Elbow JointElbow Joint

Lower end of humerus , anterior & posterior surfaces.

Upper end of ulna.

Elbow jointElbow joint ArticulationArticulation ::

1-Humero-ulnar articulation :1-Humero-ulnar articulation : between the between the trochlea trochlea of the of the humerus & humerus & trochlear notch oftrochlear notch of ulna.ulna. 2-Humero-radial 2-Humero-radial articulation :articulation : between the between the capitulum capitulum of humerus & of humerus & upper upper articulararticular surface of head of surface of head of radius. radius.

TypeType : : hinge synovial joint.hinge synovial joint.

Attachment of Attachment of the capsule of the capsule of Elbow Joint Elbow Joint

AnteriorlyAnteriorly : : above (humerus)---above (humerus)--- upper margins of upper margins of coronoid coronoid & radial fossae& radial fossae , and/ to the , and/ to the front of of med. & front of of med. & lat.epicondyles. lat.epicondyles. BelowBelow---- margin of -- margin of coronoid process of ulnacoronoid process of ulna & & anular ligamentanular ligament surrounding head of radius surrounding head of radius (In superior radio- (In superior radio-ulnar joint) ulnar joint)

PosteriorlyPosteriorly : : above (humerus)above (humerus)….…. Upper margin of Upper margin of olecranon olecranon fossa.fossa. BelowBelow–margin of –margin of olecranon olecranon process of ulnaprocess of ulna and/ to and/ to anular ligament.anular ligament.

Capsule of elbow joint at Capsule of elbow joint at thethe humerus : 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 jointLigaments 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 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.

Note that ulnar N. lies behind medial epicondyle and crosses medial ligament of elbow joint.

Movements & Relations

Movements & relations of Movements & relations of Elbow jointElbow joint Flexion :Flexion : is performed by : is performed by :

1-brachialis. 2-biceps 1-brachialis. 2-biceps brachii brachii 3-brachioradialis. 4-pronator teres. 3-brachioradialis. 4-pronator teres.

Extension :Extension : by 1-triceps. 2- anconeus. by 1-triceps. 2- anconeus. Relations :Relations :

Anteriorly :Anteriorly : brachialis, median N.,brachial brachialis, median N.,brachial artery & tendon of biceps. (contents of cubital artery & tendon of biceps. (contents of cubital fossa). fossa). Posteriorly :Posteriorly : triceps. triceps. Medially :Medially : ulnar N. ulnar N. (lies (lies behind medial epicondyle and crosses medial ligament of behind medial epicondyle and crosses medial ligament of joint). joint). laterally :laterally : common extensor tendon. common extensor tendon.

Posterior dislocations of elbow jointPosterior dislocations of elbow joint are common in are common in children because the parts of bones that stabilize the joint children because the parts of bones that stabilize the joint are are incompletely developed.incompletely developed. It usually follows falling on It usually follows falling on outstretched hand. outstretched hand.

Damage to Ulnar N. in dislocation of the joint,Damage to Ulnar N. in dislocation of the joint, leading to leading to ulnar N.palsy. ulnar N.palsy.

proximal radioulnar proximal radioulnar jointjoint 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.

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.

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

Distal radioulnar jointDistal radioulnar jointArticulation :1-rounded head of ulna. 2-ulnar notch of radius

Type : pivot synovial joint.

Ligaments : anterior & posterior Ligaments.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).

N.Supply :anterior interosseous (from median N.) & deep branch of radial nerve (post.interosseouN.)

Movements of radioulnar Movements of radioulnar jointsjoints

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 Wrist joint (radiocarpal joint)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. -Lateral lig. between styloid process of radius & scaphoid bone.

N.supply :ant.interosseous N. of median N. & posterior interosseous of radial N.

Movements

Movements of wrist jointMovements of wrist joint Flexion :Flexion : by by 1-1-flexor C.R. flexor C.R. 2-2-flexor C.U. flexor C.U. 3-3-palmaris palmaris

longus. longus. These muscles are assisted byThese muscles are assisted by 1-flexor D.S. 2-flexor 1-flexor D.S. 2-flexor D.P. 3-flexor P.L.D.P. 3-flexor P.L.

Extension :Extension : by by 1-1-extensor C.R.L extensor C.R.L 2-2-extensor C.R.B. extensor C.R.B. 3-3-ext.C.ulnaris. ext.C.ulnaris. These muscles are assisted byThese muscles are assisted by 1-extensor D. 2-extensor indicis. 1-extensor D. 2-extensor indicis. 3-extensor digiti 3-extensor digiti minimi. 4-extensor pollicis longus.minimi. 4-extensor pollicis longus.

Abduction :Abduction : by 1-flexor C.R. 2-extensor C.R.L. by 1-flexor C.R. 2-extensor C.R.L. 3-extensor C.R.B. 3-extensor C.R.B. These muscles are assisted These muscles are assisted by :by : 1-abductor P.L. 2-extensor 1-abductor P.L. 2-extensor P.L. 3-extensor P.B.P.L. 3-extensor P.B.

Adduction :Adduction : by 1-flexor C.U. 2-extensor C.U. by 1-flexor C.U. 2-extensor C.U. Range of adduction is more than abductionRange of adduction is more than abduction because because

styloid process of ulna is shorter than that of radius.styloid process of ulna is shorter than that of radius.

Relations of wrist jointRelations of wrist joint Anteriorly :Anteriorly : structures passing structures passing deep deep to flexor to flexor

retinaculum.retinaculum. Posteriorly :Posteriorly : structures in the 2 structures in the 2ndnd to 6 to 6thth

compartements ,compartements ,deep deep to extensor retinaculum.to extensor retinaculum. Medially :Medially : posterior cutaneous branch of posterior cutaneous branch of ulnar nerve.ulnar nerve. Laterally :Laterally : radial artery.radial artery.

Joints of the hand & Joints of the hand & fingers:fingers: (intercarpal (intercarpal joints) :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-Carpometacarpal & inter-metacarpalmetacarpal joints :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 Movements of the thumb at Carpometacarpal joint :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 Metacarpophalangeal jointsjoints

Between 1- heads of metacarpal bones.& 2-bases of proximal phalanges.

Condyloid synovial joint.

Ligaments :1-palmar ligaments 2-deep transverse ligaments. 3-collateral 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.

Metacarpophalangeal j.of the thumb : Flexion : by flexor pollicis longus & brevis. Extension : by ext.pollicis longus & brevis. Abduction & Adduction +opposition are performed mainly at carpo-metacarpal joint +a small amount of movement at metacarpo-phalangeal joint.

Interphalangeal joints :Interphalangeal joints :

They are hinge synovial joints.

Have the same structure as metacarpo-phalangeal joints.