75: Tarsal Coalition - Smith

Question 1

what is a tarsal coalition?

Answer 1

Tarsal coalition exists when a union causes restricted motion or absence of motion between two or more tarsal bones.

Question 2

bar vs. bridge

Answer 2

• Bar: Extraarticular coalition that occurs outside a normal joint
  
  • Calcaneonavicular Bar - these bones do not normally articulate
• Bridge: Intraarticular coalition that occurs at a normal joint site
  
  • Talocalcaneal Bridge

Question 3

most common cause of tarsal coalition in pediatric pt

most common cause of tarsal coalition in adult pt

Answer 3

congential

acquired (ex: fx calcaneus and healing forms union b/w talus and calcaneus)

Question 4

congenital etiologies

Answer 4

• Pfitzner – Incorporation of accessory ossicles into the normal tarsal bones on either side of a joint or in close approximation with one another.
  
  • issue: coalitions seen in fetuses
• Leboucq – Failure of differentiation and segmentation of primitive mesenchyme
  
  • Heritable defect (autosomal dominant)
  • Insult in first trimester

Question 5

syndesmosis vs. synchondrosis vs. synostosis

Answer 5

• Syndesmosis: Fibrous union
  
  • Incomplete union with motion
• Synchondrosis: Cartilaginous union
  
  • Incomplete union with motion
• Synostosis: Osseous union
  
  • Complete union without motion

Question 6

Downey Classification

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Answer 6

• Juvenile (osseous immaturity)
  
  • Type I: extrarticular
    
    • A: no secondary arthritis
    • B: secondary arthritis
  • Type II: intraarticular
    
    • A: no secondary arthritis
    • B: secondary arthritis
• Adult (osseous maturity)
  
  • Type I: extrarticular
    • A: no secondary arthritis
    • B: secondary arthritis
  • Type II: intraarticular
    • A: no secondary arthritis
    • B: secondary arthritis

Question 7

highest incidence joint

Answer 7

talocalcaneal 48.1%

calcaneonavicular 43.6%

Question 8

clinical s/s tarsal coalition

Answer 8

• Pain
  
  • deep aching in area of coaliton, often near sinus tarsi or entire rearfoot, may also have secondary arthritis
  • relieved with rest
  • esp w/ walking over rough uneven terrain
• Limitation of motion and rigid flatfoot
  
  • Most likely cause of unilateral pediatric flatfoot
• Muscle spasm
• No symptoms in 22% of patients
  
  • Patients often mistreated for ankle sprains and sinus tarsi syndrome

Question 9

when do the following coalitions ossify?****

talonavicular

calcaneonavicular

talocalcaneal

Answer 9

• Talonavicular Coalition: 3-5 years
• Calcaneonavicular Coalition: 8-12 years
• Talocalcaneal Coalition: 12-16 years

Question 10

most obvious clinical finding

Answer 10

limitation of motion STJ and MTJ

Question 11

what will happen in hubscher maneuver with rigid flatfoot?

Answer 11

no chang ein arch height with dorsiflexion of hallux w/ pt standing

Question 12

why do the peroneal tendons spasm with rigid flatfoot?

Answer 12

• firing peroneal tendons to keep foot in everted position (it hurts to invert)
• spasm due to rapid firing
• may need to give common peroneal n block to examine the pt
• peroneal spastic flatfoot does not always develop in tarsal coalition and there are other etiologies to peroneal spastic flatfoot

Question 13

Answer 13

• Calcaneonavicular Bar
• oblique radiograph
  
  • comma sign or anteater sign
• osseous easier to diagnose
• soft tissue coalitions
  
  • close proximity of calcaneus and navicular
  • irregualr lateral navicualr cotical surface
  • flattening of navicualr laterally
  • hypoplasia of head of talus

Question 14

Answer 14

• Talocalcaneal Coalition
• Lateral Radiograph
  
  • diminished posterior or middle facet
  • halo sign: sclerotic enhancement of sustentaculum tali
  • narrowing of posterior facet
  • talonavicular beaking
  • flattening of lateral talar process
• calcaneal axial
  
  • facet obliquity: parallel or less than 25 degrees normally
    
    • abnormal pictured below

Question 15

Answer 15

• Talonavicualar Coalition
• looks like a long talar neck
• seen on AP and lateral radiograph

Question 16

Answer 16

talocalcaneal coalition of middle facet

MRI

Question 17

Answer 17

incomplete calcaneonavicular coalition

CT scan

Question 18

ball and socket ankle joint

Answer 18

secondary arthritic change assoc with tarsal coalition

ankle starts to remodel to gain motion lost from coalesced jt

Question 19

talonavicular beaking

Answer 19

secondary arthritic change assoc with tarsal coalition

Question 20

what type of orthotics would you want to use as conservative tx?

Answer 20

orthotics that restrict STJ and MTJ motion to reduce pain and muscle spasm (keep foot everted)

Question 21

surgical treatment recommendations based on Downey classification

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Answer 21

• Juvenile
  
  • IA: resection with interposition of EDB m (Badgley 1927)
  • IB: triple arthrodesis
  • IIA: resection with interposition of arthroereisis, isiolated/single arthrodesis, triple arthrodesis
  • IIB: triple arthrodesis
• Adult
  
  • IA: resection with interposition of EDB m, triple arthrodesis
  • IB: resection with isolated/single arthrodesis, triple arthrodesis
  • IIA: isolated or single arthrodesis, triple arthrodesis
  • IIB: triple arthrodesis

arthrodesis indicated in older pts with coalition

Question 22

describe resection/interpositon with EDB

Answer 22

• Badgley 1927
• Ollier Incision
• EDB dissected from Calcaneus and reflected distally
• Resection of coalition (until you get enough STJ ROM)
• EDB placed into defect
  
  • Silicone or fat may also be used
  • Kieth needle passed out through bottom
• Bone Wax
  
  • on cut ends to create hemostasis and inhibit bone healing