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Flashcards in Microsurgery Deck (44):

What are the goals of tx of fingertip amputations?

What is the prognosis for tx?

  • Sensate Tip
  • Durable Tip
  • Bone support for nail growth


  • Improper tx may result in stiffness adn longterm functional loss


Can you draw/describe the anatomy of the finger tip?

  • Eponychium- soft tissue on dorsal surface just proximal to nail
  • Paronychium- lateral nail folds
  • Hyponychium- plug of kerabtinous material situated beneath the distal edge of nail where nail bed meets skin
  • Lunula- white portion of proximal nail, demarcates sterile from germinal matrix
  • Nail bed
    • Sterile matrix- nail adheres to nail bed
    • Germinal matrix- proximal to sterile matrix, responsible for 90% nail growth

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What is the aetiology of amputation?

  • Avulsion
  • Laceration
  • Crush


What do you see on examinatio of an amputated finger tip?

  • Characteristics of laceration
  • presence/absence of exposed bone
  • range of motion- felxor/extensor involved


What investigations useful for amputation of finger tip?

  • Xray- ap and lateral to assess Bony involvment


Describe the tx of finger tip amputations?

Non operative

  • Healing by secondary intention
    • adults/children with no bone/tendon exposed with <2cm skin loss
    • children with exposed bone


  • Primary closure- revision amputation
    • finger amputation w exposed bone and ability to rongeur bone proximally without compromising bony support to nail bed
  • Full thickness skin graft from hypothenar region
    • Fingertip ampuation with no exposed bone and >2cm tissue loss
  • Flap Reconstruction
    • exposed bone/tendon where reongeuring bone proximally is not an option



Describe the technique for secondary intention?

  • initial tx with irrigation and soft dressing
  • After 7-10 days saok in water-peroxide solution daily followed by application of soft dressing adn fingertip protector
  • complete healing takes 3-5 weeks


Describe the technique for full thickness skin grafting from hypothenar region?

  • Split skin grafts not used as
    • Contractile
    • Tender
    • Less Durable
  • Donor site is closed primarily
  • Graft is sutured over defect
  • Cotton ball secured graft helps maintain coaptation with underlying tissue
  • Ball removed after 7 days
  • Range of motion encourage after 7 dyas


Describe the technique for revision amputation?

Primary closure with removal of exposed bone

  • Must ablate remaining nail matrix
    • prevent formation of irrating nail remnants
  • If flexor/extensor tendon insertions can't be preserved disarticulate at DIPJ
  • transect digtial nerves and remaining tendoms proximal as possible
  • Plamar skin is brought over bone and sutured to dorsal skin


Can you describe the flap types available for Finger tip- to DIPJ ?

  • Straight/Dorsal Oblique lacerations
    • V-Y Advancement
    • Digital Island Artery- best axial pattern flap
  • Volar Oblique laceration
    • Cross finger Flap if >30 yrs- less stiffness
    • Thenar Flap if <30 yrs- improved cosmesis
    • Digital Island artery

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Can you describe the types of flap available for volar proximal  finger?

  • Cross finger flaps if > 30 years
  • Axial flag flap from long finger
  • Leads to less stiffness - X finger flaps

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Can you describe the types of flap available for dorsal proximal finger and MCP lesion?

  • Reverse Cross FInger 
  • Axial FLag flap from long finger


Can you describe the types of flap available for volar thumb lesion?

  • Moberg Advancement Volar flap if <2cm
  • First Dorsal Metcarpal Artery flap FDMA if >2cm

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Can you describe the types of flap available for dorsal thumb lesion?

  • First Dorsal Metacarpal Artery Flap

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Can you describe the types of flaps available for first web space lesions?

  • Z plasty with 60 degree flaps
    • can increase length by 75%
  • Posterior interosseous fasciocutanoeous flap

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Can you describe the flaps types available for dorsal hand?

  • Groin flaps

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What are the complications of flaps?

  • Flap failure
    • inadequate blood flow
    • vasospasm -> thrombosis at anastomosis
  • Hook nail deformity
    • Tight tip closure
    • insufficient bone support

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What is the epidemiology of upper extremity amputations?

  • Trauma
  • 90% occur after trauma
  • 4:1 male cf female ration
  • most occur at level of digits
  • mechanism of traumatic amputation
    • Sharp dissection
    • Blunt dissection
    • Avulsion
    • Crush


What is the imortant history and signs of amputation?


Timing of injury

  • type & location of amputation
  • preservation of amputated tissue
  • PMhx


  • Stump examination
  • zone of injury/ tissue viability/supporting tissue structures/contamination
  • Amputated portion inspected
    • level, segemental injury/ bone/soft tissue damage/ contamination



What are the indications for replantation post trauma?


  • Thumb
  • Multiple digits
  • wrist level or proximal wrist
  • Almost all parts in children


  • Individual digits distal to the insertion of Felxor digitorium superficialis- zone 1


What are the contra- indications for replantation post trauma?


  • Single digit proximal to FDS - zone 2
  • mangled limb/crush injury
  • Semgental amputation
  • prolonged ischaemic time


  • Medically unstable patient
  • disabling psychiatric illness
  • tissue contamination


Describe the transport of amputated tissue?

  • Keep with patient
  • Wrapped in gauze in lactate ringers solution
  • Placed in sealed plastic bag and placed in ice water- avoid direct contact with ice/dry ice
  • Wrap, cover and compress stump wiht moisten gauze


Describe the time to reimplantation?

  • proximal to carpus
    • warm ischaemic time <6 hours
    • cold ischaemic time <12 hrs
  • Distal to carpus ( digit)
    • warm ischaemic time <12 hours
    • Cold ischaemic time <24 hrs


Can you describe the operative sequence of replantation?

  1. Bone
  2. extensor tendon
  3. Flexor tendons
  4. Arteries
  5. Veins
  6. Nerve
  7. Skin



Can you describe the finger oder for reimplantation?

  • Thumb
  • Middle
  • Ring 
  • Small
  • Index


How is reimplantation achieved for mutliple digits?

  • Structure by structure most efficient
  • Digit by digit takes the most time


Describe the post operative care for reimplantated digits?

  • Environment
    • Warm 80F
    • avoid caffine, chocolate, nicotine
  • Monitor replant
    • Skin temperature- most reliable, concern >2o drop in < 1 hour or temp below 30oC
    • Pulse oximetry <94% - vascular compromise
  • Anticoagulation
    • adequte hydration
    • medications aspirin, heparin
  • Arterial insufficiency
    • release constriction bandages
    • place extremity in dependent position
    • consider heparinisation
    • consider stellate ganglion blockade
    • early surgical exploration
    • thrombosis secondary to vasospasm is most common cause of early implant failure
  • Venous congestion
    • elevate extremity
    • leech application
      • release Hirudin- powerful anticoagulant
      • aeromonous hydrophila infections can occur
      • Heparin soaked pledgets if no leeches


Describe the complications of reimplantiation?

  • Reimplantation failure
    • within 12 hrs- arterial thrombosis from vasospasm
  • Stiffness
    • 50% of total motion of normal digits
    • tenolysis is most common secondary procedure
  • Myonecrosis
    • > in major limb reimplantation cf digit
  • Myoglobinuria
    • muscle necrosis in larger implants
    • can lead to renal failure-> fatal
  • Reperfusion injury
    • ischaemia induced hypoxanthine conversion to xanthine
    • Allopurinol to decrease xathine production
  • Infection
  • Cold intolerance


What is the most important factor in influencing immediate and late outcome of amputations?

  • Type of Injury


Describe the regions of thumb reconstruction?

  • Region A
    • Primary closure
    • Toe to thumb
    • local flaps
  • Region B
    • Web Deepening
    • Metacarpal lengthening
    • Toe to thumb
  • Region C
    • Toe to thumb
    • Osteoplastic thumb reconstruction
    • Dorsal rotational flap
  • Region D
    • Pollicization

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What does thumb reconstruction require?

  • An intact CMCJ that is stable but also appropriately functional 


Describe the different tx of thumb reconstruction?

  • Toe to thumb procedure
    • Great toe recieves blood supply from 1st dorsal metatarsal artery & dorsalis pedis
    • morrison/wrap around allows for maintaince of length if hallux. Size and appearance are best replicated.
    • 2nd MT is not suitable for transfer
  • Web Deepening
    • ​Z plasty ( 2/4 flaps)
      • ​2 flaps provide > depth
      • if complete at 45o - relative length increase by 50%, 60o 75%
    • Brand Flaps
      • Index finger used to provide a full thickness
      • can close donor site primarily
    • Dorsal rectangular flaps
      • taken from dorsum of metacarpals
      • may require skin grafting
    • Arterilalized palmar flap
      • may use axial ( local) or island flap ( distal)
  • ​Osteoplastic reconstruction
    • ​iliac crest is used to establish mechanical length to the thumb
    • an island flap from the radial aspect of the 4th ray is combine dwiht reverse radial forearm flap to aid coverage.


What is ring avulsion injuries?

  • Sudden pull on a ring finger results in severe soft tissue injury ranging from circumferential soft tissue laceration to complete amputation
  • Skin. nerves , vessels are often damaged

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Describe the epidemiology of ring avulsion injuries?

  • Incidence 150,000 incidents of amputation & degloving in us pa
  • 5% of upper limb injuries
  • Usually involves one digit - ( ring)
  • Risk factors
    • working with machinery
    • wearing a ring


What is the aetiology of ring avulsion injuries?

  • Patients catch wedding ring or finger on moving machinery or protruding object
  • Long segment of MACRO & MICRO Vascular injury from crushing, shearing and avulsion

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What is the prognosis of avulsion injuries?

  • Outcomes of injury
    • Extent of injury is greater than what it appears
    • Poor prognosis because of long segment vascular injury
  • Outcomes of tx
    • Advances in interposition graft techniques have improved results with ring avulsion replantation


How long will avulsed digits last for?

  • As devoid of muscle avulsed digits will survive >12 h if cooled
  • Skin is the strongest part - once torn the remaining tissue quickly degloves


Can you describe the name and classification system of ring avulsion injuries?

  • Urbaniak Classification


  • Class 1= (80N) Circulation adequate->standard bone and soft tissue care
  • Class 2-=Circulation inadequate-> vessel repair
  • Class 3= ( 154N)Complete degloving or complete amputation-> amputation


what are the signs and symptoms of ring avulsion injury?

  • Hx
    • work with machinery, caught in door
  • Symptoms
    • Pain
    • Bleeding
    • Lack of sensation at tip
  • OE
    • Inspect- irrigate wound adn inspect for avulsed vessels, damaged tendons, nerves, skin edges
    • Staggered injury pattern
      • prox skin avulsion from pipj->base of digit
      • Distal bone fracture or dislocation- distal to pipj

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What investigations are helpful in dx of ring avulsion injuries?

  • Xrays of both parts as amputated part may have bone!

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Describe the tx of ring avulsion injuries?

  • Initally
    • Place amputated part in bag with saline moistened gauze , follwed by bag of ice
    • Antibiotics and tetanus prophylaxis


  • Reimplantation +/- Vein graft, DIPJ fusion
    • for disruption of venous drainage
    • disruption of venous/ arterial flow- revascularisation
    • Intact PIPJ & FDS insertion
  • ​Complete ampuation ( esp distal to PIPJ/FDS is relative CI to reimplantation

  • Revision Amputation
    • complete degloving
    • bony injury with nerve and vessel injury
    • bony amputation proximal to FDS or proximal to PIPJ
      • reimplantation likely-> poor hand function
      • consider revision amputation/ray amputation


What are the outcomes of replantation+/- vein graft , dipj fusion for ring avulsion injuries?

  • Survival
    • lower survival for avulsed digits 60% cf finger reimplantation in general 90%
    • Lower survival for complete 66% vs incomplete avulsion replantation
    • Lower survival for avulsed thumb than finger
      • surgeons attempt technically difficult rhumb where conditons are not favourable cf digits
  • Sensibility
    • most achieved Protective Sensibilty 2PD 9mm
    • Better sensibility when incomplete avulsion replantation than complete
  • Range of motion
    • Average total arc of motion (TAM) is 170-200
    • better TAM in incomplete avulsion implantation than complete


Describe the technique for reimplanatation/revascularisation?

  • under microscope
  • lateral incision on ulnar aspect
  • arteries
    • thorough debridment of non viable tissue
    • thorough arterial debridment
    • repair using vein graft-significant damage
    • may need another step- down vein graft because of difficutly of matching sizes
    • may reroute arterial pedicle from adjacent digit
  • Veins
    • repair at least 2 veins
    • important factor in revascularization failure
  • ​Bone
    • ​If amputation at DIPJ , preform primary arthrodesis DIPJ
  • ​Skin
    • ​Preform FTSG or venous flap to prevent tight closire


Describe the complications for replantation?

  • Cold Intolerance
  • Revascularization/replanatation failure
    • Sig factors is repair of <2 veins
    • Vascular damage to digital pulp
    • smoking and level of bione injury not been found to effect survival
  • Flexion Contracture
  • Malunion
  • revision surgery
  • revision amputations-> Hyperaesthesia