chapter 33 - injuries of the hand Flashcards
what is a subungual haematoma
haematoma under the nail
what causes a subungual haematoma
crushing of the terminal phalanx
how do you treat a subungual haematoma
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
what is a mallet finger? ie what is injured
disruption of the long extensor insertion to the base of the terminal phalanx, with or without a small fragment of bone
when does a mallet finger occur? example?
occurs when an outstretched finger is suddenly and forcibly flexed - eg: cricket ball strikes finger
how does a mallet finger present clinically? which 3 fingers does it usually affect?
the patient cannot extend the terminal phalanx - commonly middle, ring and little fingers
with a mallet finger, what would you find on xray?
a flexion deformity of the terminal phalanx or the small detached fragment of bone may be seen
how do you treat a mallet finger? and for how long?
- 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
- open cases - surgical repair
- 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
what is another name for the dis insertion of the flexor digitorum profundus FDP ( sport related)
rugby jersey injury
how does the FDP avulsion occur?
the finger is forcibly extended while tightly gripping the jersey - such as in a tackle situation
which finger is commonly affected in a FDP avulsion
the ring finger
how do you treat an FDP avulsion considering the time frame
< 96 hours: operative re attachment of avulsed tendon
> 96 hours: no treatment or athrodesis of DIP joint
what is a boutonniere injury?
disinsertion of the central slip of the extensor tendon from the base of the middle phalanx
when should you suspect a boutonniere injury
after an injury when there is swelling and a flexion deformity of the PIP joint
how does a boutonniere injury present clinically?
flexed PIPJ and extended DIPJ
what is the button hole effect?
it occurs when the lateral bands of the extensor tendon slip volarly and cause a true boutinniere deformity
what is the early and late treatment for a boutonniere injury
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
how does the base of the phalanx usually dislocate
base of the phalanx dislocated dorsally
how do you treat a dislocation
- reduce under general or local anaesthesia and then splint to allow the torn capsule and collateral ligaments to heal
what do you do if you cannot reduce the dislocation?
open reduction is performed DO NOT continue to violently try and reduce it
what could cause an obstruction in a dislocation
capsule
volar plate
interposition of flexor tendon
what do you call an acute tear of the ulnar collateral ligament of the thumb?
skiers thumb
what is a game keepers thumb
chronic form of ligament laxity of the ulnar collateral ligament of the thumb
what happens with chronic stress on the ulnar collateral ligament?
the pt cannot apply a pinch or key grip
name two situations in which an extensor pollicis lngus tendon may rupture
rheumatoid disease
late complication of colles fracture
how does an extensor pollicus longus tendon rupture present clinically?
pt cannot extend the IP joint of the thumb
reduced extension of MCP joint
how do you treat an extensor pollicis longus tendon rupture?
tendon transfer to replace the lost motor function
how do you treat a crush injury to the finger tip in children and adults?
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
what happens to the skin in a crush injury with avulsion of the nail base?
the skin is split laterally and or medially from the nail fold
how do you treat a crush injury with avulsion of the nail base?
place the nail back underneath the nail fold and keep it in position with a double right angled suture
treatment of fracture of the terminal phalanx
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
treatment of fractures of the middle and proximal phalanges
stable(85%): buddy strapping - finger strapped to adjacent finger and joints are left free
unstable(15%): reduction, fixation, immediate mobilisation
how does a fractured proximal phalanx involving the epiphysis present?
little or index finger stands out at an angle
treatment of a fractured proximal phalanx involving the epiphysis
reduce by closed manipulation, buddy strap, mobilise
what is another name for a fractured metacarpal neck?and why?
boxers fracture - occurs when fist hits a hard object like a jaw
which metacarpal is most commonly fractured in a boxers fracture?
5th MC neck
treatment of boxers fracture?
- crepe bandage hand and wrist and may add buddy strapping, leave mcp joints free and focus on mobilisation
- if angulation excessive -closed reduction and percutaneous K wires inserted under x ray control
fractured metacarpal shaft treatment
- crepe bandage and early mobilisation
2. if displaced and unstable need reduction and percutaneous k wire fixation
what is a bennetts fracture?
fracture- dislocation at the base of the thumb metacarpal. the joint capsule is ruptured and the metacarpal base displaced laterally
treatment of bennetts fracture
closed or open reduction
+ kirschner wires
+ POP cast for 6 weeks
