Congenital Flashcards
Embryology
1 to 2% of Newborns - 10% upper extremity, second to congenital heart diseases and anomalies
mostly spontaneously or inherited, teratogen
26 day - embryo 4mm - Limb bud - needs only 52 days to develop the whole limb - embryo 22-24mm - 8 weeks after fertilization the whole limb is developed
mostly anamolies develop in the 4-8 week
limb bud - outgrow of the mesoderm to the overlying ectoderm
somatic mesoderm: muscle, nerve, vascular elements
lateral plate mesoderm: bone, cartilage and tendon
limb development in 3 axes
3 axes of development
proximal - distal limb development:
controlled by the AER (apical ectodermal ridge) to differntiate the underlying medoderm into appropiate structures - mostly secreted fibroblast growth factors
disturbing of this axis leads to transverse defiency - newborns have little residual nubbins from loss of AER - mostly teratogen or from ischemia - not inheritable
anterior - posterior limb development:
(radioulnar axis) - ZPA (Zone of polarizing activity) - signaling molecule is the sonic hedgehog compound
disturbance leads to duplication on the ulnar side - mirror hand
dorsal-ventral limb development
not well understood (nail on the dorsum - pulp volar) - Wnt pathway - controlled by Transcription factor, Lmx-1 - Loss of Lmx-1 leads to nail-patella-syndrome
after development of the limb - Hox and T-Box genes are crucial for limb formation
Hox - patterning for many tissues - synpolydacty - hand-foot-genital syndrome - Madelung-deformity associated with Leri-Weill-dyschondroosteosis - mostly autosoma dominant conditions
T-Box - transcription factors governing both limb and organ system development (e.g. can effect the anterior-posterior axis - cardiac defect and radial deficiency - Holt-Oram-Syndrom - is associated with the Tbx5 gene - mostly autosomal dominant - genetic counseling!!!
Syndactyly
fali of digital seperation and web space formation - from distal to proximal with a regulated apoptosis
normal web space slope 45° - second and fourth web space are wider than the third one
Incidence: 1 to 2000 Newborns - 50% bilateral
10 - 40% habe a family history with autosomal dominant trait
combination with: polydactyly, clinodactyly, brachydactyly, symphalangism and synostosis
mostly ring and longfinger - about 57% - followed by the ring- and smallfinger with 27%
isolated index and longfinger or thumb and index finger are least common - this appears within syndromic cases
Classification:
complete or incomplete - joints are usually normal - the flexor and extensor mechanism is independent
complex syndactyly is marked by skeletal anomalies - mostly the tip of the fingers with loose of the nailfold and combined nailplate
evaluation:
the whole body!!! - ultrasound - MRI - to determining the flexor tendon and vascular anatomy
Management:
Timing of surgery: release after 18month show better outcome (Flatt and Ger) - goal is to complete all releases by school age
staged treatment not to compromise the vascular situation of the finger on both sides - all finger syndactyly is performed in two stages with a break of 3 month
commissure reconstruction - proximally based rectangular flap raised from the dorsum of the syndactyly - multiple techniques to reconstruct the web space - double-opposing Z-plasty or butterfly flap for mild degrees of web deepening - no graft to the web space - SCARRING!!!
first web space is a special problem and varies in extent - mostly syndromic cases - such as Apert Hand - four-flap Z plasty, transposition flaps from the radial and ulnar border of the index finger or thumb
seperation and resurfacing of the digits
basis is the Cronin technique with a combination of palmar and dorsal triangular flaps with matches zigzag incisions on both surfaces of the conjoined digits
identify the neurovascular bundles - if the common nerve and arteria is to distal maybe cutting of one arteria, vene graft or limited reconstruction, reconstuction with thickness skingraft (less contracture than split skingraft) - maybe skin from the dorsum of finger and hand with mild syndactyly
paronychial nail fold
narrow triangular flaps from the hyponychium are raised to form a nail fold on both sides
complications:
vascular compromise, infection, wound dehiscence and graft loss - always tension free wound closure - scar contraction in web space
special cases of syndactyly
Acrosyndactyly
distal fusion of digits with proximal fenestration - typical for contriction ring syndrome
50% bilateral and 50% with absence of fingers
staged procedures, often difficult, amputation of atrophic fingertips, reconstruction with vy-plasty and skin graft
Apert’s Syndrome
bicoronal craniosynostosis and midfacial hypoplasia with severe complex syndactyly of the hand and feet
mutation in the fibroblast growth factor receptor type 2 gene
maybe abnormalities of elbow and shoulder
simple syndactyly between ring- and small finger, complex syndactyly between the index-, long- and ring finger, IP Joints are stiff in the central rays, radial clinodactyly of the thumb
severe case all fingers are growth together - rosebud
capitohamate coalitio and synostosis MHK IV and V is common
upton classification
type I - spade hand - first web incomplete simple - fourth web incomplete simple
type II - spoon hand - first web complete simple - fourth web complete simple
type III - rosebud hand - first web complete complex - fourth web complete simple with synostosis of metacarpals
surgery goals:
adequate first web space - with position the thumb in 45° abduction - maybe 4 “Z”-plasty - correct the clinodactyly with a open wedge osteotomy and bonegraft - groin flap for first web space - microsurgery is possible
long fingers - from rosebud to spade hand (avoid ingrow of nail plates to the neighbor fingers - than staged careful seperation of the fingers
symbrachytactyly
short webbed digits - occurs sporadically and may be a feature of the Poland’s syndrome - absence fingers or normal fingers - normal fingers have syndactyly
Poland’s syndrome
disruption of blood flow in the subclavian artery in the embryo - spectrum of hypoplastic anomalies are produced
- aplasia of the sternal head
- aplasia of the pectoralis major
- brachydactyly of D II, II and IV
- aplasia of the pectoralis minor and latissimus dorsi
- hypoplasia of the hand
- skeletal thoracic wall anomalies
mostly the middle fingers are involved - undersized middle phalanx
Dystrophic epidermolysis bullosa
not really a congenital syndactyly - consequence of scarring of the squameous epithelial surfaces from this blistering conditions - loss of normal adhesion of the various laminae of the skin - different severe grade
Polydactyly
radial and ulnar
can occur preaxial (radial) or postaxial (ulnar)
postaxial is often inherited in african and african americans - prevalence 1 to 143 newborns
preaxial more in white population - but only prevalence from 1 to 1339 newborns
postaxial polydactyly often with white population in a syndrome (Ellis-van-Creveld syndrome)
supernummerary finger can be well developed (Type A) or just rudimentary and pedunculated (Type B)
surgery:
elliptic incision - good exposition - transfer the abductor digiti minimi to the ulnar finger
central polydactyly
uncommon in comparison to border polydactyly - ringfinger is the most duplication - followed by the longfinger and the index finger
occurs in isolation or as a part of a syndrome (Grebes’ chondrodysplasia) - often symptoms of a polysyndactyly in a complex matter
treatment is very difficult and depends on the complexity of the anomaly - a fully developed finger with full function does not require removal - seperation of the syndactyly - than removing the redundant bone - combination of osteotomy and resection to gain the correct alignement - complicated connections may better be left untreated than seperated into individual digits with limited motion and instability
Mirror hand
rare congenital anomaly characterized by symemetric duplication of the limb in the midline - one central digit with 3 digits on both sides mirrored - the thumb is absence - the radius is missing - therefore are two ulnae
classificated by Al-Quattan
- ulnar dimelia - multiple fingers with two ulnae
- intermediate form - multiple fingers with two ulna and one radius
- intermediate form - multiple fingers with one ulna and one radius
- syndromic form - bilateral mirror feet and nasal defects
- multiple hand - complete duplication of the hand with the thumb - forearm is normal
etiology
replication of the signaling center - “Zone of polarizing activity” (ZPA) - sonic hedgehog protein is transplanted
surgery
reduce number of digits to normal and create a thumb - the most radial finger undergo pollicization - the stiff radial fingers are removed
Brachydactyly
short finger - one part of the skeleton is reduced in size -
occur in isolation or with a numbers of syndromes - or as a consquence of a trauma -
Kellam’s classification
- generalized brachydactyly
- underdevelopment of the distal phalanges
- A3 brachydactyly
- D brachydactyly
- brachydactyly with metarcarpal shortening
- brachydactyly with short first metacarpal
- brachydactyly with polydactyly
- brachydactyly with syndactyly
- brachydactyly with cone-shaped epiphyses
- miscallneous
condition with autosomal dominant pattern of inheritance - after trauma - spontaneous - after infection - frostbite -
clinic:
most affected the middle phalanx, small and index finger are mostly affected
surgery:
one stage lengthening with osteotomy and soft tissue release - transversal ligaments and interosseus muscles - interposition of bonegraft and fixation with k-wires
alternative a gradual lenghtening with a distraction frame could be used - duration of about 4 month to achieve 1,5cm - pin intramedullar for alignement
cave: only surgery if necessary - when there is good function - no surgery - joint stiffness and other postoperative problems can occur - one stage procedure when there is an angulation in the bone (open wedge osteotomy with trapezoidal bone graft)
when distraction - begin after 4 - 7 days after osteotomy with 0.25 to 0.5mm twice a day - frame stays in position until bone is healed - digital physiotherapy for ROM
central hand deficiencies
so called “cleft hand” are longitudinal defiencies affecting the central digits
v-shaped cleft in the middle of the hand - may or not with absence of fingers
etiology:
belongs to the apical ectodermal ridge - where the central part degenerates with the ulnar and radial segment left intact (dactylaplasia mouse - from Ogino and collegues) - genetic reason or teratogen
often autosomal dominant trait and involved in a numbers of syndromes
- split-hand/split-foot syndrome (SHSF)
- ectrodactyly, ectodermal dysplasia and cleft lip/palate (EEC)
clinic:
unilateral or bilateral with hand and/or feet - severe cleft hands with only the ulnar finger - syndactyly to the border fingers at the cleft is common - first web space is narrowed - there are a number of pathologic bone anomalies
Classification
Manske and Halikis
- I normal web
- IIA midly narrowed web
- IIB severely narrowed web
- III syndactylized web with index finger
- IV merged web - index ray suppressed - thumb web space merged with the cleft
- V absend web - thumb elements suppressed - ulnar rays remain, thumb web space no longer present
indications for surgery:
“functional triumph - social disaster” - often cleft hands are very functional for children - surgery always should improve function
indications:
- progressive deformity (removal of transverse bones)
- deficient first web space (syndactyly seperation to prevent deviation of the longer ray - new skin to the web space)
- deformity of the cleft
- absent thumb
- the feet
transposition of D II to the base of the missing D III than fixation to the metacarpal D IV - diamond-shape flap to reconstruct the first web space (so called snow-littler-procedure - very difficult from flap design and reconstruction) - sew the A1-pulleys to reconstruct the transverse metacarpal ligament
other methods by Miura and Komada, Upton
Ueba’s technique with reconstruction of the cleft with a tendon graft
many surgery procedures can wait until the child is 1 or 2 y old
absent thumb deformity
type V cleft hand - first goal - often only a toe transfer can help, when there is no radial digit - if there is radial digit this has to be rotated and bring in opposition because the radial digit is often in the plane of the long fingers
absence of fingers
maybe in transverse or longitudinal direction -
transverse deficiency - ring constriction syndrome, symbrachydactyly and idiopathic transverse absence - proximal structures of the ray are there
longitudinal deficiency - radial deficiency - ulnar deficiency or central deficiency
constriction ring syndrome
constriction around the limbs or digits - acrosyndactyly, terminal absence and localized swelling with digital edema to the constrictions
etiology
amniotic disruptioin with release of amniotic bands - strangling the digits
complete or incomplete with or without acrosyndactyly - proximal structures are normal
classification by Patterson:
1 - simple constrictions
2 - ring accompanied by distal deformity, with or without edema
3 - rings accompanied by distal fusion, acrosyndactyly
4 - amputation
Management:
fetoscopic release of the constriction if the limb is in danger to loss
nerve palsies:
decompression if there is a nerve is successful
constriction ring:
Z-plasty or w-plasty - maybe in staged procedure in 2 times
acrosyndactyly:
techniques from the syndactyly - difficult to perform and individual planning is important
skin protuberance:
mostly seen on the dorsum of the fingers - Z-plasty is often unsatisfactory - exision plus resurfacing with full-thickness skin graft is preferred
symbrachydactyly
fused short fingers
blauth and gekeler classification:
1 - short finger type
2 - cleft hand type
3 - monodactylous type
4 - peromelic type
classification from Yamauchi:
1 - triphalangia type
hand with no missing bone - all four fingers have three phalanges, even though some phalanges are short
2 - diphalangia type
hand in which one phalanx (usually the middle) is missing in one or more digits
3 - monophalangia type
hand that has a finger or fingers with only one phalanx
4 - aphalangia type
hand in which all three phalanges are missing in a digit or digits
5 - ametacarpia type
hand with absence of a metacarpal bone, as well as three phalanges, in a digit or digits
6 - acarpia type
hand with absence of all digits and partial or complete absence of the carpal bones
7 - forearm amputation type
arm with absence of the distal portion of the forearm - usually there are rudimentary digits on the stump
occurs sporadically - in association with poland syndrome - the central deficiencies form of symbrachydactyly was previously called atypical cleft hand - but it is a transverse deficiency not a longitudinal deficiency - is a mesoderm problem - therefor the ectodermal rudimantary structures are present as “nubbins” or “buds” - (pulp, nail fold and nail)
anatomy:
in the mild forms (types 1, 2 and 3) mostly the skeletal elements are most affected - the middle phalanx are reduced in size or absent
more severe types (type 4) - central ray disappear - finger nubbins with aponeurotic attachements to extrinsic tendons around the end of the hypoplastic metacarpals - 5. ray and thumb are there in different variations - flexor and extensor system is grown - with a rudimentary extrinsic flexor system - free toe transfer is possible
monodactylic or single-digit (Type 5) - anatomy is widely abnormal - especially the tendons extensor und flexor - difficult to treat - toe transfer
type 6 and 7 no useful intrinsic muscles - nerve abnormalities are common - radial nerve always present - wrist motors are present - flexor and extensor tendons of the fingers have minimal excursion
treatment:
types 1,2 and 3
function usually excellent - maybe syndactyly seperation is needed - when there is instability because of hypoplastic bone than a phalangeal bone graft is necessary
types 4
nubbins have no function - nails can cause local irritation and infection because of paronychial deformity - mostly pincher grip between the 1. and 5. ray - prehension can be improved with osteotomy of the middle metacarpal bones - lengthening of the web space with local flaps - additional toe transfers can perform because the tendons are functional - controversial if there is a good grip between small finger and thumb - 2 toe transfers are better because of grip strength - grasp large objects - with subsequent benefit in function
type 5
free toe transfer - difficult to treat because of the tendons - 2 toe transfers are possible - improve function
type 6 and 7
limited proximal structures - vascularized toe transfer to the radial side of the forearm
