Hip Osteology

Question 1

The Sacrum

Answer 1

. Consists of 5 fused vertebrae
. Articulates with the innominate through synovial joints anteriorly and fibrous posteriorly
. The lowest part of the sacrum lies above the level of the pubic symphysis
. Sacrum has 4 pairs of sacral foramina – passages for nerves and blood vessel

Question 2

The coccyx

Answer 2

consists of 3-5 coccygeal vertebrae- 4 is most common

Question 3

Ilium

Answer 3

. flat bone
. Iliac fossa is part of the lateral abdominal wall
. The lateral aspect is the gluteal surface (gluteal attachment site)
. The roughened posterior surface is the iliac tuberosity for the attachment of the sacroiliac ligament

Question 4

Ischium

Answer 4

During sitting weight of body sits onto the two ischial tuberosities

Ischial ramus combines with the pubic ramus to form ischiopubic ramus

Forms 2/5 of the acetabulum

Question 5

The Pubis

Answer 5

Hyaline cartilage forms the pubic symphysis connects innominate bones anteriorly

Superior ramus continues acetabulum

Forms 1/5 of the acetabulum

Pubic tubercle- prominent attachment site

Flattened inferior ramus extends posterolaterally from the body to fuse with the ischium

Question 6

The obturator foramen

Answer 6

Created by the innominate bones

The obturator membrane is attached to the margins of the foramen except for the superior portion

Question 7

Pelvic girdle

Answer 7

Supports and protects pelvic viscera

Supports bodyweight transmission

Allows walking gait in an upright position

Attachment for muscles
Females - support for the birth canal

Question 8

The acetabulum

Answer 8

Orientated laterally, anteriorly and inferiorly

As a result the anterior aspect of the femoral neck articulates with the joint capsule

Question 9

Female vs Male pelvis

Answer 9

Female
Female
Smaller bones
Pelvis is broader, shallower, and has greater capacity (childbearing adaptation)
Ischial tuberosities shorter but further apart
Larger angle at pubic arch, ca 90-100

Male
Thicker, heavier bones to support larger build
Pelvis is narrower and deeper
Ischial tuberosities longer and sharper
More acute angle at pubic arch, ca 60-79

Question 10

Femoral head and neck

Answer 10

Smooth and covered in articular cartilage apart from a small hallow in the center (fovea capitis) which allows for ligamentum teres attachment.

The neck attaches the head to the shaft and is approx. 5cm in length at 125 .

The neck joins the shaft anteriorly at the intertrochanteric line and posteriorly the intertrochanteric crest

Question 11

Arthrology of the hip joint

Answer 11

Head of femur + acetabulum of the innominate bone

Multi-axial synovial ball and socket

Has to be able to support full body weight when standing on one leg

Joint needs stability even at the expense of limitation of range of movement

Question 12

Arthrology of the acetabulum

Answer 12

Deepened by acetabular labrum – fibrocartilaginous ring which deepens acetabulum

• Hemispherical hollow
• Lunate surface - articulating surface - hyaline cartilage
• Deep central non-articular part – acetabular fossa

Question 13

Articular surface- femoral head

Answer 13

Cancellous bone enclosed in a layer of compact bone
Hyaline cartilage
2/3 sphere – ‘ellipsoid’
Fovea capitis – attachment site of ligamentum teres

Question 14

Joint Capsule

Answer 14

Surrounds hip joint
➢ Very strong
➢ Thicker anteriorly and superiorly
➢ Attaches to the acetabular margin and extends to the intertrochanteric line
➢ Lined internally with synovial membrane

Question 15

Ligaments of the hip joint

Answer 15

ILIO-FEMORAL LIGAMENT – limits extension, adduction and lateral rotation

PUBO-FEMORAL LIGAMENT – limits extension, abduction and lateral rotation

ISCHIO-FEMORAL LIGAMENT – limits extension, abduction and medial rotation

Question 16

Ilio

Answer 16

Strengthens joint anteriorly

▪ Divides into 2 bands (superior and inferior) → forms Y shape

▪ Origin - AIIS and adjacent acetabular rim

▪ Insertion - upper and lower parts of the intertrochanteric line

Question 17

Pubo

Answer 17

Strengthens joint antero-inferiorly

Origin – iliopubic eminence and superior pubic ramus

Insertion – lower part of intertrochanteric line

Blends with the inferior part of the iliofemoral ligament

Between the iliofemoral and pubofemoral ligaments the capsule is at its thinnest independent study

Question 18

Ischio

Answer 18

Strengthens joint posteriorly
Spiral ligament
Laterally and upwards around capsule

Origin – body of ischium below and behind acetabulum

Insertion – neck and root of the greater trochanter

Question 19

Femoral triangle

Answer 19

Femoral vein
Femoral artery
Femoral nerve
Inguinal lymph nodes
Lateral to medial “reverse van”

Question 21

Borders of the femoral triangle

Answer 21

Inguinal ligament (superior)
Sartorius(laterally)
Adductor longus (medially)