[Investigation and treatment of metatarsalgia due to avascular osteonecrosis of a sesamoid].

The Renander disease or avascular osteonecrosis of one (or two) sesamoid of the first metatarsal is a rare and poorly studied pathological entity. It is part of the differential diagnosis of metatarsalgia, a more common complaint in clinical practice. We report the case of a 14-year-old patient presenting with pain on the plantar area of the left first metatarsal, aggravated while fencing. Clinical examination and MRI suggested avascular osteonecrosis of the medial sesamoid, for which conservative treatment resolved the complaints. The presentation of this clinical case gives the opportunity to present a review of the diagnostic and therapeutic approaches of this pathology.