Congenital Deformities
Progressive macrodactyly **Increased rate of growth in 1st years of life and tends to cease at maturity
Macrodystrophia lipomatosis progressiva
Isolated non-progressive or static macrodactyly **Growth rate is proportionate to the patient
Macrodactyly simplex congenita
What is the genetic trait of cleft foot?
autosomal dominant trait
Where is the most common location for syndactyly?
between 2nd and 3rd toes
Premature metatarsal growth plate closure
brachymetatarsia
Clinical findings of fibular hemimelia
-A leg that is moderate or significantly shorter than the other -Abnormal positioning of the knee and/or ankle -Ankle and/or knee instability -Dimpled skin over the site of the deformity
Stanitski and Stanitski for fibular hemimelia
***Fibula I - Nearly normal II - Small or miniature fibula, regardless of its position in the limb III - Complete absence of the fibula ***Tibiotalar joint and distal tibial epiphyseal morphology H - Horizontal V - Valgus (triangular distal tibial epiphysis) S - Spherical (ball and socket ankle) ***Presence of a tarsal coalition (denoted with a lowercase c) ***Number of foot rays, medial to lateral - Denoted 1-5 example: IIHc5 fibular hemimelia **know this one!!!
Achterman and Kalamchi Classification for fibular hemimelia
***based on fibular morphology Type IA: The proximal fibular epiphysis is distal to the level of the tibial growth plate with the distal fibular epiphysis proximal to the talar dome. Type IB: The proximal fibula is absent for 30-50% of its length. The distal fibula is present but does not adequately support the ankle. Type II: The fibula is completely absent. *he said this one doesn't make sense
What is the BIGGEST complaint with brachymetatarsia?
**cosmetic other complaints: -metatarsalgia -painful callus formation -contracted digit -foot wear problems
Associated Deformities with fibular hemimelia (a lot!!!)
-Fibular abnormality, ranging from minimal shortening to complete absence of the fibula -Proximal femoral focal deficiency (PFFD) -Coxa vara -Femoral hypoplasia with external rotation -Lateral patella subluxation -Hypoplastic lateral femoral condyle -Genu valgus with lateral mechanical axis displacement -Flattened tibial eminence -Short and/or bowed tibia -Ankle valgus -Ball-and-socket ankle -Absent tarsal bones -Tarsal coalitions -Absent foot rays
Possible Etiologies of macrodactyly?
-Vasomotor distrubances -Mechanical in utero mechanical abnormalities -Twisting of umbilical cord around a segment -Defective fetal position -Lymphatic defect -Local abnormalities of growth limiting factor -Localized form of neurofibromatosis
All structures are affected by macrodactyly EXCEPT?
-blood vessels -tendons
What is another name for Split-hand/split-foot malformation (SHFM) ?
-cleft foot -lobster claw -congenital central limb ray deficiency -ectrodactyly (nonspecific term for congenital absence of fingers or toes)
What are other names for fibular hemimelia?
-congenital longitudinal -deficiency of the fibula congenital absence of the fibula -aplasia or hypoplasia of the fibula -postaxial hypoplasia of the lower extremity *The name depends on the extent of the abnormality
What are the main features of cleft foot (SHFM)?
-syndactyly -median clefts of the hands and feet -aplasia and/or hypoplasia of the phalanges, metacarpals and metatarsals.
Clinical signs and symptoms of SHFM.
-unstable WB -physical pain on ambulation -painful: HAV, IPK, medial deviation of 5th toe -emotional disturbance -ulcers -shoe discomfort
What is the prevalence of cleft foot?
0.1:10,000 *very rare especially in the US
Name at least 4 syndromes polydactyl has been associated with.
1. Ellis-van Creveld syndrome 2. trisomy 13 3. tibial hemimelia 4. trisomy 21
List the steps of the formation of callus after the initiation of osteotomy in callus distraction procedure.
1. Initiation of osteotomy distraction 2. gap filled with hematoma & fibrous exudate 3. immature connective tissue 4. vascular channels appear 5. callus begins to form (3 weeks)
List 4 associated conditions of ectrodactyly.
1. cleft lip/palate 2. syndactyly/polydactyly 3. deafness 4. triphalangeal thumb
What are the two forms of ectrodactyly?
1. typical form 2. atypical form
What is the incidence of polydactyly?
1.7 cases per 1000 live births
What is the incidence of syndactyly ?
1/2000-2500 live births
What percentage of syndactyly occurs in only toes alone?
20%
Polydactyly is bilateral in _____% of cases.
25-50%
What digit is most commonly affected by macrodactyly?
2nd digit
How long does it take for the actual callus to begin to form in callus distraction procedure?
3 weeks *Longitudinally orientated fibers *Central growth zone in center of gap -Fibroblasts & chondrocytes
In polydactyly, positive family history exits in ______% of cases.
30%
In callus distraction the radiolucent growth zone is abated at ________ weeks post distraction.
4 weeks
At what age does brachymetatarsia first appear?
4-15 years old
When does corticalization occur post callus distraction?
4-6 months
What is the distraction delay in callus distraction procedure?
5-7 days
When do appendages normally separate individually?
6th and 8th weeks of embryologic development
What is the recommendation for the maximum amount of attempted correction in fibular hemimelia?
7.5-15 cm
Venn-Watson classification for polydactyly
A - wide metatarsal B - T-shaped metatarsal C - Y-shaped metatarsal D - Partial polydactyly E - Complete duplication
What is the classification system used for SHFM?
Blauth and Borish Classification **Classified deformity according to partial or complete aplasias and severity
What is the main complaint for syndactyly in the foot?
COSMETIC *emotional and psychological problems can be of great concern for patient *in the hands it can be both fxn and cosmetic
What is important to take into consideration of the soft tissue in callus distraction?
Muscles, ligaments, and NV structures must be able to accommodate the amount and rate of lengthening
Presence of one or more extra or supernumerary digits or metatarsals
Polydactyly
What is the most common type of polydactyly?
Postaxial polydactyly (lateral ray) *occurs in 80% of cases *then preaxial followed by central
What is the primary surgical goal in the treatment of SHFM?
RESTORE FUNCTION
What is the standard tx of choice for polydactyly?
Removing the extra digit by disarticulation is the standard treatment.
What is a NEW classification system for polydactyly?
SAM classification system S=syndactylism to the adjacent toe A=Angulation/deviation M=metatarsal extension graded 0, 1, 2 **looks at slide 10 of pediatric polydactyly
limb malformation involving the central rays of the autopod
Split-hand/split-foot malformation (SHFM)
failure of differentiation in which the digits fail to separate into individual appendages.
Syndactyly
Temtamy & McKusick classification for Polydactyly
Type 1-Duplication fo the 1st digit Type 2-Polydactyly of a triphalangeal 1st digit Type 3-Polydactyly of the 2nd digit Type 4-Polysyndactyly
How old should you wait to perform removal of polydactyly extra digit?
Waiting until 9-12 months of age is advisable to decrease anesthesia risk.
In prenatal dx of polydactyly, fetal phalageal buds can be seen using transvaginal ultrasound as early as _____ weeks and reliably by _____ weeks of pregnancy.
as early as 9 weeks and reliably by 13 weeks
Which ectrodactyly form is characterized as: -Isolated -Unilateral -No evidence of inheritance
atypical form
What is the treatment of choice for brachymetatarsia?
callus distraction
How is macrodactyly diagnosed?
dx based on exclusion *Must exclude other causes of digital enlargement Eg: haemangioma, lymphangioma, arteriovenous fistula, lipomatosis, neurofibromatosis, dactylitis, other tumours
true or false? It is safe to preform callus distraction on a smoker.
false
true or false? Syndactyly is more common in females than males.
false
true or false? Polydactyly is more common in whites than blacks.
false **Incidence is higher in blacks (3.6-13.9 cases per 1000 live births) than in whites (0.3-1.3 cases per 1000 live births).
True or false? In callus distraction for bracymetatarsia the patient must remain nonweightbearing during the distraction period.
false *mobilization and WEIGHTBEARING
true or false? In fibular hemimelia most often both legs are affected.
false *most often only one leg is affected
true or false? Brachymetatarsia is more common in men than women.
false! ******Female:male (25:1)
true or false? Macrodactyly is autosomal dominant in inheritance.
false! ***no evidence of inheritance
true or false? Post-axial forms of polydactyly are less common than pre-axial.
false! *pre-axial forms are less common!
true or false? Macrodactyly is usually bilateral.
false! *usually unilateral
True or false? There is one known cause for brachymetarsia.
false. possible causes: -congenital (ex: Down's syndrome) -developmental -iatrogenic -post-traumatic -idiopathic
How does the callus of callus distraction differ from a fracture callus?
fracture callus is more bulbous in shape and does NOT have longitudinal striations that callus distraction provides
What is a good treatment option for limb length discrepancy less than 2 cm?
heel lift
Ilizarov's Law of Tension-Stress
living tissue, when it is subject to slow steady distraction, can become metabolically activated in both the biosynthetic and proliferative pathways
local gigantism of one or more digits
macrodactyly
In callus distraction, preservation of the ________________ is critical to timely and efficient callus production.
periosteum
Where is a good location to get a skin graft for syndactyly procedure?
sinus tarsi
In regards to the physiology behind the callus distraction period, it causes interruption of ____________________ stage and controlled mechanical instability just prior to mineralization.
soft callus stage
What is the treatment for macrodactyly?
surgical *wat to do it early childhood before digit becomes larger than the rest *growth arresting procedures=epiphysiodesis *reduction procedures
Davis and German, 1930 is a classification system for?
syndactyly Incomplete: webbing does not extend to distal aspect of digits Complete Simple: phalanges are not involved (just soft tissue) Complex syndactyly refers to fingers joined by bone or cartilaginous union, usually in a side-to-side fashion at the distal phalanges. Complicated: phalanges are involved
What happens to the 3rd and 5th toe with a 4th metatarsal brachymetatarsia?
the 3rd and 5th toe often migrate into the area of the 4th
What is the predictive cause of macrodactyly?
thought to be caused by excessive growth of embryonic tissue
true or false? Better results have been reported if surgical treatment of SHFM is performed at an early age, 1-2 years.
true
true or false? Bilateral involvement of SHFM of the hands and feet is often associated with positive family history.
true
true or false? In fibular hemimelia males are affected twice as often as females.
true
true or false? In fibular hemimelia, the fibula can be completely missing.
true
true or false? Macrodactyly occurs more commonly in hands than feet.
true
true or false? Polydactyly has slight predilection for males over females.
true
true or false? The corticotomy is done AFTER the external fixator is in place.
true
true or false? The first metatarsal is pre-axial polydactyly and the lesser digits are considered post-axial.
true
Which Blauth and Borish Classification is described by: -normal metatarsal -aplastic lesser toes
type I
Which Blauth and Borish Classification is described by: -partial hypoplasia or synostosis of metatarsal bones
type II
Which Blauth and Borish Classification is described by: -4 metatarsals present
type III
Which Blauth and Borish Classification is described by: -3 metatarsals present
type IV
Which Blauth and Borish Classification is described by: -2 metatarsals present = LOBSTER CLAW FOOT
type V
Which Blauth and Borish Classification is described by: -1 metatarsus present (MONODACTYLOUS)
type VI
Which ectrodactyly form is characterized as: -Familial, autosomal dominant inheritance -Bilateral -Often associated with ectrodactyly of the hand
typical form
How can SHFM be detected prenatally?
ultrasound