![]() ![]() Pain is typically during toe off phase of gait. Bipartite sesamoids can predispose to hallux valgus deformity as twice higher incidence is noted in patients with Hallux Valgus. A Bone scan or magnetic resonance imaging (MRI) scan may help in differentiating between the two. The synchondrosis between the sesamoid fragments can also disrupt with injury leading to symptoms and makes it difficult to distinguish whether some of these partite sesamoids are actually ununited fractures. Some of these divided sesamoids do undergo osseous union with time. Bipartite sesamoid has narrow and distinct regular edges and also are usually larger than single sesamoid. Ninety percent involve tibial sesamoid and 80%-90% are bilateral. Studies quote the incidence of bipartite sesamoids to be between 7 and 30. ![]() Bipartite sesamoids are a normal anatomical variant. Ossification of sesamoids often occurs from multiple centres and this is the reason for bipartite sesamoids. Sesamoids ossify between the ages of 6 and 7. The deep transverse metatarsal ligament attaches to the fibular sesamoid. The abductor hallucis and adductor hallucis tendons have fibrous insertions into the tibial and fibular sesamoids respectively. There is no direct connection between sesamoids and flexor hallucis longus tendon that runs between them. The sesamoids are suspended by a sling like mechanism sesamoid ligaments to the corresponding aspect of metatarsal head (Figure (Figure1). The inferior surface of the sesamoid is covered by a thin layer of flexor hallucis brevis tendon and superior surface is articular. The sesamoids are connected to the plantar aspect of proximal phalanx through plantar plate which is continuation of the flexor hallucis brevis tendon. In severe cases of hallux valgus the intersesamoid ridge atrophies and can be obliterated. The crista provides intrinsic stability to the complex. A crista or intersesamoid ridge separates the medial and lateral metatarsal facets. The sesamoids articulate on their dorsal surface with the plantar facets of metatarsal head. There are two sesamoids, tibial (medial) and fibular (lateral) sesamoids. The two sesamoid bones of the big toe metatarsophalangeal joint are contained within the tendons of Flexor Hallucis Brevis and forms portion of the plantar plate. Where fracture and avascular necrosis can be ruled out, injection under fluoroscopic guidance may help to avoid operative intervention. Conservative measures should be first line in most cases. Our recommendations are that early consideration of magnetic resonance imaging and discussion with a specialist musculoskeletal radiologist may help to identify a cause of pain accurately and quickly. Differential diagnoses and management strategies, including conservative and operative are outlined. We review evidence on approach to history, diagnosis and investigation of sesamoid pain. This article reviews the anatomy, development and morphological variability present in the sesamoids of the great toe. Modern imaging techniques can be helpful. There are a number of forefoot pathologies that can present similarly to sesmoid pathologies and likewise identifying the particular cause of sesamoid pain can be challenging. The painful sesamoid can be a chronic and disabling problem and isolating the cause can be far from straightforward. ![]()
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