Upper Limb Bones Flashcards
What is another name for the scapula?
Shoulder blade
The scapula connects the upper limb to the main trunk of the body by articulating with which two bones? At which two joints?
Humerus - glenohumeral joint
Clavicle - acromioclavicular joint
What is the rough shape of the scapula?
Triangular (and flat)
What is another term for the anterior surface of the scapula? Why is it give this name?
Costal
This side faces the ribcage
The costal surface of the scapula has a concave depression over most of its surface called…
The subscapular fossa
Name a muscle that originates from the subscapular fossa.
Subscapularis
Which hook-like projection lies just underneath the clavicle on the superolateral surface of the costal scapula?
Coracoid process
Name a muscle that attaches at the coracoid process.
Pectoralis minor
Name two muscles that originate at the coracoid process.
Coracobrachialis
Biceps brachii
The lateral surface of the scapula faces which bone?
Humerus
What is the name given to the shallow cavity which articulates with the humerus to form the glenohumeral joint?
Glenoid fossa
Where is the glenoid fossa located on the scapula?
The superior part of the lateral border
What is meant by the term tubercle?
A roughening of the bone
Where is the supraglenoid tubercle? Which muscle attaches here?
Immediately superior to the glenoid fossa
Long head of the biceps brachii
Where is the infraglenoid tubercle? Which muscle attaches here?
Long head of the triceps brachii
The majority of which group of muscles attaches at the posterior surface of the scapula?
Rotator cuff muscles
Which structure of the posterior surface of the scapula ‘divides’ it in two?
Spine of the scapula
Is the infraspinous fossa, convex or concave in shape? Which muscle originates here?
Convex
Infraspinatus
Is the supraspinous fossa, convex or concave in shape? How does its shape and size compare to the infraspinous fossa? Which muscle originates here?
Convex
Smaller and more convex that infraspinous fossa
Supraspinatus
What is the name given to the projection of the spine of the scapula that arches over the glenohumeral joint? What articulates here?
Acromion
Scapula with the clavicle at the acromioclavicular joint
What bones articulate at the glenohumeral joint?
The glenoid fossa of the scapula with the humerus
Which bones articulate at the acromioclavicular joint? What is the position of this compared to the glenohumeral joint (shoulder joint)?
The clavicle and the acromion of the scapula
Superior to the shoulder joint
Are fractures of the scapula relatively common or uncommon?
Uncommon
Fractures of the scapula usually indicate severe…
Chest trauma
How is a fractured scapula treated?
Without much intervention, tone of surrounding muscles holds pieces of scapula together for healing to occur
Where does the serratus anterior originate and attach? What nerve innervates it?
Originates from ribs 1-8
Attaches at the costal face of the scapula
Long thoracic nerve
Damage to the long thoracic nerve can have what effect on the scapula?
Winged scapula
What is another name for the clavicle?
Collarbone
What sort of bone is the clavicle classed as?
Long bone
What are the three main functions of the clavicle?
Attaches the upper limb to the trunk
Protects the underlying neurovascular structures supplying the upper limb
Transmits force from the upper limb to the axial skeleton
The clavicle is an S shaped bone, which end forms the convex and which end forms the concave aspects of the clavicle?
Medial end is convex
Lateral end is concave
What is another name for the medial and lateral ends of the clavicle?
Medial - sternal
Lateral - acromial
What is a facet with regards to anatomy?
A small smooth area on a bone that is usually an articular surface
What articulations are there at the sternal end of the clavicle?
Articulation of the clavicle with the manubrium of the sternum at the sternoclavicular joint
The inferior end of the sternal clavicle is marked by a rough oval depression, what is this for?
The costoclavicular ligament
What articulations take place at the acromial end of the clavicle?
Acromion of the scapula with the clavicle at the acromioclavicular joint
Which two ligaments attach at the acromial end of the clavicle? At which structures? Which is more medial?
Conoid ligament at the conoid tubercle
Trapezoid ligament at the trapezoid line
Conoid ligament is more medial
The conoid tubercle makes up the _________ part of the _____________________ ligament. The trapezoid ligament makes up the ________ part of the _______________ ligament
Medial
Coracoclavicular
Lateral
Coracoclavicular
The coracoclavicular ligament is a very strong structure, what is its function?
To suspend the weight of the upper limb from the clavicle
Is the clavicle commonly fractured?
Yes, most commonly fractured bone in the body
What is a common cause of clavicle fractures?
FOOSH
What is the most common area for fracture of the clavicle? What is the most common point of fracture of the clavicle?
Middle 1/3 (thinnest here)
Junction of the medial 2/3 and lateral 1/3
What happens to the two fragments of the clavicle in a clavicle fracture?
Medial fragment is displaced superiorly by the sternocleidomastoid muscle
Lateral fragment is displaced inferiorly by the weight of the arm and medially by the pectoralis major
What nerves may be damaged in a fracture of the clavicle? What do these nerves innervate? What can this result in?
The suprascapular nerves
Lateral rotators of the upper limb
Unopposed medial rotation of the upper limb (waiters tip)
The head of the humerus is connected to the greater and lesser tubercles by the…
Anatomical neck
What is the position of the greater tubercle on the humerus? Is it on the anterior or posterior surface of the humerus?
Laterally on the humerus
Has an anterior and posterior face
The greater tubercle serves as attachment site for which three of the rotator cuff muscles?
Supraspinatus
Infraspinatus
Teres minor
What is the location of the lesser tubercle on the humerus? Is it located on the anterior or posterior face of the humerus?
More medially located
Has only an anterior face
Which muscle attaches at the lesser tubercle?
Subscapularis
What is the name given to the groove between the tubercles? What runs through this groove?
Intertubercular sulcus
The tendon of the long head of the biceps brachii
What are the edges of the intertubercular sulcus known as? What connects here?
Lips
Tendons of the pectoralis major, teres major and latissimus dorsi
Where is the surgical neck on the humerus?
Runs from the tubercles to the shaft of the humerus
The surgical neck of the humerus is a common site for…
Fracture of the humerus
What can cause fracture of the surgical neck of the humerus? (2)
Direct blow to the area
FOOSH
In a surgical neck fracture, what two nearby neurovascular structures can be affected?
Axillary nerve
Posterior circumflex artery
Axillary nerve damage will result in paralysis of which two muscles?
Deltoid and teres minor muscles
Name two bony landmarks on the shaft of the humerus.
Deltoid tuberosity
Radial groove
What is the deltoid tuberosity?
A roughened surface on the lateral side of the humeral shaft where the deltoid muscle attaches
Where does the radial groove run?
Diagonally down the posterior surface of the humerus parallel to the deltoid tuberosity
What two structures run in the radial groove?
Radial nerve
Profunda brachii artery
What muscles attach anteriorly to the humerus alongside its shaft? (4)
Coracobrachialis
Deltoid
Brachialis
Brachioradialis
What muscles attach posteriorly to the shaft of the humerus? (2)
Medial and lateral heads of the triceps
A mid-shaft fracture could easily damage which structures? Why?
Radial nerve and profunda brachii artery
They are tightly bound in the radial groove
The radial nerve innervates the ______________ of the wrist. In the case of damage to this nerve, what will occur?
Extensors
Unopposed flexion of the wrist - ‘wrist drop’
The lateral and medial borders of the humerus form medial and lateral __________ __________. What is found immediately distally to these?
Supraepicondylar ridges
Lateral and medial epicondyles
Compare the structure of the lateral supraepicondylar ridge compared to the medial supraepicondylar ridge.
Lateral ridge is more roughened as it is the site of attachment for many of the extensor muscles in the posterior forearm
Which is larger, the medial or lateral epicondyle
Medial epicondyle
Where does the ulnar nerve pass into the forearm?
Along the posterior side of the medial epicondyle
Where are the trochlea and capitulum located?
Both on the distal end of the humerus
Trochlea is located medially
Capitulum is located laterally
Does the trochlea or the capitulum extend to the posterior of the humerus?
The trochlea
Name the three depressions found on the distal portion of the humerus. What is their function?
Coronoid fossa
Radial fossa
Olecranon fossa
They accommodate the forearm bones during movement at the elbow
What articulations are there at the proximal region of the humerus?
Articulation with the scapula at the glenohumeral joint
What articulations are there at the distal end of the humerus?
Ulna articulates with the trochlea
Radius articulates with the capitulum
At the elbow joint
Name two common fractures of the distal humerus.
Supracondylar fracture
Medial epicondyle fracture
What is the common cause of a supracondylar fracture?
Falling onto a flexed elbow
Direct damage or swelling as a result of a supracondylar fracture can affect which vessel? Leading to what?
Brachial artery
Volkmann’s ischaemic contracture
What can Volkmann’s ischaemic contracture cause?
Uncontrolled flexion of the hand
Damage to the median, ulnar or radial nerves
What nerve can be damaged in a medial epicondyle fracture? What can this result in?
Ulnar nerve
Ulnar claw
Loss of sensation over medial 1.5 fingers of the hand on dorsal and palmar surfaces
What are the two bones in the forearm? Which is located more medially?
Ulna and radius
Ulna
What is the general role of the ulna? What is the general role of the radius?
Acts as a stabilising bone
Pivots to produce movement
What does the proximal end of the ulna articulate with?
The trochlea of the humerus at the elbow joint
Name 5 landmarks of the proximal ulna.
Trochlea notch Radial notch Tuberosity of ulna Coronoid process Olecranon
What is the olecranon? Which muscle attaches here?
Projection of bone that extends proximally forming part of the trochlear notch
Triceps brachii to its superior surface
What is the coronoid process?
The ridge of the bone projecting outwards anteriorly forming part of the trochlear notch
What forms the trochlear notch? What rough shape does it it take? What does it articulate with?
Olecranon and coronoid process
Wrench shaped
The trochlea of the humerus
Where is the radial notch located? What does this articulate with?
On the lateral side of the trochlear notch
The head of the radius
Where is the tuberosity of ulna? Which muscle attaches here?
Immediately distal to the coronoid process
Brachialis muscle
What is the rough shape of the ulnar shaft? How many surfaces and borders does it have? What happens to its width as it moves distally?
Triangular
Three surfaces, Three borders
Width decreases distally
What are the three surfaces of the ulnar shaft?
Anterior
Posterior
Medial
What are the three borders of the ulnar shaft?
Posterior
Interosseous
Anterior
What muscle attaches at the anterior surface of the ulnar shaft?
Pronator quadratus muscle distally
Which surface of the ulnar shaft is the site of attachment for many muscles?
Posterior
Which border of the ulnar shaft is palpable along its entire length?
Posterior
What is the interosseous border of the ulnar shaft the site of attachment for?
The interosseous membrane which spans the distance between the ulna and radius
How does the ulna terminate at its distal end?
In a rounded head with a distal projection called the styloid process
What articulations are present at the distal end of the ulna?
The head of the ulna articulates with the ulnar notch of the radius at the distal radio-ulnar joint
What is the most likely fracture of the ulna? What causes it? What effect does this have on the proximal ulna?
A fracture in the shaft
Often the ulna being hit by an object
Pulled posteriorly by the normal muscle tone
What can cause a fracture of the olecranon process? What can displace part of the fragment proximally?
Falling on a flexed elbow
Triceps brachii
The interosseous membrane attaches…
What is the clinical significance of this with regards to fractures?
The ulna and radius
Force of trauma from one bone can easily be transmitted to the other - resulting in fractures of both forearm bones
What are two classical fractures involving both the ulna and radius?
Monteggia’s fracture
Galeazzi’s fracture
In a Monteggia’s fracture, which bone is fractured and which bone is dislocated?
Ulna - fractured
Radius - dislocated
In a Galeazzi’s fracture, which bone is fractured and which bone is dislocated?
Ulna - dislocated
Radius - fractured
The radius articulates in which four places?
Elbow joint
Proximal radioulnar joint
Wrist joint
Distal radioulnar joint
How does the radius articulate at the elbow joint?
Elbow joint is partly formed by articulation of the head of the radius with the capitulum of the humerus
How does the radius articulate at the proximal radioulnar joint?
Articulation between the radial head and radial notch of the ulna
How does the radius articulate at the wrist joint?
Articulation between the distal end of the radius and the carpal bones
How does the radius articulate at the distal radioulnar joint?
Articulation between the ulnar notch and head of the ulna
Name 3 important bony landmarks of the proximal end of the radius (proximally to distally)
Head
Neck
Radial tuberosity
Which muscle attaches at the radial tuberosity?
Biceps brachii
What is the neck of the radius?
Narrow area of bone between the radial head and radial tuberosity
The head of the radius is thicken on which side? Why? What rough shape does it take?
Medially
Forms part of the proximal radioulnar joint here
Disk shaped structure
What happens to the diameter of the radial shaft as it moves distally?
Increases
What is the rough shape of the shaft of the radius? How many borders/surfaces does it have?
Triangular
3
Where does the pronator teres muscle attach to the radius?
In the middle of the lateral surface of the shaft
What shape does the distal region of the radius form?
Rectangular end
The lateral side of the radius projects distally as the…
What structure exists on the medial surface of the distal radius? What joint does this form?
Styloid process
Ulnar notch, articulates with the head of ulna to form the distal radioulnar joint
How is the wrist joint formed at the distal end of the radius?
Articulation of the radius with the scaphoid and lunate
Name 3 common types of fractures of the radius, which is most common?
Colles’ fracture (most common)
Fractures of the radial head
Smith’s fracture
What is a Colles’ fracture? What can cause it? What happens to structures distal to the fracture? What can this result in?
Fracture of the distal radius
FOOSH
Displaced posteriorly
Dinner fork deformity
What is a common cause of fractures of the radial head? What happens to cause the fracture?
FOOSH
Radial head is forced into the capitulum of the humerus
What causes a Smith’s fracture? What happens to the distal fragment of the radius?
Fall onto the back of the hand
Distal fragment displaced anteriorly (opposite of Colles’ fracture)
The bones of the hand can be divided into which three categories? (Proximal to distal)
Carpal bones
Metacarpals
Phalanges
How many carpal bones are there? Where are they located?
8
Wrist area
How many metacarpals are there?
5
One for each digit
How many phalanges are there? Where are they located?
In the fingers/thumb
Three for each finger
Two for the thumb
How are the carpal bones organised?
Into two rows - proximal and distal
What bones exist in the proximal row of the carpal bones? (Lateral to medial)
Scaphoid
Lunate
Triquetrum
Pisiform
What type of bone is the pisiform? Where is it formed?
A sesamoid bone
Within the tendon of the flexor carpi ulnaris
What bones exist in the distal row of the carpal bones? (Lateral to medial)
Trapezium
Trapezoid
Capitate
Hamate
What is the hook of hamate?
A projection on the palmar surface of of the hamate
Which carpals articulate with the radius to form the wrist joint?
Scaphoid and lunate
What do the distal carpals articulate with?
The metacarpals
What are the two carpal bones that are most commonly fractured? What is the usual mechanism of injury?
Scaphoid, Lunate
FOOSH
What is the classical clinical feature of a scaphoid fracture?
Pain/tenderness in the anatomical snuffbox
What are the dangers of a scaphoid fracture?
The blood supply of the proximal part of the scaphoid can be cut off causing it to undergo avascular necrosis
Patients with missed scaphoid fracture are likely to develop…
Arthritis in later life
A lunate fracture occurs when there is ___________________ of the wrist
Hyperextension
A lunate fracture is associated with damage to which nerve?
Median nerve
Where do the metacarpals articulate proximally and distally?
With the carpals proximally
With the proximal phalanges distally
How is each metacarpal numbered?
I - V (thumb to little finger)
What is the shape of the medial and lateral surfaces of the metacarpals? What is the purpose of this?
Concave
Allows attachment of the interoessei muscles
Name two common fractures of the metacarpals. Which metacarpal does each fracture affect?
Boxer’s fracture - 5th metacarpal neck
Bennett’s fracture - 1st metacarpal base
What usually causes a boxer’s fracture? What happens to the the distal part of the fracture and finger in this case?
Striking a hard object with a clenched fist
Displaced posteriorly. Shortening of finger
What causes Bennett’s fracture?
Hyperabduction of the thumb
What are phalanges?
The bones of the fingers
