Joints of Upper limb pdf - د. نوفل الحديثي

Upper limb articulations

OBJECTIVES

…



To classify joints according to their shape &

structure



To describe the anatomy of upper limb joints



To apply to some clinical conditions

JOINTS:



Joints are sites where skeletal structures (bones &/or cartilages) are

connected to each other



Joints are designed for movements though some are immobile



All bones (except the hyoid) are connected to joints

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There are 230 joints in human body!

Structural types:

Fibrous joints:

-Articulating surfaces are fastened together by dense connective tissue

containing collagen

-Most of them are immobile

-Examples; skull sutures, tibiofibular joints

Cartilagenous joints:

-Articulating surfaces are connected by hyaline cartilage or fibrocartilage

-They provide little or no movement

1- Primary cartilagenous joints;

bone meets hyaline cartilage, like the costo-chondral

joint

2- Secondary cartilagenous joints (symphesis);

Bones covered by a hyaline cartilage &

held by fibrocartilage, like intervertebral discs

Synovial joints:

Characterized by:

1- Surrounded by a joint capsule

2- Supported by ligaments

3- Lined with synovial membrane

4- Covered by hyaline cartilage

5- Contains synovial fluid

example

Possible movement

Description

Joint type

Hip, shoulder

Free + rotation

Ball-shaped head +

cup-shaped socket

1- Ball & socket

Metacarpo-phalyngeal

Free without rotation

Oval condyle +
elliptical cavity

2- Condyloid

Morphological types:

example

Possible movement

Description

Joint type

Intermetacarpal

Sliding or twisting

Articulating surfaces are flat or

slightly curved

3- Gliding

Elbow

Flexion-extension

Convex surface + concave one

4- Hinge

example

Possible

movement

Description

Joint type

Atlantoaxial

Rotation

Cylindrical surface + ring

surface

5- Pivot

Carpometacarpal joint

of thumb

Mainly movements

in two planes

Articulating surface is both

convex & concave against

complementary surface

6- Saddle

Joint stability:

The stability of joint is maintained by three main factors:

• Morphological

• Lligamentous

• Muscular

All these factors usually share in joint stability, although one of them will

prdominates in specific joints

The shoulder joint:

• The shoulder is the region of

upper limb attachment to the

trunk and neck.

• The bony framework of the

shoulder

consists

the

clavicle,

scapula

the

proximal end of the humerus

• The shoulder constitutes 3

joints; the sternoclavicular,

the

acromioclavicular

glenohumeral joints.

Sternoclavicular joint:

•It is synovial & saddle-shaped.

•The

articular

cavity

completely separated into two

compartments by an articular

disc.

•It allows movement of the

clavicle, predominantly in the

anteroposterior

and

vertical

planes, although some rotation

also occurs.

Ligaments:

•Anterior and posterior sternoclavicular ligaments are anterior and posterior,

respectively, to the joint;

•Interclavicular ligament links the ends of the two clavicles to each other

•Costoclavicular ligament is positioned laterally to the joint and links the

proximal end of the clavicle to the first rib and related costal cartilage.

Acromioclavicular joint:

- A small synovial joint between the small oval facet on the medial surface of the

acromion and a similar facet on the acromial end of the clavicle.

- It allows movement in the anteroposterior and vertical planes together with

some axial rotation.

•The acromioclavicular joint is surrounded by a joint capsule and is reinforced

by a small acromioclavicular ligament superior to the joint

•A much larger coracoclavicular ligament, is an important strong accessory

ligament, providing much of the weight bearing support for the upper limb on

the clavicle and maintaining the position of the clavicle on the acromion &

comprises an anterior trapezoid and a posterior conoid ligaments (which

attaches to the related tubercles on the clavicle).

Glenohumeral joint:

-A synovial ball and socket articulation between the head of the humerus and the

glenoid cavity of the scapula.

-It is multiaxial with a wide range of movements provided at the cost of skeletal

stability.

-Joint stability is provided, instead, by the rotator cuff muscles, the long head of the

biceps and extracapsular ligaments.

The articular surfaces:

• The large spherical head of the humerus

accounts three folds the area of the

small glenoid cavity of the scapula.

• Each of the surfaces is covered by

hyaline cartilage.

• The glenoid cavity is deepened and

expanded

peripherally

fibrocartilaginous collar (the glenoid

labrum), which attaches to the margin of

the fossa.

• Superiorly, this labrum is continuous

with the tendon of the long head of the

biceps brachii muscle, which attaches to

the supraglenoid tubercle and passes

through the articular cavity

Synovial membrane:

-The synovial membrane attaches

to the margins of the articular

surfaces and lines the joint capsule

-It protrudes through apertures in

the fibrous membrane to form

bursae, which lie between the

tendons of surrounding muscles

and the fibrous membrane.

-The most consistent is the bursa of

subscapularis, which lies between

the subscapularis muscle and the

capsule.

The fibrous membrane (capsule):

• The capsule attaches to the

margin of the glenoid cavity,

outside the attachment of the

glenoid labrum and the long head

of the biceps brachii, and to the

anatomical neck of the humerus

• On the humerus, the medial

attachment occurs more inferiorly

& more loose to accommodates

abduction of the arm

Ligaments:

•The joint capsule is thickened anterosuperiorly in three locations to form superior,

middle, and inferior

glenohumeral ligaments

, which pass between the superomedial

margin of the glenoid cavity to the lesser tubercle & anatomical neck of the humerus

•Coracohumeral ligament

lies superiorly between the base of the coracoid process

and the greater tubercle

•Transverse humeral ligament

lies between the greater and lesser tubercles of the

humerus

The surrounding muscles:

• Tendons of the rotator cuff muscles (the

supraspinatus,

infraspinatus,

teres

minor, and subscapularis muscles)

blend with the joint capsule & form a

collar that surrounds the joint except

inferiorly

• This cuff holds the head of the humerus

in the glenoid cavity of the scapula

without

compromising

the

arm's

flexibility and range of motion.

Blood supply:

Branches of the anterior and posterior

circumflex humeral and suprascapular

arteries.

Innervation:

• Posterior cord of the brachial plexus

• Suprascapular n

• Axillary n

• Lateral pectoral n

The elbow joint:

A complex joint involving three separate

articulations, which share a common

synovial cavity:

1- The joints between the trochlear notch of

the ulna and the trochlea of the humerus

2- The joint between the head of the radius

and the capitulum of the humerus

These two joints are primarily involved with

hinge-like flexion-extension of the forearm

on the arm & represent the principal elbow

joint.

3- The joint between the head of the radius

and the radial notch of the ulna (proximal

radio-ulnar joint) is involved with pronation

and supination of the forearm

• Articular surfaces of the bones are covered with hyaline cartilage

• Synovial membrane originates from the edges of the articular cartilage and

lines the deep surface of the joint capsule & all capsular contents apart

from the articular surfaces

-The synovial membrane is separated from the capsule by pads of fat in

regions overlying the coronoid fossa, the olecranon fossa, and the radial

fossa.

-These fat pads accommodate the articular parts during extension and flexion

of the elbow.

-Attachments of the brachialis and triceps to the joint capsule overlying these

regions pull these pads out of the way when the adjacent bony processes are

moved into the fossae

Ligaments:

1- Medial & lateral collateral ligaments:

thickenings in the fibrous membrane

to support the flexion and extension

movements

2- Annular ligament:

the joint capsule

is reinforced laterally where it cuffs the

head of the radius with a strong

annular ligament which separates from

the capsule posteriorly.

The anular ligament of radius and

related joint capsule allow the radial

head to slide against the radial notch

of the ulna and pivot on the capitulum

during pronation and supination.

Vascular supply:

Anastomosis around the elbow

Innervation:

Predominantly by branches of the radial and musculocutaneous nerves.

There may be some innervation by branches of the ulnar and median nerves

Basic movements of the elbow:

The distal radio-ulnar joint:

-Occurs between the head of the ulna with the ulnar notch of the radius, and with a

fibrous articular disc, which separates the joint from the wrist joint

- The articular disc is attached by its apex to the ulna & by its base to the angular

margin of the radius near the ulnar notch

-Synovial membrane is attached to the margins of this joint and is covered on its

external surface by a fibrous joint capsule

-The distal radio-ulnar joint allows the distal end of the radius to move

anteromedially over the ulna

Wrist joint :

In anatomy the wrist includes:

• Inferior RUJ

• Radiocarpal J

• Intercarpal J

The radiocarpal joint:

-Is a synovial joint between the distal end of

the radius and the articular disc overlying

the scaphoid & lunate bones

-The articular surfaces of the carpals form

an oval shape with a convex contour, which

articulates with the corresponding concave

surface of the radius and articular disc

-The wrist joint allows movement around

two axes (abduction-adduction & flexion-

extension)

-Because the radial styloid process extends further distally than does the

ulnar styloid process, the hand can be adducted to a greater degree than it

can be abducted

-The capsule of the wrist joint is reinforced by radiocarpal & ulnocarpal

ligaments

-Radial and ulnar collateral ligaments span the distance between the styloid

processes of the radius and ulna and the adjacent carpal bones.

Carpal joints:

-The synovial joints between the carpal bones share a common articular

cavity.

-The joint capsule of the joints is reinforced by numerous ligaments.

-Although movement at the carpal joints (intercarpal joints) is limited, they do

contribute to the positioning of the hand in abduction, adduction, flexion,

and, particularly, extension.

Carpometacarpal joints:

-Are 5 in number

-The

saddle

joint

between

metacarpal I and the trapezium,

imparts a wide range of mobility

to the thumb

-Other CMCJ are much less

mobile allowing only limited

gliding movements

-Movement

the

joints

increases medially so metacarpal

V slides to the greatest degree

Metacarpophalangeal joints:

-These are condylar joints, which allow

all movements except rotation

- The capsule of each joint is reinforced

by the palmar ligament and by medial

and lateral collateral ligaments

-The three deep transverse metacarpal

ligaments

connecting

the

palmar

ligaments of these joints to each other

-The absence of this ligament, and the

presence of a saddle joint between

metacarpal I and the trapezium, are

responsible for the increased mobility of

the thumb

Interphalangeal joints:

-The interphalangeal joints of the hand are hinge joints that allow mainly

flexion and extension.

-They are reinforced by medial and lateral collateral ligaments and palmar

ligaments.