SPECT/CT in Osteochondroses and Osteonecrosis

Abstract

Although osteochondrosis and osteonecrosis comprise of a distinct spectrum of disease entities, these terms are often confused as they show several etiological and clinical similarities. However, osteochondroses will only affect the epi- and apophyses of the developmental bone whereas osteonecrosis will present at any age in the epiphyseal as well as the nonepiphyseal bone.

Osteochondroses are characterized by an abnormal endochondral ossification at the epiphyses and apophyses of the developing skeleton and include a wide spectrum of disease entities of which Legg–Calve–Perthes disease, Scheuermann’s disease, and Osgood–Schlatter syndrome are the most infamous. No single etiology has been identified, but an inciting vascular event is assumed to cause ischemia and necrosis and eventual revascularization of the affected developmental bone. In the foot and ankle region, the predominant osteochondroses are Freiberg’s disease, Kohler’s disease, and Sever’s disease.

Any disruption of the bony vascular supply can lead to bone infarction, osteonecrosis, or avascular necrosis, which are used interchangeably to describe the subsequent bony abnormalities. Traumatic fractures are unquestionably the primary cause of osteonecrosis, but several other predisposing factors including the use of corticosteroids and alcohol have been identified. In theory, any bone in the foot or ankle can be affected; however, the talar dome is definitely a predilection site for the occurrence of osteonecrosis as well as the calcaneus, the navicular bone, and the metatarsal distal epiphyses.

In this chapter, we review the clinical and imaging features of osteochondroses and osteonecrosis by reviewing some typical cases.