Revision: frxs

Question 63

clavicle frx cause, result, who is most at risk, state of acromioclavicular joint

Answer 63

cause: -indirect force from outstretched hand through forearm and arm to shoulder
- fall directly onto shoulder
- during delivery if the baby is broad-shouldered (but the bones usually heal fast)
result: -med frag is pulled up due to sternocleidomastoid muscle
- lat frag drops as trapezius cannot hold the weight of the U/limb -> shoulder drops
- lat frag can also be pulled med by adductor muscles eg pec M.
- due to the subcut position, the end of the superior directed frag is prominent -> palpable a/o apparent

very frequent, esp in children, where it is often incomplete -> greenstick frx -> 1 side of bone is broken and other is bent

the strong coracoclavicular ligament usually prevents disloc of AC joint

Question 64

cause of clavicle frx

Answer 64

-indirect force from outstretched hand through forearm and arm to shoulder

• fall directly onto shoulder
• during delivery if the baby is broad-shouldered (but the bones usually heal fast)

Question 65

result of clavicle frx

Answer 65

-med frag is pulled up due to sternocleidomastoid muscle

• lat frag drops as trapezius cannot hold the weight of the U/limb -> shoulder drops
• lat frag can also be pulled med by adductor muscles eg pec M.
• due to the subcut position, the end of the superior directed frag is prominent -> palpable a/o apparent

Question 66

people most at risk of clavicle frxs

Answer 66

clavicle frxs are very frequent, esp in children, where it is often incomplete -> greenstick frx -> 1 side of bone is broken and other is bent

Question 67

state of acromioclavicular joint after clavicle frx

Answer 67

the strong coracoclavicular ligament usually prevents disloc of AC joint

Question 68

scapula frx cause, complications, most common site, treatment

Answer 68

caused by severe trauma eg a pedestrian-vehicle accident

usually also involves frxed ribs

often involves acromion

little treatment is needed as the bone is surrounded by muscle

Question 69

types of humeral frx

Answer 69

frxs to surgical neck (the most common)

avulsion frx of greater tubercle of humerus

transverse and spiral frx of shaft

intercondylar frx

Question 70

avulsion frx

Answer 70

fragment of bone tears away from main mass due to physical trauma

Question 71

frx to surgical neck of humerus cause and result

Answer 71

cause: minor fall onto a hand is transmitted to humerus, esp common in the elderly w/ osteoporosis
result: often 1 fragment is pushed into the spongy bone of the other (impacted frx) -> the site is sometimes stable -> humerus can be moved w/ little pain

axillary nerve injury

Question 72

impacted frx

Answer 72

one bone is firmly driven into another

Question 73

avulsion frx of greater tubercle of humerus found most commonly in, cause, result

Answer 73

seen most commonly in middle aged and elderly

cause: usually from a fall onto the acromion, although it can also be due to a fall onto the hand when the arm is abducted
result: subscapularis pulls the humerus into medial rotation

Question 74

transverse frx of shaft of humerus cause, result, healing

Answer 74

cause: direct blow to arm (fall on outstretched hand leads to spiral frx)
result: deltoid pulls prox frag laterally
healing: as the humerus is surrounded by muscle and a well developed periosteum, it heals well

Question 75

spiral frx of humeral shaft cause, results in

Answer 75

caused by a fall on outstretched hand, leads to foreshortening

Question 76

intercondylar frx of humerus cause, result

Answer 76

caused by a severe fall on a flexed elbow

results in the olecranon process being driven like a wedge between the med and lat condyles

Question 77

radius and ulna injury characteristics, types

Answer 77

characteristics: due to the IO membrane the frx of 1 bone usually leads to the dislocation of the other
- direct injury leads to transverse frx at middle third of bone
- usually is the result of severe injury
types: -Colle’s frx w/ avulsion of ulnar styloid process
- epiphyseal plate injuries

Question 78

Colle’s frx cause, found most commonly in, result, healing, site, result in ulna

Answer 78

cause: forced dorsiflexion of wrist due to breaking fall w/ hand

found most commonly >50 years old in women (as they are more at risk from osteoporosis)

result: -complete transverse frx of distal 2cm
- distal fragment is displaced dorsally and comminuted (broken to pieces)
- posterior displacement and tilt of distal frag of radius -> DINNER FORK DEFORMITY
- radial angulation of wrist, radial shortening

heals well due to good blood supply

site is distal end of radius

results in avulsion of ulnar styloid

Question 79

result of Colle’s frx

Answer 79

• complete transverse frx of distal 2cm
• distal fragment is displaced dorsally and comminuted (broken to pieces)
• posterior displacement and tilt of distal frag of radius -> DINNER FORK DEFORMITY
• radial shortening and radial angulation of wrist
• results in avulsion of ulnar styloid

Question 80

avulsion of ulnar styloid cause

Answer 80

colle’s frx, as the radius no longer projects more distally than the ulna

Question 81

epiphyseal plate injuries of radius cause, most common in, result

Answer 81

cause: distal radius frx where the frx line extends through dist epiphyseal plate

most commonly found in older children due to freq falls where the force is transmitted from hand to radius and ulna

result: the healing process can lead to malalignment of plate and disturbance of radial growth

Question 82

scaphoid frx cause, site, diagnosis, healing

Answer 82

cause: fall on palm of abducted hand
site: across narrow part of scaphoid
diagnosis: easily misdiagnosed on x rays as a severely sprained wrist
- however after 10-14 days later x rays show frx due to bone resorption
healing: takes more than 3 months normally due to poor blood supply
- can lead to necrosis of prox scaphoid/degenerative joint disease of wrist, may need to be fused surgically (arthrodesis)

Question 83

metacarpal frx cause, healing

Answer 83

if only 1 MC is frx then the closely bound other MCs hold it in place

if, due to severe crushing injury to hand, >1 MC is frxed, leads to instability

boxer’s frx is the 5th MC:

cause: head of bone rotates over distal end of shaft leading to flexion deformity from a punch w/ closed hand and abducted wrist

good blood supply leads to quick healing

Question 84

phalanges frx cause, result

Answer 84

crushing injuries are common and very painful

distal phal: comminuted and haematoma forms (very painful)

middle and prox phals: from crushing/hyperextension

Question 85

hamate frx result

Answer 85

ulnar nerve and artery damage

non union of frxed bony parts due to traction from muscles