1.
3 main themes for CVT Surgery: 1. correction through staged multiple incision technique with extensive soft tissue release
2. single-staged posteromedial approach or single-stage dorsal approach
3. minimally invasive technque with casting
2.
Characteristic pattern of CVT: Rockerbottom
3.
Clinical Presentation of CVT: 1. 'Persian Slipper foot' -->
-FF that is DF & ABducted
-RF in equniovalgus
-exaggerated convex medial longitudinal column
-elevated claw lateral toes
2. bony prominence at talar head usually with thick callus formation creating rockerbottom foot shape
3. deformity is RIGID especially after 2 yo
4.
DDX of CVT?: 1. Positional calcaneovalgus--> flexible deformity-foot DF'ed & everted, often tangential against leg
2. Posteromedial bowing of tibia --> forces foot to compensate in overpronation
3. congenital absence of fibular --> lack of structural buttress at ankle mortise -lead to ankle valgus that may mimic flatfoot deformity
4. congenital oblique talus --> contracture are suppler & more reducible, the TN joint is reduced upon PF of FF against RF
5. idiopathic flatfeet
5.
Describe how NAVICULAR is in CVT: -navicular displaces dorsolateral on the talar head & neck
-becomes more wedge-shaped & hypoplastic at is plantar aspect
6.
Describe how TALAR HEAD is in CVT: -talar head becomes flattened dorsally & articular surface expands to accomodate the displaced navicular body dorsally
7.
Describe single-staged posteromedial appraoch: Seimon's technique uses single dorsal approach to release EHL, peroneous tertius & TNJ
Then...
reduction & pinning of the TNJ & percutaneous achilles tendon lengthening
GOOD: good correction of plantar grade, painless feet after ~41 months
8.
Describe the first theme: correction through staged multiple-incision technique: 1. 1st stage = lengthening EDL, EHL, & TA tendons, release of vestigial TC ligament with TNJ & CCJ capsulaotomies through dorsal incision
2. 2nd stage = Achilles tendon lengthening with posterior ankle & STJ capsulotomies through posteromedial incision
BAD: high complication rates- stiffness, weakness, AVN of talar head, pseudoarthrosis, skin sloug, wound necrosis
9.
Describe the ligaments within the midtarsal & rearfoot region: -ligmanets within midtarsal & rearfoot become ATTENUATED OR CONTRACTED overtime depending on relationathip to the displaced osseious structures
10.
Describe the minimally invasive sx + casting: Dobbs et al: approach involves percut pinning of TNJ after manual manipulation based on Ponsetti technique
Then...
percut Achilles tendon lengthening + casting
11.
Describe the position of the calcaneus in CVT: -calcaneus is rotated posterolaterally & there is underdevelopment & sometimes absent of anterior & middle subtalar facet with hypoplasia of the sustentaculum tali
-thus NO SUPPORT TO TALAR HEAD & THE CUBOID can often times be laterally displaced
12.
Describe what happens when the TN joint becomes dislocated: -dislocation of TN joint creates structural limitation
-talar head is trapped in a PF'ed & medial position thus there is decreased contact between the trochlea of the talar body & the tibial plafond
13.
Early RADIOGRAPHIC findings of CVT: 1. vertical talus
2. AJ in equinus
3. ABducted FF (talar bulge, concave lat column)
4. increased Kite's angle
5. increased lateral talocalc angle
14.
Epi of CVT: 1. 1/10,000 live births with ~1/2 occuring as idiopathic deformity of one or more limbs
2. 50% associated with above etiologic factors
3. MALES>>FEMALES
15.
Goal of CVT treatment?: 1. restore anatomic relationship of naviular, talus, & calcaneus asap
2. reestablish WB capacity of 1st ray
16.
How can MRI be used for CVT?: -aid in dx of CVT by allowing better viewing of cartilaginous anlage of bones esp navicular
17.
Is the deformity RIGID?: YES, esp after age 2
18.
Late RADIOGRAPHIC findings of CVT: 1. Kohler-like changes to navicular
2. anterior calcaneal beaking
3. altered CCJ surfaces
4. MT primus elevatus w/dorsal bunion (PL failure)
5. small talus
6. persisting TNJ dislocation
19.
Lateral dynamic view: -actively DF'ing & PF'ing FF
-In CVT,
max DF wil show fixed hindfoot equinus & max PF will show irreducible TNJ
20.
Ligaments that become CONTRACTED:: 1. Dorsal talonavicular
2. calcaneofibular
3. interosseous talocalcaneal
4. posterior capsules of the ankle & STJ
21.
Ligaments that become OVERSTRETCHED:: 1. ligaments plantar to the talocalcaneoavicular joint
2. calcaneonavicular (SPRING) ligament
3. anterior fibers of teh deltoid ligament
4. medial fibers of the bifurcate ligament
22.
Natural History of CVT: 1. rigid characteristics due to severe muscle imbalances, bony dislocation, & 2ndary soft tissue contractures
2. left untreated --> significant pain & disability with callus formations along medial plantar aspect where head of talus protrudes
23.
Nonsurgical tx of CVT: 1. Serial manipulation + casting to stretch anterior shin, ankle & STJ capsules, & musculotendinous soft tissues structures
*because of RIGIDITY of CVT, serial casting is not enough -- need to prepare foot for osseious & soft tissue surgical proceudre
2. manipulations= PF & inversion of FF while counterpressure applied to medial aspect of talar head -held for several minutes allowing TNJ to stretch --cast foot & change every 1-2 weeks
24.
Presentation of CVT in Children: 1. 'peg-leg' gait --> limited FF push off, no heel contact, shortened cadence
2. CVT does not delay a child's ability to walk & may often not be apparent until child starts to ambulate
25.
Primary ossification of navicular:: age 2.5-5 years
26.
Risk factors for CVT: -same as etiologies
1. CVT from acquired deformity like cerebral palsy
-cerebral palsy: mother < 20 or >40 yo, low birth weight, premature birth, male gender, multiple gestation, & intrauterine viral infection
27.
Surgical tx for recurrent deformity: 1. salvage procedures
-ST arthrodesis (in older children)
-triple arthrodesis (considered in most adolscent pt)
-talectomy (for severe deformities usually in adulthood)
28.
What angles will you check on AP VIEW?: 1 TALOCALCANEAL (KITE'S) Angle
-NORMAL in child <5 yo: 20-40 degrees
-if increased angle--> indicate hindfoot VALGUS
2. TALO-1st MET
-NORMAL: -10 to +30 degrees
29.
What angles will you check on LATERAL VIEW?: 1. talocalcaneal
2. tibiacalcaneal
3. tibiotalar (can reach 90-180 with CVT)
4. talar-1st met angle
30.
What are genetic evidence for CVT?: 1. sarcomere gene mutation in skeletal muscles associated with distal arthrogryposis
2. trisomy 18 (edwards)
3. trisomy 14 (patau)
4. partial trisomy of 12q and 16p
5. HOXD10, CDMP-1, & GDF5 mutations
31.
What happens to the peroneal reticulum & what is the consequence?: 1. Peroneal retinaculum attenultes, allowing peroneal tendons to sublux anteriorly on fibular & create a more DF pull rather than PF & evert
32.
What happens to the posterior tibialis & what is the consequence?: 1. Post tibialsis tendon is subluxed anteriorly & becomes attenuated as it passes inferior to the midfoot
33.
What happens to the superior and inferior extensor retinaculum?: 1. sup & inf extensor retinaculum become one fibrous mass which shortens course of anterior compartment tendons & increases their mechanical advantage
34.
What happens tot he triceps surae?: 1. triceps surae become broad & shortened overtime with calcaneus in everted & valgus position in accordance to Davis' Law
35.
What is congenital vertical talus (CVT)?: Rigid dorsal dislocation of the navicular ont he talar head & neck with a fixed equinus contracture of the hindfoot
36.
What is the definitive age of surgery?: 12-18 months
37.
What is the most likely pathophysio mechanism responsible for CVT?: heterogenous
1. result of arrested osseous foot development in the embryo at end of 2nd & beginning of 3rd intrauterine life
2. spinal cord lesion in early embryonic life results in muscular contractures -- eventually displacing osseous & hindfoot structures
3. CVT is associated with
-CNS conditions (arthrogryposis, neurofibromatosis, sacral agenesis, myelomeningocele,)
-chromosomal aberrations (Down's, Marfan, Patau, Freeman Sheldon, Edwards syndromes)
-acquired deformities (cerebral palsy, polio, spinal muscular dystrophy)
38.
What ist he current STANDARD OF CARE FOR CVT?: 1. INITIATING SERIAL MANIPULATION OF THE FOOT with casting in combo with EARLY SURGICAL INTERVENTION
39.
What must CVT be distinguished form?: OBLIQUE talus (milder condition)
40.
When are best results produced?: when surgery is performed prior to age 2
