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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 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.
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Outline: Talar Neck Fractures Anatomy Incidence Imaging Classification
Management Complications Talar body, head and process fractures Subtalar dislocations Classification Management Outcomes
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Anatomy Surface 60% cartilage No muscular insertions
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Inferior view of talus, showing
Blood Supply 4 primary arterial sources: Artery of tarsal canal Artery of tarsal sinus Dorsal neck vessels Deltoid branches lateral medial Inferior view of talus, showing vascular anastomosis
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Vascularity Artery of tarsal canal supplies majority of talar body
Top View Side View Deltoid Branches Superior Neck Vessels Artery of Tarsal Canal Posterior tubercle vessels Artery of Tarsal Canal Superior Neck Vessels Posterior tubercle vessels Artery of Tarsal Sinus Artery of Tarsal Sinus
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Vascularity Talus ORIF Technique
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Incidence 2 % of all fractures 6-8% of foot fractures
High complication rates avascular necrosis post-traumatic arthritis malunion
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Mechanism of Injury Hyperdorsiflexion of the foot on the leg
Neck of talus impinges against anterior distal tibia, causing neck fracture If force continues: talar body dislocates posteromedial often around deltoid ligament
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Injury Mechanism Previously called “aviator’s astragalus”
Usually due to motor vehicle accident or falls from height Approximately 50 % of patients have multiple traumatic injuries
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Biomechanics Theoretical 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
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Imaging Complex 3-D structure Multiple plain film orientations:
AP, Lateral, Broden, & mortise views demonstrates joint congruity of ankle and subtalar joint Canale view for longitudinal alignment: approximately 15° IR to get calcaneous out of view Canale View
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Canale View Slight ankle plantarflexion with knee bent to rest foot on the table 15 degree pronation Xray Tube 15 degree from vertical Canale View
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CT Scan Most useful assessment tool for surgical planning
Confirms displacement Demonstrates subtalar joint reduction, comminution, osteochondral fractures/debris
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MRI Scan Primary role in talus injuries is to assess complications, especially avascular necrosis May be poor quality if extensive hardware present Zone of osteonecrosis following distribution of Artery of Tarsal Canal
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Talar Neck Fractures: Classification
Hawkins, 1970 Predictive of AVN rate Widely used
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Hawkins Classification Hawkins, LR, JBJS, 52A: 991, 1970
Nondisplaced <10% Subtalar Displacement <40% Subtalar & TC ~90% *Pantalar 100% Talus ORIF Technique *Canale, ST, JBJS, 60A: 143, 1978
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Hawkins 1 Type I: undisplaced AVN rate 0 – 13 %
Uncommon as most talar neck fractures are displaced
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Hawkins 2 Displaced fracture with subtalar subluxation / dislocation
A) fracture line enters subtalar joint B) subtalar joint intact AVN 20 – 50 % Most common type
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Hawkins 3 Subtalar and ankle joint dislocated
Talar body extrudes, usually around deltoid ligament Commonly open fractures, reduction very difficult Closed: plantar flex foot & flex knee Open: joy sticks AVN 83 – 100 %
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Hawkins 4 Added to classification by Canale, 1974
Incorporates talonavicular subluxation Rare variant Complex talar neck fractures which otherwise do not fit classification are included as Type 4 injuries
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Classification: Comminution:
An important additional predictor of results, especially regarding prognosis re: Malunion Subtalar joint arthritis Included in AO-OTA classification as a modifier
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Goals of Management Immediate reduction of dislocated joints
Vascularity Cutaneous tension Vascular compromise Anatomic fracture reduction Stable fixation Facilitate union Avoid complications
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Definitive Treatment Prompt anatomic operative reduction
“die is cast” with injury Use “joy stick” K-wires for reduction Articular bone affects ROM (V, Sup, PF) Maintenance of reduction with HW Screws (AP, PA), countersink Plates (2.0 mini condylar or T) Dual incisions Do not dissect capsular attachments Maintain as much soft tissue attachments Talus ORIF Technique
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Treatment of Talar Neck Fractures
Emergent reduction of dislocated joints Stable internal fixation Debridement of subtalar joint Maintain as much soft tissue/vascular attachments Choice of fixation and approach depends upon personality of fracture
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Treatment of Talar Neck Fractures
Post operative rehabilitation: Sample protocol: Initial immobilization, 2-6 weeks depending upon soft tissue injury and patient factors, to prevent contractures and facilitate healing Non weight-bearing, Range of Motion therapy until 3 months or fracture union
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Hawkins I Fracture Options:
Non Operative & Non-Weight-Bearing Cast for 4-6 weeks followed by removable brace and motion OR: Percutaneous screw fixation and early motion
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Hawkins II, III, and IV Fractures:
Results dependent upon development of complications Osteonecrosis Malunion Arthritis
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Case Example 29 yo male ATV rollover Isolated injury LLE
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These injury films are tough to interpret, but close review demonstrates the dislocated talar body with some comminution.
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Diagnosis “Hawkins’ 3” talar neck fracture
Associated comminution, probably involving medial column and subtalar joint
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Controversies for this Case:
???? Surgical timing Closed reduction Surgical approach Fixation
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Surgical Timing In general: emergent reduction of dislocated joints
Allow life threatening injuries to take priority and resuscitate adequately first
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Closed Reduction? May be very useful, particularly if other life threatening injuries preclude definitive surgery Difficult in Hawkins’ 3 and 4 injuries
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Closed Reduction Technique:
Adequate sedation Flex knee to relax gastrocs Traction on plantar flexed forefoot to realign head with body Varus/valgus correction as necessary Direct pressure on talar body Adjunct: traction pin, general anesthetic, etc Avoid repetitive reduction attempts in order to avoid skin compromise or tearing
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Closed Reduction Example
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External Fixation Limited roles:
Multiply injured patient with talar neck fracture in whom definitive surgery will be delayed Temporizing measure to stabilize reduced joints Construct bridges tibia – calcaneus – midfoot
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Surgical Approaches: Options
1 incision techniques: Anteromedial or Anterolateral Problem: difficult to visualize the entire talar neck and subtalar joint without significant soft tissue stripping and devascularization Problem: usual medial comminution inhibits accurate read of fracture reduction
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Surgical Approaches: Options
2 incision technique: (generally preferred) Anteromedial and lateral/anterolateral Problem: 2 skin incisions, close together Benefit: excellent fracture visualization at critical sites of reduction and subtalar joint with less stripping
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1st Approach: Anteromedial
Medial to TibAnt Make incision more posterior for talar body fractures to facilitate medial malleolar osteotomy
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1st Approach: Anteromedial
Provides view of neck alignment and medial comminution Extend incision distally to talonavicular joint – hardware is placed distal to proximal and needs to be well countersunk to avoid impingement
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2nd Approach: Lateral Tip of Fibula directly anterior
Mobilize EDB as sleeve Protect sinus tarsi contents
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2nd Approach: Lateral Visualizes Anterolateral alignment and subtalar joint Facilitates Placement of “Shoulder Screw” or lateral plate
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2 incisions: Skin bridge
Narrow skin bridge but generally well tolerated Talus fractures generally have less soft tissue problems compared to plafond or calcaneus fractures
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Fixation Options Stable Fixation to allow early motion is the goal
1200 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
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Surgical Tactics: Fixation
Anterior Partial threaded screws Fully threaded screws Mini-fragment plates (2.0, 2.4 mm) Posterior Lag screws Implant selection depends upon injury, degree of comminution, bone quality
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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 motion Avoid excessive posterior capsular stripping Creates potentially 3 incisions (posterior, medial, lateral) 90°
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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
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Anterior Screw Fixation:
This example: 4.0 mm partially threaded compression screws through non-comminuted columns Mini-fragment (2.4 mm) screws for osteochondral fragments Consider Titanium for MRI
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Plate Fixation: Very useful in comminuted fractures:
2.0 or 2.4 mm plates Easiest to apply to lateral cortex – impinge on medial side
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Hawkins 3 Talus ORIF Technique
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Talus ORIF Technique
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Complications AVN Malunion Nonunion Arthritis
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Results Chateau, Indy, 2002 JOT Harborview, 2002 OTA 23 pts, 20 mo F/U
Dual, mini fragment “Low” rate AVN Harborview, 2002 OTA 60 fx, 30 mo F/U w/in 24 hr (40 pts)/ Dual 91% Worse results with: Comminution Open Osteonecrosis 39% (II) 56% to collapse 64% (III) 67% to collapse Elgafy, Foot Ankle 2000 60 fx Arthritis: Ankle 25%, Subtalar 53% AVN 16% Talus ORIF Technique
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AVN: Incidence after Talus Fracture
Canale (1972): I: 15 % II: 50 % III: 85 % IV: 100 % Behrens (1988): Overall 25 % Ebraheim/Stephen (2001): Overall 20 %
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AVASCULAR NECROSIS AVN does not = poor result
Rates with Hawkins Class AVN does not = poor result ? MRI-probably not prognostic ? Does early ORIF minimize AVN Talus ORIF Technique
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AVN: Diagnosis Hawkins’ Sign: Xray finding 6-8 weeks post injury
Presence of subchondral lucency implies revascularization
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AVN: Imaging Plain radiographs: sclerosis common, decreases with revascularization MRI: very sensitive to decreased vascularity
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Hawkins 3 Talus ORIF Technique
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|Osteonecrosis without collapse
1 year follow-up |Osteonecrosis without collapse Talus ORIF Technique
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Bilateral Injuries Fixed at 72 hours
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2 years – Pain, Stiffness, Limp
Hawkins III Hawkins II
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AVN Treatment: Precollapse: Postcollapse: Modified WB PTB cast
Compliance difficult Efficacy unknown Postcollapse: Observation “Blair fusion” is one option if symptomatic
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Malunion: Incidence Common: up to 40% Most often Varus
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Malunion: Diagnosis Varus hindfoot, midfoot supination on clinical exam Dorsal malunion on Xray
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Malunion Mechanical effects
> 3 degrees malunion: decreased subtalar ROM (Daniels TR, JBJS 1996) > 2mm: altered subtalar contact forces (Sangeorzan J Orthop Res 1992)
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Clinical Effect of Malunion
More pain Less satisfaction Less ankle motion Worse functional outcome
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Malunion Rx: Talus osteotomy Calcaneus osteotomy
Possible midfoot osteotomy Tendo Achilles Lengthening
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Arthrosis (Subtalar) Pain &/or stiffness – 16 (52%)
Dx arthrosis – 6 (19%) Subtalar arthrodesis – 3 (10%) Talus ORIF Technique
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Post Traumatic Arthritis
Incidence of post-traumatic arthritis 30-90 % 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.
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Post-Traumatic Arthritis
Most commonly involves Subtalar joint Rx: Arthrodesis 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.
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Nonunion Uncommon, even with AVN Delayed Union very common
Frequently results in late malalignment
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Talar Body Fractures Treatment strategy and outcomes similar to talar neck fractures Medial or Lateral Malleolar Osteotomy frequently required
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Medial Malleolar Osteotomy
Predrill and pretap malleolus Osteotomy aims just off the medial corner of mortise to facilitate interdigitation Chevron, straight, or stepcut techniques Osteotome to crack cartilage helps avoid mortise malalignment
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Talar Body + Fibula Fracture
Visualize body through the fibula fracture
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Talar Body Case Example
58 year old female 4 week old fracture Missed initially
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Case, cont’d Extensive comminution into subtalar joint
Poor bone quality
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Selected Rx: Primary Arthrodesis
Tricortical bone graft to reconstitute talar height
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Osteochondral Injuries
Frequently encountered with talus neck and body fractures Require small implants for fixation Excise if unstable and too small to fix
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Osteochondral Injuries
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Osteochondral Fragment Repair
Large fragment repaired, small fragment excised
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Talar Head and Process Fractures
Treat according to injury Operate when associated with joint subluxation, incongruity, impingement or marked displacement Fragments often too small to fix and require excision
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Case Example: Talar Head Fracture
Talar head injury Subtle on plain x-ray
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Talar Head Fracture, continued
CT demonstrates subtalar injury and subluxation
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Treatment of Talar Head Fracture
Required 2 incisions to debride subtalar joint from lateral approach, and reduce / stabilize fracture from medial side
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Lateral Process Example
Usually require CT scan Often excised due to size of fragments Difficult to achieve union
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Lateral Talar Process Fractures
“Snowboarder’s fracture” Mechanism: may occur from inversion (avulsion injury) or eversion and axial loading (impaction fracture) Often misdiagnosed as “ankle sprain” Best results if treated early, either by immobilization, ORIF or fragment excision If diagnosed late consider fragment excision as attempts to achieve union often fail
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Talus Fracture AO/ASIF Classification
Lateral Process (81-A2.1)
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Treatment Options Non-operatively for minimally displaced fractures
Excision of fragment Isolated mini fragment screws Mini plate fixation
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Fracture Complications
Extend into subtalar joint Accelerated post-traumatic arthritis pain stiffness disability subsequent surgery for subtalar joint fusion
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Mini Plate Procedure Lateral approach Subtalar chondral debris removed
Impaction elevated if present & filled with allograft if required Preliminary 0.45 Kirschner wire (K-wire) fixation. 2.0 mm “T” plate applied upside down Lag screw fixation - avoiding overcompression with comminution
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Talar Fracture Isolated Lateral Process
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Talus Fracture Lateral Process & Talar Neck
Marginal Impaction Comminuted Fracture
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Posterior Talar Process Fracture
2 components: medial and lateral tubercle Groove for FHL tendon separates the two tubercles Differentiate fracture from os trigonum – well corticated, smooth oval or round structure
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Posterior Talar Process Fractures
Medial tubercle fracture: “Cedell’s fracture” Lateral tubercle: “Shepherd’s fracture” Treatment: immobilize or excise or ORIF
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Treatment Usually associated with Talar Neck Fx
Posteromedial Approach behind Neurovascular Bundle Medial Malleolar Osteotomy – usually not effective for exposure or fixation
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Example – 18 yo “Car Surfer”
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CT Evaluation
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Treatment – 3 Incisions
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Subtalar Dislocations
Spectrum of injuries Relatively Innocent Very Disabling
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Classification Usually based upon direction of dislocation:
Medial dislocation: 85 %, low energy Lateral dislocation: 15 %, high energy
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Other Important Considerations:
All have prognostic significance: Open vs Closed High or low energy mechanism Stable or unstable post reduction Reducible by closed means or requiring open reduction Associated impaction injuries
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Important Distinction:
Total talar dislocation, or pan talar dislocation Results from continuation of force causing subtalar dislocation High risk of AVN, usually open, poor prognosis Open pantalar dislocation with skin loss showing Incongruent reduction: Result was AVN and pantalar fusion
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Management of Subtalar Dislocation
Urgent Closed reduction: Adequate sedation Knee flexion Longitudinal foot traction Accentuate, then reverse deformity Successful in up to 90 % of patients
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Open Reduction: More likely after high energy injury
More likely with lateral dislocation Cause: soft tissue interposition (Tib post, FHL, extensor tendons, capsule) bony impaction between the talus and navicular
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Rehabilitation: Stable injuries: Unstable injuries:
4 weeks immobilization Physio for mobilization Unstable injuries: Usually don’t require internal fixation once reduction achieved If necessary – external fixation or transarticular wire fixation
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Outcome of Subtalar Dislocations:
Less benign than previously thought Subtalar arthritis: Up to 89 % radiographically Symptomatic in up to 63 % Ankle and midfoot arthritis less common
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Summary: Talar Neck Fractures Anatomy Incidence Imaging Classification
Management Complications Talar body, head and process fractures Subtalar dislocations Classification Management Outcomes
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Selected References Hawkins LG 1970 Fractures of the neck of the talus. J Bone Joint Surg Am 52(5): Canale ST, Kelly FB, Jr Fractures of the neck of the talus. Long-term evaluation of seventy-one cases. J Bone Joint Surg Am 60(2): 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): Metzger MJ, Levin JS, Clancy JT 1999 Talar neck fractures and rates of avascular necrosis. J Foot Ankle Surg 38(2): 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):
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Selected References Recent 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: Vallier HA, Nork SE, Barei DP, Benirschke SK, Sangeorzan BJ. Talar neck fractures: results and outcomes. J Bone Joint Surg 2004; 86-A: 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): plate fixation discussed Vallier HA, Nork SE, et al. Surgical treatment of talar body fractures. J Bone Joint Surg 2004; Supp 1: ; and 2003; 85-A: 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: best current info on subtalar dislocations
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References Cont. Biomechanics
Sangeorzan BJ, Wagner UA, et al. Contact characteristics of the subtalar joint: the effect of talar neck misalignment. J Orthop Res 1992; 10(4): 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 ; 78: 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): Attiah M, Sanders DW et al. Comminuted talar neck fractures: a mechanical study of fixation techniques. J Ortho Trauma 2007; 21:
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