What is the treatment for an accessory bone in the ankle?

Treatment for Accessory Bone in Ankle

Initial treatment for an accessory bone in the ankle should be conservative, including rest, ice, compression, elevation, activity modification, and appropriate orthotic support for 6-8 weeks before considering surgical intervention. 1, 2

Diagnosis and Assessment

• Imaging studies:

  • Radiographs (anteroposterior and lateral views) are the initial diagnostic tool 1, 2
  • MRI is preferred over bone scan for symptomatic accessory ossicles as it allows visualization of bone marrow edema, synchondrosis, and associated tendon pathology 1
  • CT may be useful to confirm presence of accessory ossicle, fragmentation, or fracture 1

• Clinical presentation:

  • Pain localized to the area of the accessory bone
  • Possible redness and swelling 2
  • Symptoms often worsen with activity and improve with rest 3
  • May be mistaken for avulsion fracture 2

Conservative Management (First-Line Treatment)

1. Initial treatment (first 3-5 days):

   • RICE protocol (Rest, Ice, Compression, Elevation) 1, 2
   • Ice application for 20-30 minutes, 3-4 times daily 4
   • Avoid activities that cause pain 4

2. Supportive measures:

   • Appropriate footwear modifications (open-backed shoes for posterior accessory bones) 1
   • Orthotic devices or heel lifts 1, 3, 5
   • Splinting or bracing to stabilize the area 2, 5

3. Pain management:

   • NSAIDs for pain and inflammation 1
   • Avoid corticosteroid injections near the Achilles tendon 1

4. Activity modification:

   • Decreased weight-bearing activities 1
   • Stretching exercises as appropriate 1, 5

5. Duration of conservative treatment:

   • Continue for 6-8 weeks if improvement is noted 1, 2
   • If no improvement after 6-8 weeks, consider referral to foot and ankle specialist 1

Advanced Conservative Measures

If initial conservative treatment shows partial improvement:

• Immobilization with cast or fixed-ankle walker-type device 1
• Physical therapy focusing on:
  • Joint mobilization 5
  • Progressive strengthening 5
  • Proprioceptive training 4
  • Taping techniques 5

Surgical Management

Consider surgical intervention only if:

• Conservative treatment fails after 6 months 2
• Patient has persistent pain affecting quality of life 5
• Functional limitations persist despite adequate conservative management 6

Surgical options depend on the specific accessory bone:

• For accessory navicular: Excision of the accessory bone and reattachment or advancement of the posterior tibial tendon 5
• For os trigonum: Resection of the accessory bone 1
• For Haglund's deformity: Resection of the prominent posterior superior aspect of the calcaneus and inflamed bursa 1

Special Considerations

• Post-stroke patients: Accessory navicular syndrome may develop during rehabilitation due to overactivity of posterior tibialis muscle 3
• Athletes: May require more aggressive treatment due to higher functional demands 7
• Children and adolescents: Conservative management is strongly preferred as first-line treatment 2

Monitoring and Follow-up

• Regular assessment of pain levels and functional improvement
• Gradual return to activities as symptoms improve
• If symptoms persist or worsen despite appropriate conservative management, reassess diagnosis and consider advanced imaging or specialist referral 1, 6

Pitfalls to Avoid

• Misdiagnosis as fracture leading to unnecessary immobilization 7
• Failure to recognize accessory bones as potential pain generators 6
• Premature surgical intervention before adequate trial of conservative measures 2
• Inadequate attention to biomechanical factors contributing to symptoms 5