10. Femoris ossis luxatio. Luxation of the thigh bone. A fracture of the neck of this bone is sometimes mistaken for a luxation. The head of the thigh bone may be luxated downwards, forwards, inwards, outwards, and backwards. This luxation, like that of the humerus, is always perfect, and most frequently happens inward and downward, the head of the bone tending towards the large foramen of the os pubis.

When the luxation is outwards, the bone generally slips upwards at the same time; if inwards and down5 X2 wards, the leg is longer and more bent than the other, and the knee and foot turn outwards: the head of the bone is thrust near the lower part of the inguen and the foramen of the os pubis; sometimes the pressure of a nerve, which communicates with the bladder, or of the crural, causes a suppression of urine, or a numbness in the leg. A hollow cavity is perceived in the buttock, usually filled by the great trochanter; and if the reduction is long neglected, the limb withers. The patient will be always lame; the knee of the luxated limb cannot be brought to the other; and the chief pain will be felt in the groin, without the grating observed when the bone is fractured, on moving the limb. If the luxation is backwards, the limb is drawn upwards, and a cavity is perceived in the groin, with a tumour in that part of the buttock where the head of the bone and the trochanter are lodged. The limb is shortened, the foot bends inward, the heel does not touch the ground, but the patient seems to stand on his toes, and the luxated limb is more easily inflected than extended: in this case, many stand and walk firmly without the bone being reduced, provided their shoe has a higher heel.

A fractured neck of the thigh bone is distinguished from a luxation of its head, when the thigh bone is luxated by an abscess, without any external violence, but only by walking or rising up; when unattended with' pain, tumour, or inflammation; or when the whole limb may be bent, and turned about the acetabulum without the noise usually heard in fractures: the contrary signs indicate a fracture.

In reducing the luxated head of the thigh bone, a longitudinal extension will not suffice, but it must be according to the direction of the cervix."when a thigh is dislocated inward, or outward, follow," says Mr. Kirkland,"celsus's advice in laying the patient on one side, so that the part into which the bone hath slipped be always uppermost, and that from which it hath receded, lowermost; by which means the extension may be made in any direction you have a mind, and your own invention will point out to you twenty ways of securing the patient upon a bed (for a table is usually too high), so that a proper resistance be made to the extension. This done, the knee bent, and a towel fixed properly above it, you must place yourself on that side of the thigh to which the bone is dislocated, with your knee near the head of the bone, and both hands on the opposite side of the knee of the patient, an assistant being fixed at the ankle. The extension may then gradually be begun by three or four men, with the thigh rather in a state of flexion; and when there is reason to think that the head of the bone is brought to a level with the socket, the extension being steadily continued, the knee may be bent near to the abdomen, and, at the same time, whilst the knee pushes the bone towards its place, the ankle must be moved in the same, but the knee of the patient in a contrary, direction. Thus the head will always go into the socket, provided a due extension is made before you attempt to return it."

Sometimes the head of the thigh bone is pushed between the ischium and sacrum; in this case, except the patient is exhausted, before attempting the reduction, it will be most eligible to reduce him by brisk cathartics, given at short intervals; for the case, in this way, is better ascertained, and the reduction more easily effected. London Medical Journal, vol. v. p. 412; Bell's Surgery, vol. vi. p. 252; White's Surgery, p. 163; Edinburgh Medical Commentaries, vol. ii. p. 40.

11. Fibulae: luxatio. Luxation of the fibula. This bone may be separated from the tibia, either at the lower or superior part. In the former case it generally proceeds from a luxation of the foot externally; this bone must, therefore, be reduced, bound up, and the case treated according to the directions given for luxations of the knee and patella. See Bell's Surgery, vol. xi. p. 273.

Malleoli luxatio. Luxation of the ankle. See N° 21.

12. Genu luxatio. Luxation of the knee, is usually partial. If complete, it is easily reduced, but cannot be retained, because the cross ligaments are broken. A luxated knee pan is a necessary attendant of a luxated knee, and often taken for it; but in a proper luxation of the knee the tibia recedes from the femur, either backwards or to either side, but never forward, because the patella hinders it. In this part dislocations are easily discovered.

If the luxation is partial, the patient must be placed on a table, one assistant taking hold of his thigh, and another extending his leg; in the mean time, the operator may reduce the bone with his hands. In children and young persons, if the extension is made with violence, it endangers a separation of the epiphyses, a worse disease than the luxation. See Bell's Surgery, vol. vi. p. 269; White's Surgery, p. 165.

13. Humeri luxatio. Luxation of the humerus. The head of this bone may slip out before, behind, (even under the scapula,) or downwards; but never upwards, except the acromion and coracoid processes are fractured. When the humerus is luxated downward, there is a cavity in the upper part of it perceptible to the eye in some instances, but to the finger in all, and a tumour in the arm pit, because the head of the bone is lodged there. The luxated arm is longer than the other, and when it can be moved or extended, it gives exquisite pain in lifting it to the mouth.