Licence: Public Domain Mark
Credit: Outlines of human pathology / by Herbert Mayo. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
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![5. The fifth period extends from the fiftieth or sixtieth day to the fifth or sixth month. During this period, the texture of the ossified callus becomes closer and more com- pact ; the ossific process at the same time gradually extends into the soft substance which joins the ends of the bone. The broken extremities thus become united by a layer of newly-formed and compact bone. This is called the defini- tive callus. In proportion as the definitive callus is esta- blished, the provisional callus diminishes in volume. 6. The sixth period extends from the sixth to the tenth or twelfth month. In this the provisional callus is entirely absorbed; and the definitive callus, losing its primitive compactness, is wrought into cells and canals, by which the continuity of the medullary cavity of the bone is restored, [c. 6.] The changes, the succession of which has been described, are the natural consequences of a fracture, and are intended to minister to its reparation. But in order to render them effectual, certain conditions must be observed. a. The ends of the broken bone must be kept at rest. Mo- tion causes the absorption of the lymph effused between them, and converts the provisional callus into a membranous capsule. The extremities of the bone enclosed within this capsule are sometimes partially united by fibrous substance; but in general they move freely on each other; the opposed sur- faces being formed partly of smooth bone of unusual com- pactness, partly of firm animal matter. The friction of the ununited ends upon each other causes them to enlarge, and shapes them into determinate articular faces, flat if the frac- ture has been oblique, concave and convex if the fracture has been transverse. The former I have seen in the tibia, the latter in the ulna and in a rib. [c 40. c. 41. c. 42.] This degeneration of the restorative process constitutes a false joint. Such a case is not hopeless : there are several means by which a new action may be excited in and around the fracture, which will lead to its consolidation. These are, rubbing the ends of the bone roughly together; the introduction of a seton between them, to be retained for weeks, if necessary; their removal by the saw.](https://iiif.wellcomecollection.org/image/b21066735_0041.jp2/full/800%2C/0/default.jpg)
