REDUCTION.

After extension by pulleys in the axis of the body has failed, reduction of this luxation has been accomplished by extension downward and outward, with some manipulation of the head of the bone and probably with rupture of the ligament. It is obviously a better plan to unhook the neck by circumduction. of the extended limb inward, with eversion enough to disengage it from the edge of the pelvis. The head then lies upon the dorsum, and if the outer branch of the Y is broken, is not inverted. The reduction may then be accomplished as usual in the dorsal dislocation, although rotation would be less effectual than if the ligament were entire.1

EVERTED DORSAL DISLOCATION.

It has been before stated that inversion of the limb in the dorsal luxations is due to the tense outer branch of the Y ligament. When the injury has been such as to rupture these fibres, the limb may still be inverted; but it can also be freely everted. Having escaped from the socket under

1 The following case well illustrates the mechanism of the supraspinous luxation, and is taken from Hamilton ("Practical Treatise," etc., p. 649): "Lente relates a case [of ischiatic luxation] under the care of Dr. Hoffman, in the New York City Hospital, in which, when the extension was suddenly relaxed by cutting the cord, and the thigh at the same instant was abducted and rotated outward, the head of the femur left the ischiatic notch and rose upon the dorsum ilii, assuming a position directly above the acetabulum and below the anterior superior spinous process, from which position it was with great difficulty subsequently returned to the socket."

If this luxation was really "ischiatic," as stated, and therefore "below the tendon," the forcible outward rotation of the thigh ruptured both the tendon and the outer part of the Y ligament, or in any case the latter; after which the head of the bone was free to turn forward and rise on the ilium toward the spine, the limb being of course everted, and the head of the bone perhaps engaged above the remaining ligament.

these circumstances, the bone may occupy any point upon the dorsum within the range of the inner fasciculus. The limb is then shortened in proportion to its upward displacement, the foot being sometimes everted a little, sometimes lying flat upon the bed, or even directed. backward, the head of the femur facing accordingly, and as has been elsewhere remarked — in the direction of its internal condyle. The femur is suspended midway between the inner branch of the Y and the obturator tendon. Theoretically it may be luxated either below or above this tendon; but in the former case the degree and nature of the force required to break the outer band would be likely to rupture the tendon also. If the head of the femur is driven upward and backward above the obturator tendon, the same forced eversion which would sever the inner branch of the Y ligament would relax this tendon, and so contribute to prevent its rupture. The tendon may then lend its aid in giving position to the limb.2

1 Everted dorsal dislocation. (See note, p. 88.)

FIG. 40.1

2 For an old case of this sort, with an analysis of the muscular action, see a paper by Dr. Gordon in the Dublin Hospital Gazette, Nov. 1, 1845, p. 87.

Mr G. R. Symes has described a case (“On an Unusual Form of Dislocation of the Hip Joint," by Glasscut R. Symes, one of the Surgeons of Stevens's Hospital, Dublin Quarterly Journal of Medical Science, 1864, vol. xxxviii.) in which the right leg was shortened two inches, the foot extremely everted, the buttock flattened, and the head of the femur two inches below the anterior superior spinous process of the ilium. The limb remained unreduced after protracted efforts by manipulation and

REDUCTION.

The limb should be flexed and inverted, with adduction if necessary, to make room for the head of the bone to slide upon the ilium; and the dislocation is then practically a simple dorsal dislocation, and easily reduced. Or if not, perhaps the whole upper part of the capsule is detached, making the luxation irregular.

The rupture of the outer fasciculus of the Y ligament deprives the operator of much of the advantage of rotation. The limb, after flexion and rotation inward, may be reduced by direct traction toward the socket, with local guidance.1

pulleys, during which it was repeatedly inverted and everted. The failure to reduce the limb was attributed by Mr. Symes to a "button-hole” laceration. In a similar case, or even if the head of the femur were engaged in the interstices of the rotators, I should attempt to liberate it by circumducting it to the thyroid foramen.

A case of everted dorsal dislocation has been reported by Dr. Van Buren ("Contributions to Practical Surgery," by W. H. Van Buren, M. D., etc., Philadelphia, 1865, p. 157). The limb was shortened an inch, and slightly everted, there being some obstacle to inversion. The trochanter was an inch and a half behind and above its usual position, and the head of the bone was obscurely felt in the back part of the sciatic notch. After repeated attempts at reduction by manipulation, the bone was reduced by pulleys applied to the thigh in a flexed position.

For a case probably everted dorsal, but classed by Cooper as anomalous, see Morgan (Guy's Hospital Reports, No. 1, p. 82). The left leg was shortened two inches, the foot excessively everted, so as almost to give the toes a direction backward, but when placed side by side with the other foot remained in that position. The leg was to some extent susceptible of all the natural motions, with the exception of rotation. The trochanter could not be felt; but the head of the bone was apparently lying between the anterior inferior spinous process of the ilium and the junction of that bone with the pubes. Traction was made from the knee against counter-extension with the foot in the perinæum. The patient was then directed to raise his shoulders from the bed, extension was suddenly increased with forcible inward rotation of the thigh, and the head snapped into the socket.

1 The following interesting case (reported by Dr. Shrady in the New York Journal of Medicine, March, 1860, p. 255) occurred in the hospital

IRREGULAR DISLOCATIONS.

IN WHICH THE Y LIGAMENT IS WHOLLY BROKEN.

IN rare instances the Y ligament may be completely ruptured by forced extension of the limb, or by an upward thrust, while the lower half of the capsule remains comparatively sound. But it has been shown that the position of the great majority of dislocations is determined by this ligament; and until it is likewise shown that when it is broken the luxated limb will be compelled, in obedience to other mechanical agents, muscular or capsular, to assume positions equally constant, it is fair to consider such luxations as irregular. When any mechanism shall be shown always to give to a luxated limb, after the Y ligament has been torn asunder, the same position under the same circumstances, the luxation may be withdrawn from the present category, and classed as "regular."

When the Y ligament is wholly broken, and the head of the femur is dislocated upward upon the edge of the socket, either

wards of Dr. Willard Parker. The patient was crushed to the ground by a gravel car falling upon the small of his back. The left limb was rotated outward and shortened three inches, the thigh slightly adducted and flexed, the knee slightly advanced and semi-flexed, and the toe so everted that the heel rested against the inner aspect of the opposite leg, just above the ankle. Passive rotation was very painful; the buttock of the affected side was much fuller than the other, and the post-trochanteric depression was obliterated. Only the tips of the toes touched the floor. The vertical distance from the trochanter to the crest of the ilium was shortened three quarters of an inch. (If this statement is correct, the apparent shortening of three inches was probably due to the flexed knee.) The head of the bone could be felt, but not very distinctly, in a direction forward and upward from the trochanter. Several efforts to reduce the limb by flexion and adduction were unsuccessful. The thigh was at last rotated inward, extension made in the direction of the socket, and the head of the bone guided by direct manipulation into its place.

inside or outside the iliacus tendon, there is little or no shortening, and no flexion; but the eversion of the foot is marked. The head is felt in the groin, and is reduced by flexion and inversion.

If the head of the bone under these circumstances be displaced toward the thyroid opening, there is abduction of the leg, produced chiefly by the fascia lata, with some flexion due to the adductors; but the flexion is less than in the regular thyroid dislocation, and the knee can be depressed, with a little effort, to the natural position. It is possible that such a dislocation might simulate the thyroid displacement; but it may be distinguished from this by the greater abduction and less considerable flexion of the limb.

If the head be now carried farther downward, the flexion becomes more considerable, though less than if the Y ligament were entire. Such may have been the condition of the parts in some of the cases of downward dislocation before referred to, where the head was said to have been felt near the tuberosity, and where the flexion was inconsiderable.

If the head of the bone be now carried behind the tendon of the obturator internus muscle, there is a flexion of the femur at an angle of 45°, but with such exaggerated inversion as to distinguish it from the regular dislocation below the tendon. The thigh then faces completely inward, and instead of crossing its fellow is even a little abducted. The leg, which is bent by the tense flexors of the thigh, stands at right angles with it.

If the head of the bone be carried upward upon the dorsum, the limb, while it faces directly inward toward its fellow, is no longer flexed, as in the regular dorsal dislocation, but lies flat upon the table. The head, being now detached from the socket, may be carried round upon the dorsum and hooked above the rectus muscle in front, a position of the parts which, owing to the great strength of the Y ligament, is prob