Mr. Bell observes, that in the reduction of these dislocations (viz. of the metacarpus and fingers), the bone should not be pulled down till it be somewhat raised or elevated from the contiguous bone; for, as all the bones of the fingers and thumbs, as well as those of the metacarpus, are considerably thicker at their extremities than in any other part, these projections are apt to be forced against each other when the extension is made in a straight direction. See Bell's Surgery, vol. vi. p. 249, 251; White's Surgery, p. 163.

17. Nasi ossis luxatio. Luxation of the bone of the nose. This accident is easily discovered by the eye and the touch. The reduction is effected by a quill put up the nostrils, and then with the fingers replacing the bones. After the reduction a sticking plaster may be applied. Bell's Surgery, vol. vi. p. 184.

18. Olecrani luxatio. Luxation of the elbow. A perfect luxation of this joint rarely happens, except the olecranon is fractured, or the ligament greatly-weakened. This luxation may be backward (which is most frequent), forward, outward, or inward. If backward, the arm appears crooked and shorter, and cannot be extended: in the internal part of the flexure the humerus will be prominent; in the external, the olecranon, with a large cavity between both bones. When from the fracture of the olecranon, the elbow is pushed forward, the os humeri will stick out behind, the ulna is prominent on the fore part, and a cavity appears in proportion to the luxation. If external, the tumour.is so too, and vice versa.

In a violent luxation, or one of long standing, the bone cannot be replaced without great difficulty, as the ligaments are strong and the processes numerous. Recent and slighter luxations are more easily restored.

If the ligaments and tendons are rigid, emollient applications should be used some time before attempting the reduction; the egg liquor is useful in this case. See Anchylosis.

In reducing this luxation an extention must be made, until the fore arm can be bent; and then the reduction is easily accomplished by bearing upon the lower end of the humerus with one hand, and by taking hold of the wrist and bending the elbow with the other. If it is on cither side, the hand of the patient must be turned inward or outward, at the same instant, as the case requires. After reduction, the arm should be hung in a sling for some time, that the parts may recover their tone. See Bell's Surgery, vol. vi. p. 239. White's Surgery, p. 162.

19. Patellae luxatio. Luxation of the knee pan, may happen externally and internally. In order to its reduction, the patient's leg must be pulled straight, or if he can, he may stand on it erect; then the operator, taking firm hold of the patella with his fingers, may force it into Its place. Nothing but rest is afterwards required. Bell's Surgery, vol. vi. p. 267. White's Surgery, p. 165.

20. Pedis ossium luxatio. See 9.

21. Tali luxatio, seu malleoli. Luxation of the ankle. Dr. Hunter observes, that when there is a luxation of the malleolus internus, there is generally a fracture of the fibula; but that if the person is of a weak constitution, ligaments may be relaxed without a fracture.

If the ankle is luxated inwardly, the bottom of the foot turns outward; if outwardly, the contrary. If forward, the heel becomes shorter, and the foot longer than usual; if backwards, the heel is lengthened, and the foot shortened. This kind of luxation is usually attended with great pain, and other very violent symptoms; and the difficulty of reducing the ankle is proportioned to the violence of the cause. The patient should be placed on a table or bed, and the leg, with the knee bent, firmly secured by an assistant or two. The foot is now to be put into that situation which tends most effectually to relax all the muscles which belong to it; and an assistant must be desired to extend it in that direction till the most prominent point of the astragalus has clearly passed the end of the tibia, when the bone will slip, or may be easily forced into its place. The patient should keep in bed until the fever and the symptoms of irritation leave him, and he is in some measure able to rest upon his ankle. See Bell's Surgery, vol. vi. p. 274. White's Surgery, p. 166.

22. Vertebrarum luxatio. Luxation of the vertebra. The vertebrae are rarely perfectly luxated. Those of the neck and loins are more subject to this accident than those of the back, because they are more moveable and smooth, are destitute of those cavities with which the vertebras of the back are furnished, and have a thicker cartilage interposed betwixt each. Luxations of the vertebrae must be imperfect, unless attended with a fracture, and a laceration of the spinal marrow, an accident quickly fatal. The imperfect luxations are scarcely less fatal; and they most frequently happen in the upper vertebrae of the neck. Dislocation or crookedness of the dorsal vertebrae sideways, is called contortio.

The vertebrae of the back cannot move in any great degree without a fracture: their upper or lower apophyses, and sometimes only one, is misplaced; for great violence is generally required in order to a partial luxation. When a vertebrae is luxated without a fracture, the body leans to one side, or forward: if the left side is affected, the patient leans to the right, and vice versa.

The common signs of a luxation of the vertebrae in the back are, that the back is crooked and unequal; the patient can neither stand nor walk, and his whole body seems paralytic; all the parts below the luxation arc insensible and immovable; the excrements and the urine are retained, or discharged involuntarily; the lower parts mortify, and the patient soon dies.

All the luxations in the spine are very dangerous, from the injury done to the spinal marrow, and the difficulty of reducing them. The danger is also greater, the nearer the luxation is to the head; as from the vertebrae of the neck and back, the nerves which supply the heart and intestines are chiefly derived. When several vertebrae are luxated, the bad symptoms are not so violent.

For reducing the vertebrae of the neck, see Colli luxatio. When both the apophyses of the vertebrae are dislocated, the patient must be laid on his belly over some round body, and two assistants may depress both ends of the luxated spine on each side, which elevates, and gradually extends the vertebrae, the spina dorsi being thus bent in form of an arch. The surgeon next presses down the inferior dislocated and prominent-vertebra, and, at the same instant, expeditiously pushes the superior part of the body upwards. If the first attempt fails, it must be repeated two or three times. When the left apophysis only is displaced, after the patient is laid in the same posture, one assistant may depress the left coxa, and the other the right humerus; and the reverse, if the injury is on the other side. After the reduction, it may be necessary to take some blood, and compresses wrung out of spirit of wine should be applied, and then the napkin and scapulary. See London Medical Journal, vol. i. p. 326, 327. Bell's Surgery, vol. vi. p. 196; and White's, p. 156. Boer-haave's Aphorisms. Petit's Diseases of the Bones. London Medical Observations and Inquiries, vol. ii. p. 99, etc. Gooch's Cases and Remarks. Pott's General Remarks on Fractures and Dislocations. Kirkland's Observations on Pott's Remarks. Medical Museum, vol. ii. p. 406. Heister's, Wiseman's, Bell's and White's Surgery.