MSK- arm Flashcards
What are the functions of the clavicle? (3)
-attatches the upper limb to the trunk -protects the underlying neuromuscular structures supplying the upper limb. -transmits force from the upper limb to the axial skeleton.
How do clavicular fractures commonly occur?
FOOSH
where is the most common point for a clavicle to fracture?
medial 2/3 and lateral 1/3
After a clavicle fracture where are the segments displaced to and why?
-lateral end is displaced inferiorly by the weight of the arm and medially by pectorals major. -medial end is displaced superiorly by the SCM.
What nerves may be damaged in a clavicular fracture and why?
The upwards movement of the medial part may damage the supra scapular nerve.
What is the common position for someone who has damaged their supra scapular nerves to present with?
The lateral rotators of the arm and shoulder are deinnervated which results in unopposed medial rotation of the upper limb- the ‘waiters tip position’
What would you be concerned about if someone presented with a scapular fracture?
Chest trauma, as scapular fractures are rare and usually indicative of severe chest trauma.
After a scapular fracture, what treatment is needed?
trick question (i’m so sneaky), The natural tone of muscles in the are hold the fragments in place, so it can be left to heal naturally.
During a surgical neck fracture of the humerus what structures are at risk?
axillary nerve and posterior circumflex artery
What happens when the axillary nerve is damaged?
paralysis of the deltoid and theres minor, weakness to the triceps, so the patient will be unable to abduct their arm. There will also be loss of sensation over the ‘regimental badge’ area.
What structures are at risk during a mid-shaft humeral fracture?
the radial nerve and profound brachii run close to the humerus in the radial groove.
What sign would be an indication of radial nerve damage?
Wrist drop. As the extensors of the wrist are deinnervated. There may also be sensory loss in the portion innervated by the radial nerve.
What are the two common fractures of the distal humerus? Give a brief description of each.
-Supraepicondylar fracture- falling on a flexed elbow, it’s a fracture spanning the the gap between the two epicondyles. It can result in damage to the blood supply to the forearm via the brachial artery. -Medial epicondylar fracture- it could cause damage to the ulnar nerve, causing ulnar claw and loss of sensation over the medial 1 and 1/2 fingers of the hand on the dorsal and palmar surfaces.
What are Volkmann’s ischaemic contractures?
uncontrolled flexion of the hands, as the flexors become fibrotic and short.
What are the four articulations of the radius?
- elbow- head of the radius with the capitulum of the humerus -proximal radioulnar joint- radial head and radial notch of the ulnar. -wrist joint- articulation between the distal end of the radius and the carpal bones -distal radioulnar joint- ulnar notch and the head of the ulna
What’s the difference between a Colles’ fracture and a Smith’s fracture?
Colles’- the most common type of radial fracture, caused by FOOSH, the distal 2cm are displaced posteriorly, causing a ‘dinner fork deformity’. Smith’s- A fracture caused by falling onto the back of the hand, the opposite of a Colles’. the distal 2cm is now placed anteriorly.
Name this fracture
Colles’ fracture
Name this fracture
Smith’s fracture
What are the two common ulnar fractures?
Montaggia’s fracture- force from behind the ulna. The proximal shaft of the ulna is fractured, and the head of the radius dislocates anteriorly at the elbow.
Galeazzi’s fracture- a fracture to the distal radius, with the ulna head dislocating at the distal radio-ulnar joint
What’s the mneumonic used to remmeber the carpal bones, and what they stand for?
Some Lovers Try Positions That They Can’t Handle
Scaphoid, Lunate, Triquetral, Pisiform, Trapezium, Trapezoid, Capitate, Hamate
name these structures:
A- Scaphoid, B-Lunate, C-Triquetral, D-Pisiform, E-Trapezium, F-Trapezoid, G-Capitate, H-Hamate
1-radius, 2-ulna, 3-metacarbal bones
How does a scaphoid fracture occur?
FOOSH
What is wrong on this x-ray?
Scaphoid fracture
What are the borders of the axilla?
**Apex **– Also known as the axillary inlet, this is formed by lateral border of the first rib, superior border of scapula, and the posterior border of the clavicle.
Lateral wall – Formed by intertubecular groove of the humerus.
**Medial wall **– Consists of the serratus anterior and the thoracic wall (ribs and intercostal muscles).
Anterior wall – Contains the pectoralis major and the underlying pectoralis minor and the subclavius muscles.
Posterior wall – Formed by the subscapularis, teres major and latissimus dorsi.
What are the three entry’s to the axilla?
Quadrangular Space
Clavipectoral Triangle
Cervicoaxillary canal
What are the borders of the quadrangular space?
- inferior border of subscapularis (and teres minor)
- superior border of teres major
- lateral border of the long head of triceps brachii
- it’s lateral border is the surgical neck of humerus
What passes through the quadrangular space?
It allows access to the posterior arm and shoulder area, including for the axillary nerve and posterior circumflex humeral artery.
The opening in the anterior wall of the axilla is the clavipectoral triangle, but what are its borders?
- inferior border of the clavicle
- medial border of the deltoid
- superior border of pectoralis major
What enters the axilla through the clavipectoral triangle?
Cephalic vein, while the medial and lateral pectoral nerves leave.
What are the borders of the cervicoaxillary canal and where can it be found?
It’s located at the apex of the axilla. It’s bound by the 1st rib, clavicle, and superior edge of the scapula. This is how the brachial plexus enters the arm.
What are the contents of the axilla?
- Axillary artery
- Axillary vein
- Brachial plexus
- Biceps brachii and corocobrachialis
- Axillary Lymph nodes
What are the divisions of the brachial artery which can be found in the axilla? (3)
one medial to the pectoralis minor, one posterior to pectoralis minor, and one lateral to pectoralis minor. The medial and posterior parts travel in the axilla.
What lymph nodes can be found in the axilla?
pectoral, subscapular, humeral, central and apical
What is thoracic outlet syndrome?
- vessels and nerves may become compressed between the bones in the apex.
- caused by trauma or repetative motion
- It often presents with pain in the affected limb, tingling, muscle weakness and discolouration of the arm
how can a lymph node biopsy cause a winged scapula?
The axillary clearance can cause long thoracic nerve damage
Is the brachial formed of the anterior or posterior rami of C5-T1? And what does this make the fibres, afferent or efferent?
Anterior, so the fibres are efferent!
Alice Eats Dicks Alot (Anterior are Efferent e.g. movement Dorsal rami are Afferent e.g. Sensory)
What are the three trunks in the brachial plexus?
Superior, middle and inferior
What are the cords of the brachial plexus, which divisions are they made up of, and what are they named relative to?
The axillary artery
- Lateral- anterior division of the superior and middle trunks
- posterior- posterior division of all three trunks
- medial- anterior division of the inferior trunks
What are the branches of the brachial plexus (top to bottom)
MAMRU
Musculocutaneous, axillary, median, radial, and ulnar
What are the nerve roots of the musculocutaneous nerve?
C5-7
What are the nerve roots of the axilliary nerve?
C5+C6
What are the nerve roots of the Median nerve?
C6-T1
What are the nerve roots of the Radial nerve?
All roots (C5-T1)
What are the nerve roots of the ulnar nerve?
C8+T1