Hip joint

Dr. Heba Kalbouneh

Associate Professor of Anatomy and Histology

A joint is where two or more bones meet. Also known as an articulation

Joints can be classified either by:

the tissue that holds the bones together

or the degree of movement they provide

Synovial joints

Fibrous joints

Cartilaginous joints

Joints

Permits free movement

Limited or no movement

Fibrous joints are connected by dense connective tissue and have no joint cavity.

Cartilaginous joints are connected by cartilage and have no joint cavity.

Synovial joints have a synovial, fluid-filled cavity that surrounds the articulating bones.

Synarthrosis: Joints that do not provide any movement.

Amphiarthrosis: Joints that only provide a small degree of movement.

Diarthrosis: Joints that allow free movement

FIBROUS JOINTS

In a fibrous joint, the two bones are

connected by dense fibrous connective tissue

These joints can be either synarthrotic or

amphiarthrotic

There are three different types of fibrous

joints:

Suture: between the flat bones of the skull

Gomphosis: The roots of a tooth and the

alveolar sockets in the maxilla or mandible

Syndesmosis: interosseous membrane

Sutures

Sutural ligament

These joints are synarthrotic

Gomphoses occur only between

the teeth and adjacent bone. In

these joints, short collagen

tissue fibers in the periodontal

ligament run between the root

of the tooth and the bony socket

These joints are synarthrotic

Gomphoses

Syndesmoses

These joints are amphiarthrotic

CARTILAGINOUS JOINTS

In a cartilaginous joint, the two bones are

connected by cartilage

These joints can be either synarthrotic or

amphiarthrotic

There are two types of cartilaginous joints:

Synchondroses: growth plate

Symphyses: intervertebral joints, symphysis

pubis

Intervertebral joints

Symphysis pubis

Synovial joints Synovial joints are most commonly found

throughout the limbs.

In order for the joint to be classified as

synovial:

Both adjacent bones participating in

the joint must be lined with hyaline

cartilage (articular cartilage)

The joint is encompassed in a capsule

that encases the joint cavity.

The interior of the capsule is lined

with a synovial membrane that is

responsible for producing and secreting

synovial fluid

Synovial fluid lubricates the joint,

which aids in reducing the friction

between the bones’ ends as they

articulate with each other

Further reinforcement of the capsule is

provided by ligaments, tendons and

skeletal muscle

Bursae are fibrous, slightly flattened sacs,

lined with synovial membrane and containing a

thin film of synovial fluid.

These structures are usually found between

bone and other tissues, such as skin, tendons,

muscles, and ligaments.

Bursae function to cushion the movement

between these structures as they rub together.

Bursae and Tendon sheaths

Bursae Tendon sheath

A tendon sheath is a

membrane that wraps

around a tendon, which

allows the tendon to stretch

and prevents it from

adhering to the overlying

fascia. This sheath also

produces a fluid, known as

synovial fluid, which keeps

the tendon moist and

lubricated.

Gliding (plane) Joint

Ball and Socket Joint

Example: shoulder and

hip joints

Hinge Joint

Example: elbow and

knee joints

Pivot Joint

Example: atlanto-

axial joint

Saddle Joint

Synovial joints

Ellipsoid Joint:

Example: wrist joint

Socket Ball

Type Synovial

Multi-axial

Ball-and-socket joint

Acetabulum

Articular surfaces: a-Head of femur

b-Lunate surface of

acetabulum

Head

Lunate surface

Acetabular fossa

Head of femur

The acetabular labrum is a

ring of fibrocartilage that

surrounds the acetabulum of

the hip.

The labrum deepens this

cavity and effectively

increases the surface (and

strength) of the hip joint

3-Nerve

Supply: Femoral nerve

Obturator nerve

Sciatic nerve

Referred Pain From the Hip

Joint

The femoral nerve not only

supplies the hip joint but, via

the intermediate and medial

cutaneous nerves of the

thigh, also supplies the skin

of the front and medial side

of the thigh. It is not

surprising, therefore, for pain

originating in the hip joint to

be referred to the front and

medial side of the thigh. The

obturator nerve supplies both

the hip and knee joints. This

would explain why hip joint

disease sometimes gives rise

to pain in the knee joint.

Sciatic

The capsule of the hip is attached

Medially: is attached to the margin of the

acetabulum

Laterally: is attached to the trochanteric

line anterioly and just proximal to the

intertrochanteric crest posteriorly

Capsule

Part of the neck

posteriorly is extra -

capsular

Anterior

Posterior

Lines the capsule as well as any

intracapsular bony surfaces not lined

with articular cartilage

Thus, where the capsule attaches to

the femur, the synovial membrane

reflects proximally along the

femoral neck to the edge of the

femoral head.

Subsynovial retinacular arteries

(branches of the medial and a few

from the lateral femoral circumflex

artery) supply the head and neck of

the femur

The synovial membrane

Subsynovial retinacular arteries

Provide one pathway for the

blood supply to the

femoral head

Medial and lateral circumflex femoral arteries

The main blood supply is from the retinacular arteries arising as branches from the circumflex

femoral arteries (especially the medial circumflex femoral artery).

Artery to the head of femur

Acetabular branch of obturator artery (patent in approx. 30% )

Blood supply of the head of the femur

Do you remember epiphyseal

growth plate ????

Subsynovial retinacular arteries

Acetabular branch of obturator artery

This fracture cuts off most of the

retinacular blood supply to the head

Avascular necrosis is common

Note that blood supply via

ligamentum teres is negligible in

adult life

The upper end of the

femur is a common

site for fracture in the

elderly

Anatomic knowledge of the blood supply to the femoral head explains

why avascular necrosis of the head can occur after fractures of the neck

of the femur.

In the young, the epiphysis of the head is supplied by a small branch of

the obturator artery (acetabular branch), which passes to the head along

the ligament of the femoral head. The neck of the femur receives a

profuse blood supply from the medial femoral circumflex artery. These

branches ascend along the neck deep to the synovial membrane toward

the femoral head. As long as the epiphyseal cartilage remains, no

communication occurs between the two sources of blood. In the adult,

after the epiphyseal cartilage disappears, an anastomosis between the

two sources of blood supply is established. Fractures of the femoral neck

interfere with or completely interrupt the blood supply from the root of

the femoral neck to the femoral head. The scant blood flow along the

small artery that accompanies the round ligament may be insufficient to

sustain the viability of the femoral head, and ischemic necrosis gradually

takes place.

Important

Iliofemoral ligament

Pubofemoral ligament

Ischiofemoral ligament

Main ligaments of the hip joint 5 ligaments

All three ligaments are oriented in a

spiral fashion around the hip joint

so that they become taut when the

joint is extended

This stabilizes the joint and reduces

the amount of energy required to

maintain a standing position

Iliofemoral ligament Anterior

Pubofemoral ligament Anterior

Ischiofemoral ligament

Posterior

Fovea capitis

The ligament of head of

femur (ligamentum teres)

is weak and of little

importance in

strengthening

the hip joint. Usually, the

ligament contains a small

artery to the head of the

femur

The acetabular notch is bridged by

the

Transverse acetabular ligament

Flexion is performed by the iliopsoas, rectus femoris, and sartorius

Extension is performed by the gluteus maximus and the hamstring muscles

Abduction is performed by the gluteus medius and minimus, assisted by the sartorius,

tensor fasciae latae, and piriformis

Adduction is performed by the adductor longus and brevis and the adductor fibers of the

adductor magnus. These muscles are assisted by the pectineus and the gracilis

Lateral rotation is performed by the short lateral rotator muscles and assisted by the

gluteus maximus

Medial rotation is performed by the anterior fibers of the gluteus medius and gluteus

minimus and the tensor fasciae latae

Movements of the hip joint

ANGLE OF INCLINATION

It is the angle between the neck and shaft of

the femur, typically ranges from 120 ° to 135 °

degrees

Is about 160 ° in the young child and about

125° in the adult

More than 135º: coxa valga

Less than 120º: coxa vara

Approx. 125º

Allows high degree of freedom ( by moving the

longitudinal axis of femur away from hip joint

Dislocation of the hip

The hip is usually dislocated backwards and

this is produced by a force applied along the

femoral shaft with the hip in the flexed position

(e.g. the knee striking against the opposite seat

or in car accident

The sciatic nerve, is in a close posterior relation

with the hip joint therefore, it is in a danger of

damage in these injuries

Iliopsoas bursa

Lies between the iliopsoas

tendon and the hip joint