Fracture (mechanics)

“ Fractures are generally the result of great force applied directly to the shaft of a bone, or to its extremity; but they are also not unfrequently caused by twisting of the limb whilst the muscles are in a powerful action. Bones are broken transversely; but more frequently there is a degree of obliquity in the fracture, and the fragments are generally detached. A bone may be split longitudinally, as from a musket-ball striking its shaft in the centre ”

“ There are certain fallacies to be guarded against. For example, a fracture may exist and yet unnatural mobility may not be present, because the bones are impacted into one another, or because the fracture is an incomplete one. Again, the extreme tension of the swollen tissues overlying the fracture may prevent the recognition of movement between the fragments. Deformity also may be absent—as, for instance, when there is no displacement of the fragments, or when only one of two parallel bones is broken, as in the leg or forearm. ”

“ In injuries resulting from indirect violence, however, pain localised to a spot at some distance from the point of impact is strongly suggestive of fracture—as, for example, when a patient complains of pain over the clavicle after a fall on the hand, or over the upper end of the fibula after a twist of the ankle. Pain elicited by attempts to move the damaged part, or by applying pressure over the seat of injury, is more significant of fracture. ”

“ A fracture which only involves a portion of the thickness of the bones, so that its continuity has not been entirely lost or a fragment has not been completely detached, is called an incomplete fracture. A fracture which involves the entire thickness of the bone, so that it is divided into two or more distinct fragments, is called a complete fracture. ”

“ It is needless for the apparatus to extend as high up as in a fracture of the arm. What effect, in sustaining the fragments, would casts of a roller have, when applied to the body of the bone, above the place of division? Their only advantage would consist in compressing the brachial and triceps muscles, and in that way preventing their action. ”

“ A simple fracture is where the bones are broken, but there is no external wound, and when the bones are set they heal for the most part readily. But a compound fracture is one in which the bone pushes through the skin, the muscles are lacerated, or, by the agent that breaks the bone, an external wound made, and air admitted. The laceration of the muscles and the admission of air, especially the presence of air, causes inflammation, the wound suppurates, sloughs, instead of healing, and ulceration is produced; it then becomes necessary to amputate, and the patient, being reduced, often dies. ”

“ Fig. 75.—Longitudinal section of Femur showing recent Fracture of Shaft with overriding of Fragments.
In adults, when due to direct violence, the fracture is usually transverse, and may be attended with comparatively little displacement. Indirect violence, on the other hand, usually produces an oblique fracture, which is frequently comminuted and often compound. The break is most commonly situated a little above the middle of the shaft, the obliquity being downward, forward, and medially, and of such a nature that the fragments tend to override one another (Fig. 75) . ”

“ A man, in the Hotel-Dieu, fractured the rotula of each knee, in the operating room, by means of convulsive motions, produced by the operation of lithotomy.
5. The action of external bodies, can alone produce a longitudinal fracture, as when a person falls on a sharp projecting piece of timber: but this may also produce a transverse fracture. On the other hand, muscular action can never give rise to any but the latter kind, since the direction of this fracture is at a right angle with that of the extensors. ”

“ When one bone is broken there may be only a point of tenderness and swelling about the vicinity of the break and no displacement or grating sound. When in doubt as to the existence of a fracture always treat the limb as if a fracture were present. ”

“ The direction of the force, too, as already observed, when on the subject of fracture, is an important assistant in diagnosis; from falls or blows upon the shoulder we may expect fracture, from falls on the elbow or palm, luxation. In dislocation an indistinct feeling, sometimes amounting to obscure crepitation, is occasionally perceived during rotation of the limb; and this arises from one or more of the tendinous attachments of the muscles having, during their disruption, torn away a portion of their osseous attachment. ”

“ A fracture is said to be simple, where there is no wound of the superimposed integuments. The external parts may be bruised, or the deep structure much injured, with laceration of the vessels and rapid and great swelling; or there may be little or no injury of the soft parts. Great danger may exist without division of the integuments; these, yielding under the force, may remain entire, whilst by great and direct violence the bone is comminuted, the muscles broken up, and the vessels and nerves torn,—the limb is infiltrated with blood, and must become gangrenous as soon as reaction takes place. ”

“ Most of the phenomena which accompany fractures of the fore-arm (5) , are evidently the result of a displacement of the fragments; a displacement, not, in general, very perceptible in the longitudinal direction of the bones, because the muscular action, tending to produce it in that direction, is not very powerful. When it does occur in this way, it is most frequently the immediate effect of the stroke that produced the fracture. ”

“ When the fracture exists at the superior part of the radius, it is essential, after the removal of the apparatus, to make the limb very frequently perform all its natural motions. In such a case, indeed, the parts sometimes swell, become stiff, and an anchylosis of the fore-arm may be the consequence, as Ambrose Pare observes, in his book on fractures, where he says he has seen many accidents of this kind. ”

“ Wedge-shaped fractures of this bone were apt to show multiple secondary wave fissures concentric with the main line, and consequently free comminution. I saw several examples, the loose fragments being remarkably numerous. Plate XIX. is an example of an oblique fracture produced by a bullet which has ploughed across the bone, displacing large fragments anteriorly, but finely comminuting the bone in its course, and leaving small fragments of the mantle on its way. Plate XX. is an example of the rare condition of transverse fracture. ”

“ Any blow delivered at or near the basic level tends primarily to involve the weaker area, the base, passing secondarily upwards on to the vault. One may go even so far as to say that in most combined vault and basic fractures, the vault fracture is a secondary development, the basic fracture being the primary lesion. ”

“ Whenever it sustains a fracture, it is always by a true counter-stroke, resulting from a fall, sometimes on the great trochanter, and at other times on the sole of the foot or the knee. But fractures produced in the first mode, are much more frequently met with in practice, than those produced in the second, doubtless because, in the latter, the motion is weakened by the extent of parts through which it is distributed, previously to its arrival at the neck of the os femoris. ”

“ The symptoms of fracture are pain, loss12 of motion, change of position, change of contour of the fleshy parts, and most important of all, a light crackling sound when the limb is moved—crepitation the surgeons call it.
Pain following an injury that might produce a fracture is not necessarily proof positive of the existence of a fracture. Pain may and often does follow a bruise, sprain, or dislocation, in a greater degree than that following a fracture. Loss of motion, too, is quite as marked in dislocations and severe sprains as in fractures. ”

“ Clinical Features.—The limb is at once rendered useless, and there is great swelling from effusion of blood in the region of the fracture. This, together with the muscularity of the part, often renders an accurate diagnosis as to the site and direction of the fracture exceedingly difficult. The shortening varies from 1/2 inch to 3 or 4 inches—averaging about 1 inch in adults—and eversion is always marked. Mobility may be detected and crepitus elicited without disturbing the patient, by placing the hand under the seat of fracture and gently attempting to raise the limb ”

“ A small degree of force, judiciously directed according as the displacement is inward or outward, is sufficient to effect the reduction, which even takes place of its own accord, under this process. If the surgeon lays his hands on the place of fracture, it is rather to examine the state of the fragments, than to assist in bringing them into apposition. ”

“ Simple Fracture is a condition where the continuity of the bone has been broken without serious destruction of the soft structures adjacent, and where no opening has been made to the surface of the flesh. Such fractures do not reduce the bone to fragments. Long bones are frequently subjected to simple fracture, while short thick bones, such as the second phalanx, may suffer multiple or comminuted fractures. ”

“ If a wound in the soft parts accompany the fracture, whether it be produced by the same cause, or by the subsequent passage of the fragments through the integuments, and whether it communicate with the articulation or not, it is necessary, as soon as suppuration has taken place, to renew the dressings every day or every other day, taking care, in the mean time, to supply, by the hands of an assistant, the want of extension by means of the apparatus. ”

“ It is no uncommon experience to find a patient walk into hospital with an impacted fracture of the neck of the femur or a fracture of the fibula; or to be able to pronate and supinate the forearm with a greenstick fracture of the radius or a fracture of the ulna.
Pain.—Three forms of pain may be present in fractures: pain independent of movement or pressure; pain induced by movement of the limb; and pain elicited on pressure or “tenderness.” In injuries by direct violence, pain independent of movement and pressure is never diagnostic of fracture, as it may be due to bruising of soft tissues. ”

“ Some enumerate also the capillary fracture, but it is a very narrow fissure which eludes the senses, and therefore, being often overlooked owing to the symptoms of it not being obvious, it occasions death. An indentation is not a division of a bone, and, therefore, such an injury is not properly called a fracture, but is, as it were, a protrusion and bending of the skull inwardly, forming a hollow without a solution of continuity, as when vessels made of copper, or the raw hide of an ox, are struck on the outside. ”

“ They occur, in general, in two ways, being the result, sometimes of the action of external bodies, immediately applied, and at other times of the same action, operating by way of a counter-stroke. The occasional percussion of a body on the fore-arm, furnishes an example of the first mode of fracture. ”

“ When the fracture takes place at one end, if at the head of the thigh, the middle part of a thong wrapped round with wool, so that it may not cut the parts there, is to be applied to the perinæum, and the ends of it brought up to the head and given to an assistant to hold, and applying a ligature below the fracture, we give the ends of it to another assistant to make extension. ”

“ In cases of fracture in either of the bones of the forearm, it is easier to effect a cure if the upper bone be broken, although it be the thicker one, both because the sound bone is situated below, and forms a support to it, and because the deformity is more easily concealed, there being a thick mass of flesh on the upper side, except near to the wrist. But the lower bone is without a covering of flesh, is not easily concealed, and requires stronger extension. ”

“ For instance, the line of gravity of the body is, by some cause, removed behind it; the anterior muscles contract themselves to bring it forward again; the extensors act on the rotula; it is broken, and a fall ensues. Again, the leg is suddenly thrown into a state of violent extension; the extensors act with great force; a fracture is the consequence, and the patient falls. A soldier once fractured his rotula in kicking at his serjeant; thus the olecranon, in like manner, has been broken by throwing a stone. ”

“ The seat of fracture should be exposed by one or more incisions so placed as to enable the muscles to be separated and to give access to the callus. When the limb is straight, it is only necessary to gouge away the exuberant callus that interferes with rotatory movements; but when there is an angular deformity the bones must, in addition, be divided and re-set, and, if necessary, mechanically fixed in good position. In comparatively recent cases it is sometimes possible, without operation, to re-fracture the bones and to set them anew. ”

“ The deformity is usually angular, with the apex towards the palm, and if union takes place in this position, the power of grasping is interfered with. Unnatural mobility and crepitus can usually be recognised, but, on account of the swelling and tenderness, the fracture is apt to be overlooked. Firm union takes place in two or three weeks. In oblique and comminuted fractures, union may take place with overlapping, producing a deformity which may prevent the wearing of a glove or of rings. In compound fractures, non-union sometimes occurs, and causes persistent disability. ”