fractures of the talus and subtalar dislocations

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David Sanders MD, MSc, FRCSC London Health Sciences Centre University of Western Ontario London, Ontario, Canada Fractures of the Talus and Subtalar Dislocations

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Fractures of the Talus and Subtalar Dislocations. David Sanders MD, MSc, FRCSC London Health Sciences Centre University of Western Ontario London, Ontario, Canada Created March 2004; Revised August 2006 Revised May 2011. Outline:. Talar Neck Fractures Anatomy Incidence Imaging - PowerPoint PPT Presentation

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  • David Sanders MD, MSc, FRCSC

    London Health Sciences CentreUniversity of Western Ontario London, Ontario, Canada

    Created March 2004; Revised August 2006 Revised May 2011

    Fractures of the Talus and Subtalar Dislocations

  • Outline:Talar Neck FracturesAnatomyIncidenceImagingClassificationManagementComplicationsTalar body, head and process fractures

    Subtalar dislocationsClassificationManagement Outcomes

  • Surface 60% cartilageNo muscular insertionsAnatomy

  • Blood Supply4 primary arterial sources:Artery of tarsal canalArtery of tarsal sinusDorsal neck vesselsDeltoid branchesmediallateralInferior view of talus, showing vascular anastomosis

  • VascularityArtery of tarsal canal supplies majority of talar bodySide ViewTop ViewDeltoid BranchesPosterior tuberclevesselsArtery of TarsalSinusArtery ofTarsal CanalSuperior Neck VesselsSuperior Neck VesselsArtery of TarsalSinusArtery ofTarsal CanalPosterior tuberclevessels

  • Talus ORIF TechniqueVascularity

    Talus ORIF Technique

  • Incidence2 % of all fractures6-8% of foot fracturesHigh complication ratesavascular necrosispost-traumatic arthritismalunion

  • Mechanism of InjuryHyperdorsiflexion of the foot on the leg

    Neck of talus impinges against anterior distal tibia, causing neck fractureIf force continues:talar body dislocates posteromedialoften around deltoid ligament

  • Injury MechanismPreviously called aviators astragalus

    Usually due to motor vehicle accident or falls from height

    Approximately 50 % of patients have multiple traumatic injuries

  • BiomechanicsTheoretical shear force across talar neck:1200 N during active motion [Swanson 1992]Fracture fixation must withstand this force to permit active motion in the postoperative phase

  • ImagingComplex 3-D structureMultiple plain film orientations:AP, Lateral, Broden, & mortise views demonstrates joint congruity of ankle and subtalar jointCanale view for longitudinal alignment: approximately 15 IR to get calcaneous out of view

    Canale View

  • Canale ViewSlight ankle plantarflexion with knee bent to rest foot on the table15 degree pronationXray Tube 15 degree from vertical

    Canale View

  • CT ScanMost useful assessment tool for surgical planningConfirms displacementDemonstrates subtalar joint reduction, comminution, osteochondral fractures/debris

  • MRI ScanPrimary role in talus injuries is to assess complications, especially avascular necrosisMay be poor quality if extensive hardware presentZone of osteonecrosis following distribution of Artery of Tarsal Canal

  • Talar Neck Fractures: ClassificationHawkins, 1970

    Predictive of AVN rate

    Widely used

  • Talus ORIF TechniqueHawkins ClassificationHawkins, LR, JBJS, 52A: 991, 1970Nondisplaced
  • Hawkins 1Type I: undisplacedAVN rate 0 13 %

    Uncommon as most talar neck fractures are displaced

  • Hawkins 2Displaced fracture with subtalar subluxation / dislocation

    A)fracture line enters subtalar jointB) subtalar joint intact

    AVN 20 50 %Most common type

  • Hawkins 3Subtalar and ankle joint dislocatedTalar body extrudes, usually around deltoid ligamentCommonly open fractures, reduction very difficultClosed: plantar flex foot & flex kneeOpen: joy sticksAVN 83 100 %

  • Hawkins 4Added to classification by Canale, 1974Incorporates talonavicular subluxationRare variantComplex talar neck fractures which otherwise do not fit classification are included as Type 4 injuries

  • Classification:Comminution:An important additional predictor of results, especially regarding prognosis re:MalunionSubtalar joint arthritis

    Included in AO-OTA classification as a modifier

  • Goals of ManagementImmediate reduction of dislocated jointsVascularityCutaneous tensionVascular compromiseAnatomic fracture reductionStable fixationFacilitate unionAvoid complications

  • Talus ORIF TechniqueDefinitive TreatmentPrompt anatomic operative reductiondie is cast with injuryUse joy stick K-wires for reductionArticular bone affects ROM (V, Sup, PF)Maintenance of reduction with HWScrews (AP, PA), countersinkPlates (2.0 mini condylar or T)Dual incisionsDo not dissect capsular attachmentsMaintain as much soft tissue attachments

    Talus ORIF Technique

  • Treatment of Talar Neck FracturesEmergent reduction of dislocated jointsStable internal fixation Debridement of subtalar jointMaintain as much soft tissue/vascular attachmentsChoice of fixation and approach depends upon personality of fracture

  • Treatment of Talar Neck FracturesPost operative rehabilitation:Sample protocol:Initial immobilization, 2-6 weeks depending upon soft tissue injury and patient factors, to prevent contractures and facilitate healingNon weight-bearing, Range of Motion therapy until 3 months or fracture union

  • Hawkins I FractureOptions:Non Operative & Non-Weight-Bearing Cast for 4-6 weeks followed by removable brace and motionOR:Percutaneous screw fixation and early motion

  • Hawkins II, III, and IV Fractures:Results dependent upon development of complicationsOsteonecrosisMalunionArthritis

  • Case Example29 yo maleATV rolloverIsolated injury LLE

  • These injury films are tough to interpret, but close review demonstrates the dislocated talar body with some comminution.

  • DiagnosisHawkins 3 talar neck fractureAssociated comminution, probably involving medial column and subtalar joint

  • Controversies for this Case:Surgical timingClosed reductionSurgical approachFixation

  • Surgical TimingIn general: emergent reduction of dislocated joints

    Allow life threatening injuries to take priority and resuscitate adequately first

  • Closed Reduction?May be very useful, particularly if other life threatening injuries preclude definitive surgeryDifficult in Hawkins 3 and 4 injuries

  • Closed Reduction Technique:Adequate sedationFlex knee to relax gastrocsTraction on plantar flexed forefoot to realign head with bodyVarus/valgus correction as necessaryDirect pressure on talar bodyAdjunct: traction pin, general anesthetic, etcAvoid repetitive reduction attempts in order to avoid skin compromise or tearing

  • Closed Reduction Example

  • External FixationLimited roles:Multiply injured patient with talar neck fracture in whom definitive surgery will be delayedTemporizing measure to stabilize reduced joints Construct bridges tibia calcaneus midfoot

  • Surgical Approaches: Options1 incision techniques:Anteromedial orAnterolateral

    Problem: difficult to visualize the entire talar neck and subtalar joint without significant soft tissue stripping and devascularizationProblem: usual medial comminution inhibits accurate read of fracture reduction

  • Surgical Approaches: Options2 incision technique: (generally preferred)Anteromedial and lateral/anterolateral

    Problem: 2 skin incisions, close togetherBenefit: excellent fracture visualization at critical sites of reduction and subtalar joint with less stripping

  • 1st Approach: Anteromedial Medial to TibAntMake incision more posterior for talar body fractures to facilitate medial malleolar osteotomy

  • 1st Approach: AnteromedialProvides view of neck alignment and medial comminutionExtend incision distally to talonavicular joint hardware is placed distal to proximal and needs to be well countersunk to avoid impingement

  • 2nd Approach: LateralTip of Fibula directly anteriorMobilize EDB as sleeveProtect sinus tarsi contents

  • 2nd Approach: LateralVisualizes Anterolateral alignment and subtalar jointFacilitates Placement of Shoulder Screw or lateral plate

  • 2 incisions: Skin bridgeNarrow skin bridge but generally well toleratedTalus fractures generally have less soft tissue problems compared to plafond or calcaneus fractures

  • Fixation OptionsStable Fixation to allow early motion is the goal1200 N stress across talar neck during early motion (Swanson JBJS 1992)That is a lot of force! 2 A to P screws only resists about 1 kN of stress so need more fixation

  • Surgical Tactics: FixationAnteriorPartial threaded screwsFully threaded screwsMini-fragment plates (2.0, 2.4 mm)PosteriorLag screwsImplant selection depends upon injury, degree of comminution, bone quality

  • Posterior to Anterior Fixation:Screw fixation stronger from posterior than from anteromedial (T Bray)Screws perpendicular to fracture site 2 PA screws in compression are able to withstand the theoretical shear force of active motionAvoid excessive posterior capsular strippingCreates potentially 3 incisions (posterior, medial, lateral)

  • Anterior Screw Fixation:Screw fixation alone is acceptable for non-comminuted fractures, but consider adding a plate if there is comminution. Easy to insert under direct visualization This example: displaced type 2: 4 A-P screws including medial buttress fully threaded cortical screws and lateral shoulder screws

  • Anterior Screw Fixation:This example: 4.0 mm partially threaded compression screws through non-comminuted columnsMini-fragment (2.4 mm) screws for osteochondral fragmentsConsider Titanium for MRI

  • Plate Fixation:Very useful in comminuted fractures:2.0 or 2.4 mm plates Easiest to apply to lateral cortex impinge on medial side

  • Talus ORIF TechniqueHawkins 3

    Talus ORIF Technique

  • Talus ORIF Technique

    Talus ORIF Technique

  • ComplicationsAVNMalunion

    NonunionArthritis

  • Talus ORIF TechniqueResultsChateau, Indy, 2002 JOT23 pts, 20 mo F/UDual, mini fragmentLow rate AVN Elgafy, Foot Ankle 200060 fxArthritis:Ankle 25%, Subtalar 53%AVN 16%Harborview, 2002 OTA60 fx, 30 mo F/Uw/in 24 hr (40 pts)/Dual 91%Worse results with:ComminutionOpenOsteonecrosis39% (II) 56% to collapse64% (III) 67% to collapse

  • AVN: Incidence after Talus FractureCanale (1972): I: 15 %II: 50 %III: 85 %IV: 100 %Behrens (1988):Overall 25 %Ebraheim/Stephen(2001):Overall 20 %

  • Talus ORIF TechniqueAVASCULAR NECROSIS Rates with Hawkins ClassAVN does not = poor result? MRI-probably not prognostic ? Does early ORIF minimize AVN

    Talus ORIF Technique

  • AVN: DiagnosisHawkins Sign: Xray finding 6-8 weeks post injuryPresence of subchondral lucency implies revascularization

  • AVN: ImagingPlain radiographs: sclerosis common, decreases with revascularizationMRI: very sensitive to decreased vascularity

  • Talus ORIF TechniqueHawkins 3

    Talus ORIF Technique

  • Talus ORIF Technique1 year follow-up|Osteonecrosis without collapse

    Talus ORIF Technique

  • Bilateral Injuries Fixed at 72 hours

  • 2 years Pain, Stiffness, LimpHawkins IIIHawkins II

  • AVN Treatment:Precollapse:Modified WBPTB castCompliance difficultEfficacy unknown

    Postcollapse:ObservationBlair fusion is one option if symptomatic

  • Malunion: IncidenceCommon: up to 40%

    Most often Varus

  • Malunion: DiagnosisVarus hindfoot, midfoot supination on clinical exam

    Dorsal malunion on Xray

  • MalunionMechanical effects> 3 degrees malunion: decreased subtalar ROM (Daniels TR, JBJS 1996)> 2mm: altered subtalar contact forces (Sangeorzan J Orthop Res 1992)

  • Clinical Effect of MalunionMalunion:More painLess satisfactionLess ankle motionWorse functional outcome

  • Malunion Rx:Talus osteotomyCalcaneus osteotomyPossible midfoot osteotomyTendo Achilles Lengthening

  • Talus ORIF TechniqueArthrosis (Subtalar)Pain &/or stiffness 16 (52%)Dx arthrosis 6 (19%)Subtalar arthrodesis 3 (10%)

    Talus ORIF Technique

  • Post Traumatic ArthritisIncidence of post-traumatic arthritis30-90 %

  • Post-Traumatic ArthritisMost commonly involves Subtalar joint

    Rx: Arthrodesis

  • NonunionUncommon, even with AVN

    Delayed Union very common

    Frequently results in late malalignment

  • Talar Body FracturesTreatment strategy and outcomes similar to talar neck fracturesMedial or Lateral Malleolar Osteotomy frequently required

  • Medial Malleolar OsteotomyPredrill and pretap malleolusOsteotomy aims just off the medial corner of mortise to facilitate interdigitationChevron, straight, or stepcut techniquesOsteotome to crack cartilage helps avoid mortise malalignment

  • Talar Body + Fibula FractureVisualize body through the fibula fracture

  • Talar Body Case Example58 year old female4 week old fractureMissed initially

  • Case, contdExtensive comminution into subtalar jointPoor bone quality

  • Selected Rx: Primary ArthrodesisTricortical bone graft to reconstitute talar height

  • Osteochondral InjuriesFrequently encountered with talus neck and body fracturesRequire small implants for fixationExcise if unstable and too small to fix

  • Osteochondral Injuries

  • Osteochondral Fragment RepairLarge fragment repaired, small fragment excised

  • Talar Head and Process FracturesTreat according to injuryOperate when associated with joint subluxation, incongruity, impingement or marked displacementFragments often too small to fix and require excision

  • Case Example: Talar Head FractureTalar head injurySubtle on plain x-ray

  • Talar Head Fracture, continuedCT demonstrates subtalar injury and subluxation

  • Treatment of Talar Head FractureRequired 2 incisions to debride subtalar joint from lateral approach, and reduce / stabilize fracture from medial side

  • Lateral Process ExampleUsually require CT scanOften excised due to size of fragments Difficult to achieve union

  • Lateral Talar Process FracturesSnowboarders fractureMechanism: may occur from inversion (avulsion injury) or eversion and axial loading (impaction fracture)Often misdiagnosed as ankle sprainBest results if treated early, either by immobilization, ORIF or fragment excisionIf diagnosed late consider fragment excision as attempts to achieve union often fail

  • Talus Fracture AO/ASIF ClassificationLateral Process (81-A2.1)

  • Treatment OptionsNon-operatively for minimally displaced fractures

    Excision of fragment

    Isolated mini fragment screws

    Mini plate fixation

  • Fracture ComplicationsExtend into subtalar joint

    Accelerated post-traumatic arthritis pain stiffness disability subsequent surgery for subtalar joint fusion

  • Mini Plate ProcedureLateral approachSubtalar chondral debris removedImpaction elevated if present & filled with allograft if requiredPreliminary 0.45 Kirschner wire (K-wire) fixation.2.0 mm T plate applied upside downLag screw fixation - avoiding overcompression with comminution

  • Talar FractureIsolated Lateral Process

  • Talus FractureLateral Process & Talar NeckMarginal ImpactionComminuted Fracture

  • Posterior Talar Process Fracture2 components: medial and lateral tubercleGroove for FHL tendon separates the two tuberclesDifferentiate fracture from os trigonum well corticated, smooth oval or round structure

  • Posterior Talar Process FracturesMedial tubercle fracture: Cedells fractureLateral tubercle: Shepherds fracture

    Treatment: immobilize or excise or ORIF

  • TreatmentUsually associated with Talar Neck FxPosteromedial Approach behind Neurovascular BundleMedial Malleolar Osteotomy usually not effective for exposure or fixation

  • Example 18 yo Car Surfer

  • CT Evaluation

  • Treatment 3 Incisions

  • Subtalar DislocationsSpectrum of injuries

    Relatively Innocent

    Very Disabling

  • ClassificationUsually based upon direction of dislocation:

    Medial dislocation: 85 %, low energyLateral dislocation: 15 %, high energy

  • Other Important Considerations:Open vs Closed

    High or low energy mechanism

    Stable or unstable post reductionReducible by closed means or requiring open reduction

    Associated impaction injuriesAll have prognostic significance:

  • Important Distinction:Total talar dislocation, or pan talar dislocationResults from continuation of force causing subtalar dislocationHigh risk of AVN, usually open, poor prognosisOpen pantalar dislocation with skin loss showing Incongruent reduction: Result was AVN and pantalar fusion

  • Management of Subtalar DislocationUrgent Closed reduction:Adequate sedationKnee flexionLongitudinal foot tractionAccentuate, then reverse deformity

    Successful in up to 90 % of patients

  • Open Reduction:More likely after high energy injuryMore likely with lateral dislocationCause:soft tissue interposition (Tib post, FHL, extensor tendons, capsule)bony impaction between the talus and navicular

  • Rehabilitation:Stable injuries: 4 weeks immobilizationPhysio for mobilizationUnstable injuries:Usually dont require internal fixation once reduction achievedIf necessary external fixation or transarticular wire fixation

  • Outcome of Subtalar Dislocations:Less benign than previously thoughtSubtalar arthritis:Up to 89 % radiographicallySymptomatic in up to 63 %Ankle and midfoot arthritis less common

  • Summary:Talar Neck FracturesAnatomyIncidenceImagingClassificationManagementComplicationsTalar body, head and process fractures

    Subtalar dislocationsClassificationManagement Outcomes

  • Selected ReferencesHawkins LG 1970 Fractures of the neck of the talus. J Bone Joint Surg Am 52(5):991-1002.Canale ST, Kelly FB, Jr. 1978 Fractures of the neck of the talus. Long-term evaluation of seventy-one cases. J Bone Joint Surg Am 60(2):143-56.the two classics on talus fractures. Rates of AVN, classification, etc. Good descriptive papers.Additional Clinical papers:Elgafy H, Ebraheim NA, Tile M, Stephen D, Kase J 2000 Fractures of the talus: experience of two level 1 trauma centers. Foot Ankle Int 21(12):1023-9.Metzger MJ, Levin JS, Clancy JT 1999 Talar neck fractures and rates of avascular necrosis. J Foot Ankle Surg 38(2):154-62.Pajenda G, Vecsei V, Reddy B, Heinz T 2000 Treatment of talar neck fractures: clinical results of 50 patients. J Foot Ankle Surg 39(6):365-75.

  • Selected ReferencesRecent Literature:Sanders DW, Busam M, Hattwick E, Edwards JR, McAndrew MP, Johnson KD. Functional outcomes following displaced talar neck fractures. J Orthop Trauma 2004; 18: 265-270.Vallier HA, Nork SE, Barei DP, Benirschke SK, Sangeorzan BJ. Talar neck fractures: results and outcomes. J Bone Joint Surg 2004; 86-A: 1616-1624.-Good outcome papers on talar neck

    Fleuriau Chateau PB, Brokaw DS, Jelen BA, Scheid DK, Weber TG. Plate fixation of talar neck fractures: preliminary review of a new technique in twenty-three patients. J Orthop Trauma. 2002;16(4):213-9.-plate fixation discussed Vallier HA, Nork SE, et al. Surgical treatment of talar body fractures. J Bone Joint Surg 2004; Supp 1: 180-92; and 2003; 85-A: 1716-24- good talar body review and surgical technique Bibbo C, Anderson R, Marsh WH. Injury characteristics and the clinical outcome of subtalar dislocations: a clinical and radiographic analysis of 25 cases. Foot ankle int 2003: 24: 158-63.-best current info on subtalar dislocations

  • References Cont.BiomechanicsSangeorzan BJ, Wagner UA, et al. Contact characteristics of the subtalar joint: the effect of talar neck misalignment. J Orthop Res 1992; 10(4): 544-51.Daniels TR, Smith JW, Ross TI. Varus malalignment of the talar neck. Its effect on the position of the foot and on subtalar motion. J Bone Joint Surg Am. 1996; 78: 1559-67.Swanson TV, Bray TJ, Holmes GB Jr. Fractures of the talar neck. A mechanical study of fixation. J Bone Joint Surg Am 1992; 74(4): 544-51.Attiah M, Sanders DW et al. Comminuted talar neck fractures: a mechanical study of fixation techniques. J Ortho Trauma 2007; 21: 47-51.

  • Return to Lower Extremity IndexIf you would like to volunteer as an author for the Resident Slide Project or recommend updates to any of the following slides, please send an e-mail to [email protected]

    *Thank you

    This project was performed at the Vanderbilt University Medical Centre With the collaboration of Matt Busam, Emily Hattwick, Ken Johnson and Mark McAndrew.*************Fractures of the talar neck are difficult injuries. While complications are frequent, the exact incidence is unclear from the literature. Depending upon the study, osteonecrosis rates have varied from 10 to 100 per cent in displaced fractures. Similarly, the incidence of post traumatic arthritis can vary greatly.

    The variations in reported outcomes are multifactorial but have led to difficulty in predicting a result for an individual patient.

    *The incidence of post traumatic arthritis, for example, varies from 30 to 90 per cent depending upon whether one is relying upon radiographic, clinical or functional outcome measures.

    (click to animate)

    While these outcome measures are important, it would be useful to know what the likelihood of requiring salvage surgery such as a subtalar fusion is. Use of a hard endpoint such as the need for secondary surgery can identify patients with a worse outcome, and allow us to compare and evaluate causes of treatment failure.