• 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 (ASIS). 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).Page 1
• 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 cmbehind the anterior superior
iliac spine.
The dorsal segment forms less than the posterior one-third of the crest. It has a lateral and a
medial slope separated by a ridge.
ANTERIOR BORDER OF ILIUM :
Anterior border starts at the anterior superior iliac spine and runs downwards to the acetabulum.
The upper part of the border presents a notch, while its lower part shows an elevated area
called the anterior inferior iliac spine. The lower half of this spine is large, triangular and rough.
POSTERIOR BORDER OF ILIUM :
Posterior border extends from the posterior superior iliac spine to the upper end of the posterior
border of the ischium. A few centimetres below the posterior superior iliac spine it presents
another prominence called the posterior inferior iliac spine. Still lower down the posterior border
is marked by a large deep notch called the greater sciatic notch.
MEDIAL BORDER :
Medial border extends on the inner or pelvic surface of the ilium from the iliac crest to the
iliopubic eminence. It separates the iliac fossa from the sacropelvic surface. Its lower rounded
part forms the iliac parts of the arcuate line or inlet of pelvis.
GLUTEAL SURFACE :
Gluteal surface is the outer surface of the ilium, which is convex in front and concave behind,
like the iliac crest. It is divided into four areas by three gluteal lines.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
superior iliac spine, runs backwards and then
