Osteoperiostitis and Osteoporosis

OSTEOPERIOSTITIS (osteoperiostitis), a term used to denote any kind of inflammatory process in a bone in the event that it involves both the outer periosteum and the bone marrow tissue with its cancellous substance. Very rarely are both of these parts affected simultaneously from the very beginning; in the majority of cases, the inflammation, having started in one of them, successively spreads to the other via the vascular sheaths passing through the Haversian and Volkmann canals. In suppurative processes and tuberculosis, such a transition occurs more often in cases of bone marrow involvement than in cases of periosteal involvement; with syphilis, the opposite is true. Due to the fact that the vessels of the Haversian canals are connected to both the periosteal and the bone marrow vessels, the nutrition of the cortical layer of the bone in isolated periostitis (see) may remain undisturbed even in the case of detachment of the periosteum and the destruction of its vascular connections with the underlying bone tissue (by pus, caseous masses, etc.), or necrosis occurs only in the nearest layers of the compact substance adjacent to the affected periosteum. The same can be said about isolated (so-called central) osteomyelitis (see). Conversely, in osteoperiostitis, the cortical layer over the corresponding extent almost necessarily undergoes necrosis throughout its entire thickness due to the involvement of all the vessels nourishing it in the process. This kind of bone lesion, as it involves all its constituent elements (periosteum, compact and cancellous substance with bone marrow), is also designated as panostitis. OSTEOPOROSIS (from the Greek osteon—bone and poros—opening, pore), rarefaction of bone, a process of the disappearance of bone substance with the widening of all pre-existing cavities within it (canals of the cortical layer, bone marrow spaces). Osteoporosis is a consequence of the predominance of resorption processes over bone formation processes. Such a predominance may depend either on increased resorption of bone substance with normal (or reduced) formation (as, for example, in inflammatory osteoporosis) or on the weakening (sometimes even complete cessation) of apposition with normal resorption (e.g., in old age, in neurotic atrophies, osteopsathyrosis, scurvy, etc.). The lime content in the rarefied bone tissue often remains normal, but it can also be lowered. According to distribution, local and general osteoporosis are distinguished. General osteoporosis is observed: 1) in certain forms of bone atrophy (senile, marantic; see Bone); 2) in certain avitaminoses (see), specifically in the lack of antirachitic vitamin D or antiscorbutic vitamin C in the diet; 3) in so-called osteopsathyrosis (see). Local osteoporosis is encountered: 1) in neurotic atrophy of bones and atrophy from disuse (see Bone); 2) in osteomalacia (see) and fibrous osteitis in combination with osteosclerosis (see); 3) in chronic osteomyelitis of various origins (nonspecific and specific), accompanied by the development of granulation tissue in the bones, the cells of which destroy the bone substance like osteoclasts (see Bone and Osteomyelitis); the latter type of process bears the name of caries (see); 4) in many (so-called central) bone tumors, both primary myelogenic (myelomas, various types of soft sarcomas, angiomas) and metastatic (osteoclastic cancers, malignant hypernephromas, melanotic sarcomas, etc.).