Central necrosis of the tibia, long central sequestrum.
Sequestrum inside of a core of new-bone tissue, arranged much like a puzzle.
Necrosis of tibia, showing sequestra after removal. (All three specimens from the Buffalo Museum.)
The packing of old bone cavities is of importance, and operators should appreciate the reason for so treating them. The packing is essentially a foreign material which the tissues will naturally endeavor to extrude as they did the sequestrum. The method of extrusion is by filling up beneath and around it with granulation tissue, which later may ossify. The packing is therefore a constant provocation to the formation of this tissue, which is now desirable, and is used mainly for this purpose. It is antiseptic material, and will serve to prevent decomposition of the pyoid material which would otherwise fill such a cavity as the result of waste—Nature’s effort at formative material gone to waste. A number of years ago Gunn suggested the use of wax for this purpose, wax being plastic and incapable of absorption. A piece of white wax was heated in hot water, molded with the fingers to fit the cavity, where it served the purpose of a packing, and was reduced in size with each dressing, as was necessary to permit it still to remain. It is not now used as much as it deserves to be. (See [p. 431].)
In favorable cases it may be possible to so thoroughly cleanse the bone cavity without the use of caustics as to justify the attempt, after rigid asepsis, of allowing it to fill with blood, which will coagulate and organize into connective tissue. When this effect is desired the wound should be covered with green silk protective, over which the other dressing may be snugly applied. This healing by the aseptic blood clot is the ideal method when possible.
The extent to which regeneration of bone is possible is often amazing, especially in the young. Thus after removal of the entire shaft of a tibia there may result, in time, not a complete restoration to former integrity, but, in addition, the formation of so much new osseous material as to restore a great degree of strength, and which shall, with the compensatorily hypertrophied fibula, make the leg as useful as ever. In the thigh, however, complete necrosis of the femur means amputation, as it will also in the arm unless the necrotic portion is but a small proportion of the length of the humerus. The treatment of necrosis of the skull, or, in fact, of any bone in the body which is accessible, is based practically on the principles already laid down.
BONE TRANSPLANTATION AND TRANSFERENCE.
In the effort to atone for extensive loss of bone many experiments have been tried, first on animals and afterward on men, success with the former having lent much prospect to the latter. It has been learned, for instance, that portions of living bone can be removed from some of the lower animals and transferred into a bed of more or less healthy sterile human tissues, often with the result that a fragment thus transplanted becomes vitalized and incorporated, and serves the purpose for which it was intended; still these efforts do not in all instances succeed. However, experience has led to the effort to utilize some portion of the patient’s own osseous system. This becomes more easily possible in the case of the forearm or leg where, especially in the latter, a small or less important bone can be utilized to take the place of the greater. Thus, when the entire shaft of the tibia has been removed for necrosis resulting from acute osteomyelitis, the fibula has been sawed across, opposite the site of the ends of the lacking tibial shaft, and transplanted into the trough-shaped depression, thus making it functionate for the lost tibia. Huntington has recently reported a case in which not only was this done, but later the upper and lower ends of the fibula attached to the tibia, with good bony union and with an almost perfect functional result. This will illustrate what elsewhere may be done in this direction.