MSK Flashcards
What happens on clavicular fracture to the fragments?
Medial fragment moves superiorly due to unopposed scm action
Lateral fragment moves inferiorly due to limb weight and medially due to unopposed adductor pull
What is the first bone to start ossification? When?
Clavicle, 5/6th week
What is the last long bone to finish ossification? When?
Implication
How to overcome it?
Clavicle! 35-30 yrs
Potential to misinterpret epiphysis as a fracture
Image both clavicles, should be the same
Commonest site of humerus fracture?
What sort of fracture do they tend to be? Implication?
Surgical neck
Impacted - often stable and able to move arm passively
How would the arm be positioned if the greater tubercle was avulsed on the humerus? Why?
Medially rotated
Lack of attachment of lateral rotating muscles infraspinatous and teres minor leading to unopposed subscapularis medial rotation
How would a fractured shaft of humerus position post fracture? Why?
Proximal portion abducted by unopposed deltoid
How could a midshaft humerus fracture occur?
Direct blow
How could a surgical neck humerus fracture occur?
FOOSH in elderly with osteoporosis
How does a greater tubercle of humerus avulsion commonly occur?
Fall onto acrominion
How could an intercondylar fracture of the humerus occur?
Fall onto flexed elbow driving olecranon up
What is a colles fracture?
What position does it end up in? With what signs?
What other fracture commonly accompanies it?
Complete transverse fracture of distal 2cm of humerus
Distal fragment displaced dorsally and proximally
Radial styloid becomes proximal to ulna styloid
Dinner fork deformity
Avulsion of the ulna styloid
How does pain from a fractured scaphoid present?
Lateral wrist
Worse on dorsiflexion and abduction of hand
Telescoping thumb produces pain
What condition occurs if a scaphoid fracture undergoes avascular necrosis? What may have to occur then?
Degenerative joint disease of the wrist - may need fusing
What protective factors do the metacarpals have if fractured?
Closely bound so stable
Good blood supply
What is a boxers fracture?
Fracture of fifth metacarpal by hitting with the wrong knuckles
How do fractured phalanges usually occur? What type of fracture do they tend to be? Why is this important?
Crush injury
Comminuted
Close association with flexor tendons thus needs to be carefully realigned.
Where is the weakest point of the clavicle?
The join between the medial and lateral thirds
Define myotome
What does this imply for muscles?
What group of muscles of the upper limb are made from a single myotome?
The unilateral embryological muscle mass receiving innervation from a single spinal cord segment or spinal nerve
Most muscles consist of multiple myotomes
The intrinsic muscles of the hand (T1)
Sensation to the upper shoulder is provided by…
The supraclavicular nerves C3/C4
Sensation to the lateral arm is provided by?
Superior (c5/c6) and inferior (c5/c6) lateral cutaneous nerves of the arm
Nerves that supply sensation to the forearm and origin nerves
Lateral cutaneous nerve to the forearm - musculocutanious
Medial cutaneous nerve to the forearm - brachial plexus
Posterior cutaneous nerve to the forearm - radial
Sensation provided by ulnar nerve
Medial palm and dorsum with medial 1.5 digits
Sensation provided by median nerve directly
Lateral palm and lateral 3.5 digits palmer and tips of dorsal
Sensation provided by radial nerve directly
Lateral dorsum of hand and lateral 3.5 fingers except the tips.