Embryology
Picture ID
Anomalies 1
Anomalies 2
Surgery
1
100 POINTS EACH
Limb bud formation begins by ___ weeks
Hand plate visible by ____ weeks
All limb structures present by ___ weeks
Limb bud formation begins by 4 weeks
Hand plate visible by 5 weeks
All limb structures present by 8 weeks
1
300 POINTS
What is this deformity? What syndrome is it most commonly associated with?
Clinodactylyl (angulation deformity due to bracketed epiphysis at middle phalanx)
Seen in almost 80% of people with Down Syndrome
1
800 POINTS
Describe the Blauth Classification. Hint: comment on size of thumb, thenar musculature, webspace, and joints.
Classification of thumb dysplasia
Type I: Minor hypoplasia, normal thenar muscles, webspace, and carpus
Type II: Contracted webspace, underdeveloped/absent thenar muscles, unstable MP UCL
Type IIIA: Marked hypoplasia, metacarpal hypoplasia, stable CMC joint
Type IIIB: Same as IIIA with UNstable CMC joint
Type IV: "Pouce flottant" floating thumb, with vascular abnormalities, absent metacarpal, neural rings, etc
Type V: Absent thumb
1
100 POINTS
Failure of what process in utero causes syndactyly?
Apoptosis
1
200 POINTS
What is the treatment of choice for Blauth Type II-IIIA hypoplasia?
Opponensplasty + webspace deepening/tendon recon etc.
2
800 POINTS
What growth factor regulates proximodistal growth?
FGF (Fibroblast growth factor)
2
300 POINTS
Amniotic Band Syndrome
2
300 POINTS
Describe the "radial club hand" deformity.
Shortening of the forearm and radial deviation of the wrist due to hypoplasia or aplasia of radius
2
400 POINTS
What is pollex abductus?
Abnormal connection between EPL and FPL
2
100 POINTS
Where does a pollicization most often borrow from?
Index finger
3
400 POINTS
What growth factor dictates anteroposterior growth?
SHH (sonic hedgehog)
3
150 POINTS
What medication did this pregnant woman take that caused this associated birth anomaly? (BONUS 50: What was the indication for this drug in pregnancy?)
Thalidomide
Morning sickness
3
200 POINTS
What is the most common site of congenital amputation?
Proximal third of forearm (below elbow)
3
200 POINTS
Define:
simple vs complex syndactyly
complete vs incomplete syndactyly
Simple: skin involvement only
Complex: bone involvement
Complete: Fusion from webspace to fingertip
Incomplete: Fusion of webspace, does not extend all the way to fingertip
3
300 POINTS
What is the most common forearm procedure performed for ulnar deficiency?
Corrective osteotomy of the radius, to address bowing
4
DAILY DOUBLE
What growth factor regulates dorsoventral differentiation?
Wnt gradients, LMX-1, EN-1
4
500 POINTS
What is the anomaly and what syndromes is this XR MOST LIKELY to be associated with?
Radial aplasia, associated with TAR (thrombocytopenia absent radius)
This is less likely to be VACTERL, Holt-Oram, or Fanconi Anemia because thumbs are intact/normal appearing
4
200 POINTS
Define camptylodactyly
Tightness of skin, fascia, or FDS causing flexion contracture at IP joint, most often in SF
4
200 POINTS
What percentage of trigger thumbs seen in infancy will resolve spontaneously by 1 year?
30%
4
300 POINTS
What is the timing for syndactyly release?
3-9 months if there are digits of unequal length involved
Otherwise release at 1-2 years
5
600 POINTS
What is the apical ectodermal ridge and what is the zone of polarizing activity? Be specific.
AER - area of growth in proximodistal axis
ZPA- area of growth in anteroposterior/radioulnar axis
5
700 POINTS
Name the defect and what syndrome it is most often associated with?
Triphalangeal thumbs, associated with Diamond Blackfan Anemia
Also associated with Holt-Oram, Aase, and Townes-Brock syndromes
5
200 POINTS
In mirror hand, the hand is usually missing what digit?
Complete duplication of ulnar portion of hand, usually missing thumb
5
100 POINTS
What is the most common anomaly of the human hand?
Polydactyly
5
200 POINTS
What is an indication to do surgical amniotic band release early in infants?
Usually done at 1-2 years
Can be done earlier is there is impending autoamputation or necrosis