XX--Ray Rounds: Ray Rounds: (Plain) Radiographic Evaluation (Plain) Radiographic Evaluation

of the Ankleof the Ankle

AnatomyAnatomy

Complex hinge jointComplex hinge jointArticulations among:Articulations among:–– FibulaFibula–– TibiaTibia–– TalusTalus

Tibial Tibial ““plafondplafond””–– Distal tibial articular Distal tibial articular

surfacesurface

Complex ligamentous Complex ligamentous systemsystem

AnatomyAnatomy

Medial malleolusMedial malleolus–– Distal tibiaDistal tibia–– Medial supportMedial support

Lateral malleolusLateral malleolus–– Distal fibulaDistal fibula–– Lateral supportLateral support

TalusTalus–– TrapezoidTrapezoid--shapedshaped

Mortise (tibial plafond, medial & lateral Mortise (tibial plafond, medial & lateral malleolimalleoli))-- Constrained articulation with the talar domeConstrained articulation with the talar dome

AnatomyAnatomySyndesmotic ligament Syndesmotic ligament complexcomplex–– Axial, rotational, & Axial, rotational, &

translational stabilitytranslational stability–– Four ligaments:Four ligaments:

Anterior tibiofibular Anterior tibiofibular ligamentligamentPosterior tibiofibular Posterior tibiofibular ligamentligamentTransverse tibiofibular Transverse tibiofibular ligamentligamentInterosseous ligamentInterosseous ligament

AnatomyAnatomy

Deltoid (medial) Deltoid (medial) ligament complexligament complex–– Superficial (contributes Superficial (contributes

little to stability)little to stability)Tibionavicular ligamentTibionavicular ligamentTibiocalcaneal ligamentTibiocalcaneal ligamentSuperficial Tibiotalar Superficial Tibiotalar ligamentligament

–– Deep (primary medial Deep (primary medial stabilizer)stabilizer)

Intraarticular:Intraarticular:Deep tibiotalar Deep tibiotalar ligamentligament

AnatomyAnatomy

Lateral (fibular Lateral (fibular collateral) ligament collateral) ligament complexcomplex–– Anterior talofibular Anterior talofibular

ligament (weakest)ligament (weakest)–– Posterior talofibular Posterior talofibular

ligament (strongest)ligament (strongest)–– Calcaneofibular Calcaneofibular

ligamentligament

Indications for Ankle RadiographsIndications for Ankle RadiographsOttawa Ankle RulesOttawa Ankle Rules–– Age 55 years or olderAge 55 years or older

Indications for Ankle RadiographsIndications for Ankle RadiographsHow good are the Ottawa Rules?How good are the Ottawa Rules?–– When originally published:When originally published:

100% sensitivity & 40% specificity for detecting 100% sensitivity & 40% specificity for detecting malleolar fracturesmalleolar fractures

–– Subsequent studies: Subsequent studies: Lower sensitivity (93% to 95%) and specificity (6% Lower sensitivity (93% to 95%) and specificity (6% to 11%) than originally thoughtto 11%) than originally thoughtNot perfect, but still a good toolNot perfect, but still a good tool

Other indicationsOther indications–– The patient cannot communicate (altered The patient cannot communicate (altered

mental status, alcohol intoxication, or other)mental status, alcohol intoxication, or other)–– Pain and swelling do not resolve within 7Pain and swelling do not resolve within 7--10 10

days after injury days after injury –– Anytime your history and physical donAnytime your history and physical don’’t give t give

you enough informationyou enough information

Normal ankle (AP view)

Normal ankle (Mortise view)

Normal ankle (Lateral view)

AP View of the AnkleAP View of the Ankle

DE: Talar Tilt: < 2 degrees of angulation is Nl

DE

AP View of the AnkleAP View of the Ankle

Talar Tilt: > 2 degrees angulation may indicate medial or lateral disruption

Tib-fib Clear Space > 5mm or Tib-fib Overlap < 10mm may indicate syndesmotic injury

Lateral View of the AnkleLateral View of the AnkleDome of the talus: centered under and congruous with tibial plafond

Posterior tibial tuberosityfractures & direction of fibular injuries can be identified

Avulsion fractures of the talus by the anterior capsule can be identified

Any deformity to the talus, calcaneusor subtalar joint

Calcaneal FracturesCalcaneal FracturesBohler’s Angle 30-35 degrees is normal

Others:

Critical Angle of Gissane

Broden’sViews

Mortise View of the AnkleMortise View of the AnkleAP view taken with the foot AP view taken with the foot in 15in 15--20 degrees of internal 20 degrees of internal rotation to offset the rotation to offset the intermalleolar axisintermalleolar axis

Medial clear spaceMedial clear space–– > 4mm may indicate > 4mm may indicate

lateral talar shiftlateral talar shift

Talar tilt, TibTalar tilt, Tib--fib Overlap, fib Overlap, TibTib--fib clearspace (see AP fib clearspace (see AP view)view)

Talocrural angle (angle b/w Talocrural angle (angle b/w plafond parallel and plafond parallel and intermalleolar line)intermalleolar line)–– Normal is 8Normal is 8--15 degrees 15 degrees

(where the lines intersect)(where the lines intersect)–– Smaller angle may indicate Smaller angle may indicate

fibular shorteningfibular shortening

Mortise View of the AnkleMortise View of the Ankle

mm

Normal AP & lateral right ankle X Ray

mm

AP View:

Widened medial clear space

Mortise View:

Open mortise (decreased tib-fib overlap)

= Syndesmotic injury

= Surgical referral

(“needs a screw”)

28 y/o M who “twisted” his left ankle while playing basketball 1 day ago

Danis-Weber Type B fibular ankle fracture

Ankle Fracture ClassificationAnkle Fracture Classification

DanisDanis--Weber ClassificationWeber Classification–– Defined by location of the Defined by location of the

fracture linefracture line

Type A: below the tibiotalar jointType B: at the level of the tibiotalar jointType C: above the tibiotalar joint

– Syndesmotic ligament compromise

LaugeLauge--Hansen Hansen ClassificationClassification–– Infrequently used, Infrequently used,

clinically; mostly academicclinically; mostly academic

mm

Mortise view:

Weber C fracture with open mortise and widened medial clear space

= deltoid & syndesmotic ligament tears, with fracture

= surgical referral

mm

25 y/o volleyball player “landed wrong”on the right foot, “hurting” the ankle

Exam with positive talar tilt

Lateral ligament tears

-ATFL

-CFL

Radiographic Stress Tests of the AnkleRadiographic Stress Tests of the AnkleTalar Tilt Stress Test–– Stabilize the leg with one Stabilize the leg with one

hand while inverting plantar hand while inverting plantar flexed heel with the otherflexed heel with the other

Contralateral ankle used for Contralateral ankle used for comparisoncomparisonLine is drawn across the Line is drawn across the talar dome and tibial vaulttalar dome and tibial vault

–– Degree of lateral opening Degree of lateral opening angle is measuredangle is measured

–– Normal tilt is less than 5 Normal tilt is less than 5 degdeg

–– Standing Talar Tilt Stress Standing Talar Tilt Stress Test:Test:

may be more sensitivemay be more sensitivePatient stands on an Patient stands on an inversion stress platform inversion stress platform with the foot and ankle in with the foot and ankle in 40 deg of plantar flexion 40 deg of plantar flexion and 50 deg of inversionand 50 deg of inversion

Grade III ATFL ankle sprain

25 y/o male tennis player “torqued” his right ankle

Exam with positive anterior drawer sign

Radiographic Stress Tests of the AnkleRadiographic Stress Tests of the Ankle

Anterior Drawer Test– Abnormal anterior

translation is between 5 to 10 mm, or 3 mm more than other side

External Rotation Stress Test– Evaluates syndesmotic &

deep Deltoid ligaments– Difference in width of

superior clear spacebetween medial and lateral side of the joint should be < 2 mm

mm

AP View:

Widened medial clear space

Decreased tib-fib overlap

= Medial & syndesmotic ligament compromise

= surgical referral

mmNormal AP & lateral views

Open mortise

= “needs a screw”

mm

Weber Type A lateral malleolar fracture

Treat conservatively

mm

Open mortise with high fibular fracture

Name?

Maissoneurve fracture

= surgical referral

mm

Salter-Harris fracture, type II

= Refer for ORIF

S A L T ERStraight Above beLow Through CERush

1 2 3 4 5

mm

Lateral ligamentous injury

Medial malleolar avulsion fracture

Surgical referral

mm

Nondisplaced spiral fibular fracture

= CR & immobilization

mm

Posterior malleolar avulsion fracture

mm

Abnormal Bohler’s angle

= Calcaneal Fx

“Surgerize!”

mm

Medial malleolar fracture

= refer for screw fixation

mm

Medial malleolar Fx

Widened medial clear space: talar dislocation

Open mortise: syndesmotic injury

Maissoneurve Fx

= Surgery

mm

Bimalleolar fractures

Osteopenic appearing bone

Surgical referral

Tx osteoporosis prn

mm

Diagnosis?

Charcot’s foot

mm

Anterolateral tibial epiphyseal fracture

aka: Tillauxfracture

Tillaux FractureTillaux FractureFracture of the Fracture of the anterolateral tibial anterolateral tibial epiphysis epiphysis MechanismMechanism

Avulsion of epiphyseal Avulsion of epiphyseal fragment due to the fragment due to the strong anterior strong anterior tibiofibular ligament tibiofibular ligament External rotational force External rotational force across the ankleacross the ankle

Commonly seen in Commonly seen in adolescentsadolescentsTreatment: ORIFTreatment: ORIF

mm

Calcaneal osteomyelitis

= IV Abx

= Surgical I & D if chronic

mm

Calcaneal fracture

= ORIF

mm

Mortise view

AP view

Lateral view

Pilon fracture(Comminuted tibial plafond compression

fracture)

Management?

mm

Positive talar tilt stress test

Surgery

s/p Fall while rockclimbing Treatment ?

ConclusionConclusion

Plain radiographic Plain radiographic anatomy of the anatomy of the ankleankle

Indications for Indications for plain radiographs plain radiographs of the ankleof the ankle

Direct and indirect Direct and indirect signs of injury on signs of injury on plain radiographsplain radiographs