The bony manifestations of syphilis occur as secondary and tertiary lesions, and as Keyes, of New York, has pointed out, these so-called “nodes” are simply local periosteal congestions, accompanied by serious effusions without cell hyperplesia. Any bone in the body may be affected by syphilis, but certain of them suffer by preference, such as the thin bones of the nose and pharynx—that is, those exposed to climatic changes and injuries, such as the bones of the skull, ulna, tibia, etc.
We must call special attention to injury as a powerful pre-disposing cause of bone syphilis, for, when we consider that bone lesions may be the only manifestations of existing syphilis, with the presence of a bone lesion before us, with an antecedent history of an injury, we must not forget that we may overlook the true nature of the disease, and hence must be constantly on the alert for the syphilitic taint.
Lancereaux classified the bone lesions under three heads, viz.:
(a) Inflammatory osteo-periostitis.
(b) Gummy tumor of bone.
(c) Dry caries, atrophic form.
(1) Inflammatory osteo-periostitis is the most frequent form, and is characterized by inflammatory phenomena, vascularization and exudation of a serio-glutinous material. It may be either diffuse or circumscribed, and located, as its name implies, in the area of contact with the osseous and periosteal surfaces. The pain is aching, acute, throbbing or boring in character, while tenderness upon pressure and percussion is most exquisitely excruciating. The diagnosis of inflammatory osteo-periostitis is comparatively easy, if we remember the characteristics, viz., an oval, painful, boggy or even hard bony lesion, accompanied by nocturnal exacerbations of pain, with a concomitant or antecedent history of syphilis. Ostitis with parenchymatous thickening is somewhat less positive in its character, but with nocturnal pains which are usually constant.
(2) Gummy tumor of bone develops either under the periostum, in the substance of bone, or in the medullary canal. It is simply an intensification of the process found in the inflammatory form just described, the difference being that the cell hyperplasia is more abundant. Much of the new material collects in a circumscribed space, and being more rapidly formed and less capable of organization, it entails more profound lesions by its retrograde metamorphosis. Generally tumor of the bone is, therefore, a much more serious form of disease than osteo-periostitis.
In the long bones the medullary canal is the usual seat of deposit. The bone becomes hypertrophied in a porous manner, the Haversian canals and canaliculi become enlarged and filled with a gummy material which resembles a solution of gum arabic. In the flat bones, especially the cranial bones, the cancellar tissue is attacked, and may cause a separation of the two tables, and often necrosis of one or the other plates results. If it happens to be the inner one which undergoes carious degeneration, brain symptoms will develop.
(3) Dry Caries.—According to Virchow, dry caries is always due to syphilis. This affection is a miniature gummy ostitis. Around one of the vascular canals the gummy material is deposited, this gummy material being later absorbed, leaving a stellate induration. This goes on leaving a funnel-shaped depression, its point leading into the diploe, which may be plainly appreciated by palpation. The essential features of this caries is the fact that no sequestra are formed, no pus extruded, nor is the skin but rarely involved.