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PELVIC (GIRDLE) BONE
HIP BONE
FEMUR
04/07/2016
BAAB @2016
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1. Sacrum, Hip bone: 2. Ilium, 3. Ischium, 4. Pelvis 5. Pubic symphisis
6. Acetabulum 7. Obtulator foramen
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The pelvis (plural pelvises) is either the lower part of
the trunk of the human body between the abdomen and
the thighs (sometimes also called pelvic region of the
trunk) or the skeleton embedded in it (sometimes also
called bony pelvis, or pelvic skeleton or the pelvic
girdle).
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The pelvic region of the trunk includes the bony pelvis,
the pelvic cavity (the space enclosed by the bony
pelvis), the pelvic floor, below the pelvic cavity, and
the perineum, below the pelvic floor.
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The pelvic skeleton is formed in the area of the back,
by the sacrum and the coccyx and anteriorly and to the
left and right sides, by a pair of hip bones.
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The gap enclosed by the bony pelvis, called the pelvic cavity, is the
section of the body underneath the abdomen and mainly consists of
the reproductive organs (sex organs) and the rectum.
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This gap is also called the pelvic inlet superiorly and pelvic outlet
inferiorly.
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Structure
The pelvic skeleton includes several structures:
◦ posteriorly (in the area of the back), by the sacrum and the
coccyx.
◦ laterally and anteriorly (forward and to the sides), by a pair of
hip bones. Each hip bone consists of 3 sections, ilium,
ischium and pubis.
◦ In childhood, these sections of hip bone are separate bones,
joined by the triradiate cartilage. During puberty, they fuse
together in the acetabulum to form a single bone.
Fig. The lateral view of the hip bone to show the acetabular location
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The two hip bones are joined anteriorly at the pubic
symphysis by a fibrous cartilage covered by a hyaline
cartilage, the interpubic disk, within which a nonsynovial cavity might be present.
◦ Two ligaments, the superior and inferior pubic ligaments,
reinforce the symphysis.
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Posteriorly, the hip bones form sacroiliac joints, formed
between the auricular surfaces of the sacrum and the two
hip bones.
◦ These are amphiarthroses, almost immobile joints enclosed by
very taut joint capsules reinforced by ventral interosseous, and
dorsal sacroiliac ligaments.
Pelvic cavity:
 typically defined as a small part of the space enclosed
by the bony pelvis, delimited by the pelvic brim above
and the pelvic floor below; alternatively, the pelvic
cavity is sometimes also defined as the whole space
enclosed by the pelvic skeleton, subdivided into
◦ the greater (or false) pelvis, above the pelvic brim
◦ the lesser (or true) pelvis, below the pelvic brim
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the pelvic floor (or pelvic diaphragm), below the pelvic
cavity (soft tissue)
the perineum, below the pelvic floor
Joints:
 Sacroiliac joint is formed between the auricular
surfaces of the sacrum and the hip bone.
 The most important accessory ligaments of the
sacroiliac joint are the sacrospinous and sacrotuberous
ligaments which stabilize the hip bone on the sacrum
and prevent the promontory (prominent or protuberant
part between the 5th lumbar and sacrum) from tilting
forward.
 Additionally, these two ligaments transform the greater
and lesser sciatic notches into the greater and lesser
foramina, a pair of important pelvic openings
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The iliolumbar ligament is said to be the lower border
of the thoracolumbar fascia, the lateral lumbosacral
ligament is partly continuous with the iliolumbar
ligament.
The sacrococcygeal symphysis is the joint between the
sacrum and the coccyx.
It is facilitated by a series of ligaments as ALL
(Anterior Longitudinal Ligaments) and PLL (Posterior
L. L.)
Hip joint, between the acetabular fossa of the hip bone
and hemispherical head of the femur.
◦ It is reinforced by the extracapsular iliofemoral,
ischiofemoral and pubofemoral ligaments.
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Functions:
The skeleton of the pelvis is a basin-shaped ring of
bones connecting the vertebral column to the femur.
Its primary functions are to bear the weight of the upper body
when sitting and standing
transferring that weight from the axial skeleton to the lower
appendicular skeleton when standing and walking
Compared to the shoulder girdle, the pelvic girdle is thus strong
and rigid, hence it provides attachments for and withstanding the
forces of the powerful muscles of locomotion and posture.
Its secondary functions are to contain and protect the pelvic and
abdominopelvic viscera (inferior parts of the urinary tracts,
internal reproductive organs).
providing attachment for external reproductive organs and
associated muscles and membranes.
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 The
pelvic inclination angle is the single most
important element of the human body posture and is
adjusted at the hips. measured by the assessment of the
posture.
 In
later stages of pregnancy the fetus's head aligns
inside the pelvis, and joints of bones soften due to the
effect of pregnancy hormones, letting the pelvis outlet
widen somewhat to allow the fetus passage through the
maternal pelvic opening.
Measurement of the pelvis
measurements were made on pregnant women to
determine whether a natural birth would be possible,
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The following common variations were found
◦ The gynaecoid pelvis is the so-called normal female pelvis.
Found in about 50 per cent of specimens. Its inlet is either
slightly oval, with a greater transverse diameter, or round. The
interior walls are straight, the subpubic arch wide, the sacrum
shows an average to backward inclination, and the greater
sciatic notch is well rounded. Because this type is spacious and
well proportioned there is little or no difficulty in the birth
process.
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The platypelloid pelvis found Less than 3 per cent of women. has a
transversally wide, flattened shape, is wide anteriorly, greater sciatic
notches of male type, and has a short sacrum that curves inwards
reducing the diameters of the lower pelvis. Giving birth with this type
of pelvis is associated with problems, such as transverse arrest.
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The android pelvis is found in one third of white women and in one
sixth of non-white women. It is a female pelvis with masculine
features, including a wedge or heart shaped inlet caused by a prominent
sacrum and a triangular anterior segment. The reduced pelvis outlet
often causes problems during child birth.
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The anthropoid pelvis type found in ¼ of white women and almost ½
of non-white women characterized by an oval shape with a greater
anteroposterior diameter. It has straight walls, a small subpubic arch,
and large sacrosciatic notches. The sciatic spines are placed widely
apart and the sacrum is usually straight resulting in deep nonobstructed pelvis.
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Sexual dimorphism
Body locomotion efficiency and wide birth canal are
two conflicting demands confronting the natural
selection. These contrasting features resulting into a
conflict referred to as the "obstetrical dilemma".
The female pelvis, or gynecoid pelvis,has evolved to
its maximum width for childbirth — a wider pelvis
would make women unable to walk. In contrast,
human male pelvises are not constrained by the need
to give birth and therefore are more optimized for
bipedal locomotion.
Male pelvis
Female pelvis..
The principal differences between male and female true
and false pelvis include:
◦ The female pelvis is larger and broader than the male pelvis
which is taller, narrower, and more compact.
◦ The female inlet is larger and oval in shape, while the male
sacral promontory projects further (i.e. the male inlet is more
heart-shaped).
◦ The sides of the male pelvis converge from the inlet to the
outlet, whereas the sides of the female pelvis are wider apart.
◦ The angle between the inferior pubic rami is acute (70 degrees)
in men, but obtuse (90-100 degrees) in women. Accordingly,
the angle is called subpubic angle in men and pubic arch in
women. Additionally, the bones forming the angle/arch are
more concave in females but straight in males.
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The distance between the ischial bones is small in
males, making the outlet narrow, but large in females,
who have a relatively large outlet. The ischial spines
and tuberosities are heavier and project farther into the
pelvic cavity in males. The greater sciatic notch is
wider in females.
The iliac crests are higher and more pronounced in
males, making the male false pelvis deeper and more
narrow than in females.
The male sacrum is long, narrow, more straight, and
has a pronounced sacral promontory. The female
sacrum is shorter, wider, more curved posteriorly, and
has a less pronounced promontory.
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The acetabula are wider apart in females than in males.
In males, the acetabulum faces more laterally, while it
faces more anteriorly in females. Consequently, when
men walk the leg can move forwards and backwards in
a single plane. In women, the leg must swing forward
and inward, from where the pivoting head of the femur
moves the leg back in another plane. This change in the
angle of the femoral head gives the female gait its
characteristic (i.e. swinging of hips).
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The femur is the only bone located within the human
thigh. It is both the longest and the strongest bone in
the human body, extending from the hip to the knee.
Its length on average is 26.74% of a person's height, a
ratio found in both men and women and most ethnic
groups with only restricted variation
It is a bone of the lower limb but its proximal part
associate closely to the pelvis through a strong hip
joint.
Important features of this bone include the head,
medial and lateral condyles, patellar surface, medial
and lateral epicondyles, and greater and lesser
trochanters.
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The head is where the bone forms the hip joint
with the hip bone (innominate bone).
The condyles are the points of articulation
(connection) with the tibia, which is a leg bone.
The patellar surface is the groove where the
bone articulates with the patella, or kneecap.
articulation with the tibia and kneecap form the
knee joint.
The epicondyles and trochanters are all
important attachment sites for various strong
muscles.
Structure
 The femur is the only bone in the thigh.
 The two femurs converge medially toward the knees,
where they articulate with the proximal ends of the
tibiae.
 The angle of convergence of the femora is a major
factor in determining the femoral-tibial angle.
 In females the femora converge more than in males
because the pelvic bone is wider in females.
 In the condition genu valgum (knock knee) the
femurs converge so much that the knees touch one
another.
 The opposite extreme is genu varum (bowleggedness).
 In the general population of people without either
genu valgum or genu varum, the femoral-tibial angle
is about 175 degrees.
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The femur is categorised as a long bone and comprises a
diaphysis (shaft or body) and two epiphyses (extremities)
that articulate with adjacent bones in the hip and knee.
Fig: The upper extremity of right femur viewed from behind
and above, showing head, neck, and the greater and lesser
trochanter. This forms a proximal articulation of the femur.
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The head of the femur, which articulates with
the acetabulum of the pelvic bone, composes
2/3 of a sphere. It has a small groove, or
fovea, connected through the round ligament
(ligamentum teres capitis femoris) to the
sides of the acetabular notch, also is
connected to the shaft through the neck or
collum.
The neck is 4–5 cm. long which forms an
angle with the shaft in about 130 degrees.
This angle is highly variant. In the infant it is
about 150 degrees and in old age reduced to
120 degrees on average
◦ coxa valga - abnormal increase in the angle
◦ coxa vara - abnormal reduction in the angle
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two trochanters, greater and lesser trochanter
are two prominences found in the area of
transition between the H/N and the shaft of the
femur.
greater trochanter is almost box-shaped and is
the most lateral prominent of the femur, its
prominence is variant mostly in females located
higher than the collum and reaches the midpoint
of the hip joint.
About the junction of the upper one-third and
lower two-thirds on the intertrochanteric crest is
the quadrate tubercle located
In a small anatomical study it was shown that the
epiphysial line passes directly through the
quadrate tubercle
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The femur develops from the limb buds as a
result of interactions between the ectoderm
and the underlying mesoderm, formation
occurs roughly around the fourth week of
development.
Function:
1. Attachment of strong muscles divided into
three compartment of the thigh.
2. Body force distribution from the trunk
down to the ground.