excite us to the early employment of the means of reduction; although the hitherto known cases do not irrevocably prove the actually resulting reduction, as the lengthening of the limb effected, and the diminished lameness, perhaps, depend on the displacement of the pelvis, or the position of the head of the thigh-bone in the ischiatic pit.

(1) I have observed one case of dislocation on both sides, in which the walking was at first extremely difficult, but from the fifteenth year and onwards so improved, that now, when the patient is about twenty years old, there is scarcely any trace of peculiar gait to be noticed.

(2) PRAVAZ (a) communicates a case of reduction of congenital dislocation of the thigh, in a girl eight years old, by gradual lengthening of the limb, and by violent abduction, assisted by a methodical pressure on the great trochanter. If the reduction be ensured by long-continued rest, various movements of the limb should be performed, the body still being at rest. He believes that even in the cases in which there is not any existing cotyloid cavity, a dislocation of the head of the thigh-bone downwards causes slight halting. A second case happened in a boy of eight years, in whom the reduction was effected by gradual extension, kept up for several months, after which gymnastic exercises were used, which were proper for strengthening the joint and perfecting its coaptation (b). GUÉRIN effected a cure in six cases. H. JOFFRE (e) refers to the two cases of PRAVAZ, denies the observations of HUMBERT (d), and thinks that in them no perfect reduction was found, but that merely the head of the bone was situated in the ischiatic pit.

HEINE, of Cannstadt, has given a very clever apparatus, which, with continued extension, permits every other seemingly necessary movement and direction of the extremity. But notwithstanding all his care and perseverance, he could not, in this dislocation of the thigh, effect any result (e).

GUERIN (f) makes a preparatory and continued extension, by which the shortened muscles are lengthened and are brought to stretch out; cutting through the muscles which do not lengthen; extension of the shortened ligaments, and where this is impossible, cutting them through; reduction and its preservation by apparatus. According to PRAVAZ (9) every congenital dislocation may be reduced, if it be possible to bring the thighs up to the shoulders, without bending the legs against the thighs (h).

OF DISLOCATION OF THE KNEE-CAP.

(Luxatio Patellæ, Lat. ; Verrenkung der Knieschiebe, Germ. ; Luxation de la Rotule, Fr.) LE VACHER et PICQUET, Theses de variis patellæ luxationibus. Paris, 1761. 4to. BOYER, above cited, vol. iv. p. 347.

COOPER, A., above cited, p. 178.

MALGAIGNE, Mémoire sur la détermination des diverses espèces de Luxation de la Rotule. Paris, 1837.

1083. Dislocation of the Knee-cap may happen in two different directions, viz., outwards and inwards; the former kind of displacement is much more common than the latter. These dislocations may be complete or incomplete; in the first the cap leaves the joint-surfaces of the thighbone, and rests on one or other protuberance; in the second it still partially touches the corresponding surface. Diagnosis of dislocation of the kneecap is always easy; the limb is outstretched; and if it be attempted to bend the leg, the pain is increased; the knee has lost its natural form. In

(a) Révue Médicale, April, 1835. (b) Annales d'Hygiène publique; in FRORIEP's Notizen, No. 122.

(c) Journal des Connaissances Medico-Chirurgicales, May 1838, p. 180.

(d) P. HUMBERT and N. JACQUIER, Essai et Observations sur la manière de réduire les Luxations spontanées ou symptomatiques de l'Articulation ileo-femorale; méthode applicable aux luxations congénitales et aux luxations anciennes

par cause externe. Paris, 1835; with Atlas of 20 plates.

(e) Ueber spontane und congenitale Luxationen, so wie über einen neuen Schenkelltals-BürchApparat. Stuttgardt, 1842.

(f) Gazette Medicale de Paris, 1841, No. 7-10. (g) Bulletin de l'Academie Royale de Médecine, vol. vii. p. 5.

(h) A. SANSON; in Rev. de Specialités, 1841, Feb. -Journal de Médecine de Lyon, 1841, Nov. p.iši.

dislocation outwards the prominence of the inner condyle is felt through the skin, and upon the outer condyle, and if the dislocation be complete on its outside, a considerable swelling is produced by the knee-cap. In dislocation inwards, the outer condy leis felt and the prominence of the kneecap on the inner condyle. This dislocation is nearly always incomplete. COZE's observation of a dislocation of the knee-cap, in which it was half twisted round itself, has been denied (a).

WOLF (b) has noticed a complete twisting round of the knee-cap.

1084. The causes of dislocation of the knee-cap are mostly, external violence acting on the bone in moderate bending, or complete straightening of the leg, and after driving it to one or other side. Also any circumstance by which the foot is turned outwards whilst the knee turns in, may produce this dislocation. If the ligaments of the knee-cap be very relaxed, or the condyles of the thigh little prominent, this dislocation may be produced by slight causes.

In general, dislocations of the knee are not dangerous; but when the violence producing them acts very severely upon the knee-joint serious symptoms may be caused by the contusion.

1085. In reducing this dislocation, which cannot always be effected at the first attempt, the patient should be laid upon his back, the leg straightened as much as possible, and the thigh bent at the hip-joint, the knee-cap is then to be pressed directly forwards, and when its great ridge is lifted over the edge of the condyle, it is drawn into place by the action of the muscles. The knee should be enveloped in cloths dipped in a dispersing wash; and the patient kept quiet in bed till the pain and swelling have ceased. Should the knee-cap be disposed again to be dislocated, the knee must be supported by means of an elastic knee-bandage.

I have seen a congenital dislocation of the knee-cap on both sides, in an aged man. The knee-cap rested entirely on the outer side, so that the middle of the knee-joint was completely void. The knee-cap was so movable, that in the straight position of the leg it could easily be brought to its proper situation, but on the slightest movement was again displaced. Both knees were very much twisted inwards, the legs and feet very much outwards. The man's gait was very difficult and unsteady. PALLETTA (c) has examined a case of congenital dislocation of the knee-cap.

XII. OF DISLOCATION OF THE KNEE-JOINT.

(Luxatio Genu, Lat.; Verrenkung des Kniees, Germ. ; Luxation de Genou, Fr.) VON SIEBOLD'S Chiron., vol. i. p. 33.

BOYER, above cited, vol. iv. p. 365.

COOPER, A., above cited, p. 184.

1086. Dislocations of the knee are rare, on account of the great strength of the joint. The shin-bone may, however, be displaced forwards, backwards, and to one side or other from the joint-surfaces of the thigh-bone. These displacements are mostly incomplete. The ligaments and tendons which strengthen the knee are always in these dislocations, either much torn or much stretched; even the vessels and nerves may be torn, or the joint-ends of the bones thrust out through the skin. These dislocations cannot be mistaken, on account of the projections which the shin-bone and condyles of the thigh form in opposite directions.

(a) Mém. de la Société d'Emulation. Paris, 1826, vol. xviii.

(b) RUST's Magazin, vol. xxvii. p. 476
(c) Exercitationes Pathologica, p. 91.

1087. The reduction of these dislocations is not usually accompanied with difficulty. Sufficient extension of the leg is made, and then the displaced joint-end of the shin-bone is pressed into its place, one hand grasping it, whilst the other has hold of the lower end of the thigh-bone. After the reduction, inflammation must be prevented or got rid of, and the union of the ligaments effected, by strict antiphlogistic treatment, and by keeping the limb quiet, fastening it up in a pair of splints. When all swelling and pain have subsided the limb may be cautiously moved. If the joint remain weak, volatile rubbings must be employed, and a kneeband used for some time to give support. If the inflammation be severe, anchylosis, suppuration, gangrene, and so on, may take place, and the treatment must be guided according to the rules laid down for wounds of joints. If the joint-ends of the bones be thrust through the skin, there may be such destruction, that immediate amputation is requisite. Single cases in which the preservation of the limb is possible cannot refute these principles.

If the ligaments connecting the semi-lunar cartilages with the shin-bone be relaxed, they may by external violence, by pushing with the toes of the outward-turned foot and so on, remove the semi-lunar cartilages from their position. At the same time severe pain, swelling, incapability of stretching out the foot, without much alteration of form in the knee come on. The natural position of the cartilages is most certainly restored, when the leg is bent back as much as possible, by which the pressure of the thigh-bone on the semi-lunar cartilages is removed, and they return to their place, when the leg is extended. The weakness of the joints is to be removed, by volatile rubbings and the like, and the recurrence of this accident prevented, by a properly applied knee-band (ASTLEY COOPER.)

WUTZER (a) observed a congenital bending forwards of both legs, depending on dislocation at the knee-joint. KLEBERG (b) describes a congenital dislocation of the left knee forwards, where, with the thigh extended, the leg was bent forward at the knee, and lay obliquely upwards in such way, that the points of the toes touched the right side of the belly; the legs could be easily returned to their natural position; they, however, immediately resumed their previous position, whilst the child himself had not any voluntary influence over their movements. Bending the leg back against the thigh to an obtuse angle, and fixing it in this position, by a thin cloth passed round the middle of the thigh and leg, in a short time restored the natural position and mobility of the leg.

XIII.-OF DISLOCATION OF THE SPLINT-BONE. (Luxatio Fibulæ, Lat. ; Verrenkung des Wadenbeines, Germ.; Luxation du Péroné, Fr.) BOYER, above cited, vol. iv. p. 375.

1088. The splint-bone may be dislocated at its upper or lower end, forwards or backwards. This can always be readily distinguished, as the head of the bone can be felt if there be not any considerable swelling.

In order to reduce this dislocation, it is only necessary to press the dislocated head into its place, and to fix it there with compresses and bandages. The dislocation of the upper end may be accompanied with fracture of the shin-bone, in which with the reduction of the fracture follows also that of the dislocation. Not unfrequently, owing to relaxation of the ligaments, dislocation of the upper end of the splint-bone takes place; its reduction in this case is easy, but just as speedily does the displacement recur. The bone is to be kept in place by rest, and by fixing it with bandages; the weakness of the joint should be sought to be removed by friction, blistering, and the like.

(a) MÜLLER'S Archiv. für Anatomie und Physiologie, 1825, pt. iv. P. 385.
(b) Hamburger Zeitschrift, vol. vi. pt. ii.

XIV. OF DISLOCATION OF THE ANKLE-JOINT.

(Luxatio Tali, Lat.; Verrenkung des Fussgelenkes, Germ.; Luxation du Pied, Fr.)

DESAULT, above cited, vol. i. p. 423.

BOYER, above cited, vol. iv. p. 375.
COOPER, ASTLEY, above cited, p. 238.

DUPUYTREN; in Annuaire Medico-Chirurgical des Hôpitaux et Hospices de Paris. Paris, 1819. 4to.; with copper-plates.

1089. Dislocations of the foot are frequent, and may occur inwards and outwards, forwards and backwards; the dislocation inwards is the most common; those forwards and backwards are much rarer than those on either side. They are generally complete or incomplete, simple or compound.

1090. In the dislocation inwards, produced by violent turning of the foot outwards, the joint surface of the astragalus is placed beneath the inner ankle, and the lower end of the shin-bone so thrust inwards, that the skin is ready to burst by its pressure; the inner edge of the foot is inclined downwards, the outer upwards, the sole of the foot outwards and its back inwards. This dislocation may be accompanied with considerable tearing of the ligaments, with fracture of the outer ankle or of the middle of the splint-bone, or of the lower end of the shin-bone, the soft parts may be torn, the joint surface of the astragalus or of the shin-bone be thrust through the skin, or there may be at the same time dislocation of the astragalus from its connexion with heel- and navicular bones. In the latter case, the integuments are often uninjured, and the ligaments between the astragalus, heel-, and navicular bone suffer only considerable extension; often, however, are all these ligaments and integuments so torn, that the astragalus is merely attached at some parts.

The dislocation outwards, is consequent on violent inclination of the foot inwards; the astragalus is thrust beneath the outer ankle, the inner edge of the foot is turned upwards, the outer inwards, the sole inwards, the back outwards. This dislocation may be connected with fracture of the lower end of the splint-bone and of the inner ankle. Usually is there also in lateral dislocation, a more or less decided inclination of the foot forwards or backwards.

1091. The symptoms mentioned of lateral dislocation are so distinct that it cannot be mistaken even when considerable swelling has taken place. But this swelling may render difficult the diagnosis of the different complications.

1092. In dislocation of the foot forwards, which arises from violent extension of the foot, and is rarer than that backwards, the joint-surfaces of the astragalus are in front of the shin-bone, the foot fixedly bent, the heel shortened, and the ACHILLES' tendon nearer the back of the leg.

In dislocation backwards, which may be consequent on a fall, with the sole of the foot on an oblique surface, the foot is outstretched and shortened, the heel more prominent, the ACHILLES' tendon projects from the back of the leg, the joint-surface of the astragalus is felt on the back of the shin-bone, the under end of which forms a hard projection on the middle of the instep and rests on the navicular bone and only on a small portion of the articular surface of the astragalus in front. This disloca

tion is always accompanied with fracture of the splint-bone of the inner ankle, or the latter is torn off.

This dislocation may be incomplete, so that the shin-bone rests half upon the navicular, whilst the other half remains on the astragalus. The foot then seems but little shorter, the heel projects a little, the toes are pointed downwards, so that the patient cannot put the whole sole of the foot on the ground, the heel is drawn up, and the foot to a great extent immovable; the splint-bone is broken.

1093. Dislocations of the foot are always important, because they presuppose great violence; and severe inflammation, and dangerous symptoms ensue from the tearing of the ligaments and from the dragging of the tendons and soft parts. Even in slighter degrees, stiffness of the joint is to be feared. There often remains so great weakness of the ligaments of the joint that the dislocation is reproduced by the slightest effort, if the joint be not strengthened by some mechanical apparatus. The dislocations forwards and backwards, are generally less dangerous, than the lateral dislocations and rarely accompanied with evil complications. Even if the dislocation be not reduced, the foot is not completely unfit for use; but very considerable deformity remains. Lateral dislocations are not always equally dangerous; they often are soon cured without any weakness or interference in the motions of the joint remaining. Dislocation outwards is mostly accompanied with more injury than that inwards. Simultaneous fracture of bones or tearing of soft parts render the case so much more dangerous; though experience shows that, in most cases, the limb may be preserved.

1094. The reduction of dislocation of recent occurrence, is usually not very difficult. The patient lies down, one assistant grasps with both hands the lower part of the shin-bone, and another, or in dislocation aside the Surgeon himself takes hold of the foot. The former makes counter-extension in the direction of the shin-bone, the other extension, (in which the leg is bent at right angle on the thigh,) first in the direction which the foot had, and when the ligaments and tendons are sufficiently stretched, he brings the foot into its proper place. In dislocations backwards, the Surgeon with one hand presses the heel forwards, and with the other the shin-bone backwards, and the contrary in dislocation forwards. Complete reduction is indicated by the natural direction and form of the foot and its capability of motion. The ankle-joint should then be enveloped in linen, dipped in dispersing fluid, and fastened with a circular bandage applied in a figure of form. Chaff bags are to be applied on each side of the leg and splints upon them which extend over the anklejoint as in fracture of the leg. The leg must always be bent at the kneejoint, and laid on a cushion, to relax the muscles. Antiphlogistic treatment must be employed proportionate to the constitution, the dressings moistened with dispersing fluid, and replaced every five or six days. When the pain and swelling have subsided, careful motion must be used, but only after a month, may the patient be allowed to walk gently about.

If dislocation of the foot inwards, be accompanied with fracture of the splint-bone, its re-dislocation is most effectually prevented by the apparatus used for fractured splint-bone, which may be also applied in dislocation outwards, the splint with the chaff bag being put on the outside of the leg. In dislocation of the foot backwards, re-displacement may be prevented by placing a splint and cushion beneath it, (so that both project beyond the heel,) and a small cushion on the lower part of the shin-bone,