Sesamoid Problems

Epidemiology

• Tibial sesamoid is 10x more commonly bipartite
• Tibial sesamoid is most commonly affected in all pathologies
• Athletes are the most commonly affected group

Anatomy

• Lie within Flexor Hallucis Brevis (FHB) tendon
• Stabilized by intersesamoid and sesamoidometatarsal ligaments
• Function:
  • Increase lever arm of FHB
  • Protect Flexor Hallucis Longus (FHL)
  • Distribute load

Common Pathologies

Stress Fracture

• Most common
• Avascular necrosis (AVN) & sesamoiditis are likely stress fractures
• Non-union of the fracture is the main cause of symptoms

Symptomatic Bipartite Sesamoid

• Usually exacerbated by exercise
• Can be due to a single traumatic dorsiflexion event – turf toe

Osteoarthritis

• Sesamoid/MT OA can be isolated or part of Hallux Rigidus

Overload

• If there is another mechanical foot problem – cavus is typical
• Plantarflexed 1st ray overloads the sesamoids

Diabetic Feet

• Ulceration can occur and expose the sesamoids

Clinical Evaluation

History & Examination

• History of dorsiflexion injury
• Point tenderness under big toe
• Exacerbating activities – dorsiflexion (e.g., running)
• Other foot or systemic problems – cavus?

Imaging

• Sesamoid view X-rays
• Standing AP
• Bone Scan/MRI
• Bone scan shows high uptake, which is usually enough
  • MRI provides no further relevant information

Management Options

Non-Operative

• Cut-out padding
• Rocker bottom shoe
• Activity modification

Surgical Options

Therapeutic/Diagnostic Injection

• Probably worthwhile before considering surgery

Sesamoidectomy

• No significant reduction of FHB power unless both sesamoids resected
• Complications:
  • Medial plantar digital nerve injury – right over tibial sesamoid
  • Cock-up toe – if both excised
  • Hallux Valgus – medial sesamoidectomy
  • Hallux Varus – lateral sesamoidectomy

Sesamoid Shaving

• Alternative to sesamoidectomy, partial removal of sesamoid

Bone Grafting

• Has been successful for non-unions

ORIF

• ORIF with micro Ackutrak or Barouk screws has good results