Tiffany's Foot and Ankle Flashcards
(26 cards)
What is the Coleman block test?
Assesses hindfoot deformity flexibility in cavovarus foot. Place 1inch block under lateral foot. Eliminates plantarflexed 1st ray and forefoot pronation from contributing to hindfoot deformity.
- If flexible, hindfoot corrects. Correct forefoot only
- If not flexible, does not correct. Need to correct both hind and forefoot
What is the peek-a-boo heel test?
Anterior standing exam. See if varus heel peeking around ankle
How do you assess a cavovarus foot radiographically?
On AP
1. Talar-1st MT angle: forefoot adduction
2. Talonavicular angle: overcoverage
3. Talocalcaneal angle: hindfoot varus
Lateral
1. Meary’s (talar-1st MT angle): cavus
2. Calcaneal pitch: cavus
3. Medial cuneiform height
4. Sinus tarsi see-through sign
What is the talonavicular angle?
On AP XR, demonstrates navicular coverage. Angle between
- Line connecting talus articular surface
- Line connecting navicular articular surface
Normal <7deg
What is talonavicular uncoverage?
Look at talonavicular angle (normally <7deg)
Uncovered when navicular subluxed lateral on talus
Ex: forefoot abduction in planovalgus foot
What is talonavicular overcoverage?
Look at talonavicular angle (normally <7deg)
Overcovered when navicular subluxed medial on talus
Ex: forefoot adduction in cavovarus foot
What is the talar-1st MT angle on AP XR of the foot?
Axis of talus should be parallel to 1st MT axis
If not, there is either forefoot abduction or adduction
What is Meary’s angle (lateral talar-1st MT angle)?
Angle between axis of talus and 1st MT on lateral XR
Normally angle = 0, meaning they are in line
If angle apex upwards, then pes cavus
If angle apex downwards, then pes planus
What is calcaneal pitch?
On weight bearing XR. Angle between inferior border of calcaneus and horizontal
Normal = 20-30deg
Pes planus <20
Pes cavus >30
What is medial cuneiform height?
On WB lateral foot XR, height of medial cuneiform from floor
Average = 2cm
Higher in cavus, lower in planus
What are 3 radiographic methods of determining if a foot is in pes planus or cavus?
- Meary’s (Talar-1st MT) angle
- Calcaneal pitch
- Medial cuneiform height
What are 2 radiographic methods of determining if the forefoot is in abduction or adduction?
On AP XR
1. Talar-1st MT angle
2. Talonavicular angle
What radiographic angle is used to determine hindfoot alignment?
On AP XR: talocalcaneal angle
What is the sinus tarsi see-through sign?
Indicates hindfoot varus
What is Charcot Marie Tooth (CMT)?
Hereditary motor sensory neuropathy causing cavovarus foot
Autosomal dominant, PMP 22 gene
Describe the muscle imbalance in CMT (4)
- Foot intrinsic (EHB, EDB) weakness causes claw toes
- Weak tib ant, unopposed peroneus longus. Causes 1st ray plantarflexion (cavus and pronation)
Compensatory hindfoot varus - Weak peroneal brevis, unopposed tib post. Hindfoot varus no longer compensatory now
- Hand intrinsic weakness causes wasting
What are the types of CMT?
Type 1: demyelinating: slow nerve conduction. Causes cavus foot
Type 2: Wallerian degeneration. Milder. Causes flaccid foot
What is the clinical presentation of CMT? (6)
- Cavovarus foot
- Sensory deficits
- Recurrent ankle sprains
- Excessive lateral foot WB causing pain and 5th MT #
- Calluses under MT heads and lateral border
- Claw toes
What is part of your physical exam for CMT? (7)
- Neuro exam
- Coleman block test
- Peek-a-boo heel
- Gait: steppage or unsteady
- Drop foot
- Silfverskiold
- Hand: interosseous wasting
What are orthopaedic manifestations of CMT other than in the foot and hands? (2)
- Scoliosis
- DDH
What are orthotic options for cavovarus foot? (3)
- Full-length semi-rigid insole w depression for 1st ray and lateral wedge. For mild deformity
- Supramalleolar orthosis. For more severe deformity
- AFO. If equinus is also present
List the surgical soft tissue management options for cavovarus foot (5)
- Plantar fascia release. Steindler stripping: release from calcaneus
- Peroneus longus to brevis transfer
- Posterior tibial tendon transfer to dorsum of medial cuneiform
- Gastroc recession or TAL
- Lateral ankle ligament reconstruction
- Jones procedure
What is the purpose of plantar fascia release in the management of CMT?
Indicated for cavus deformity
Steindler stripping: release fascia from calcaneus
What is the purpose of a peroneus longus to brevis transfer in the management of cavovarus foot?
Indication: plantarflexed 1st ray
Transfer decreases plantarflexion force by peroneus longus
Restores eversion power