Microsurgery Flashcards
1
Q
What are the goals of tx of fingertip amputations?
What is the prognosis for tx?
A
- Sensate Tip
- Durable Tip
- Bone support for nail growth
Prognosis
- Improper tx may result in stiffness adn longterm functional loss
2
Q
Can you draw/describe the anatomy of the finger tip?
A
- 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
3
Q
What is the aetiology of amputation?
A
- Avulsion
- Laceration
- Crush
4
Q
What do you see on examinatio of an amputated finger tip?
A
- Characteristics of laceration
- presence/absence of exposed bone
- range of motion- felxor/extensor involved
5
Q
What investigations useful for amputation of finger tip?
A
- Xray- ap and lateral to assess Bony involvment
6
Q
Describe the tx of finger tip amputations?
A
Non operative
- Healing by secondary intention
- adults/children with no bone/tendon exposed with <2cm skin loss
- children with exposed bone
Operative
-
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
7
Q
Describe the technique for secondary intention?
A
- 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
8
Q
Describe the technique for full thickness skin grafting from hypothenar region?
A
-
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
9
Q
Describe the technique for revision amputation?
A
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
10
Q
Can you describe the flap types available for Finger tip- to DIPJ ?
A
- 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
11
Q
Can you describe the types of flap available for volar proximal finger?
A
- Cross finger flaps if > 30 years
- Axial flag flap from long finger
- Leads to less stiffness - X finger flaps
12
Q
Can you describe the types of flap available for dorsal proximal finger and MCP lesion?
A
- **Reverse Cross FInger **
- Axial FLag flap from long finger
13
Q
Can you describe the types of flap available for volar thumb lesion?
A
- Moberg Advancement Volar flap if <2cm
- First Dorsal Metcarpal Artery flap FDMA if >2cm
14
Q
Can you describe the types of flap available for dorsal thumb lesion?
A
- First Dorsal Metacarpal Artery Flap
15
Q
Can you describe the types of flaps available for first web space lesions?
A
- Z plasty with 60 degree flaps
- can increase length by 75%
- Posterior interosseous fasciocutanoeous flap
16
Q
Can you describe the flaps types available for dorsal hand?
A
- Groin flaps
17
Q
What are the complications of flaps?
A
-
Flap failure
- inadequate blood flow
- vasospasm -> thrombosis at anastomosis
-
Hook nail deformity
- Tight tip closure
- insufficient bone support
18
Q
What is the epidemiology of upper extremity amputations?
A
- 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
19
Q
What is the imortant history and signs of amputation?
A
Hx
Timing of injury
- type & location of amputation
- preservation of amputated tissue
- PMhx
O/E
- Stump examination
- zone of injury/ tissue viability/supporting tissue structures/contamination
- Amputated portion inspected
- level, segemental injury/ bone/soft tissue damage/ contamination
20
Q
What are the indications for replantation post trauma?
A
Primary
- Thumb
- Multiple digits
- wrist level or proximal wrist
- Almost all parts in children
Relative
- Individual digits distal to the insertion of Felxor digitorium superficialis- zone 1
21
Q
What are the contra- indications for replantation post trauma?
A
Primary
- Single digit proximal to FDS - zone 2
- mangled limb/crush injury
- Semgental amputation
- prolonged ischaemic time
relative
- Medically unstable patient
- disabling psychiatric illness
- tissue contamination
22
Q
Describe the transport of amputated tissue?
A
- 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
23
Q
Describe the time to reimplantation?
A
-
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
24
Q
Can you describe the operative sequence of replantation?
A
- Bone
- extensor tendon
- Flexor tendons
- Arteries
- Veins
- Nerve
- Skin
BEFAVNS
25
Can you describe the finger oder for reimplantation?
* Thumb
* Middle
* Ring
* Small
* Index
26
How is reimplantation achieved for mutliple digits?
* **Structure by structure most efficient**
* Digit by digit takes the most time
27
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
28
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**
29
What is the most important factor in influencing immediate and late outcome of amputations?
* **Type of Injury**
30
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
31
What does thumb reconstruction require?
* An **intact CMCJ t**hat is **stable** but also **appropriately functional **
32
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.
33
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
34
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**
35
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**
36
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
37
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
38
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**
39
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
40
What investigations are helpful in dx of ring avulsion injuries?
* Xrays of both parts as amputated part may have bone!
41
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**
Operative
* **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
42
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
43
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**
44
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**
