An Atypical Presentation of Hallucial Sesamoid Avascular Necrosis: A Case Report

Osteonecrosis of the Sesamoid Bones: Two Case Reports

“…Post-traumatic sesamoid bone fracture is also a cause of osteonecrosis [10]. It is suggested that, in non-traumatic cases, spontaneous osteonecrosis develops secondary to microvascular events where arterial anastomoses are insufficient or arterial support is deformed [8]. Our second case had a history of trauma, but our first case was consistent with spontaneous non-traumatic osteonecrosis.…”

“…Young adults, like the patients described in our case reports, and women are more frequently affected. The contributing factors are generally structural foot defects such as pes cavus and hallux valgus that increase micro trauma risk, and sports activities [8,9]. Repetitive stress, presence of cavus deformity, and exposure to excessive plantar flexion are also listed among the causes of sesamoid injury and avascular necrosis [3].…”

A cintilografia óssea como exame complementar no diagnóstico da necrose avascular de sesamoide

“…The sesamoids are surrounded by a fibrous ligament structure that forms the sesamoid-phalangeal apparatus and moves under the head of the metatarsal head, thus playing an important role as shock absorbers and thereby facilitating gentle footfall from the heel to the extremity of the toes. They also increase the muscle strength at the impulsion stage of gait and protect the metatarsophalangeal joint and the tendon of the long and short flexors of the hallux (4) . Regarding the physiopathology of the osteonecrosis, changes to the vascular supply to the accessory center of the sesamoid or fragility of the ossification centers have been reported.…”

“…It is worsened by forced dorsiflexion of the hallux until becoming incapacitating. Antalgic supination of the forefoot while walking is noted (2)(3)(4)8,10) . Bone scintigraphy is fundamental for early diagnosis, since scintigraphic abnormalities often precede the radiographic findings.…”

“…In the plantar projection, vessels penetrate the non-joint surfaces of the sesamoid bones, thus forming a second source of vascularization. Lastly, small vessels also penetrate the sesamoid bones by means of the medial and lateral capsular adnexa (4,6) . Disorders of the sesamoid bones are a cause of metatarsal pain and, because of the complex anatomy and numerous pain-sensitive structures in the region, their differential diagnosis may be challenging, taking into consideration the possible causes of congenital, traumatic, arthritic, infectious and ischemic nature.…”