“…Thus, in the past decade similar effects were observed after retinoid therapy [1], It is gener ally agreed that bone toxicity includes premature epiphys ial closure in children, spurring along the anterior margins of spines (often mimicking a diffuse idiopathic skeletal hyperostosis), periostitis, ossification of ligamentous inser tions and osteoporosis [2][3][4][5], So far, mainly the effects of isotretinoin (13-cis-retinoic acid) and etretinate (Ro 10-9359) have been studied. Results from studies at the National Institutes of Health (Bethesda, Md., USA) indi cate that etretinate treatment induces predominantly peripheral, extraspinal tendon and ligament calcification, whereas isotretinoin therapy has been associated with a high rate of spinal ligament calcification [6], Little is known about skeletal changes after acitretin (Ro 10-1670) treatment.…”