Causes / typical injury mechanism: Numerous pathologies fall under the category of hallux sesamoid bone injury, including sesamoiditis, chondromalacia, stress fracture, osteochondral fracture, and osteonecrosis. The majority of these pathologies stem from repetitive stress injuries. Other mechanisms include hyper-dorsiflexion of the great toe.

Classic history and presentation: Classically, this injury presents in an athlete whose sport relies heavily on the lower extremities and repetitive loading of the metatarsophalangeal (MTP) joint of the great toe, most frequently dancers and runners complaining of pain in the plantar forefoot.

Prevalence: The hallucal sesamoid complex is involved in 9% of foot and ankle injuries and 1.2% of running injuries. The tibial sesamoid is more commonly injured.

In the pediatric and adolescent populations, there is a 6:1 female-to-male ratio of hallucal sesamoid complex injury, with individuals aged between 12 and 20 years typically affected.

Risk factors:

• Athletics, specifically running and dancing
• Cavus feet

Pathophysiology:

• Acute fracture – The most common mechanism is forced dorsiflexion of the first MTP joint.
• Stress fracture – Repetitive overuse injury.