WINDSOR UNIVERSITY SCHOOL OF MEDICINE MD 1 dr kola.
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Transcript of WINDSOR UNIVERSITY SCHOOL OF MEDICINE MD 1 dr kola.
Osteology of the upper extremity
WINDSOR UNIVERSITY SCHOOL OF MEDICINE MD 1
dr kola
Also called Collar bone Elongated S-shaped bone Has no medullary cavity First long bone to ossify
via intramembranous ossification beginning during the 5th and 6th embryonic weeks at the shaft
2nd Ossification ends between 25 and 31 years
clavicle
Has two ends and a shaft
Sternal end also called the medial end is wedge shaped or triangular, articulates with the manubrium of sternum (sternoclavicular joint)
Acromial end is flat and articulates with the acromium of the scapula at the acromioclaviular joint
Shaft Medial two thirds of the shaft is convex
anteriorly The lateral one third is flat and concave
anteriorly
Surfaces Superior surface is smooth and lies just
deep to platysma muscle and skin.
The inferior surface is rough due to attachment of ligaments.
Towards the acromial end, the conoid tubercle gives attachment to the conoid ligament which is a part of the medial side of coracoclavicalucular ligament.
The trapezoid line also at the acromial end gives attachment to the trapezoid ligament from the lateral side of the coracoclavicalucular.
The subclavian groove-Groove for the subclavius muscle in the medial two thirds
Impression for the costoclavicular ligament-
Rough depressed oval area that attaches to the 1st rib and the clavicle
Fracture One of the most fractured bonesAn indirect blow transmitted from an
outstretched hand or a fall directly on the shoulder
Weakest part of the clavicle is the junction of the medial two thirds and the lateral one third.
Applied anatomy
The medial fragment is elevated by the sternocleiodomas-toid muscle
The lateral fragment drops
Greenstick fracture in children
Also called shoulder blade On the posteriolateral aspect of the thorax Overlies 2nd to 7th ribs 2 surfaces 3 angles 3 borders
scapula
Surfaces Posterior surface Spine:divides it into supraspinous fossa and
infraspionous Spine has a deltoild tuberoisty Ends distally in a flat acromion
Costal surface attachment for the subscapularis muscle
Borders Medial border also called vertebral border Lateral or axillary border: runs
superiolaterally towards the apex of the axilla (thickest) and ends superiorly in the lateral angle
Superior borders: thinnest and marked with a suprascapular notch near the junction of the medial two thirds and lateral one third
Arm bone Largest bone in the upper limb Articulates with the scapula and ulna
Long bones with two ends and a shaft
humerus
Proximal end
Head, neck and tubercles Head is rounded for articulataion with the
glenoid cavity of the scapula at the glenohumeral joint
Neck
Anatomical neck and surgical neck Anatomical neck is the neck that
circumscribes the head separating it from the tubercles
Line of attachment of the glenohumeral capsule
Surgical neck: distal to the head and tubercles. Easily fractured
Tubercles Greater tubercle
which is lateral Lesser tubercle
which is anterior Intertubercular
sulcus or bicipital groove which separates the two, allowing for the passage of long head of biceps brachii
Shaft has two prominent features
Deltoild tuberousity Lies laterally for attachment of deltoid
muscle
Radial groove: radial nerve and the deep artery of the arm
Inferior end of the shaft widens as the sharp medial and lateral supracondylar ridges amd med distally in the medial and altera; epicondles
Distal ends Condyle: trochlea, capitulum,
olecranon,coronoid and radial fossae together with the distal end of the humerus make up the condyle
Condyle as two articular surfaces
Radial head and capitulum Proximal end of ulna and
trochleaFossae Anteriorly coronoid fossa
recieves the coronoid process of the ulna on flexion full and radial fossa recieves the head of the radius
Posteriolry the olecranon fossa accomadates olecraon process on full extension
Surgical neck: Axillary nerve and posterior circumflex humeral artery
Midshaft: radial nerve and deep artery of the arm
Supracondylar: Median nerve and brachial artery
Avulsion of medial epicondyle: Ulnar nerve
Fractures of the humerus
Stabilizing bone of the forearm Medial and longer Proximal end for articulation Olecranon and coronoid process Inferior to the coronoid process is the ulnar
tuberosity Lateral side is the radial notch Inferior to the radial notch on the shaft is
the supinator crest and closer to it is the supinator fossa.
ulnar
Shaft is thick and cylindrical proximally but it tapers distally and ends in the ulnar styloid process
The ulna does not participate in the wrist joint
Lateral and shorter bone of forearm Proximally head of radius articulates with
capitulum of the humerus Head also articulates with radial notch of
ulnar head is covered with articular catilage The neck of the radius is a constriction
distal to the head Radial tuberosity: demarcates the head from
shaft
radius
Shaft of radius enlarges distally Distal end on the medial side has an ulnar
notch Lateral side terminates in a radial styloid
process larger then ulnar styloid process and extends farther distally
Dorsal tubercle which allows for passage of tendons
The two bones on the internal aspect have an interroseous border for attachment of the interrouseous membrane of the foream
Usually a transverse fracture at the same level:
Colle’s fracture: most common fracture. The distal fragment is displaced dorsally
Mechanism: forced dorsiflexion of the outstrecthed hand trying to ease a fall
Fracture of the forearm bones
These small bones give flexibility to the wrist.
‘ SHE LOOKS TOO PRETTY TRY TO CHASE HER’ From lateral to medial, the four carpal bones in the
proximal row are the:• Scaphoid (G. skaphé, skiff, boat): a boat-shaped
bonethat articulates proximally with the radius, and has
a prominent scaphoid tubercle; it is the largest bone in the proximal row of carpals.
Carpal bones
• Lunate (L. luna, moon): a moon-shaped bone between the scaphoid and the triquetral bones; it articulates proximally with the radius and is broader anteriorly than posteriorly.
• Triquetrum (L. triquetrus, three-cornered): a pyramidal bone on the medial side of the carpus; it articulates proximally with the articular disc of the distal radio-ulnar joint.
• Pisiform (L. pisum, pea), a small, pea-shaped bone that lies on the palmar surface of the triquetrum.
From lateral to medial, the four carpal bones in the distal row
• Trapezium (G. trapeze, table): a four-sided bone on the lateral side of the carpus; it articulates with the 1st and 2nd metacarpals, scaphoid, and trapezoid bones.
Trapezoid: a wedge-shaped bone that resembles the trapezium; it articulates with the 2nd metacarpal, trapezium, capitate, and scaphoid bones.
• Capitate (L. caput, head): a head-shaped bone with a
rounded extremity is the largest bone in the carpus; itarticulates primarily with the 3rd metacarpal distally,
and with the trapezoid, scaphoid, lunate, and hamate.
• Hamate (L. hamulus, a little hook): a wedge-shaped bone on the medial side of the hand; it articulates with the 4th and 5th metacarpal, capitate, and triquetral bones; it has a distinctive hooked process, the hook of the hamate, that extends anteriorly.
Fracture of ScaphoidMost frequently
fractured carpal bone
Pain experienced on the lateral side of the wrist mostly during dorsiflexion and abduction
Avascular necrosis can occur due to loss of blood supply to the proximal part of the scaphoid
Fracture of Hamate This may cause
injury to the ulnar nerve sometimes the ulnar artery also
It is composed of five metacarpal bones (metacarpals).
Each metacarpal consists of a base, shaft, and head.
The proximal bases of the meta carpals articulate with the carpal bones, and the distal heads of the metacarpals articulate with the proximal phalanges,
and form the knuckles of the hand. The 1st metacarpal (of the thumb)
is the thickest and shortest of these bones.
Metacarpal bones
Fracture of fifth metarcarpal
Common with unskilled boxers who punch with a closed fist
Boxers fracture
Each digit (finger) has three phalanges except for the first (the thumb), which has only two.
Each phalanx has a base proximally, a shaft (body), and a head distally.
The proximal phalanges are the largest, the middle ones are intermediate in size, and then distal ones are the smallest. The shafts of the phalanges taper distally.
The terminal phalanges are flattened and expanded at their distal ends, which underlie the nail beds.
phalanges