12 - Elbow-Radioulnar

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Elbow Joint
Lower end of humerus , anterior &
posterior surfaces.
Upper end of ulna.
Elbow joint

Articulation :
1-Humero-ulnar articulation :
between the trochlea of the
humerus & trochlear notch of
ulna.
2-Humero-radial articulation :
between the capitulum of humerus
& upper articular surface of head
of radius.

Type : hinge synovial joint.
Attachment of the capsule of Elbow
Joint

Anteriorly :
above (humerus)--- upper
margins of coronoid & radial
fossae , and/ to the front of of
med. & lat.epicondyles.
Below--- margin of coronoid
process of ulna & anular ligament
surrounding head of radius
(In superior radio-ulnar joint)
 Posteriorly :
above (humerus)…. Upper
margin of olecranon fossa.
Below–margin of olecranon
process of ulna and/ to anular
ligament.
Capsule of elbow joint at the
humerus :
Synovial membrane
– lines the inner surface of
capsule and covers the fatty
pads in the floors of
coronoid, radial, &
olecranon fossae.
- it is continuous below
with the synovial
membrane of proximal
radioulnar joint.
N.Supply :
median , ulnar
,musculocut. & radial
nerves.
Ligaments of elbow joint
Lateral (radial collateral)
ligament
-superiorly : it is attached to lateral epicondyle
of humerus.
-inferiorly : it is attached to anular ligament.
Medial (ulnar collateral )
ligament : it is triangular in shape and
Note that ulnar N. lies behind medial epicondyle
and crosses medial ligament of elbow joint.
consists of 3 bands.
-Anterior band : from medial epicondyle of
humerus, to medial border of coronoid process
of ulna.
Posterior band : from medial epicondyle of
humerus, to medial border of olecranon
process of ulna.
-Transverse band : between medial borders
of coronoid process & olecranon process of
ulna.
Movements & Relations
Movements & relations of Elbow joint

Flexion : is performed by :
1-brachialis. 2-biceps brachii
3-brachioradialis. 4-pronator teres.
 Extension : by 1-triceps. 2- anconeus.
 Relations :
Anteriorly : brachialis, median N.,brachial artery & tendon of biceps.
(contents of cubital fossa).
Posteriorly : triceps.
Medially : ulnar N.
(lies behind medial epicondyle and crosses medial ligament of joint).
laterally : common extensor tendon.
 Posterior dislocations of elbow joint are common in children
because the parts of bones that stabilize the joint are incompletely
developed. It usually follows falling on outstretched hand.
 Damage to Ulnar N. in dislocation of the joint, leading to ulnar
N.palsy.
proximal radioulnar joint
Articulation : between
1- The circumference of the head of
radius & anular ligament . and
2- The radial notch of ulna.
Type : Pivot synovial J.
Capsule : It continuous with that of
elbow joint.
Synovial membrane : cotinuous above with
that of elbow.
 Nerve supply : median, ulnar,
musculocutaneous, and radial nerves.
Relations : anteriorly : radial N.(in front of
lateral epicondyle). Posteriorly : supinator +
common extensor origin
Annular ligament :
-strong fibrous band, surrounding head
of radius, keeping it in contact with
radial notch of ulna.
-it is attached
to anterior & posterior
margins of radial notch of ulna.
-superiorly : it is continuous with capsule
of elbow j.
Distal radioulnar joint
Articulation :1-rounded head of
ulna. 2-ulnar notch of radius
Type : pivot synovial joint.
Ligaments : anterior & posterior
Ligaments.
N.Supply :anterior interosseous
(from median N.) & deep branch of
radial nerve (post.interosseouN.)
Articular disc of fibrocartilage
: -it is triangular and separates this
joint from wrist joint. Extends
between : 1-styloid process of ulna
(apex). 2-lower border of ulnar
notch of radius (base).
Movements of radioulnar joints
Pronation : What is pronation ?
-it is performed by pronator teres & pronator quadratus.
-radius crosses in front of ulna.
Supination : What is supination ?
-It is performed by supinator. & biceps.
The axis around which pronation &
supination occur is an imaginary line between the
heads of radius & ulna.
Intiation of pronation & supination : by
brachioradialis.
Wrist joint (radiocarpal joint)
Articulation :1-distal end of radius +
articular disc of inf. radioulnar joint (above)
so, head of ulna does not share in this joint.
2-scaphoid, lunate and triquetral bones
(below).
The joint cavity does not communicate
with that of distal radioulnar j. or with
cavities of intercarpal joints.
Type :ellipsoid synovial joint.
 Ligaments :
-Ant.,& post. strengthen the capsule.
-Medial lig. between styloid process of ulna
& triquetral bone.
N.supply :ant.interosseous N. of median Lateral lig. between styloid process of radius
& scaphoid bone.
N. & posterior interosseous of radial N.
Movements
Movements of wrist joint





Flexion : by 1-flexor C.R. 2-flexor C.U. 3-palmaris longus. These
muscles are assisted by
1-flexor D.S. 2-flexor D.P. 3-flexor P.L.
Extension : by 1-extensor C.R.L 2-extensor C.R.B. 3-ext.C.ulnaris.
These muscles are assisted by
1-extensor D. 2-extensor indicis.
3-extensor digiti minimi. 4-extensor pollicis longus.
Abduction : by 1-flexor C.R. 2-extensor C.R.L.
3-extensor C.R.B. These muscles are assisted by :
1-abductor P.L. 2-extensor P.L. 3-extensor P.B.
Adduction : by 1-flexor C.U.
2-extensor C.U.
Range of adduction is more than abduction because styloid process
of ulna is shorter than that of radius.
Relations of wrist joint




Anteriorly : structures passing deep to flexor retinaculum.
Posteriorly : structures in the 2nd to 6th compartements ,deep
to extensor retinaculum.
Medially : posterior cutaneous branch of ulnar nerve.
Laterally : radial artery.
Joints of the hand & fingers:
(intercarpal joints) : Articulation :1-between individual
bones of the proximal row of the
carpus. 2-between individual bones of
the distal row of carpus.
3-between proximal & distal rows of
carpal bones, (midcarpal joint).
Plane synovial joint.
Capsule surrounds the joint.
Ligaments :ant.,post., & interosseous .
N.supply: ant.intero., deep branch of
radial and ulnar N.
 Movements :just gliding movement.
Carpometacarpal & inter-metacarpal
joints :
Plane Synovial joints.
Between distal carpal bones & the
bases of metacarpal bones.
They have a gliding movement.
C.M. joint of the thumb :
between trapezium & base of 1st
metacarpal bone.
• Saddle-shaped synovial joint.
Movements of the thumb at
Carpometacarpal joint :
Flexion : flexor pollicis
longus, brevis & opponens
pollicis.
Extension : extensor
pollicis longus & brevis.
Abduction : abductor
pollicis longus & brevis.
Adduction : adductor
pollicis
Rotation (opposition) :
the thumb is rotated
medially by Opponens
pollicis.
Metacarpophalangeal joints
Between 1- heads of
metacarpal bones.& 2-bases of
proximal phalanges.
Condyloid synovial joint.
Metacarpophalangeal j.of the
thumb : Flexion : by flexor pollicis
longus & brevis. Extension : by
ext.pollicis longus & brevis.
Abduction & Adduction +opposition
are performed mainly at carpometacarpal joint +a small amount of
movement at metacarpo-phalangeal joint.
Ligaments :1-palmar
ligaments
2-deep
transverse ligaments.
3collateral ligaments.
Movements :flexion :lumbrical
+interossei ,assisted by F.D.S &
F.D.P. extention :ext.Digitorum
,ext.indicis and ext.digiti minimi.
Abduction :by dorsal interossei.
Addution : by palmar interossei.
Interphalangeal joints :
They are hinge
synovial joints.
Have the same
structure as metacarpophalangeal joints.
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