MSK Bones of the upper limb Flashcards
What muscle(s) originate from the coracoid process of the scapula?
Short head of biceps brachii
Pectoralis minor
Coracobrachialis
What muscle(s) originate from the supraglenoid tubercle of the scapula?
Long head of biceps brachii
What muscle(s) originate from the infraglenoid tubercle of the scapula?
Long head of triceps brachii
How are scapula fractures treated?
Uncommon - indicative of severe chest trauma
Does not require much intervention as tone of surrounding muscles holds scapula together well.
What causes winging of the scapula?
The serratus anterior attaches to costal face of scapula and pulls it against the ribcage. Serratus anterior is innervated by the long thoracic nerve, if the nerve is damaged the scapula protrudes when the arms are pushed against a wall.
List the muscles that attach to the shaft of the clavicle?
- deltoid
- trapezius
- subclavius
- pec maj
Which ligaments attach to the lateral end of the clavicle? And what are the bony landmarks they attach to?
Conoid tubercle - conoid ligament attaches (medial part of the coracoclavicular ligament)
Trapezoid line - trapezoid ligament attaches (lateral end of coracoclavicular ligament)
(function of the coracoclavicular ligament is to suspend weight of upper limb)
What is the most common site of fractures to the clavicle?
What position does the fractured clavicle undertake?
What are some possible complications?
Most commonly fractured bone in body
Most common point of fracture is the junction between medial 2/3 and lateral 1/3
Lateral end displaced inferiorly and medially by weight of the arm and pec major
Medial end pulled superiorly by sternocleidomastoid muscle
The supra scapular nerves (medial, intermedial, lateral) may be damaged by upwards movement of the medial part of fracture. These nerves innervate lateral rotators so damage results in medial rotation of upper limb - ‘waiters tip’ position
Which muscle(s) attach to the greater tubercle of the humerus?
3 of the rotator cuffs: (the 3 at the back as the greater tubercle is at the back)
- infraspinatus
- supraspinatus
- teres minor
Which muscle(s) attach to the less tubercle of the humerus?
The remaining rotator cuff - subscapularis
What runs through the intertubecular sulcus?
Tendon of the long head of biceps brachii
Tendons of pec major, teres maj, latissimus dorsi attach to lips of the intertubecular sulcus
What damages can occur from fractures to the surgical neck of the humerus?
Vulnerable structures -
- Axillary nerve, paralysis of deltoid and teres minor, loss of sensory of regimental badge area (patient unable to abduct arm)
- Posterior circumflex artery
What are the bony landmarks of the humeral shaft?
Deltoid tuberosity - deltoid attaches
Radial groove - posterior surface of humerus, radial nerve and profound brachii artery lie in this groove
List the muscles that attach anteriorly and posteriorly to the shaft of the humerus?
Anteriorly: Coracobrachialis Brachialis Brachioradialis Deltoid
Posteriorly:
Medial and lateral heads of triceps
What are the complications of a mid-shaft fracture to the humerus?
Radial nerve and profunda brachii artery could easily be damaged
Radial nerve innervates wrist extensors - damage results in wrist drop (unopposed flexion), also sensory loss to dorsal surface of hand and proximal ends of lateral 3 1/2 fingers
What are the names of the bony landmarks on the humerus that articulate with the ulna and radius?
The trochlea articulates with the ulna
The capitulum articulates with the radius
What are the 3 depressions at the distal humerus and what is their function?
Coranoid fossa - above trochlea, accommodates coranoid process of the ulna when elbow flexed
Radial fossa - above capitulum, accommodates radius when flexed
Olecranon fossa - posterior, accommodates olecranon process of ulna when extended
Where does the ulnar nerve pass into the forearm?
Posterior side of the medial epicondyle of the humerus
What are the common fracture sites at the distal humerus?
What are the possible complications?
Common fractures are supracondylar (fall on a flexed elbow, fracture between two epicondyles) and medial epicondlye fractures.
Damage or swelling can cause interference of the blood supply to the forearm from the brachial artery - volkmanns ischaemic contracture.
A medial epicondyle fracture could damage the ulnar nerve - forms ‘ulnar claw’ - little and ring fingers flexed, with loss of sensation
Describe the locations of the bony landmarks at the proximal ulna, and their functions
Olecranon - a bony prominence palpated as the ‘tip of the elbow’, triceps brachii attaches
Coronoid process - projects outwards anteriorly
Trochlear notch - wrench shaped, made up of the olecranon and coronoid process
Radial notch - lateral surface of trochlear notch, articulates with head of radius
Tuberosity of ulna - roughening distal to coronoid process where the brachialis attaches
What are the 3 surfaces and 3 borders of the shaft of the ulna? and their attachments
3 surfaces:
Anterior - pronator quadratus attaches
Posterior - many muscles attach e.g. carpi flexors, indices extensors
Medial
3 borders:
Posterior
Interosseous - site of attachment of interosseous membrane
Anterior
What bony landmarks are at the distal end of the ulna?
Much smaller in diameter than proximal
There is a distal projection called the styloid process which articulates with the ulnar notch of the radius to form the distal radio-ulnar joint
What are the most common fractures to the ulna?
(Usually the radius also fractures)
The shaft is most likely to fracture, and muscle tone pulls the proximal ulna posteriorly
Less common - olecranon process can fracture if patients falls on flexed elbow, and the triceps brachii can pull a fragment proximally
Classical fractures:
Monteggias fracture - from force behind the ulna, proximal ulna fractures and head of radius dislocates from elbow
Galeazzis fracture - fracture to distal radius with the ulna dislocating at the distal radio-ulnar joint
What are the articulations of the radius?
- articulates at the elbow with capitulum of the humerus
- articulates at proximal radio-ulnar joint with the radial notch
- articulates at the distal radio-ulnar joint with the ulna notch
- articulates at the wrist with scaphoid and lunate
What are the important bony landmarks at the proximal end of the radius?
The radial head - disc shaped with concave articulating surface, involved in proximal radio-ulnar joint
The radial neck - narrow area between the head and tuberosity
The radial tuberosity - a bony projection which is the attachment of biceps brachii
Describe the shape of the radial shaft and its attachments
The radial shaft is triangular in shape and expands in diameter as it moves distally
The middle and lateral surface is the attachment of the pronator teres muscle
What are the important bony landmarks at the distal end of the radius?
Styloid process - a distal projection in which brachioradialis attaches
Ulnar notch - on medial surface for articulating with the head of the ulnar
Two facets on distal surface for articulation with scaphoid and lunate
What is a colles and smiths fracture?
Colles fracture (most common) is a fracture of the distal radius due to a fall on an outstretched hand. The wrist and hand are displaced posteriorly forming a 'dinner fork' deformity Smiths fracture is a fracture due to falling on the back of the hand, the distal fragment is displaced anteriorly
Describe how a fracture of the radial head occurs?
A fall on an outstretched hand causes the radial head to be forced into the capitulum, causing it to fracture
List the carpal bones in order
Left hand
Trapezium trapezius capitate hamate (has a hook)
Scaphoid lunate triquetrum pisiform (sesamoid in flexor carpi ulnaris tendon)
What are the causes and complications of a lunate fracture?
Fail on an outstretched hand causing hyperextension of the wrist
Can have some median nerve damage
Describe the general shape of the metacarpals
Each metacarpal has a base, shaft and head
They articulate proximally with the carpals and distally with the proximal phalanges
The medial and lateral surfaces are concave allowing for attachment of the interossei muscles
What are the names of the common fractures to the metacarpals?
Boxers fracture: fracture of 5th metacarpal neck and the distal part is displaced posteriorly, shortening the finger
Caused by clenched fist hitting hard object
Bennets fracture: fracture of 1st metacarpal base extending to the carpometacarpal joint
Caused by hyperabduction of thumb
