Where is sesamoiditis pain typically located?

Sesamoiditis Pain Location

Sesamoiditis pain is typically located under the first metatarsophalangeal joint (the ball of the foot beneath the big toe), specifically at the hallucal sesamoid bones. 1

Anatomical Location and Characteristics

• The hallucal sesamoid bones are embedded in the flexor hallucis brevis tendon and connected by the intersesamoid ligament and plantar plate beneath the first metatarsal head 2
• Pain is concentrated at the plantar aspect of the first metatarsal head where the sesamoid apparatus acts as a pulley to help pull the big toe down during walking 2
• The first metatarsal articulation bears approximately one-third of the weight of the forefoot, making this area susceptible to repetitive pressure injuries 2
• Pain is typically exacerbated by weight-bearing activities, particularly when pushing off during walking or running 3

Diagnostic Considerations

• Sesamoiditis presents as localized pain and tenderness directly under the first metatarsal head 3, 4
• The condition can affect either the medial (tibial) or lateral (fibular) sesamoid, though the medial sesamoid is more commonly affected due to bearing more weight 5
• Sesamoiditis may be confused with other conditions that cause pain in the same region, such as:
  • Sesamoid stress fractures or acute fractures 3, 4
  • Sesamoid nonunions 3
  • Avascular necrosis of the sesamoids 5
  • Chondromalacia of the sesamoid 3
  • Gout affecting the sesamoid 6

Imaging Findings

• On bone scintigraphy, sesamoiditis appears as increased uptake in the affected sesamoid bone 1
• MRI is useful for diagnosing sesamoiditis and can show bone marrow edema and other stress-related changes 1
• CT can help distinguish between sesamoiditis, stress fractures, and bipartite sesamoids 1
• Radiographs are often normal in early sesamoiditis but may show sclerosis or fragmentation in chronic cases 4

Clinical Pearls

• Sesamoiditis pain is often described as a deep, aching pain that worsens with activities that involve pushing off with the big toe 3
• Pain may be accompanied by swelling and difficulty wearing shoes 3, 4
• Bipartite sesamoids (a normal anatomical variant) can sometimes be mistaken for fractures on imaging 4
• In athletes, particularly those involved in activities requiring repetitive forefoot loading (dancers, runners), sesamoiditis is more common 5

Common Pitfalls

• Failing to differentiate sesamoiditis from other causes of forefoot pain such as Morton's neuroma, which typically causes pain between the third and fourth metatarsal heads 7
• Misdiagnosing a bipartite sesamoid (normal variant) as a fracture 4
• Overlooking systemic conditions like gout that can present with sesamoiditis-like symptoms 6
• Missing avascular necrosis of the sesamoid, which can present similarly to sesamoiditis but requires different management 5

Remember that accurate localization of pain to the sesamoid region is essential for proper diagnosis and management of sesamoiditis.