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Flashcards in Thumb Reconstruction Deck (24):
1

What is the ideal timing of acquired thumb defect reconstruction

  • Delayed - to allow pt to determine level of functional disability
  • ACute - if exposed PP/avulsed pulp

2

How do you classify acquired thumb defects?

BY LOCATION

  • proximal 1/3 => MC
  • middle 1/3 
    • A- proximal => IP
    • B- distal =>PP to DIP
  • Distal 1/3 => DP

A image thumb
3

What are treatment goals and options for acquired thumb defect in distal 1/3 (distal to IP jt)

  • ISSUE; soft tissue coverage. Length adeqaute if amputated thorugh IP jt.
  • Goal: well padded, sensation, painless. Length can be maintaine, does not need to be increased

 

TREATMENT OPTIONS

  • <50% of DP pulp
    • 2' intention (best 2PD <1.5cm2defect)
    • skin graft (FT)
    • local flap V-Y
  • >50% of DP pulp
    • Local flap
      • neurovascular island, crossfinger, moberg
    • Distant free flap
      • toe pulp
  • VOLAR defects
    • best flap includes cross finger, moberg, neurovasc island littler flap
  • DORSAL defects
    • best flap is FDMA

4

What are treatment goals and options for acquired thumb defect in middle 1/3

Split into 2 regions - distal half of PP shaft and DIP)

Goals: maintain/restore length for pinch and grasp

TREATMENT

Phalangization = restoring funcitonal length, no change in absolute length:

  • Deepen webspace - require at least half PP, gain 2cm
    • If linear scar contracture:
      • zplasty,  4 flap zplasty, jumping man (4flap opposing z plasty
    • If broad constracture:
      • FTSG, local flap (DMCA, dorsal rotation)
      • regional (reverse radial forearm, PIA)

 

A image thumb
5

What are treatment goals an options for acquired thumb defect in middle 1/3

split into regions - proximal half of PP shaft and MCPjt

GOALS: lengthen bone that is present or add bone and coverage

 

TREATMENT OPTIONS

  • MC lengthening
  • On-top plasty (pollicization of injured digit)
  • Osteoplastic recon
  • Wrap-around toe transfer - all ST, no bone harvest

 

6

What are prerequisites for MC lengthening

  • at least 2/3rd of MC
  • good CMC ROM with no arthritis
  • good ST coverage of distal stump
  • motivated patient

 

=> done w web deepenign procedure

=>gain 3-3.5cm

7

What are principles for MC lengthening

  • stable ex-fix
  • maintained extraosseous and meduallry blood supply
  • 1mm/day distraction rate
  • consolidation phase prior to removal

ADVANTAGE

  • good sensation to tip, no donor site morbidity, satisfactory cosmesis

DISADVANTAGE

  • prolonged course, may get hardware issues/nonunion 

8

What are the steps for osteoplastic reconstruction

Requires functional thenar musculature and CMC jt

OPTIONS (4)

  • Reverse radial forearm osteocutaneous flapw LABC n
  • Neurocutaneous free flap w ICBG
  • Staged ICBG and groin flap and little NV island
    • ICBG and ST vascularized coverage with groin flap
      • BG secured w plate/screws to remaning PP
    • Division of groin flap pedicle @ 2-3wks (also may need debulking procedures)
    • Inset of sensory tissue at pulp with neurovascular littler island flap (ulnar D3/4) @ 3-6mths

ADVANTAGES

  • sensate pulp, good length restoration

DISADVANTAGE

  • multiple procedures, bone resorption, bulkiness

9

What are treatment goals an options for acquired thumb defect of proximal 1/3 (from metacarpal neck to CMC jt)

ISSUES - loss of length, function and thenar musculature is compromised

GOAL - length restored and function

 

TREATMENT

  • Nonmicrosurgical - Pollicization
  • Microsurgical - toe transfer

10

Describe the principles of whole great toe trasnfer

  • Harvest ipsilateral at level of MTPjt. Leave intact MT head.
  • A: common digital atery arises from branch of dorsalis pedis (either FDMA or deep plantar a)
  • V: VC and superficial dorsal vein
  • N: common digital nerve and deep peroneal branch
  • Tendons: FHL> FPL, EHL>EPL, EHB>EPB

 

A image thumb
11

What are goals of thumb reconstruction?

  • Adeqaute length- at least hald of PP
  • Sensation
  • Strength - based on thenar musculature
  • ROM - based on CMC
  • Stability
  • painless
  • Durable cover

12

What are etiologies of thumb deformities?

CONGENITAL

  • Failure of formation
    • radial longitudinal deficiency                       (RLD)->hypoplasia
    • transverse arrest
  • Failure of differentiation
    • symbrachydactyly
  • Duplication
  • Constriction band syndome

ACQUIRED

  • Trauma
  • Tumor extirpation

13

What is the epidemiology of congenital thumb defomrities

  • 11% of birth defects
  • 50% are duplications
  • most sporadic except TRIPHALANGEAL THUMB (AD)

14

What syndromes are associated with thumb hypoplasia?

  • Fanconi (renal tubules)
  • Aperts (crnaiofacial)
  • Ruberstein Taybi (pseudo hyper paraT)
  • Holt-Oram (CVS anomalies)
  • TAR (Thrombocytopenia absent radius)
  • VACTERL (vertebral, anal, cardiac, TE fistula, Renal, Limb)

15

When is ideal timing for thumb reconstruction?

  • 1-2yr

Because

  • 7mths grasp
  • 12mths pinch
  • 18mths release

16

How do you classify the hypoplastic thumb?

Blauth Classification

  • TYPE 1 - generalized hypoplasia, normal Fx
  • TYPE 2
    • Thenar hypoplasia
    • UCL instability
    • narrowed 1st web space
    • all bones present but hypoplastic
    • *polex abductus - connection b/w EPL/FPL causing no IP f and UCl attenuation
  • TYPE 3
    • Thenar muscle absense/sever hypoplsia
    • UCL absent
    • abnormal extrinsic tendons/muscle
    • Bone abnormalty: 
      • TYPE 3A - CMC stable - child uses thumb for prehension
      • TYPE 3B - CMC unstable - child bypasses thumb for prehension
  • TYPE 4
    • Pouce flottant
    • Thumb remnant connected by skin pedicle, NV bundle and 1st DIO- absence of remaining intrinsic/extrinsic
  • TYPE 5
    • complete absence of thumb

17

How do you manage thumb hypoplasia

Based on Blauth classification of thumb hypoplasia

TYPE 1 - normal Fx- NO Tx

TYPE 2

  • 1st web space widening
    • 4flap z plasty, dorsal trasnposition +/- release of 1t DIO fascia/myotomy
  • UCL instability +/- polex abductus
    • release UCL and advance proximally
    • release anomalous ocnnection sb/w EPL FPL UCL
    • D4 FDS transfer
  • Lack of opposition/abduction
    • D4 FDS transfer - preferred
    • Huber opponensplasty w AbDM

TYPE 3

  • TYPE 3A - CMC stable - child uses thumb so reconstruct
    • improve ROM w TT (EIP to EPL, D4 FDS to FPL). WEbspace widening, jt stbailization as above)
  • TYPE 3B - CMC unstable - child bypasses thumb
    • ablation & pollicization

TYPE 4

  • ablation & pollicization

TYPE 5

  •  pollicization

18

What are indications for pollicization

  • Congenital thumb hypoplasia Type 3B, 4, 5
  • Presence of >3digits
  • thumb hypoplasia in isolation without RLD

19

Describe the steps for pollicization

  • Skin incision design for scar free 1st web
  • Dissection of NV structures
    • ligate off radial br of D3 from CDA
    • save dorsal vein
    • interfascicular dissection of D2 CDN
  • Dissection of IO and tendons
    • release A1, dissect IO off PP base w strip of periosteum
  • MC shortening
    • osteotomy distal to epiphyseal plate at MC head
      • preserve D2 MC base in place for ECBR/FCR
      • D2 MC head =>trapezium
      • D2 MCPjt => new CMC
      • D2 PIPjt =>new MCP
  • Transpose and fix D2
    • release TMClig
    • position D2 in 120pronation, 40abduction
  • Muscle/tendon reassignment
    • 1st DIO =>APB (reinsert on radial lig)
    • 1st PIO =>AdP (reinsert on ulnar lig )
    • EIP =>EPL
    • EDC D2 =>APL
    • FDP=>FPL
  • Postop
    • long arm thumb spica 3wks
    • AROM/PROM at 3wks
  •  

20

What are complications for pollicization

EARLY

  • venous compromise

LATE

  • 1st web space contracture
  • excessive length
  • stiffness
  • malrotation
  • lack of opposition

21

What are important factors to determine durign assessment of thumb duplication

  • joint stability
  • anomalous musculotenidnous interconnections
  • nail plate abnormalities
  • convergeance or divergeance of distal segments

22

How do you classificy thumb duplication?

Wassel classification

Type 1 - 2-6% - bidid DP, common epiphyseal plate, nailplate may be bifid too or just wide

 

Type 2- 12-18% - entire duplicated DP, enlarged PP head

 

type 3 - 6% - bifid PP

 

Type 4 - 50% ** Most common ** entire duplicated PP, enlarged MC head

 

Type 5 - 4-14% - Bifid MC

 

Type 6 - 3% - least common - Entire duplicated MC

 

Type 7 - 6-20%- Triphalnageal thumb - bifrucation at MCPjt or CMC joint - assocaited w syndromes (Fanconi, HO )

23

How do you manage thumb duplications?

According to Wassel classification type

 

In General

  • zigzag skin incision
  • ablation of more radial/hypoplastic
  • contouring of base of proximal bone
  • RCL recon
  • centralization of extensor tendons
  • reattach intrinsics
  • Kwire fixation 4wks and long thumb spica

TYPE 1/2/3/4 (bifid/duplicate DP, bifid/duplicate PP)

  • conservative if well aligned (Type 1-2)
  • Ablate radial/hypoplastic one - recon RCL, wedge osteotomy if needed, realign intrinsics, extrinsics
  • Bilhaut (type 1-2) - coapt equal portion of both DP one/ST/nail - not prefered

TYPE 5/6 (bifid/duplicate MC)

  • need to widen 1st web space, recontour bone abnormalities, relaing ext/intrin, recon RCL

TYPE 7 - Further subclaassified by Manske

  • TR/TU/TRU - triphalangeal thumb on radial, ulnar or both sides and assin # based on wassel

 

24

What are complications post ablation of duplicate thumb

  • residual angle deformity
    • undercorrected
    • epiphyseal growth
    • imbalance of intrinsic/ext tendons
  • collateral instability
  • Loss of motion of IP jt