Osteonecrosis del escafoides tarsiano

Osteonecrosis (ON) of the tarsal navicular bone has been described in children (Köhler's disease) and in adults. Köhler's disease belongs to the group of osteochondroses, is relatively rare, and usually has a self-limited and reversible clinical course. In adulthood, this is also an uncommon entity. There are two distinct forms of this condition: the idiopathic or spontaneous ON also known as Müller-Weiss disease, which appears in patients without risk factors for osteonecrosis, and secondary ON caused by well-recognized predisposing factors or by traumatic injuries. Spontaneous ON or Müller-Weiss disease is seen most frequently in middle- aged women and it's usually bilateral; in secondary ON, the age and sex distribution is dependent upon the primary disease, although it generally affects younger patients without gender differences, and the involvement is unilateral. ON of the adult navicular is usually more severe than Köhler's disease. In absence of treatment, it is characterized by a chronic clinical course, with collapse, deformity and osseous fragmentation, severe and sometimes devastating pain and disability, and progressive flatfoot deformity with secondary talonaviculocuneiform osteoarthritis. A high level of awareness of this condition is needed to prompt diagnosis and treatment before advanced collapse occurs. Although uncommon, it should be included in the differential diagnosis of adult patients with midfoot pain.