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Flashcards in Congenital Hand Deck (76)
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1

List the top 3 most common congenital hand anomalies

  1. Polydactyly
  2. Syndactyly
  3. Camptodactyly

2

what is the LEAST common ray pair involved in syndactyly? why?

  • thumb-index
  • first to separative via apoptosis

3

in patients w non-syndromic isolated syndactyly, when do you perform release?

  • 6-9 mos: border digits, complex (skeletal involvement) or complicated
  • up to 2 years: central digits, simple

4

what is your differential of a child of 6 months with a flexed thumb?

  • delayed maturation of radial/extensor neuromuscular unit
  • trigger thumb
  • clasped thumb
  • camptodactyly of thumb

5

what syndromes are associated w longitudinal radial deficiency?

  • Fanconi anemia
  • Thrombocytopenia absent radius (TAR) Syndrome
  • VATER (vertebral, anal atresia / imperforate anus, TE fistula, esophageal atresia, renal)
    • or VACTERL (vertebra, anal atresia, cardiac, TE fistula, esophageal atresia, renal, lower limb abn)
  • Holt-Oram (associated cardian anom)
  • Duanne radial ray syndrome
  • HFM
  • Nager Syndrome
  • Thalidomide syndrome
  • various chromosomal aberrations

6

what is Bower's criteria?

  • criteria that indicates temporal age-related involution of hemangioma
  • 50% by 5 yrs, 70% by 7 yrs, 90% by 9 years

7

DEFINE THE FOLLOWING TERMS:

  • AMELIA
  • PHOCOMELIA
  • ACROSYNDACTYLY
  • CAMPTODACTYLY
  • CLINODACTYLY
  • BRACHYMETACARPIA
  • SYMBRACHYDACTYLY

 

  • Amelia: congenital absence of limb(s)
  • Phocomedial: upper extremity longitudinal intersegmental deficiency
  • Acrosyndactyly: distal lateral fusion between adjacent digits (skin/soft tissue+/- bone) with proximal separation
  • Camptodactyly: congenital (or adolescent) volar flexion deformity  of PIPJ, typically D4.5
  • Clinodactyly: congenital radial flexion deformity in radial-ulnar plane of PIPJ, typically D5
  • Brachymetacarpia: congenital short metacarpal
  • Symbrachydactyly: short, hypoplastic digits with proximal soft tissue fusion

8

Summarize temporal embryologic development of the upper extremity

  • development occurs during critical period of rapid embryo growth from 4 to 8 weeks
  • @ 4 wks, limb bud develops as an invagination of mesoderm into ventrolateral wall ectoderm
  • Weeks 5-6: flat, paddle-shaped hand-plate develops
  • Weeks 6-8: finger separation occurs in steps: 5 mesenchymal condensations, digits webbed, separation complete - via fragmentation of AER and apoptosis
  • Week 8: embryogenesis complete, skeletal structures are cartilage
  • Week > 8: enlargement, maturation, differentiation of existing structures
  • Month 4-5: sweat gland and nail growth and development

9

List the 3 spatial axis pattern formation

  • Proximodorsal
  • Radioulnar
  • Dorsoventral

10

describe spatial patterning or formation of the upper extremity during embryogenesis

  • Proximo-distal
    • Signalling centre is apical ectodermal ridge - a condensation of ectoderm overlying the limb bud
      • It's function is to program proximo-distal growth, and digit separation (via interdigital apoptosis)
    • Also involved is the progress zone, an underlying layer of mesenchymal cells
      • It's function is to program lateral/distal growth
    • How it work:
      • AER releases FGF2, FGF4, FGF8 as signalling molecules
      • Amount of time spent in the progress zone determines differentiation - for example cells that leave PZ from earliest to latest are destined to be: shoulder, humerus/arm, forearm, hand
  • Radioulnar
    • Signalling centre is Zone of Polarizing Activity - mesenchymal cells along the posterior (ULNAR) ridge of the limb
    • Overall is responsible for positioning ulnar characteristics
    • How it works: ZPA secretes sonic hedgehog in varying concentrations - high concentrations promote dorsal/ULNAR differentiation and low concentrations promote volar/RADIAL differentiation
  • Dorsoventral
    • signalling centre in dorsal ectoderm, releases Wingless type (Wnt) gene signaling

11

what is the first and last carpal bone to ossify?

  • Capitate - 3 to 6 mos
  • Pisiform - 6 - 8 years

12

What are general treatment goals when considering a congenital upper extremity defect of the hand?

  • power grasp
  • precision pinch
  • maintaining growth potential
  • cosmesis

13

List the IFSSH / Swanson classification of congenital upper extremity anomalies

  1. failure of formation
  2. failure of differentiation
  3. duplication
  4. overgrowth
  5. undergrowth
  6. constriction band
  7. generalized skeletal abnormality not otherwise specified

14

List examples of Swanson / IFSSH type 1:

  • failure of formation
    • transverse arrest
    • longitudinal arrest
      • pre-axial / radial longitudinal deficiency
      • axial / central longitudinal deficiency (cleft hand)
      • post-axial / ulnar longitudinal deficiency
      • longitudinal intersegmental deficiency (phocomelia)

15

list examples of swanson / IFSSH type 2:

  • failure of differentiation
    • syndactyly
    • camptodactyly
    • clinodactyly
    • flexed thumb (trigger, clasped)
    • arthrogryposis
    •  

16

list examples of swanson / IFSSH type 3

  • duplication / polydactyly
    • pre-axial / radial
    • axial / central
    • post-axial / ulnar
    • ulnar dimelia
    • triphalangism (some considered to be failure of differentiation)

17

WHAT FEATURES ARE ASSOCIATED WITH:

  • Fanconi anemia
  • VACTERYL
  • Holt-Oram
  • Duanne Radial Ray syndrome

  • Fanconi anemia: pancytopenia, ASD, various pre-axial abn
  • VACTERL:
    • vertebral, anal atresia, cardiac, TE fistula, esophageal atresia, renal, lower limb
  • Holt-Oram: septal defect + radial longitdinal def
  • Duane radial ray: ocular & radia/pre-axial

18

what derivatives of lateral plate mesoderm and what are derivatives of somatic mesoderm?

  • lateral plate: bone, cartilage tendon
  • somatic: muscle, vessels, nerves

19

What upper extremity findings are typically present (abnormal) in longitudinal radial deficiency?

  • Thumb: absent or hypoplastic
  • Wrist: radially deviated, flexed, pronated --> UNSTABLE
  • Forearm: radius hypoplastic or absent, ulna short + bowed
  • Elbow: STABLE, maybe stiff, hypoplasia of distal humerus is common
  • D5: normal or near normal appearance and function
  • Fibrous anlage: pre-axial bones/muscles/tendons coalesce, resulting in stiffness
  • Bones:
    • Radius: hypoplastic, partially absent, totally absent
    • Ulna: normal vs. short +/- bowed
    • Trapezium, scaphoid: absent > hypoplastic
    • Thumb Phalanges +/- absent
    • radial digits hyplastic / absent
  • Muscles
    • often absent: BR, EIP, ECRL, ECRB, thumb intrinsic/extrinsic, pronator/supinator
    • other radial sided muscles may be absent/hypoplastic
  • Nerves:
    • Radial nerve and MCN often absent
  • Vessels
    • Radial artery often absent
  • Soft tissue deficiency variable

20

What are treatment goals for radial longitudinal deficiency

  • Correct radial deviation
  • Balance wrist on forearm
  • Promote wrist and finger motion
  • promote growht of forearm
  • REconstruct thumb

21

Are there any useful non-operative interventions for radial longitudinal deficiency? Explain

  • non-op management is crucial to success of treatment
  • can be only treatment for less severe deformities
  • must be executed such that the radial deviation can be passively corrected prior to surgical intervention
  • splinting, serial casting, passive stretching

22

List some indications and contraindications to operative interventions in radial longitudinal deficiency

  • Indications
    • appearance
    • to achieve wrist stability
    • to promote greater finger movement (esp extensor)
  • Contraindications
    • medically unfit (ex: severe syndromic manifestations)
    • unable to passively correct radial deviation pre-op
    • bilateral invovlement w elbow stiffness
    • (older) patient that have adapted functionally

23

what are potential operative interventions that can be employed for severe radial longitudinal deviation?

  • treatment has 3 components after pre-operative physical therapy
  1. stabilization of the wrist
    1. centralization - ulna aligned to 3rd MC
    2. radialization - ulna aligned to 2nd MC (replaces radius)
    3. wrist arthrodesis
  2. Tendon transfers
    1. If ECRL/FCR are present but less functional - transfer to ECU
    2. ECU transfer / advancement - to restore wrist extension centrally or on 5th MC
    3. FCU transferred to extensors
  3. Soft tissue reconstruction (severe soft tissue contraction/deficiency w/ severe cases)
    1. Local or regional well vascularized flaps to cover radial wrist deficiency
  4. Considerations
    1. ulnar closing wedge osteotomy to address bow
    2. pollicization 6 mos after wrist stabilizing procedure

24

what is a characteristic defining feature between radial longitudinal deficiency and ulnar longitudinal deficiency

  • in radial deficiency, wrist is unstable but elbow is stable
  • in ulnar deficiency, wrist is stable and elbow is unstable.

25

what are associations w ulnar longitudinal deficiency?

  • 50% other MSK abnormalities
    • PFFD - proximal femoral focal deficiency; fibula def; club foot
    • spine abn (spina bifida)
    • c/l phocomelia
  • other syndromes: Cornelia de lange, schnizel syndrome - both have developmental delay

26

what clinical features are usually present or can be present w ulnar longitudinal deficiency?

  • forearm: short, residual radius is bowed radially
    • ulna can be hypoplastic, partial absent, absent
  • elbow: can be UNSTABLE, flxn contracture, ltd ROM
  • wrist: misisng ulnar carpus, ulnar deviation when severe
  • hand:
    • missing digits (ulnar MC or phalanges)
    • syndactyly
    • thumb abn including hypoplasia and contracture of 1st web

27

describe a treatment approach to ulnar longitudinal deficiency

  • similar philosphy to radial longitudinal deficiency - goal is to stabilize/centralize the wrist and hand, permit functional hand motion
  • non-operative treatment is mandatory - need PT, splints, serial casting to neutralize hand position
    • may be all that is needed
    • pre-requisite to surgical intervensions
  • operative interventions are limited
    • hand: release of any syndactyly including 1st web deepening, thumb recon (position, reconstruction)
    • forearm: correct radial bowing w closing wedge osteotomy; humoral osteotomy; consider radiohumeral fusion in severe cases

28

what is the transmission of cleft hand?

  • AD w strong variable penetrance; severity increases w subsequent generation; mutation on 7q

29

what are common associations w cleft hand?

list 1 uncommon association w cleft hand

  • common: bilaterality, uni/bilateral foot involvement, finger/toe syndactyly, CL/P
  • uncommon: cornealia de lange syndrome, ectrodactyly-ectodermal dysplasia clefting syndroem

30

in upper extremity embryogenesis, where is the abnormality thought to arise in cleft hand?

  • apical ectodermal ridge