Necrotic sequestra are readily recog nized by the grating sensation trans mitted through the probe. They should be removed when free in the cavity, which their mobility will readily indi cate. It is usually necessary to enlarge the opening. When the piece is large a gouge or chisel is necessary to thor oughly remove all dead bone. The Es march bandage should be used to avoid haemorrhage.
The most favorable time for the re moval of the dead shaft is when the peri osteum and granulation-tissue are in their most active regenerative stage, and before the sequestrum has become en veloped by a compact shell of new bone. This stage is recognized by frequent ex amMation of sections of the periosteum with the microscope. It is shown by the presence of numerous fibroblasts, ostea blasts, and small trabecuke in which lime-salts are beginning to be deposited. Clinically it can be recognized by crush ing of the trabeculfe by the knife. This stage is probably readied in the seventh to the eighth week of the disease. The dead bone should be removed and the re maining periosteal sheath closed by su ture, leaving a solid cord or mass of peri osteum buried in the centre of the limb, when in its most active bone-producing condition. Asepsis is of the first impor tance, Cushing (Annals of Surg., Oct., '99).
When after the removal of dead bone a long and deep gap is left, an effort should be made to encourage the pro duction of new bone. Bits of human bone will grow and develop if the chips are thoroughly asepticized, but it often suffices to make the transplantation from the bone of a living animal. Ani mals' bone, ivory, and other aseptic organic materials can be made to become healed in, and absorbed, capsulated, and partially or totally substituted by the growing bone in which they are planted and to which they furnish the irritation for osteogenesis.
In osteoplastic filling of bone-defects the following method is recommended: After the sequestrum has been removed and the bone rendered free from all ne crotic tissues, the lateral walls are cut free from the rest of the bone without destroying their attachment to the peri osteum; then a sufficient amount of the remaining bone is removed on either side of the middle and posterior portions to provide periosteum which will enable the lateral walls to be brought together in the median line and united by sutures, and yet leave sufficient periosteum to cover the entire bone, with only one line of sutures. The same end is obtained by other osteoplastic modes of operating; for instance, only a portion of the lateral wall is preserved, the upper half being resected and left in contact with the periosteum, while the lower half is re moved subperiosteally, and thus supplies the periosteum necessary to enable the upper portions of the lateral walls to unite in the median line and fill out the deficiency.
Near the epiphyseal lines the bones may be cut in wedge-shaped sections and slid toward each other to fill up a hone defect in the middle third of the shaft. The osteoperiosteal flaps may be formed from one or both lateral walls as the individual case demands. The portions of bone are fastened together by metallic sutures or by strong silk, when the neces sary tension is not too great. Care is needed in drilling the holes through the bone, and the author recommends for this purpose the use of the dental engine and drills. Osteoplastic operation should never be performed on the same day on which the sequestrotomy is done. Dress ings used in such operations must be oc clusive, but not compressive. A. Schul ten (Arch. f. klin. Chin, B. 52, II. 1, '96).
In cases in which the bone is exten sively diseased, or gangrenous osteomye litis is present, or when through exten sive suppuration the patient's life is clearly endangered, amputation is indi cated. This is especially the case when a long bone is implicated. In such a case, however, the bone should be re moved entire, section in its continuity being, as a rule, followed by recurrence.
Rickets.
Bachitis, or rickets, is a disease of infancy and childhood due to malnu trition of the osseous structures.
Symptoms..—Nocturnal restlessness, night-sweats (especially of the scalp). enlarged abdomen, and phosphaturia are the early symptoms of this affection. The osseous involvement appears soon afterward and consists of epiphyseal en largements, of which the end of the radius, the ribs, and the vertebrae are the most frequent seats. The costal dis order is followed by the deformity usu ally called "pigeon-breast." The frontal eminences and other portions of the facial bony frame-work are often en larged; the fontanelles are frequently patent and the growth is often impaired. Such children are usually susceptible to catarrhal affections of the entire respira tory tract, nose, throat, and lungs. De formity of the spine and other bones occurs as a result of the softening. Probably the most pernicious effect of this condition is its influence upon the female pelvis, distortion of which when adult life is reached impedes and sometimes totally prevents parturi tion.