Cavus and flat foot Flashcards
CAVUS FOOT TYPE
pwards of 75% of cavus deformities
are believed to be of a neurologic
origin caused by an upper or lower
motor neuron lesion.
* The muscular imbalance produced by
these neuronal lesions often leads to
progressive debilitating deformities
requiring aggressive conservative and
surgical management.
CAVUS FOOT TYPE
MUSCLE IMBALANCE
Progressive muscular atrophy/weakness to the
peroneus brevis that allows its unopposed
antagonistic counterpart, tibialis posterior, to
plantarflex the ankle joint and invert the
calcaneus at the subtalar joint.
* As the tibialis anterior weakens, the peroneus
longus pulls the first ray and forefoot into
plantarflexion and inversion.
Digits become progressively retracted and clawed
nterior crural and intrinsic stabilizer muscle weakening
* Contractures develop at the MTPJs due to the
overpowering pull of the extensors while the long toe
flexors cause contractures at IPJs producing the classic
claw-toe deformity.
* Plantarflexion of the metatarsals due to retrograde
pressure from the clawed digits and shortening of the
plantar ligaments and fascia also contribute to the high
arched cavus appearance.
CAVUS FOOT TYPE
CLINICAL EXAMINATION
neurologic testing
should be performed to rule out upper or lower
motor neuron lesions or cerebellar dysfunction.
* EMG/NCV
* The patient’s initial presenting history may be a
concern of painful sub-metatarsal calluses and/or
recurrent lateral ankle spraining and pain/instability
WB and NWB evals to determine
flexible vs. non-flexible,
weakness, and laxity.
Frontal plane assessment:
forefoot valgus & rearfoot varus
Transverse plane:
metatarsus adductus.
Sagittal plane:
anterior, posterior or combined cavus deformity
CAVUS FOOT TYPE
CLINICAL EXAMINATION cint
Limited ankle ROM due to talar neck impingement (osseous
equinus) or due to the plantigrade forefoot requiring additional
ankle dorsiflexion during stance and gait (pseudoequinus).
* STJ ROM assessed to determine if the varus calcaneal position can
be reduced to neutral alignment.
* Coleman block tes
Coleman Block Test
Placing the foot on a one-inch block with the first
ray hanging over the edge of the block.
* If the rearfoot varus deformity corrects to a more
neutral alignment, it is considered a positional type
of deformity (forefoot driven) versus a fixed
rearfoot deformity.
Contractures to the
plantar ligaments, fascia
and intrinsic musculature produce the cavus
deformity, which typically becomes more rigid
over time.
* The forefoot may demonstrate medial, lateral
or globally plantarflexed metatarsals or rays in
the sagittal plane. T
The digits are typically rigidly
extended at the MTPJs and flexed
at the IPJs due to
muscular
imbalances resulting in extensor
substitution during the swing
phase of gait.
CAVUS FOOT TYPE
RADIOGRAPHIC EXAMINATION
The weightbearing lateral radiograph is the most
important veiw to document the degree and extent
of the cavus deformity.
Meary’s Angle:
increased talar-metatarsal
declination angle
Calcaneal inclination angle:
> than 30
Bullet-hole sinus tarsi
* Retracted non-purchasing digits
CAVUS FOOT TYPE
RADIOGRAPHIC EXAMINATION (AP VIEW)
Transverse plane involvement at the mid and
forefoot levels.
* Adductus deformities of the metatarsals or
lesser tarsus are commonly observed.
Increased splaying of the first and fifth
metatarsals are also commonly observed.
In lateral column types of anterior cavus
deformities…
pronatory joint
subluxations such as increased Kite’s and Cuboid
abduction angles are observed.
CAVUS FOOT TYPE
CONSERVATIVE TREATMENT
supportive re-
alignment therapy with necessary protective
accommodation should be utilized.
* Appropriate brace, orthosis and shoe
management may buy time for progressive
neurologic cavus manifestations until surgical
intervention becomes necessary.
Anterior Cavus Foot Type Classification
Midtarsal Joint Anterior Cavus
B. Lesser Tarsus Anterior Cavus
C. Tarso-Metatarsal Joint Anterior Cavus
“Global” anterior cavus
all of the metatarsals are equally plantarflexed and lie on the same plane (perpendicular to the rearfoot).
Lateral column cavus
greater degree of hyperdeclinationof the lateral column relative to the remaining forefoot.
Medial column cavus
greater degree of hyperdeclinationof the medial column relative to the remaining forefoot.
Compensation;ANTERIOR CAVUS
Ground reactive dorsiflexion of the hyperdeclinatedforefoot producing a posterior type of foot and limb imbalance with retraction of the lesser digits.
* Subsequent STJ pronation may occur secondary to the “pseudoequinus stress” produced.
* Lateral column cavus will cause compensatory STJ pronation due to the inverted forefoot and pseudoequinus stress. A posteromedial imbalance is produced with retraction of the 4th and 5th digits.
ANTERIOR CAVUS
* Management
Appropriate cavus heel elevation wedges.
* This may be accomplished soley with the use of higher heeled shoewear for milder cases to negate the effects of the pseudoequinus stress.
* Moderate to severe anterior cavus deformities will require combination therapy of heel elevated shoewear with orthoses with appropriate sagittal plane posting.
