What is the recommended treatment for a patient with a distal fibula fracture caudal to the talar dome and an os navicular type 2 fracture?

Management of Distal Fibula Fracture Caudal to the Talar Dome with Os Navicular Type 2

For a distal fibula fracture caudal to the talar dome with an os navicular type 2, surgical management is recommended for the fibular fracture while the os navicular type 2 should be initially managed conservatively with orthotics or immobilization, with surgical excision reserved for cases that fail conservative treatment.

Diagnostic Assessment

Imaging

• Initial evaluation requires three standard radiographic views 1:

  • Anteroposterior
  • Lateral
  • Mortise views

• Weight-bearing radiographs are crucial for assessing fracture stability 1

  • Medial clear space <4 mm confirms stability
  • Additional imaging may be needed based on specific findings

• CT without contrast is recommended if radiographs are equivocal but clinical suspicion remains high 2

Treatment Algorithm

Distal Fibula Fracture Management

1. Assess fracture stability:

   • Check for medial tenderness, bruising, or swelling
   • Evaluate if fracture is above the syndesmosis
   • Look for bi- or trimalleolar involvement
   • Determine if it's an open or high-energy injury 1

2. Treatment options:

   • Unstable fractures: Surgical intervention with open reduction and internal fixation (ORIF) 1, 2
   • Stable fractures: Conservative management with immobilization 2

Os Navicular Type 2 Management

1. Initial approach:

   • Conservative management with orthotics or cast immobilization 3
   • NSAIDs for pain and inflammation control 2

2. For persistent symptoms:

   • 99mTc MDP imaging may be valuable to determine if the os navicular is symptomatic 3
   • Increased radionuclide activity will only occur on the symptomatic side even if the condition is bilateral 3

3. For failed conservative treatment:

   • Surgical excision of the accessory navicular may be the treatment of choice 3

Rehabilitation Protocol

• Early finger motion exercises to prevent stiffness 1
• A directed home exercise program is recommended after initial immobilization period 1, 2
• Limit immobilization duration to reduce complications 2

Potential Complications

• Joint stiffness
• Chronic pain
• Post-traumatic arthritis 2
• For os navicular type 2: inflammatory changes at the navicular-accessory navicular synchondrosis compatible with chronic trauma and stress fracture 3

Follow-up Recommendations

• Regular assessment of wound healing and radiographic union 2
• Monitor for hardware-related pain or complications
• Unremitting pain during follow-up warrants reevaluation 1
• Patients should be instructed to move regularly through a complete range of motion to minimize stiffness 1

Special Considerations

• Type 2 os navicular is particularly problematic in athletic adolescents 3
• The histologic examination of surgically excised specimens reveals inflammatory chondro-osseous changes in the navicular-accessory navicular synchondrosis compatible with chronic trauma and stress fracture 3
• Ensure compliance with rehabilitation protocols to optimize outcomes 2