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 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 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. 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 joint Articulation :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 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. -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 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. 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 : They are hinge synovial joints. Have the same structure as metacarpo-phalangeal joints.