chapter 33 - injuries of the hand

Question 1

what is a subungual haematoma

Answer 1

haematoma under the nail

Question 2

what causes a subungual haematoma

Answer 2

crushing of the terminal phalanx

Question 3

how do you treat a subungual haematoma

Answer 3

Heat a needle in a flame until the tip is red hot and then perforate the nail in one or two places - this allows the haematoma to drain and the tension is relieved

Question 4

what is a mallet finger? ie what is injured

Answer 4

disruption of the long extensor insertion to the base of the terminal phalanx, with or without a small fragment of bone

Question 5

when does a mallet finger occur? example?

Answer 5

occurs when an outstretched finger is suddenly and forcibly flexed - eg: cricket ball strikes finger

Question 6

how does a mallet finger present clinically? which 3 fingers does it usually affect?

Answer 6

the patient cannot extend the terminal phalanx - commonly middle, ring and little fingers

Question 7

with a mallet finger, what would you find on xray?

Answer 7

a flexion deformity of the terminal phalanx or the small detached fragment of bone may be seen

Question 8

how do you treat a mallet finger? and for how long?

Answer 8

1. a mallet finger splint to keep the terminal joint extended and allowing the proximal joints to be free to move - strapped in place for 6-8 weeks
2. open cases - surgical repair
3. Work men: if a splint cannot be used then a Kirschner wire is used in situ to keep the terminal joint extended - left in for 6 weeks

Question 9

what is another name for the dis insertion of the flexor digitorum profundus FDP ( sport related)

Answer 9

rugby jersey injury

Question 10

how does the FDP avulsion occur?

Answer 10

the finger is forcibly extended while tightly gripping the jersey - such as in a tackle situation

Question 11

which finger is commonly affected in a FDP avulsion

Answer 11

the ring finger

Question 12

how do you treat an FDP avulsion considering the time frame

Answer 12

< 96 hours: operative re attachment of avulsed tendon

> 96 hours: no treatment or athrodesis of DIP joint

Question 13

what is a boutonniere injury?

Answer 13

disinsertion of the central slip of the extensor tendon from the base of the middle phalanx

Question 14

when should you suspect a boutonniere injury

Answer 14

after an injury when there is swelling and a flexion deformity of the PIP joint

Question 15

how does a boutonniere injury present clinically?

Answer 15

flexed PIPJ and extended DIPJ

Question 16

what is the button hole effect?

Answer 16

it occurs when the lateral bands of the extensor tendon slip volarly and cause a true boutinniere deformity

Question 17

what is the early and late treatment for a boutonniere injury

Answer 17

early: splint for 4 weeks with PIP fully extended and DIP joint free
late: difficult treatment, results of surgery unpredictable and disability is often the outcome

Question 18

how does the base of the phalanx usually dislocate

Answer 18

base of the phalanx dislocated dorsally

Question 19

how do you treat a dislocation

Answer 19

1. reduce under general or local anaesthesia and then splint to allow the torn capsule and collateral ligaments to heal

Question 20

what do you do if you cannot reduce the dislocation?

Answer 20

open reduction is performed DO NOT continue to violently try and reduce it

Question 21

what could cause an obstruction in a dislocation

Answer 21

capsule
volar plate
interposition of flexor tendon

Question 22

what do you call an acute tear of the ulnar collateral ligament of the thumb?

Answer 22

skiers thumb

Question 23

what is a game keepers thumb

Answer 23

chronic form of ligament laxity of the ulnar collateral ligament of the thumb

Question 24

what happens with chronic stress on the ulnar collateral ligament?

Answer 24

the pt cannot apply a pinch or key grip

Question 25

name two situations in which an extensor pollicis lngus tendon may rupture

Answer 25

rheumatoid disease | late complication of colles fracture

Question 26

how does an extensor pollicus longus tendon rupture present clinically?

Answer 26

pt cannot extend the IP joint of the thumb | reduced extension of MCP joint

Question 27

how do you treat an extensor pollicis longus tendon rupture?

Answer 27

tendon transfer to replace the lost motor function

Question 28

how do you treat a crush injury to the finger tip in children and adults?

Answer 28

children: if bone is not exposed - apply a vaseline gauze dressing adults: immediate split skin graft workmen: nibble away bone + do primary flap repair = full or partial amputation of the tip of the terminal phalanx if bone exposed: bone nibbled back and a split skin graft applied

Question 29

what happens to the skin in a crush injury with avulsion of the nail base?

Answer 29

the skin is split laterally and or medially from the nail fold

Question 30

how do you treat a crush injury with avulsion of the nail base?

Answer 30

place the nail back underneath the nail fold and keep it in position with a double right angled suture

Question 31

treatment of fracture of the terminal phalanx

Answer 31

focus on the soft tissue injury grossly displaced fractures: kirschner wire can be used to maintain reduction, improve stability and hasten soft tissue healing child: displacement is dorsal at the epiphyses and must be replaced, the nail seperates from the nail fold and needs to be stitched in place

Question 32

treatment of fractures of the middle and proximal phalanges

Answer 32

stable(85%): buddy strapping - finger strapped to adjacent finger and joints are left free unstable(15%): reduction, fixation, immediate mobilisation

Question 33

how does a fractured proximal phalanx involving the epiphysis present?

Answer 33

little or index finger stands out at an angle

Question 34

treatment of a fractured proximal phalanx involving the epiphysis

Answer 34

reduce by closed manipulation, buddy strap, mobilise

Question 35

what is another name for a fractured metacarpal neck?and why?

Answer 35

boxers fracture - occurs when fist hits a hard object like a jaw

Question 36

which metacarpal is most commonly fractured in a boxers fracture?

Answer 36

5th MC neck

Question 37

treatment of boxers fracture?

Answer 37

1. crepe bandage hand and wrist and may add buddy strapping, leave mcp joints free and focus on mobilisation 2. if angulation excessive -closed reduction and percutaneous K wires inserted under x ray control

Question 38

fractured metacarpal shaft treatment

Answer 38

1. crepe bandage and early mobilisation | 2. if displaced and unstable need reduction and percutaneous k wire fixation

Question 39

what is a bennetts fracture?

Answer 39

fracture- dislocation at the base of the thumb metacarpal. the joint capsule is ruptured and the metacarpal base displaced laterally

Question 40

treatment of bennetts fracture

Answer 40

closed or open reduction + kirschner wires + POP cast for 6 weeks