Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

 

Complications of Talar Neck Fractures

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Overview

• Talar neck fractures can result in serious complications affecting:
  • Joint function
  • Bone viability

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Major Complications

• Post-traumatic arthritis
• Avascular necrosis (AVN)
• Malunion
• Nonunion

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Post-Traumatic Arthritis

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Subtalar Arthritis

• Most common complication
• Incidence:
  • ~50–100%

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Cause

• Cartilage damage at time of injury

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Ankle (Tibiotalar) Arthritis

• Incidence:
  • ~30%

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Avascular Necrosis (AVN) of Talus

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Definition

• Death of bone due to loss of blood supply

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Pathophysiology

• Primarily affects:
  • Body of talus
• Usually partial involvement, not entire talus

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Blood Supply of Talus

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Key Vessels

• Artery of tarsal canal (dominant)
• Deltoid branch of posterior tibial artery
• Artery of tarsal sinus

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Critical Point

• Deltoid branch may be:
  • Only remaining blood supply in displaced fractures

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Surgical Importance

• Must be preserved during surgery

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Risk Factors for AVN

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• Increased fracture displacement
• Severe injury patterns
• Open fractures

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Hawkins Classification & AVN Risk

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Overall AVN Incidence

• ~30%

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Diagnosis of AVN

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Hawkins Sign

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Definition

• Subchondral radiolucent line in talar dome

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Timing

• Appears at:
  • 6–8 weeks

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Significance

• Indicates:
  • Preserved blood supply
  • Good prognosis

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Diagnostic Value

• Sensitivity:
  • ~100%
• Specificity:
  • ~57%

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Important Note

• Absence does not confirm AVN

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Imaging

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MRI

• Detects early AVN
• Shows:
  • Reduced T1 signal

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Limitation

• May not change treatment

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Implant Consideration

• Titanium implants:
  • Less MRI artifact than stainless steel

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Nonunion

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• Incidence:
  • ~5%

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Definition

• Failure of fracture healing

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Malunion

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1. Varus Malunion

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Incidence

• ~25–30%

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Cause

• Medial comminution

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Clinical Features

• Hindfoot varus deformity
• Reduced subtalar motion
• Limited eversion
• Walking on lateral foot border

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Prevention

• Restore:
  • Articular surface
  • Alignment
  • Talar shape

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Treatment

• Medial opening wedge osteotomy

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2. Dorsal Malunion

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Mechanism

• Head heals in dorsal position

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Consequences

• Ankle impingement
• Reduced dorsiflexion

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Treatment

• Dorsal resection

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Follow-Up and Weight Bearing

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Monitoring

• Clinical assessment
• Radiographs

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Assess

• Fracture healing
• AVN development

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Weight Bearing

• Begin after:
  • Confirmed fracture healing

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Important Point

• Prolonged non-weight bearing:
  • Does not reduce AVN risk

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Key Takeaways

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• Subtalar arthritis = most common complication
• AVN risk increases with fracture severity
• Hawkins classification predicts AVN risk
• Hawkins sign = good prognostic indicator
• Malunion can significantly affect function
• Careful reduction + follow-up = critical