Defects or clefts may be seen in the growing epiphysis and are usually observed just before puberty. The basal epiphysis of the proximal phalanx of the great toe is the most common site but similar defects have been observed in a number of other epiphyses. At least some of these defects develop within a single normal appearing epiphysis and are not associated with signs or symptoms suggestive of fracture. The mechanism of formation of these defects is not clear. The defects probably close spontaneously sometime around late puberty.