Figure. Anteroposterior radiograph of the right foot.
A 17-year-old adolescent presents with right great toe pain that has persisted for 3 months. She is an avid basketball player and the pain seemed to start when she “jammed” her toe. The pain is now along the base of the great toe and she experiences sharp pain when she runs. Upon physical examination, she has tenderness over the medial sesamoid.
An anteroposterior radiograph is obtained (Figure), which shows what appears to be a bipartite tibial sesamoid (2 small sesamoid bones) located at the metatarsal head of the big toe. The patient was previously treated with 3 months in a walking boot and sesamoid pads, but the pain kept returning. Magnetic resonance imaging (MRI) of the foot reveals edema of the medial sesamoid indicating a possible nonunion of a fracture or avascular necrosis. The patient is frustrated and wants to return to sports.
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The great toe has 2 sesamoid bones embedded in the flexor hallucis brevis (FHB) tendon. The FHB tendon divides in half, with a tendon slip correlating with the medial (tibial) sesamoid and the lateral (fibular) sesamoid. The sesamoid/tendon complex helps absorb weight bearing stress, provides a fulcrum to increase metatarsophalangeal (MTP) flexion power, and reduces friction over the MTP joint. The medial sesamoid is the larger of the 2 sesamoids and more prone to injury due to increased weight bearing stresses.1
Diagnosing the exact etiology of sesamoid pain can be difficult. Pain can stem from a bipartite sesamoid, sesamoid fracture, sesamoid avascular necrosis, or FHB tendinitis. MRI is the best test to differentiate these causes of sesamoid pain.1,2
If conservative treatments fail, the most reliable surgical treatment for an early return to physical activity includes a sesamoidectomy. Athletes may notice loss of great toe push off strength after surgery, with a 16% loss with 1 sesamoid excised and a 30% loss when both are removed. Athletes may return to sport activities around 7 to 8 weeks after surgery.1,2
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
1. Cohen BE. Hallux sesamoid disorders. Foot Ankle Clin. 2009;14(1):91-104.
2. Bartosiak K, McCormick JJ. Avascular necrosis of the sesamoids. Foot Ankle Clin. 2019;24(1):57-67.