The French surgeons used to recommend this mode of applying the artificial leg, but only in cases of conical stump, or at least where the integuments were from excess of inflammation after the amputation closely ad herent to the bones.* But we have found it applicable to every case of amputation below the knee. The superiority which this wooden leg gives to amputations below the knee over all those at the ankle and through the joints of the foot is obvious. Besides saving the extra pain and risk of inflammation, it affords a much better point of support than the muti. lated foot can form.
The anterior surface of the tibia being sub cutaneous, and not covered by any artery of importance, indicates the region which should be chosen for exposing, when we would re move a portion, trephine, extract sequestra, balls, &c. Superiorly, as its external region is only covered by the origin of the tibialis anticus muscle, it is favourable to the same operation. This consideration is the more important since the publication of the very valuable observa tions of Sir B. Brodie on abscess in the can cellated structure of the tibia, a disease which till then was little understood and scarcely at all described, and which, from our own expe rience, we are inclined to think has not unfre quently cost the patient a limb, which by a more correct knowledge of the disease might have been saved.t The periosteum of this anterior surface is the subject of troublesome inflammation more fre quently than that of the other parts of the bone, in consequence of its greater exposure. Com mon inflammation of it is often productive of abscess, necrosis, &c., or in a scrofulous dia thesis, of caries ; while syphilitic inflammation is here showing itself in the form of nodes, occasioning great trouble to the surgeon and suffering to the patient, and generally leaving some permanent thickening. These nodes, which, as we have said, generally occur on the anterior surface of the bone, are sometimes thrown out upon the external and posterior parts, and when they do thus occur are doubly embarrassing to the surgeon from their deep situation among the muscles, and fiom the general similarity of the symptoms to mus cular rheumatism; the extreme tenderness of the periosteal inflammation, much more acute than that of rheumatism, and the more circum scribed nature of this tenderness, are signs which will facilitate the diagnosis, a subject, however, upon which it is not here the place to dilate.
In the fcetus, the tibia presents merely a slight curve anteriorly, which appears to be augmented in the adult by the weight of the body. The posterior muscles, stronger and more numerous, acting on the flexible bones, concur to the same end. Thus, in fractures,
particularly from indirect causes, the angle formed by the fragments of the tibia is almost always in front, and the limb bends in the situation of the fracture.
Experience proves that the two bones of the leg are more frequently broken together than singly, a fact ascribed by Boyer to the strength of the knee and ankle-joints. The direction of an oblique fracture of the tibia is generally from below upwards and from within out wards, a circumstance due to the form of the bone. The end of the upper fragment then presents itself under the skin, at the front and main part of the leg. The most frequent situa tion of fracture of either of the bones of the leg is at the lower third ; this, in the tibia, is readily accounted for by its being here more exposed to injury and being smaller and weaker than elsewhere ; in the fibula, on the contrary, this part is not weaker, but is here placed more superficial, the upper part being completely covered and much defended by a cushion of muscle. Fractures of the tibia at its upper part are less liable to displacement than lower down on account of the greater thickness of the bone, but the vicinity to the knee-joint here increases the danger of a fracture consi derably. In consequence of the thickness of the bone at this point, fractures here are ordi narily transverse, while the abundance of spongy tissue causes them to unite quickly and easily. The tibia is more frequently ;broken by itself than the fibula because it alone sus tains the whole weight of the body, while the fibula has nothing to support. In fact if the fibula is generally broken at the same time with the tibia, the injury to the fibula is but subsequent to the other, and takes place be cause this slender bone is not capable of bear ing the weight of the body, the impulse of ex ternal violence, or even the action of the mus cles, after the tibia has given way.* There is rarely much displacement, as re gards the length of the bones, at whatever point their fractures may have occurred, unless the cause has continued to act after the solu tion of continuity. This appears to result from the muscles being inserted over the whole of the bony surfaces.
When the fibula alone has been broken, there is very little deformity resulting, as the principal support of the limb still remains, particularly if the injury has resulted from external violence. When however the cause of the fracture is found in a violent twist of the ankle with dislocation, the deformity oc3a sioned by this state of the joint is more or less considerable, according to the degree of this displacement.
(A. T. S. Dodd.)