Pes Cavus Flashcards
pes cavus is a result of what
- several structural and/or positional abnormalities
- may be congenital or developmental in origin
does the term “cavus” and “pes cavus” indicate etiologies
NO! is purely descriptive
pes cavus deformities are primarily in what plane
sagittal plane
is pes cavus only an isolated sagittal plane deformity
no
what 2 deformities are likely to result in pes cavus
- inverted calcaneus (frontal plane deformity) may result with a high arch foot type
- rigid FF valgus (frontal plane deformity) is likely to compensate via STJ supination and appear as a pes cavus foot type
how may a pes cavus foot function
either pronated or supinated
how can a pes cavus be classified
fixed or functional
can pes cavus be equated with a supinated foot type
NO!
Can occur in a pronated foot
how will a FF varus with a cavus foot deformity compensate
- pronation
- high arched, pronated foot type
radiographic findings can help differentiate between what type of pes cavus
supinated vs. structurally high arched foot
describe a lateral view of a supinated foot
- increased calcaneal inclination angle
- decreased talar declination angle
- posteriorly displaced cyma line
- plantar deviation of Meary’s line
- increased stair-step effect on MTs
- bullet hole sinus tarsi
describe a DP view of a supinated foot
- decreased talocalcaneal angle
- FF adducted on the RF
- increase FF/MT overlap
describe the lateral view of a high ached foot w/o supination
- increased calcaneal inclination angle
- decreased talar declination angle
- normal Meary’s line
- normal cyma line
- normal relationship of the MTs
describe a DP view of a arched foot w/o supination
- no FF or metatarsal adduction
- normal talocalcaneal angle
- normal relationship of the MTs
what are the different ways a pes cavus foot can be categorized
- location of deformity (apex of the deformity - high point of arch)
- co-existing deformities (ie. frontal and transverse plane deformities)
- method of compensation
- etiology
what are the different pes cavus based on location
- anterior cavus
- posterior cavus
- combined cavus
what are the different types of anterior cavus
- metatarsus cavus
- lesser tarsus cavus
- forefoot cavus
describe the appearance of a metatarsus cavus (anterior cavus)
- the apex of the deformity is located as Lis Franc’s joint
- dorsal prominence may be palpated at that joint, particularly in the area of the 1st metatarsocuneiform joint
- the talus, navicular and cuneiforms will all be collinear
clinical appearance/symptoms of metatarsus cavus
- high instep
- 1st metatarsocuneiform exostosis
- shoe fitting is difficult (may be limited to low cut shoes; orthotic therapy is difficult due to limitations in shoe gear)
- normal cuboid angulation
- pseudoequinus may lead to pronation
- claw toes with anterior displacement of the fat pad plantar to the MT heads
describe the appearance of a lesser tarsus cavus (anterior cavus)
- the lesser tarsal bones are in a plantarflexed attitude
- a generalized dorsal prominence may be noted in the lesser tarsal area
what is a variant of a lesser tarsus cavus foot
plantarflexed 1st ray
describe the appearance of a FF cavus (anterior cavus)
- FF is plantarflexed at Chopart’s joint
- RF will appear to be in a dorsiflexed position
- dorsal prominence of the talar head may be present immediately anterior to the medial malleolus noted on an off-weight bearing exam (as a result of anterior impingement which may lead to bony equinus)
- navicular, cuboid, 4th and 5th MTs are plantarflexed to the RF as compared to normal
what are 2 radiographic findings of a FF cavus
- increased calcaneal inclination angle
- increased MT declination angle
what are symptoms of FF cavus
- calcaneal apophysitis in children (decreased contact surface of the calcaneus)
- claw toes
FF Cavus Variants
- plantarflexed cuboid with plantarflexed 4th and 5th MTs
- a high arched pronated foot
- actually a type of FF varus
Radiographic findings of FF Cavus Variants
- an increased calcaneal inclination angle but no FF adduction (lateral view)
- ANTERIORLY displaced cyma line (lateral view)
- increased plantar declination of the cuboid (lateral view)
- wider talo-calcaneal angle (DP view)
- plantarflexed and adducted talus (lateral view)
symptoms of FF cavus variants
- a sagittal linear crease may be found btwn the 3rd and 4th MTs
- keratoma sub 2nd, 4th/5th MT heads
- adductovarus contractures 3rd, 4th and 5th digits
- Tailor’s Buion
- postural fatigue
- HAV
what are other FF Cavus Variants
- plantarflexed cuboid with dorsiflexed 4th and 5th MTs (more common that a plantarflexed cuboid w/ plantarflexed 4th and 5th MTs)
- no pronation is required for compensation
- if pronation is present it is as a result of other influences
clinical findings of FF Cavus Variants
- plantar prominence of the styloid process of the 5th MT
- increased arch.increased calcaneal inclination angle but no adduction of the FF
- may cause apophysitis at the 5th MT base
- Tailor’s bunion/splat foot appearance (secondary to dorsiflexed 5th ray)
describe the appearance of a combined anterior cavus
- the FF is plantarflexed in 2 or more areas (tarsal-MT, lesser tarsal/ Chopart’s)
- both anterior and posterior cavus are present
- Rarest type
what is posterior cavus
-an isolated posterior cavus rarely exists (ie. untreated ruptured Achilles tendon), but instead the increased calcaneal pitch is more likely to be a result of plantarflexed attitude of the FF
what may cause a posterior cavus
- a result of pseudoequinus
- possibly as a result of intrinsic muscle spasticity (abductor hallucis?)
- may be a congenital deformity
combined/global cavus are often used interchangeable with
anterior pes cavus
pes cavus structural deformities are not associated with what
MTJ supination compensation
acquired and congenital forms of pes cavus are associated with what
MTJ supination (adduction of the FF)
acquired and congenital forms of pes cavus are not associated with what
- structural
- not limited to sagittal plane deformities
Etiologies of pes cavus
- congenital
- infectious
- neoplastic
- neurogenic
- traumatic
- biomechanical
- iatrogenic
- endocrine
- musculoskeltal
describe the congential etiologies of pes cavus
DON’T MEMORIZE
Spinal cord disorders (myelodysplasia, spina bifida with or without meningocele, myelomeningocele, etc.)
Familial degenerative nerve disease (Charcot-Marie-Tooth, Freidrich’s ataxia, Roussy-Levy syndrome)
Dejerine-Sottas syndrome (hypertrophic interstitial neuropathy)
Cerebral palsy
Muscular dystrophy
Congenital syphilis
Congenital deformity that may or may not be associated with neurogenic causes: talipes equinovarus (clubfoot),metatarsus adductus, etc.
describe the infectious etiologies of pes cavus
- poliomyelitis (viral)
- syphilis (bacterial)
describe the neoplastic etiologies of pes cavus
- benign tumors pressing on the lumbar-sacral nerve roots
- malignant tumors (rare) pressing on the lumbar-sacral nerve roots
describe the neurogenic etiologies of pes cavus
noncongeital neurological disease
describe the traumatic etiologies of pes cavus
- head injuries
- isolated nerve injuries
describe the biomechanical etiologies of pes cavus
plantarflexed 1st ray (rigid)
- uncompensated RF varus
- rigid FF valgus
describe iatrogenic etiologies of pes cavus
- prolonged bed rest
- overcorrected flatfoot surgery
describe endocrine etiologies of pes cavus
diabetes mellitus - intrinsic muscle weakness
muscle imbalance
- pes cavus deformities are assocaited with muscle imbalance, particularly when associated with neurological deficit
- both spasticity and true weakness may be associated with pes cavus
what is tonic spasticity
- increased tone in the muscle belly
- associated with guarding due to pain (protective mechanism)
- exhibit a “cogwheel” release
what is clonic spasticity
- generally associated with upper motor neuron deficit
- resistance may gradually relax with manual pressure
why is it important to differentiate between tonic and clonic spasticity
-important when considering bracing for the deformities
posterior weakness
- triceps weakness
- triceps spasticity
- tibialis posterior spasticity
triceps weakness
- decreased pull on the calcaneus may lead to increased calcaneal inclination angle
- substitution by the deep posterior group may lead to STJ supination and digital deformities
triceps spasticity
may lead to toe-walking
tibialis posterior spasticity
-may lead to constant and increased supination at the STJ
global anterior weakness
- may lead to overpowering of the superficial and deep flexors
- leads to eqinus of both the ankle and the FF
isolated muscle weakness
- result depends on how much muscle is involved
ex. the peroneus longus and tibialis anterior are antagonists. If the tibialis anterior is weak, the peroneus longus will have an unopposed pull at the first ray causing a stronger plantarflexory pull
lateral (PL) spasticity
increased plantarflexory pull on the 1st ray
function on intrinsic muscles
-act to stabilize the digits
what happens in the intrinsic muscles are weak or spastic
- digits will become dorsally contracted
- MT will then become increasingly plantarflexed, contributing to a cavus deformity
intrinsic weakness or spasticity are commonly found in what type of patient
diabetics with neuropathy
how do you compensate for a pes cavus foot type
-depends upon the location of the deformity, other associated pathology and the rigidity of the deformity
what 4 changes will occur in a pes cavus foot
- dorsal contraction of the digits
- plantarflexion of the MTS
- relative dorsiflexion of the FF on the RF due to GRF
- pseudoequinus
when are plantarflexed MTs generally present
regardless of the location of type of cavus deformity the MTs are generally plantarflexed
when is the (Paulos-) Coleman Block test used
- used to distinguish whether or not the RF position is fixed or as a result of the FF deformity
- determine whether or not an inverted RF is as a result of a plantarflexed 1st ray
how is the (Paulos-) Coleman Block test performed
-the pt stands on a block with the FF hanging off the edge
-if the RF deformity is reduced, then the RF position is flexible and may be a result of the FF deformity
OR
-the same procedure is used except that the 1st ray is hanging off of the block
treatment
b/c we are not talking about one specific entity, we cannot give one specific method of treatment
for a neurological or neuromuscular underlying pathology what needs to be addressed before treatment can commence
- determine if progressive
- take any associated muscle imbalances into consideration
- treatment may range from orthoses and shoe modifications to bracing to surgical procedures
what other treatment options are avaiable
- surgical procedures
- may include fusions (particularly if the deformities are progressive)
- osteotomies
- muscle/tendon surgeries to transfer or realign the muscle pull
describe tendon transfers
- at least 1/2 to 1 full muscle grade will be lost
- the tendon may or may not be transferred “in phase”
with claw toe deformity and plantarflexed MTs, where is the fat pad likely to be displaced
-anteriorly
what orthotic modification should be made for claw tow deformity and plantarflexed MTs
FF extensions to pad the MT heads may need to be included
pes cavus deformities are associated with what type of ankle instability
lateral ankle instability
what orthotic and shoe modification is needed for lateral ankle instability
- lateral flange on an orthosis may help prevent excessive inversion
- a lateral heel and/or sole flare on the shoe may prevent lateral instability at heel strike and mid-stance although it may force earlier and more rapid pronation
what type of bearing surface does a cavus foot have
- tripod
- excessive weight on the heel, 1st, 4th and/or 5th MTs heads
- orthoses may need to be made to increase weight bearing on the remainder of the foot
