The authors report a clinical and radiographic course of a 16 years old caucasian girl with a progressive deformation of her skeleton. The primary lesions occur in knees and wrists. This disease was at first considered as a rheumatoid arthritis, then as a dysplasia epiphysialis multiplex, and now as essential deformans osteolysis (with carpal lysis, shortening of the forearm bones, dislocation of the elbows, disparition of the humeral and femoral heads, contracture of hips and knees, posterior tarsal lysis, and kypho-scoliosis). The clinical (particularly ophtalmologic), biological (including inflammatory, phospho-calcic and nephrologic evaluation with mucopolysaccharidosis urinary excretion) and histological (skin, muscle and bone) check-up were normal. They review the different classification established on lesion topography, on association or not with a nephropathy, finally on an dominant or recessive autosomal inheritance. Then the authors think that their case is similar to the ones of Winchester and Hollister. They discuss the etiopathogenic factors, and do not consider their case as a new mucopolysaccharidosis, but rather as a generalized disease of the collagen of bones.