Dr. Fadel Naim Orthopedic Surgeon Faculty of Medicine IUG-Gaza Bones of the Upper Limb Dr. Fadel Naim Orthopedic Surgeon Faculty of Medicine IUG-Gaza

لَا أُقْسِمُ بِيَوْمِ الْقِيَامَةِ{1} وَلَا أُقْسِمُ بِالنَّفْسِ اللَّوَّامَةِ{2} أَيَحْسَبُ الْإِنسَانُ أَلَّن نَجْمَعَ عِظَامَهُ{3} بَلَى قَادِرِينَ عَلَى أَن نُّسَوِّيَ بَنَانَهُ{4}

Skeleton of the Upper Limb Each upper limb has 32 bones Two separate regions 1. The pectoral (shoulder) girdle (2 bones) 2. The free part (30 bones)

Upper Limb The pectoral girdle consists of two bones: the scapula the clavicle The free part has 30 bones 1 humerus (arm) 1 ulna (forearm) 1 radius (forearm) 8 carpals (wrist) 19 metacarpal and phalanges (hand) While progressing through a lecture, point out that many of the bones and their surface features (e.g., olecranon) may be easily palpated.

Composition of the upper limb

Pectoral Girdle clavicle scapula humerus

Clavicle The clavicle is an s-shaped bone that attaches the trunk to the upper extremity Medial 2/3 convex forward and lateral 1/3 concave forward

Clinical Connection – Fractured Clavicle A fall on an outstretched arm (F.O.O.S.H.) injury can lead to a fractured clavicle The clavicle is weakest at the junction of the two curves Forces are generated through the upper limb to the trunk during a fall Therefore, most breaks occur approximately in the middle of the clavicle

Acromial end Sternal end Conoid tubercle Trapezoid line is flat and has a small facet for articulation with the acromion Sternal end has a large facet for articulation with the manubrium, and first costal cartilage Conoid tubercle Attachment of conoid ligament of the coracoclavicular ligament Trapezoid line Attachment of trapezoid portion of the coracoclavicular ligament

Clavicle: Ligament Attachments Sternal end of clavicle to first costal cartilage: Costoclavicular ligament Conoid tubercle: Conoid portion of coracoclavicular ligament Trapezoid line: Trapezoid portion of coracoclavicular ligament

Clavicle: Muscle Attachments Deltoid Pectoralis major Trapezius Sternocleidomastoid Subclavius

Muscular, ligamentous, and fascial attachments to the clavicle

Scapula Flat triangular bone On the posterior thoracic wall Between 2nd and 7th rib

Anterior Scapula Borders: Angles: coracoid process acromion Superior Medial lateral Angles: inferior coracoid process acromion neck of scapula

Anterior Scapula acromion process coracoid process glenoid cavity superior angle subscapular fossa inferior angle

Posterior Scapula Spine of scapula Acromion: Greater scapular notch Divides the supraspinous and infraspinous fossae Serves as attachment for the deltoid and trapezius Acromion: Lateral extension of spine of scapula; Articulate with clavicle Greater scapular notch Point at which the spine of the scapula ends, but the acromion continues; Coracoid process Partially seen as it projects anteriorly;

Supraspinous fossa Infraspinous fossa Lateral border Origin of the supraspinatus muscle Infraspinous fossa Origin of the infraspinatous muscle Lateral border Attachment of: Teres major The long head of the triceps brachii Teres minor

Posterior Scapula acromion process supraspinous fossa infraspinous fossa spine lateral border medial border

Lateral Scapula Supraglenoid tubercle Infraglenoid tubercle Attachement of the long head of the biceps brachii Infraglenoid tubercle Attachement of the long head of the triceps brachii

Lateral Scapula Acromion: Superior and inferior angles Articulates with the clavicle Attachment for the trapezius and deltoid muscles; Superior and inferior angles Coracoid process: Attachment point for: The short head of the biceps brachii Corachobrachialis Pectoralis minor

The Humerus Longest and largest bone of the free part of the upper limb The proximal ball-shaped end articulates with the glenoid cavity of the scapula The distal end articulates at the elbow with the radius and ulna

The Humerus The proximal end consists of: The head Anatomical neck Greater and lesser tubercles separated from each other by an intertubercular groove (bicipital groove)

The head The head, nearly hemispherical in form Articulates with the glenoid cavity of the scapula. The circumference of its articular surface is slightly constricted and is termed the anatomical neck

The anatomical neck The anatomical neck of the humerus is an indentation distal to the head of the humerus on which the articular capsule attaches. Fracture of the anatomical neck rarely occurs.

The Greater Tubercle The greater tubercle is situated lateral to the head and lesser tubercle, and just lateral to the anatomical neck Its upper surface is rounded and marked by three flat impressions: the highest for insertion of the suprasinatus muscle the middle for the infraspinatus muscle the lowest one, and the body of the bone for teres muscle

The Lesser Tubercle The lesser tubercle is more prominent than the greater tubercle Above and in front it presents an impression for the insertion of the tendon of the subscapularis muscle

The Intertubercular (Bicipital) Groove The tubercles are separated from each other by a deep groove, the intertubercular groove (bicipital groove), which lodges the long tendon of the biceps brachii muscle

The surgical neck The surgical neck is the point distal to the tubercles at which the superior portion of the bone meets the shaft The surgical neck is a common site of fracture.

The body of the humerus has two prominent features: The deltoid tuberosity, laterally, for attachment of the deltoid muscle

Distal Humerus Medial epicondyle: Lateral epicondyle: The pronator and flexor muscles of the forearm originate here Lateral epicondyle: The extensor and supinator muscles of the forearm originate here Medial supracondylar ridge Lateral supracondylar ridge Trochlea (medial condyle): Articulates with the trochlear notch of the ulna Capitulum (lateral condyle): Articulates with the radial head

Distal Humerus Coronoid fossa: Radial fossa: Olecranon fossa: Accommodates the coronoid process of the ulna during flexion. A fat pad is situated here Radial fossa: Accommodates the head of the radius during flexion. Olecranon fossa: Accommodates the olecranon. Groove for ulnar nerve

intertubercular groove Anterior Humerus lesser tubercle medial epicondyle deltoid tuberosity trochlea coronoid fossa intertubercular groove greater tubercle capitulum lateral epicondyle

Humerus: Anterior Clavicle Acromion process Greater tubercle Coracoid process Lesser tubercle Scapula Glenoid fossa Humerus Coronoid fossa Deltoid tuberosity Medial epicondyle Lateral epicondyle Capitulum Trochlea Radius Ulna Click R Button for Slideshow

Humerus: Anterior2 Clavicle Acromion process Greater tubercle Coracoid process Lesser tubercle Scapula Glenoid fossa Humerus Coronoid fossa Deltoid tuberosity Medial epicondyle Lateral epicondyle Capitulum Trochlea Radius Ulna

Humerus: Posterior Acromion of scapula Head of humerus Spine of scapula Greater tubercle of humerus Scapula Glenoid fossa of scapula Deltoid tuberosity of humerus Humerus Medial epicondyle of humerus Lateral epicondyle of humerus Olecranon process of ulna Radius Ulna Right Arm, Posterior

Radius The radius is the lateral and shorter of the two forearm bones. Its proximal end consists of: A short cylindrical (or thick disc like) head The smooth superior aspect of the head of the radius is concave for articnlation with the capitulum of the hnmerus during flexion and extension of the elbow joint. The head also articulates peripherally with the radial notch of the ulna The head is covered with articular cartilage. A neck Relatively constricted between the head and the tuberosity. A medially directed tuberosity The oval radial tuberosity separates the proximal end of the radius from the body.

Radius

The distal end of the radius Its medial aspect forms a concavity, the ulnar notch, which accommodates the head of the ulna. Extending from its lateral aspect is the radial styloid process. The dorsal tubercle, (Lister’s) projecting dorsally lies between grooves for the passage of the tendons of forearm muscles

The radial styloid process is much larger than the ulnar styloid process and extends approximately a finger's breadth further distally This relationship is of clinical importance when the ulna and/or the radius are fractured

Radius radial tuberosity head styloid process

Ulna The stabilizing bone of the forearm is the medial and longer of the two forearm bones Its proximal end has two prominent projections: The olecranon: projects proximally from its posterior aspect The coronoid process Projects anteriorly.

The olecranon The olecranon is the most proximal posterior eminence of the ulna It is on the dorsal subcutaneous border and contains broad attachments for the triceps posteriorly Anteriorly, the olecranon forms the trochlear notch of the ulna, which articulates with the trochlea The radial notch On the lateral side of the coronoid process is a smooth, rounded concavity, which articulates with the head of the radius.

Ulna Inferior to the coronoid process is the tuberosity of the ulna for attachment of the tendon of the Brachialis muscle. Inferior to the radial notch on the lateral surface of the ulna is a prominent ridge (the supinator crest) Between it and the distal part of the coronoid process is a concavity (the supinator fossa) The deep part of the supinator muscle attaches to the supinator crest and fossa.

At the narrow distal end of the ulna is a abrupt enlargement forming a disclike head and a small, conical styloid process. styloid process

Ulna trochlear notch coronoid process head radial notch styloid process olecranon process

Ulna Distal end Proximal end olecranon Trochlear notch Coronoid process Ulnar tuberosity Head of ulna styloid process Distal end Proximal end

Bones of the Hand The skeleton of the carpus is composed of eight carpal bones (carpals) arranged in two rows of four each The pisiform is set on a plane anterior to the others and behaves as a sesamoid in the tendon of flexor carpi ulnaris, rather than participating in movements at the wrist

The carpus is markedly convex posteriorly and concave anteriorly

From lateral to medial, the bones in the proximal row of carpals are: Scaphoid Lunate Triquetrum Pisiform

From lateral to medial, the four bones in the distal row of carpals are the: Trapezium: Trapezoid: Capitate: Hamate: `

Mnemonic for Learning Carpals She Likes To Play Lunate In the moonlight Scaphoid A boat Triquetrum The third T Bone Mnemonic for Learning Carpals Pisiform Pea-shaped Hamate A hambone With a hook Trapezium: “It’s by the thumb” Capitate Trapezoid “Is by its side” Try To Catch Her

Metacarpals The first element of each ray is its metacarpal. The proximal end of a metacarpal is expanded to form a base that articulates with the carpus. The distal end of a metacarpal is expanded to form a rounded head that articulates with the proximal phalanx of the digit to form the knuckles of the fist

Phalanges Each of the four fingers contains a: The thumb has only : Proximal phalanx Middle phalanx Distal phalanx. The thumb has only : A proximal phalanx A distal phalanx.

Naming of Digits 1 2 3 4 5 Thumb Index Middle Ring Little

Manus (Hand) 3 Metacarpals (5) Digits (5) 54321 1 pollex Carpals (8) Proximal Phalanx Middle Phalanx Carpals (8) Distal Phalanx 54321 3 1 pollex Proximal Phalanx Metacarpals (5) Distal Phalanx Digits (5)