Ankle is a three bone joint composed of the tibia , fibula an talus Talus articulates with the tibial plafond superiorly , posterior malleolus of the tibia posteriorly and medial malleolus medially Lateral articulation is with malleolus of fibula
The joint is considered saddle-shaped with the dome itself is wideranteriorly than posteriorly, and as the ankle dorsiflexes, the fibula rotatesexternally through the tibiofibular syndesmosis, to accommodate thiswidened anterior surface of the talar domeThe tibiotalar articulation is considered to be highly congruent such that 1mm talar shift within the mortise decreases the contact area by 42 %
MEDIAL SIDE LATERAL SIDE LACINATE LIG. TARSAL TUNNEL
INTRODUCTIONAnkle fractures are among the most common injuries andmanagement of these fractures depends upon carefulidentification of the extent of bony injury as well as soft tissueand ligamentous damage.Once defined, the key to successful outcome followingrotational ankle fractures is anatomic restoration and healing ofankle mortise.
IMAGING AND DIAGNOSTIC MODALITIESOTTAWA ANKLE RULESTo manage the large volume of ankle injuries of patients whopresented to emergency certain criteria has been established forrequiring ankle radiographs.Pain exists near one or both of the malleoli PLUS one or more of thefollowing:•Age > 55 yrs old•Inability to bear weight•Bone tenderness over the posterior edge or tip of either malleolus .
Although the OTTAWA RULES have been validated and found to be both costeffective and reliable (up to 100% sensitivity their implementation has beeninconsistent in general clinical practice •Plain Films –AP, Mortise, Lateral views of the ankle –Image the entire tibia to knee joint –Foot films when tender to palpation – Common associated fractures are: •5th metatarsal base fracture •Calcaneal fracture
An initial evaluation of the radiograph should 1st focus on•Tibiotalar articulation and access for fibular shortening•Widening of joint space•Malrotation of fibula•Talar tilt
Identifies fractures of ◦ malleoli ◦ distal tibia/fibula ◦ plafond ◦ talar dome ◦ body and lateral process of talus ◦ calcaneous
On the anteroposterior view, the distal tibia and fibula, including themedial and lateral malleoli, are welldemonstrated . important note is that the fibular(lateral) malleolus is longer than the tibial(medial) malleolus. This anatomic feature, important for maintaining ankle stability, is crucial for reconstruction of the fractured ankle joint. Even minimal displacement or shortening of the lateral malleolus allows lateral talar shift to occur and may cause incongruity in the ankle joint, possibly leading to posttraumatic arthritis.
Quantitative analysis◦Tibiofibular overlap◦<10mm is abnormal - impliessyndesmotic injury◦Tibiofibular clear space◦>5mm is abnormal - impliessyndesmotic injury◦Talar tilt◦>2mm is considered abnormalConsider a comparison withradiographs of the normal side if thereare unresolved concerns of injury
Lateral malleolar fracture Tib/fib clear space <5mm Tib/fib overlap >10 mm No evidence of syndesmotic injury
Taken with ankle in 15-25 degrees of internal rotation Useful in evaluation of articular surface between talar dome and mortise
10 degrees internal rotation of 5th MT with respect to a vertical line
Medial clear space ◦ Between lateral border of medial malleous and medial talus ◦ <4mm is normal ◦ >4mm suggests lateral shift of talus
•Abnormal findings: –Medial joint space widening –Talocrural angle: <8 or >15 degrees –Tibia/fibula overlap:<1mmConsider a comparison withradiographs of the normal side if thereare unresolved concerns of injury
FIBULAR LENGTH: 1. Shenton’s Line of the ankle 2. The dime test
•Posterior mallelolarfractures•AP talar subluxation•Distal fibular translation&/or angulation•Syndesmotic relationship•Associated or occultinjuries –Lateral process talus –Posterior process talus –Anterior process calcaneus
The ankle is a ring ◦ Tibial plafond ◦ Medial malleolus ◦ Deltoid ligaments ◦ calcaneous ◦ Lateral collateral ligaments ◦ Lateral malleolus ◦ Syndesmosis Fracture of single part usually stable Fracture > 1 part = unstableSource: Rosen
Some ligament injuries may be diagnosed on the basis of disruption of the anklemortise and displacement of the talus; others can be deduced from theappearance of fractured bones.For example, fibular fracture above the level of the ankle joint indicates that the distal anteriortibiofibular ligament is torn.Fracture of the fibula above its anterior tubercle strongly suggests that thetibiofibular syndesmosis is completely disrupted.Fracture of the fibula above the level of the ankle joint without accompanyingfracture of the medial malleolus indicates rupture of the deltoid ligament.
Transverse fracture of the medial malleolus indicates that the deltoidligament is intact. High fracture of the fibula associated with a fracture of the medialmalleolus or tear of the tibiofibular ligament, the so-called Maisonneuvefracture (see later), indicates rupture of the interosseous membrane up tothe level of the fibular fracture
When radiographs of the ankle are normal,however, stress views are extremely important inevaluating ligament injuries . Inversion (adduction) and anterior-draw stressfilms are most frequently obtained; only rarely isan eversion (abduction)-stress examinationrequired.
Inversion stress view. (A) For inversion(adduction)-stress examination of the ankle, thefoot is fixed in the device while the patient issupine. The pressure plate, positionedapproximately 2 cm above the ankle joint, appliesvarus stress adducting the heel. (If theexamination is painful, 5 to 10 mL of 1%Xylocaine or a similar local anesthetic is injectedat the site of maximum pain.) (B) On theanteroposterior film, the degree of talar tilt ismeasured by the angle formed by lines drawnalong the tibial plafond and the dome of the talus.The contralateral ankle is subjected to the sameprocedure for comparison.This angle helps diagnose tears of thelateral collateral ligament
The anterior-draw stress film, obtained in the lateral projection, provides auseful measurement for determining injury to the anterior talofibular ligamentValues of up to 5 mm ofseparation between thetalus and the distal tibiaare considered normal;values between 5 and 10mm may be normal orabnormal, and the oppositeankle should be stressedfor comparison. Valuesabove 10 mm alwaysindicate abnormality.
Radiography after reduction should be studied withfollowing requirements in mind:•Normal relationship of ankle mortise must be restored.•Weight bearing alignment of ankle must be at right angle to thelongitudinal axis of leg•Counters of the articular surface must be as smooth as possible
Based on cadaveric study• First word: position of foot at time of injury• Second word: force applied to foot relative to tibia at time of injury Types: Supination External Rotation Supination Adduction Pronation External Rotation Pronation Abduction
• In each type there are several stages of injury• Imperfect system: – Not every fracture fits exactly into one category – Even mechanismspecific pattern has been questioned – Inter and intraobserver variation not ideal – Still useful and widely usedRemember the injury starts on the tight side of the ankle!The lateral side is tight in supination, while the medialside is tight in pronation.
Primary advantage : Characteristic fibular # pattern useful for reconstructing the mechanism of injury a guide for the closed reduction Sequential pattern – inference of ligament injuriesDisadvantages: complicated, variable inter observer reliability doesn’t signify prognosis internal rotation injuries (Weber A3) missed doesn’t indicate stability
Stage 1 Anterior tibio- fibular ligament Stage 2 Fibula fx Stage 3 Posterior malleolus fx or posterior tibio- fibular ligament4 1 Stage 4 Deltoid ligament tear or 3 2 medial malleolus fx
• Must x-ray knee to ankle to assess injury• Syndesmosis is disrupted in most cases – Eponym: Maissoneuve Fracture• Restore: – Fibular length and rotation – Ankle mortise – Syndesmotic stability
Stage 1 Transverse medial malleolus fx distal to mortise Stage 2 Posterior malleolus fx or posterior tibio-fibular ligament Stage 3 Fibula fracture,1 typically proximal to mortise, often with a 2 3 butterfly fragment
Medial injury: tranverse to short oblique medial malleolar fractureLateral Injury: comminuted impaction type distal lateral malleolar fracture
Based on location of fibulafracture relative to mortiseand appearance Weber A fibula distal to mortise Weber B fibula at levelof mortise Weber C fibulaproximal to mortiseConcept - the higher thefibula the more severe theinjury
AO classification divides the three Danis Weber types further for associated medial injuries. Alpha-Numeric Code Infrasyndesmotic=44A + Malleolar segment =4 Transsyndesmotic=44BTibia =4 Suprasyndesmotic=44C
• Maisonneuve Fracture – Fracture of proximal fibula with syndesmotic disruption• Volkmann Fracture – Fracture of tibial attachment of PITFL – Posterior malleolar fracture type• Tillaux-Chaput Fracture – Fracture of tibial attachment of AITFL
Pott fracture.In the Pott fracture, the fibula isfractured above the intact distaltibiofibular syndesmosis, the deltoidligament is ruptured, and the talus issubluxed laterally
Dupuytren fracture.(A) This fracture usuallyoccurs 2 to 7 cm abovethe distal tibiofibularsyndesmosis, withdisruption of the medialcollateral ligament and,typically, tear of thesyndesmosis leading toankle instability. (B) Inthe low variant, thefracture occurs moredistally and thetibiofibular ligamentremains intact.
Wagstaffe-LeFort fracture.In the Wagstaffe-LeFortfracture, seen hereschematically on theanteroposterior view, themedial portion of the fibula isavulsed at the insertion of theanterior tibiofibular ligament.The ligament, however,remains intact.
•Collicular Fractures INTERCOLLICULAR GROOVE –Avulsion fracture of distal portion of medial malleolus –Injury may continue and rupture the deep deltoid ligament•Bosworth fracture POSTERIOR COLLICULUS ANTERIOR COLLICULUSdislocation –Fibular fracture with posterior dislocation of proximal fibular segment behind tibia
Tibial Pilon FracturesThe terms tibial plafond fracture, pilon fracture, and distal tibialexplosion fracture all have been used to describe intraarticular fracturesof the distal tibia. These terms encompass a spectrum of skeletal injury ranging fromfractures caused by low-energy rotational forces to fractures caused byhigh-energy axial compression forces arising from motor vehicleaccidents or falls from a height. Rotational variants typically have a more favorable prognosis, whereashigh-energy fractures frequently are associated with open wounds orsevere, closed, soft-tissue trauma.
Rotational fracture of the ankle can be viewed as a continuum,progressing from single malleolar fractures to bimalleolar fractures tofractures involving the distal tibial articular surface.Lauge-Hansen described a pronation-dorsiflexion injury that producesan oblique medial malleolar fracture, a large anterior lip fracture, asupraarticular fibular fracture, and a posterior tibial fracture.Giachino and Hammond described a fracture caused by a combinationof external rotation, dorsiflexion, and abduction that consisted of anoblique fracture of the medial malleolus and an anterolateral tibialplafond fracture..
These fractures generally have little comminution, no significantmetaphyseal involvement, and minimal soft-tissue injury. They can betreated similarly to other ankle fractures with internal fixation of thefibula and lag screw fixation of the distal tibial articular surface throughlimited surgical approaches
CLASSIFICATION OF ANKLE FRACTURES IN CHILDRENSalter-Harris anatomic classification as applied to injuries of the distaltibial epiphysis.
Classification of Ankle Fracture in Children (Dias-Tachdjian)
Supination Inversion grade I adduction or inversion force avulses the distal fibular epiphysis(Salter-Harris type I or II fracture). Occasionally, the fracture istransepiphyseal; rarely, the lateral ligaments fail. grade II further inversion produces a tibial fracture, usually a Salter-Harristype III or IV and, rarely, a Salter-Harris type I or II injury, or the fracturepasses through the medial malleolus below the physis
Variants of grade II supination inversion injuries (Dias-Tachdjian classification).B.Salter-Harris I fracture of the distal tibiaand fibula.D. B. Salter-Harris I fracture of the fibula,Salter-Harris II tibial fracture.F.C. Salter-Harris I fibular fracture, Salter-Harris III tibial fracture.H.D. Salter-Harris I fibular fracture, Salter-Harris IV tibial fracture.
Supination PlantarflexionThe plantarflexion force displaces the epiphysis directly posteriorly,resulting in a Salter-Harris type I or II fracture. Fibular fractures were notreported with this mechanism. The tibial fracture usually is difficult to seeon anteroposterior x-rays
Supination External RotationIn grade I the external rotation force results in a Salter-Harris type IIfracture of the distal tibia The distal fragment is displaced posteriorly, as ina supination plantarflexion injury, but the Thurston-Holland fragment isvisible on an anteroposterior x-ray, with the fracture line extendingproximally and medially. Occasionally, the distal tibial epiphysis is rotatedbut not displaced.
In grade II, with further external rotation, a spiral fracture of the fibula isproduced, running from anteroinferior to posterosuperior (
Pronation Eversion External RotationA Salter-Harris type I or II fracture of the distal tibia occurssimultaneously with a transverse fibular fracture. The distal tibialfragment is displaced laterally, and the Thurston-Holland fragment,when present, is lateral or posterolateral . Less frequently, atransepiphyseal fracture occurs through the medial malleolus (Saltertype II).