When is rickets to be designated as late rickets? Schmorl1 writes:By late rickets I understand all cases which come under observation in the later periods of growth (after the end of the fourth year). Under the conception of late rickets are to be included, therefore, not only those cases in which the disease began in the earlier growth periods but never disappeared\p=m-\persistent rickets\p=m-\butalso those cases in which rickets developed for the first time in the later periods of growth\p=m-\late rickets in the narrower sense. Strictly speaking, only the rickets which first develops in the later growth periods merits the name of late rickets. If, however, I make the conception of late rickets as broad as I do, it is because of the impossibility in many cases of making a clear separation between persistent rickets and late rickets. Schmorl, therefore, makes age the sole criterion.Schmorl selects the end of the fourth year as the point of demar¬ cation of late rickets because, as his pathologic studies showed, active rickets becomes relatively infrequent by that time. If one consults Schmorl's table, which gives the incidence of rickets in its varying stages at the different age periods (table 1), one sees that incipient rickets was not found after the second year, and that "florid rickets" 2 had diminished from almost 100 per cent at the end of the first year to This study was aided by a grant from Mead Johnson and Company, Evansville, Ind.From the Harriet Lane Home of the Johns Hopkins Hospital and the Department of Pediatrics of the Johns Hopkins University. 1. Schmorl, G.: Die pathologische Anatomie der rachitischen Knochenerkrankung, Ergebn. d. inn. Med. u. Kinderh. 4:440, 1909. 2. By "florid rickets" Schmorl means rickets in which the lesions of the disease are in an advanced stage of development and in which no depositions of lime salts have occurred, i. e., advanced rickets without evidence of a tendency toward healing. By "healing rickets" Schmorl means rickets in which depositions of lime salts in the rachitic tissue have occurred, i. e., rickets with evidence of a tendency toward healing. By "healed rickets" Schmorl means cases in which the disease has completely died out but has left in its wake characteristic deformities in the gross or finer structure of the bones.
