Foot & Ankle Flashcards
What physcial exam finding do you expect after plantar fasciitis rupture that was not their prior?
Pes planus deformity from loss of the medial longitudinal arch.
What percent of infected total ankle arthrolasties that require explantation and abx spacer succesfully undergo component reimplantation?
Myerson et al reported only 16%.
This was because of extrensive bone loss from debridement, persistent infection, and risk of recurrent infection.
4 weeks defines as the turning pint for aute vs chronic.
How long should non-operative treatment be given for a zone 2 metatarsal base fracture before considereing operative treatment in a non-elite athlete?
6-8 weeks.
What is the most common complication of a Weil osteotomy?
Floating toe or MTP dorsiflexion contracture.
Resultes from altered mechanics where interossei go from plantarflexors to dorsiflexors.
What is ideal dorsiflexion after a 1st MTP fusion?
10-15 degrees.
What hindfoot deformity is seen after calcaneus fracture?
hindfoot varus.
How may calcaneonavicular tarsal coalitions be inherited?
What syndromes may the be present in?
Autosomal dominant
Apert syndrome or FGFR-associated craniosynostosis
What is the optimal positing for an ankle arthrodesis?
Plantigrade
10 degrees of external rotation
5 degrees valgus
5mm of posterior positioning of the talus on the tibial plafond. This decreases the lever arm of the foot during gait
How does your treatment change for an adult with a cavovarus foot that does not correct with Coleman block test vs when it does correct?
Corrects= flexible. 1st metatarsal dorsiflexion osteotomy.
Doesn’t correct= stiff. Triple arthrodesis, lateral calcaneal slide or closed wedge osteotomy.
How do you test the competency of the ATFL?
Anterior drawer in 20 degress of plantar flexion.
Compare to uninjured side.
Forward shift of more than 8 mm on a lateral radiograph is considered diagnostic for an ATFL tear.
What ligament is injured when the ankle is inverted in neutral dorsiflexion?
Calcaneal Fibular Ligament
How do you perfrom a talar tilt test?
What does it test for?
On AP of ankle measure the angle formed by tibial plafond & talar dome while an inversion force is applied to hindfoot.
< 5 degrees is normal for most ankles.
Useful to evaluate for combined injury of both ATFL and CFL ligament
Inversion test with ankle in slight dorsiflexion is best for CFL ligament alone.
What are the differences between the superficial and deep layers of the deltoid ligament?
SUPERFICIAL- Crosses both ankle and subtalar joints.
Originates from anterior colliculus and fans out to insert into the navicular neck of the talus, sustenaculum tali, and posteromedial talar tubercle.
DEEP- Corsses only ankle joint.
Functions as the primary stabilizer of the medial ankle.
Originates from inferior & posterior aspects of medial malleolus and inserts on medial nad posteromedial aspects of the talus.
What is another name for the calcaneonavicular ligament?
Spring ligament
attaches from the sustentaculum tali to the inferior aspect of the navicular.
Injury leads to flattening of the medila longitudinal arch.
What motion leads to locking of the transverse tarsal joint?
Inversion of the subtalar joint. Allows for a stable hindfoot/midfoot for toe-off.
Eversion of the subtalar joint unlocks the transverse tarsal joint. Allows for a supple foot to accommodate ground just after heel strike.
What are the three layers of the tarsometatarsal joint?
Interosseus layer- contains the lisfranc ligament. Strongest layer.
Plantar layer. Next strongest
Dorsal layer. Weakest layer
What is the first nerve the lateral plantar nerve?
What does it innervate?
Baxter’s nerve
Abductor digiti minimus
What nerves provide sensation to plantar foot?
Where is the most reliable location to test sensation from the sural nerve?
4th web space.
Provided by sural nerve 70-80% of the time.
Sural nerve at risk with extensile lateral approach to calcaneus, screw palcement for 5th metatarsal stress fracture, and achilles tendon repair especially percutaneous.
Injury to the deep peroneal nerve which can happen in trauma or charcot marie tooth will lead to weakness where?
Weak or absent EDB and EHB.
What nerve is at risk with bunion surgery?
Medial branch of superficial peroneal nerve.
Vulnerable on dorsomedial aspect of hallux.
Where does the lateral cutaneous branch of the superficial peroneal nerve exit the deep fascia?
12-15cm proximal to the tip of the lateral malleolus.
What is another name for an accessory navicular?
Os tibiale externum
Second most common ossicle in the foot/ankle after os trigonum
What is the most common sesamoid in the foot besides the hallux sesamoids?
os peroneum
located in the peroneus longus tendon.
Where is the os trigonum in relation to local anatomy?
Lateral to FHL, tibial nerve, PTT, and posterior tibial artery.
What is the etiology of a os trigonum?
This secondary ossification center forms posterior to the talus between 8-13 yrs.
Normally fuses with talus within 1 yr of froming.
If the ossicle fails to fuse it articulates with the talus through a synchondrosis.
What is a shepherds fracture?
Fracture of the posterior process of the talus.
What is an os vesalianum?
secondary ossicle at lateral base of 5th metatarsal
What should you be concerned about if there is a large amount of diastatis between an os peroneum and pain?
Peroneus longus rupture along with os peroneum fracture.
Where is the center of gravity in the body?
In standing position it is 5cm anterior to the S2 vertebral body.
What is a hopkins test used for in foot and ankle injuries?
Also known as the squeeze test.
Compression of tibia and fibula at midcalf level causes pain at syndesmosis.
What is the incidence of posttraumatic tibiofibular synostosis after Weber C ankle fractures?
10%
Surgical excision should only occur after long perior of failure to respond to non-surgical management and ossification must be “cold” on bone scintigraphy.
Describe the classifications of low ankle sprains.
Anterior drawer of the anlkle in plantar flexion tests what?
In dorsiflexion?
ATFL
CFL
Describe the Ottawa Ankle Rules?
What treatment is recommended after a grade III low ankle sprain?
Grade 3 = Complete tear of ankle ligament. Severe pain with weight bearing. Significant ecchymosis and swelling.
May benefit from a period of immobilization and non-weight bearing but should not last for longer than 10 days. Early motion leads to better recovery.
Once swelling has subsided and patient have full ROM they should begin neuromuscular training with a focus on peroneal muscles strength and proprioception training.
Functional brace to be used during strengthening phase of recovery.
What is the Gould modification?
Shortening and reinsertion of the ATFL and CFL are reinforced with inferior extensor retinaculum and distal fibular periosteum.
Most common cause of chronic pain after an ankle sprain is?
Missed injury, can include:
Missed fractures
Osteochondral lesion
Peroneal tendon injury
Syndesmosis injury
Tarsal coalition
Impingement syndromes
What is return to play after Grade 1-3 Ankle sprains?
High ankle sprain?
What is the usual mechanism of forces that cause a lisfranc injury?
Indirect rotational forces and axial load through hyperplantar flexed forefoot.
Hyperflexion/compression/abduction moment exerted on forefoot and transmitted to the TMT articulation.
Metatarsals displaced in dorsal/lateral direction.
What ligaments have to be disrupted for their to be transverse midfoot instability?
interosseous first cuneiform-second metatarsal ligament (lisfranc’s ligament) and plantar ligament between the first cuneiform and the second and third meatarsals.
What should you be concerned for when you see medial plantar brusing?
Lisfranc injury.
What lisfranc injuries can be treated non-operatively?
Sprains with no displacement on weight bearing or stress radiographs.
No evidence of bony injury on CT.
These are usually dorsal sprains.
8 weeks of cast immobilization.
Where do you make an incision to expose the 1st TMT joint?
inbetween 1st and 2nd metatarsal fro skin incision.
Joint exposed between EHL and EHB tendons.
What is the recommended postoperative care after ORIF of Lisfranc injury?
NWB for 6 weeks at least.
Gradually advance to full weight bearing at 10-12 weeks.
Early midfoot ROM
Not able to return to competitive sports for 9-12 months.
Where is a common stress fracture in ballet dancers?
base of 2nd metatarsal.
What other things should be evaluated in a healthy individual who has a foot stress fracture?
Look for associated foot deformity
Consider metabolic evaluation
What is implicated in the formation of interdigital neuromas?
distal intermetatarsal ligaments
Condition otherwise known as a Morton’s neuroma
When do you consider operative fixation of metatarsal fractures that have no TMT joint involvement?
Any displacement of the first metatarsal as there is no intermetatarsal support and it bears 30-50% of the weight.
CENTRAL METATARSALS: Sagittal plane deformity more than 10 degrees. >4mm translation. Multiple fractures
What is the risk of malunion in metatarsal fractures?
transfer metatarsalgia.
plantar keratosis.
Treat with osteotomy to correct deformity.
What inserts on the tuberosity of the 5th metatarsal?
Peroneus brevis and lateral band of plantar fascia insertion
Peroneus terius inserts on dorsal metadiaphysis
What is the blood supply to the base of the 5th metatarsal?
What zone is most prone to nonunion?
Zone 2 (true jones fracture) represents a vascular watershed area making these fractures prone to nonunion.
What mechanism typically lead to fractures in each of the 5th metatarsal base fractures?
Zone 1- plantarflexion and hindfoot inversion
Zone 2- Forefoot adduction
Zone 3- Repetitive microtrauma
Zone 3 metatarsal fractres are associated with?
cavovarus foot deformities.
Sensory neuropathies.
Stress fractures in athletes.
What should be evaluated on physical exam in patients with 5th metatarsal base fracture?
Lateral ligamentous instability
Whether there is any hindfoot varus and whether the hindfoot is correctable.
Peroneal tendon weakness
What are the union rates after IM screw for 5th metatarsal base fractures?
Approaching 100%
How long should zone 2 and 3 fractures be NWB in non-athletic individuals?
Use of extracorpeal shock wave?
Until signs of radiogrpahic callus.
More than 6 weeks for Zone 3 fractures.
Has not been show to improve or speed up union rates.
What is the post-operative protocol after IM screw fixation of 5th metatarsal fractures?
3 weeks NWB.
3 weeks of PWB with therapy focused on ROM.
Running and impact activites can begin to commence at 6 weeks if surgicla stie pain free and signs of radiographic callus.
Rate on nonunions in zone 2 5th metatarsal fractures?
15-30%
33% risk of refracture in those treated non-operatively
What is the mechanism for:
navicular tuberosity fracture?
Naviuclar body fractures?
Eversion with simultaneous contraction of PTT
May represent an acute widening/diastasis of an accessory navicular
Axial load
What is Mueller-Weiss syndrome?
Spontaneous navicular AVN
Rare
Seen in middle aged adults with chronic midfoot pain
Describe the Sangeorzan Classification of Navicular Body Fractures?
What are indications for ORIF of navicular fractures?
Avulsion fractures invovling > 25% of articular surface
tuberosity fractures with > 5mm diastais or large intra-articular fragment
Displaced or inta-articular Type I and II body fractures.
Type 3 body fractures (comminution) treated with ORIF then followed by ex-fix or primary fusion
How do you treat end stage AVN of the navicular?
Fusion of talonavicular and naviculocuneiform joints
Need to maintain or restor lateral column length.
Where is the arcuate artery?
Vascular arch that runs in the dorsal midfoot deep to the extensor tendons.
gives off dorsal metatarsal arteries that run in the 2nd, 3rd, and 4th intermetatarsal spaces.
What is the blood supply to the heel pad?
Posterior tibial artery -> Lateral plantar arterires -> medial calcaneal branch
Describe the muscle deforming forces for the following deformities.
Also describe the muscles that is weak.
What is the most common foot deformity following a stroke?
Equinovarus foot.
Use AFO and physical therapy for at least 6 months to await neuro recovery.
Overactivity of the tibialis anterior, with contributions from the FHL, FDL, and tibialis posterior.
What is the surgical treatment for a equinovarus foot?
Split anterior tibial tendon transfer (SPLATT).
Flexor hallucis longus tendon transfer to the dorsum of the foot and rleease of the flexor digitorum longus and brevis tendons at the base of each toe.
Gastrocnemius or achilles lengthening.
What treatment is recommended for a chronic foot drop?
Posterior tibial tendon transfer to lateral cuneiform +/- gastroc or Achilles tendon lengthening.
Where does an achilled tendon rupture most commonly occur?
In the hypovascular region 4-6cm above the clacaneal insertion.
What are the outcomes for the following when comparing achilles tendon ruptures treated with fuctionla bracing/casting in resting aquinus vs Operative repair:
Plantar flexion strength?
Risk of re-rupture?
Complication rate?
equivalent strength.
Generally thought to be increased risk of rerupture but this has not been found to be significant if functional rehabilitation is used.
Fewer complications than operative treatment.
When should VY advancement be considered for achilles tendon ruptures?
FHL transfer?
Chronic ruptures with defect < 3cm.
Chronic ruptures with a defect > 3cm. Requires a functioning tibial nerve.
Where is the sural nerve relative to the achilles tendon?
Lateral
So make incision just medial to achilles tendon for repairs.
Sural nerve injury higher with percutaneous repair.
What is the incidence of wound healing problems in achilles tendon repairs?
Risk factors? Which is most common?
5-10%
Smoking most common. Female gender, steroid use, and open technique.
Why may there be a delay in dianosis after an anterior tibial tendon rupture?
Because a patient my have intact dorsiflexion due to function of the EHL and EDL muscles.
Should compare strengh to contralateral side.
What is a steppage gait?
Where the hip is flexed more than normal in the swing phase to prevent toes and foot from catching due to a drop foot.
For how long should a direct repar as oppossed to a reconstruction be attempted for a tibialis anterior rupture?
< 6 weeks
Can be attempted up to 3 months but usually will require reconstruction after 6 weeks.
Some residual weakness is expected.
What other surgical procedure may need to be done to protect the repair of a tibialis tedon and optimize motion at the ankle?
Gastrocnemius recession
If less than 5 degrees of ankle dorsiflexion with the knee extended.
What are the options for a tibialis tendon reconstruction?
Sliding tendon graft- where one half of the tibialis anterior tendon is turned down to span the gap. Secured to medial cuneiform or dorsal navicular.
Interposition of autograft (hamstring or plantaris) or allograft.
EHL tenodesis or transfer- distal EHL tenodesed to EHB. Proximal EHL used as tendon graft to repair tibialis anterior insertion
What mechanism usually leads to peroneal tendon subluxation or dislocation?
Rapid dorsiflexion of an inverted foot leading to rapid reflexive contraction of PL and PB tendons.
Which peroneal tendon is usually involved in degenerative tears?
peroneus brevis
At the level of the fibular groove.
Brevis is anterior and medial to peroneus longus at the level of the lateral malleolus.
What is the primary restraint for the peroneal tendons within the retromalleolar sulcus?
Superior peroneal retinaculum.
Originates from the posterolateral ridge of the fibular and inserts onto the lateral calcaneus (peroneal tubercle)
In what patients are operative repairs indicated for peroneal tendon dislocations?
Athletes who desire a quick return to sport or presence of a longitudinal tear. -> repair of SPR and deepening of the fibular groove.
Chronic/recurrent dislocations -> In addition to groove deepening soft tissue transfer and/or osteotomy likely to be requried. Not able to repair SPR. May have hindfoot varus that needs to be corrected with osteotomy.
Treatment for simple peroneal brevis tear?
Complex tear?
Complex tear of both brevis and longus?
Core repair and tubularization of the tendon.
Debridement of the tendon with tenodesis of distal and proximal ends of the brevis tedon to the peroneus longus.
Debridement of both tendons with interposition allograft if they have preserved muscle excursion.
Debridement of both tendons with FHL transfer if they have no muscle excursion.
What is an option for a patient with chronic peroneal tendon pathology and varus hindfoot alignment besides a calcaneal osteotomy?
Subtalar arthrodesis.
What is the most common cause of osteomyelitis after foot puncture wounds?
Pseudomonas.
Staph aureus is the most common cause of infection.
10% of foot puncture wounds will develop infection.
Recommended abx for foot puncture wounds?
Ciprofloxacin or levofloxacin.
Want to cover for pseudomonas.
Alternative abx ceftaxidime or cefepime.
What foot deformity is found in adult acquired flatfoot deformity?
Pes planus
Hindfoot valgus
Forefoot varus
Forefoot abduction
In late posterior tibial tendon insufficiency what is failing?
Static hindfoot stabilizers and collapse of the medial longitudinal arch:
Spring ligament complex
Plantar fascia
Plantar ligaments
Early disease is loss of medial longitudinal arch dynamic stabilization
What motions within the foot and ankle does the posterior tibial tendon contribute to?
Acts as a hindfoot invertor.
Adducts and supinates the forefoot during the stance phase of gait.
Acts as a secondary plantar flexor of the ankle.
Describe the classification of PTTI?
What should be on your differential for causes of adult pes planus?
PTTI
Midfoot pathology- Osteoarthritis or chronic lisfranc injury.
Incompetent spring ligament- primary static stabilizer of the talonavicular joint.
Non-operative treatment for PTTI?
AFO initial treatment for stages II-IV
Walking cast/boot for 3-4 months in stage I disease
For stage I and II custom molded in shoe orthosis. Medial heel lift and longitudinal arch support. Medial forefoot post indicated if fixed forefoot varus is present.
Operative intervention for Stage I PTTI that has failed non-op treatment?
Tenosynovectomy.
Operative intervention for Stage II PTTI?
Contraindications?
FDL transfer. Calcaneal osteotomy. TAL. +/- forefoot correction osteotomy. +/- spring ligament repair. +/- PTT debridement.
Lateral column lengthening for talonavicular uncoverage.
Medial column arthrodesis if deformity is at naviculocuneiform joint.
Contraindications: Hypermobility, neuromuscular conditions, severe subtalar arthritis, obesity (relative), and age > 60-70 (relative).
Operative treatment for Stage II PTTI with 1st TMT hypermobility?
Need to include a first TMT joint arthrodesis along with the usual calcaneal osteotomy and TAL.
+/- lateral column lengthening and PTT debridement.
What is a contraindication for isolated subtalar arthrodesis to treat PTTI?
Any fixed forefoot supination/varus.
Doing this without addressing the forefoot witll overload the lateral border of the foot.
What tendons become a deforming froce in hallux valgus?
Adductor tendon becomes deforming force- inserts on fibular sesamoid and lateral aspect of proximal phalanx.
Lateral deviation of EHL further contributes to deformity.
Plantar and lateral migration of abductor hallucis causes muscle to plantar flex and pronate phalanx.
Describe the four radiographic measurements used in evaluation of hallux valgus?
What are normal values for each?
For Hallux valgus categories of Mild, Moderate, and Severe describe the radiographic indications and the recommended procedure?
What are the surgical indications for the specific conditions as they relate to hallux valgus?
What is the main blood supply to the talar body and dome?
Deltoid artery.
Extra-0sseous blood supply.
In what patients can a supramalleolar osteotomy be considered for ankle arthritis?
near normal ROM
Minimal talar-tilt or varus heel alingment.
Medially focused ankle arthritis. Stage 2 or 3a according to the Takakura-Tanaka classification for varus-type osteoarthritis.
A claw toes deformity is characterized by?
MTP hyperextension with PIP and DIP flexion.
Analogous to intrinsic minus deformity in the hand.
MTP plantar plate becomes insufficient over time and translates dorsally.
Most common etioloty is synovitis. Also caused by trauma or missed compartemnt syndrome.
Hammer toe deformity is characterized by?
PIP Flexion, DIP Extension, MTP Neutral or extended.
Deformity can be rigid or flexible.
Most common deformity of lesser toes. More common in older women.
What treatment is recommended for a rigid hammer toe that has failed non-operative treatment?
PIP resection arhtroplasty +/- tenotomy and tendon transfers.
EDL Z-lengthening, tenotomy, and dorsal capsular release depending on severity of MTP hyperextension.
PIPJ arthrodesis is an option.
What are characteristic findings of a bunionette of radiographs?
Increased 4-5 IMA ( Normal 6.5-8 degrees)
Increased lateral deviation angle (Normal 0-7 degrees)
Increased width of MT head (Normal <13mm)
What are two major classification systems for diabetic foot ulcers?
Wagner
Brodsky Depth-Ischemia Classification
What is detritic synovitis
Cartilage and bone distributed in synovium
Describe the anatomy of the interdigital nerve of the foot?
Lies plantar to the transverse intermetatarsal ligament between the metatarsal heads.
Composed of the confluence of the branches of the lateral and medial plantar nerves.
Morton’s Neuroma most commonly involves the 2nd and 3rd interdigital nerve between the metatarsal heads.
What causes compression of Baxter’s nerve?
Baxter nerve = first branch of the lateral plantar nerve.
Compressed between fascia of abductor hallucis longus and medial side of quadratus plantae.
Common nerve entrapment in the running athlete.
Operative treatment in most cases which is surgical release of abductor hallucis fascia.
A disrupted spring ligament causes what deformity?
Flatfoot deformity.
What subtle foot deformity does this image most likley indicate?
The figure demostrates a right sided “peak-a-book sign” where you can see the medial border of the heel. This indicates hindfoot varus.
This patient likely has a subtle cavovarus foot (SCF) and would benefit from an orthotic with lateral hindfoot posting and first metatarsal head recess.
What is the structure labeled in A in the photo?
What is the clinical relevance?
Peroneus quartus
Supernumary muscle arising most commonly from the peroneus brevis. The presence is not uncommon, up to 21% of the time and is associated with lateral ankle pain and peroneal tendon symptoms.
