CLINICAL DIAGNOSIS (_continued_) SKIAGRAPHY As an aid to the differentiation of _gouty_ from _non-gouty_ forms of _arthritis_ skiagraphy has scarcely fulfilled the somewhat optimistic claims at one time made on its behalf. As to _acute_ gout, radiography reveals nothing abnormal in the bones, though Tousey holds that this of itself at once enables us to exclude _osteomyelitis_, which, he says, “these cases sometimes resemble.” Turning now to _chronic articular gout_, Huber in 1896 drew attention to certain _focal areas of rarefaction_, or diminished density, in the distal extremities of the phalanges. These localised transparent areas in the bone-ends are discrete, circular, or oval in shape. When located near the edges of the bones, they are of segmental contour, and, viewed in profile, give the appearance of small punched-out holes, simulating syphilitic dactylitis. Despite their proximity to the diseased joints, they apparently do not communicate with the articular cavities. These bony changes Huber held distinctive of gout, and Koehler, Drinberg, and Jacobsohn and other subsequent writers confirmed Huber’s findings, and, like him, held these areas of rarefaction to be the result of _uratic deposits_ at their sites. Strangeways has dissected bones in which these transparent areas were demonstrated by X-rays. The examination revealed that the bone was definitely excavated, filled with a gelatinous-looking substance, and in advanced cases of gout, moreover, a characteristic deposit of urates clung, as it were, to the margins of the cavities. Similar focal areas of decreased density were noted by Strangeways in certain cases of _rheumatoid arthritis_, and both he and Burt found it impossible on the X-ray findings to differentiate between these and gout, _i.e._, without invoking the aid of clinical data. [Illustration: Radiographs of the Foot and Hand, showing extensive bony and other changes in long-standing Gout.] Apart from these transparent areas, Wynne many years ago pointed out that small _nodes_ or _bony deposits_ are sometimes met with flanking the sides of the phalanges. More recently Ironside Bruce by _radiography_ has again drawn attention to these bony outgrowths near the extremities of the phalanges (Bruce’s nodes). At first these were thought by Bruce to be composed of _urates_, but Strangeways from a study of macerated specimens has demonstrated their true _bony_ nature, and also that _uratic deposits are not opaque to X-rays_, as was formerly thought. In skiagrams of chronic gout all stages of _ankylosis_ may be seen in the interphalangeal joints. In some it is merely fibrous, in others merging therefrom into bony, and not infrequently true synostosis is observed. Deflections or subluxations are frequent features, due either to the thrust of tophi or small bony outgrowths or to peri-articular contractures.