1. 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.

2. Outline: Talar Neck Fractures Anatomy Incidence Imaging Classification
Management
Complications
Talar body, head and process fractures
Subtalar dislocations
Classification
Management
Outcomes

3. Anatomy
Surface 60% cartilage
No muscular insertions

4. 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

5. 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

6. Vascularity
Talus ORIF Technique

7. Incidence 2 % of all fractures 6-8% of foot fractures
High complication rates
avascular necrosis
post-traumatic arthritis
malunion

8. 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

9. 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

10. 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

11. 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

12. 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

13. CT Scan Most useful assessment tool for surgical planning
Confirms displacement
Demonstrates subtalar joint reduction, comminution, osteochondral fractures/debris

14. 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

15. Talar Neck Fractures: Classification
Hawkins, 1970
Predictive of AVN rate
Widely used

16. 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

17. Hawkins 1 Type I: undisplaced AVN rate 0 – 13 %
Uncommon as most talar neck fractures are displaced

18. Hawkins 2 Displaced fracture with subtalar subluxation / dislocation
A) fracture line enters subtalar joint
B) subtalar joint intact
AVN 20 – 50 %
Most common type

19. 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 %

20. 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

21. Classification: Comminution:
An important additional predictor of results, especially regarding prognosis re:
Malunion
Subtalar joint arthritis
Included in AO-OTA classification as a modifier

22. Goals of Management Immediate reduction of dislocated joints
Vascularity
Cutaneous tension
Vascular compromise
Anatomic fracture reduction
Stable fixation
Facilitate union
Avoid complications

23. 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 (AP, PA), countersink
Plates (2.0 mini condylar or T)
Dual incisions
Do not dissect capsular attachments
Maintain as much soft tissue attachments
Talus ORIF Technique

24. 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

25. 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

26. 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

27. Hawkins II, III, and IV Fractures:
Results dependent upon development of complications
Osteonecrosis
Malunion
Arthritis

28. Case Example
29 yo male
ATV rollover
Isolated injury LLE

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

30. Diagnosis “Hawkins’ 3” talar neck fracture
Associated comminution, probably involving medial column and subtalar joint

31. Controversies for this Case:
????
Surgical timing
Closed reduction
Surgical approach
Fixation

32. Surgical Timing In general: emergent reduction of dislocated joints
Allow life threatening injuries to take priority and resuscitate adequately first

33. Closed Reduction?
May be very useful, particularly if other life threatening injuries preclude definitive surgery
Difficult in Hawkins’ 3 and 4 injuries

34. 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

35. Closed Reduction Example

36. 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

37. 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

38. 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

39. 1st Approach: Anteromedial
Medial to TibAnt
Make incision more posterior for talar body fractures to facilitate medial malleolar osteotomy

40. 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

41. 2nd Approach: Lateral Tip of Fibula directly anterior
Mobilize EDB as sleeve
Protect sinus tarsi contents

42. 2nd Approach: Lateral
Visualizes Anterolateral alignment and subtalar joint
Facilitates Placement of “Shoulder Screw” or lateral plate

43. 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

44. 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

45. 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

46. 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°

47. 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

48. 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

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

50. Hawkins 3
Talus ORIF Technique

51. Talus ORIF Technique

52. Complications
AVN
Malunion
Nonunion
Arthritis

53. 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

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

55. 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

56. AVN: Diagnosis Hawkins’ Sign: Xray finding 6-8 weeks post injury
Presence of subchondral lucency implies revascularization

57. AVN: Imaging
Plain radiographs: sclerosis common, decreases with revascularization
MRI: very sensitive to decreased vascularity

58. Hawkins 3
Talus ORIF Technique

59. |Osteonecrosis without collapse
1 year follow-up
|Osteonecrosis without collapse
Talus ORIF Technique

60. Bilateral Injuries Fixed at 72 hours

61. 2 years – Pain, Stiffness, Limp
Hawkins III
Hawkins II

62. AVN Treatment: Precollapse: Postcollapse: Modified WB PTB cast
Compliance difficult
Efficacy unknown
Postcollapse:
Observation
“Blair fusion” is one option if symptomatic

63. Malunion: Incidence
Common: up to 40%
Most often Varus

64. Malunion: Diagnosis
Varus hindfoot, midfoot supination on clinical exam
Dorsal malunion on Xray

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

66. Clinical Effect of Malunion
More pain
Less satisfaction
Less ankle motion
Worse functional outcome

67. Malunion Rx: Talus osteotomy Calcaneus osteotomy
Possible midfoot osteotomy
Tendo Achilles Lengthening

68. Arthrosis (Subtalar) Pain &/or stiffness – 16 (52%)
Dx arthrosis – 6 (19%)
Subtalar arthrodesis – 3 (10%)
Talus ORIF Technique

69. 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.

70. 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.

71. Nonunion Uncommon, even with AVN Delayed Union very common
Frequently results in late malalignment

72. Talar Body Fractures
Treatment strategy and outcomes similar to talar neck fractures
Medial or Lateral Malleolar Osteotomy frequently required

73. 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

74. Talar Body + Fibula Fracture
Visualize body through the fibula fracture

75. Talar Body Case Example
58 year old female
4 week old fracture
Missed initially

76. Case, cont’d Extensive comminution into subtalar joint
Poor bone quality

77. Selected Rx: Primary Arthrodesis
Tricortical bone graft to
reconstitute talar height

78. Osteochondral Injuries
Frequently encountered with talus neck and body fractures
Require small implants for fixation
Excise if unstable and too small to fix

79. Osteochondral Injuries

80. Osteochondral Fragment Repair
Large fragment repaired, small fragment excised

81. 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

82. Case Example: Talar Head Fracture
Talar head injury
Subtle on plain x-ray

83. Talar Head Fracture, continued
CT demonstrates subtalar injury and subluxation

84. Treatment of Talar Head Fracture
Required 2 incisions to debride subtalar joint from lateral approach, and reduce / stabilize fracture from medial side

85. Lateral Process Example
Usually require CT scan
Often excised due to size of fragments
Difficult to achieve union

86. 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

87. Talus Fracture AO/ASIF Classification
Lateral Process (81-A2.1)

88. Treatment Options Non-operatively for minimally displaced fractures
Excision of fragment
Isolated mini fragment screws
Mini plate fixation

89. Fracture Complications
Extend into subtalar joint
Accelerated post-traumatic arthritis
pain
stiffness
disability
subsequent surgery for subtalar joint fusion

90. 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

91. Talar Fracture Isolated Lateral Process

92. Talus Fracture Lateral Process & Talar Neck
Marginal Impaction
Comminuted Fracture

93. 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

94. Posterior Talar Process Fractures
Medial tubercle fracture: “Cedell’s fracture”
Lateral tubercle: “Shepherd’s fracture”
Treatment: immobilize or excise or ORIF

95. Treatment Usually associated with Talar Neck Fx
Posteromedial Approach behind Neurovascular Bundle
Medial Malleolar Osteotomy – usually not effective for exposure or fixation

96. Example – 18 yo “Car Surfer”

97. CT Evaluation

98. Treatment – 3 Incisions

99. Subtalar Dislocations
Spectrum of injuries
Relatively Innocent
Very Disabling

100. Classification Usually based upon direction of dislocation:
Medial dislocation: 85 %, low energy
Lateral dislocation: 15 %, high energy

101. 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

102. 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

103. 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

104. 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

105. 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

106. 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

107. Summary: Talar Neck Fractures Anatomy Incidence Imaging Classification
Management
Complications
Talar body, head and process fractures
Subtalar dislocations
Classification
Management
Outcomes

108. 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):

109. 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

110. 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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