The pelvis is a bony ring formed by the fusion of three bones - the ilium, ischium, and pubis. It supports the spine and forms sockets called acetabula that connect to the femoral heads. The sacrum fuses five vertebrae into a triangular bone and connects the pelvis to the spine. The hip joint is a ball and socket joint that connects the femur to the acetabulum, allowing movement and bearing weight. It is supported by muscles, tendons, ligaments, and a protective labrum and joint capsule that surround it.

1. PELVIS HIP ANATOMY
• BY
• Dr T Devi vara prasad

2. Anatomy of the pelvis
• The pelvis is a symmetrical bony ring interposed between the vertebrae of the
sacral spine and the lower limbs, which are articulated through complex
joints, the hips. It supports the spinal column and connects the upper body to
the lower extremities.
• It consists of three strong bones fused together: the ilium, ischium and pubis.
These bones merge to form bilateral concave sockets named acetabulum
• The ilium is the largest flat bone located on either side of the upper portion of
the pelvis, including the iliac crest, which is the protruding tip bone of the
pelvis that is easily felt with palpation.
• The pubis is the smallest bone at the anterior side of the pelvis. Both ends of
the pelvis are fused by the symphysis pubis consisting of a cartilaginous
flexible tissue.

3. The sacrum
The sacrum consists of five fused vertebrae (S1
to S5) adopting a triangular shape located in the
posterior side of the pelvis. The upper, wider
region of the sacrum articulates with the ilium
(sacroiliac joint) on each side. In the lower
portion it connects to the tail bone or coccyx
formed by five small fused bones.
The sacrum is particularly important in forming
and stabilising the pelvic ring via the presence of
numerous ligaments between bones and allows
the connection of muscles of the pelvis and
muscles of the hip joint (gluteus maximus, iliacus
and piriformis).

4. The hip is a major ball-and-socket joint connecting the long bones of the lower limbs
(femur) to the pelvis. This joint allows a wide range of movements of the lower limbs
and is used when walking, running, climbing, lunging and bending. Because it bears
the body weight, the hip joint is supported by large muscles, strong tendons and
ligaments.
The hip joint is protected by articular cartilage, which is a layer of elastic yet tough
connective tissue surrounding both the femoral head and the acetabulum. The
cartilage ad rotating inside the socket and importantly it absorbs shock impacts.
Overuse of the cartilage is often leading to degeneration or osteoarthritis of the hip.
Anatomy of the hip
• The hip joint consists of the round head of the
thighbone named femur, which inserts into the
pelvis ring in a socked called acetabulum. The
femoral facilitates the movement of the joint by
reducing the friction of the femoral hehead
continues distally with the femoral neck and
the greater trochanter. The latter is the
protruding portion of the femur bone that can be
felt laterally at the higher thigh, below the pelvis.

5. Anatomy of the femur
• The femur or thighbone is the longest
and strongest bone in the human
skeleton. It extends from the hip to the
knee joint. The femoral head is the
distal (upper) end of the femur that
inserts into the acetabulum of the hip
joint. As it descends towards the knee,
it is separated from the longest tubular
bone, or shaft, by the femoral neck.

6. Ligaments of the pelvis and hip
• The bones of the pelvis are held together by a large
number of ligaments and muscles. The stability and
flexibility of thehip joint is provided by two
structures: the ligaments, made of strong connective
tissue, which connect bones to bones, and the tendons,
which connect muscles to bones.
• Iliofemoral ligament is the strongest ligament in the
body. It is Y-shaped and extends from the lower front
iliac spine of the coccyx to the femur trochanter
(intertrochanteric line). This ligament prevents the
extension of the femur in a standing position
• Ischiofemoral ligament begins at
the ischium, posteriorly to the acetabulum
• Pubofemoral ligament originates lateral to the pubis
adjacent to the iliofemoral ligament.
• Ligamentum teres is smaller ligament that connects
the higher extremity of the femoral head to the
acetabulum. It contains an artery that supplies blood
to the femoral head.

7. The labrum and capsule
• The labrum is a cuff made of fibro-cartilaginous
rim covering the edge of the acetabular cavity of
the pelvis. It consists of two parts, one in contact
to the femoral head and the other connecting
with the joint capsule. The labrum can be subject
to tear and injury.
• The capsule of the hip is an essential bundle of
strong ligaments that surround the hip to
consolidate the joint elements and hold the
femoral head in place during movement. The
ligaments are
the iliofemoral, pubofemoral and ischiofemoral.
The capsule produces synovial fluid to keep the
hip joint lubricated and facilitate the sliding of
the joint components.

8. Bursas of the hip
A bursa is a fluid-filled sac, functioning as a cushion
to absorb shock and facilitate gliding of muscles and
bones around the joint. The hip has two main bursas:
The great trochanteric bursa is located on the great
trochanter where the large ilio-psoas muscles of the
hip joint are attached. This is quite a large bursa and
is known for the related pathology, hip
bursitis (trochanteric bursitis).
The ilio-psoas bursa is located on the inner side of
the hip. Also this bursa is subject to inflammation or
bursitis, albeit less commonly.

9. Muscles of the pelvis
The muscles of the pelvis and hip
control the vast range of
movement of the legs and torso.
On the posterior side they are
the glutei and on the anterior
side the hip muscles extending
into the thighs.