has come about through gradual departure of the articular head from the acetabulum. I am not aware that there is any evidence, that so-called congenital dislocation of the hip may not be acquired at, or after birth. It is rare that anything is known of the condition until the child begins to walk, and in double dislocation it is likely to be overlooked a much longer time, because the disability being the same on both sides, the gait, although a waddling one, does not exhibit itself as a lameness.

This much, however, may be reasonably assumed, that whether the dislocation occur in utero or out, there must be some congenital laxity or defect of the ligaments of the hip joint as a predisposing cause.

The frequency of occurrence is difficult to estimate. It has been deemed a rare condition, and yet the number of cases which sprang up from all over the country in response to Dr. Lorenz's offer to treat them gratuitously is the best evidence that it is not so unusual as heretofore believed. It seems probable that in the past, many cases have remained in obscurity, because the condition was deemed hopeless, or at least that the methods then in vogue afforded so little that physicians and parents preferred to let the cases take their

course.

In a single year fifty-one new cases applied at the Hospital for Ruptured and Crippled, New York City.

At the time of Dr. Lorenz's visit here in Boston, no less than twenty cases gathered at the Children's Hospital in response to an invitation issued by the surgeons of that institution.

In every city visited by Dr. Lorenz, cases of congenital hip dislocation appeared by the score. In Chicago, if newspaper and medical journal reports may be believed, by the hundreds.

All this is evidence of the most convincing character, that this accident of fetal or infant life is not rare, but of relatively frequent occurrence.

The anatomical changes accompanying congenital hip dislocation are of such character, that if they remain uncorrected, great incapacity for locomotion and usefulness in later life results. The head of the femur occupies a movable position upon the dorsum of the ilium, above and back of the acetab

ulum, and moves or slides up and down at each step, giving the wobbling gait which must be inseparable from such instability of the head of the femur. All available evidence indicates that the acetabulum is always present-sometimes imperfect, but often normal or nearly so. The head of the femur has sometimes been found distorted, flattened and smaller than normal, with a shortened neck and depressed to nearly a right angle with the shaft. The capsular ligament is elongated, thickened and sometimes narrowed in the middle

to something like an hour-glass shape. The ligamentum teres is absent. All these changes are sure to be exaggerated with lapse of time, hence the insuperable obstacles of advanced youth to reduction. The adductor muscles act constantly in a

way to push the whole femur to a higher level and become one of the most serious obstacles to reduction and maintenance of correct posture. With the lapse of time, then, the acetabulum becomes shallower, the head of the femur smaller and

more distorted, the capsular ligament elongated, thickened and constricted, and the adductor muscles shortened. Obviously early childhood-the earlier the better-is the choice of time for reduction, because the anatomical structures concerned have not yet suffered permanent physical change, and therefore lend themselves more readily to reposition and correct functional activity.

It is estimated by Dr. Lorenz that it is useless, in unilateral cases, to attempt reduction after the ninth year, although he has in a few instances succeeded. In bilateral cases he places

the limit at six years. This difference seems surprising, but the obstacle in bilateral cases is not the difficulty of reducing the dislocations, but in keeping them reduced. In unilateral cases there is a well strong leg to take the brunt of locomotion when the child begins to walk again, but in the bilateral, both legs are defective, both must equally have the brunt of work, when the retention dressing is removed.

It is claimed, and upon good grounds, that a shallow acetabulum deepens after reduction and fixation is established, in other words, that the presence of the head of the femur, after being readjusted in its normal place, brings about a salutary change in the acetabulum. Dr. Lorenz thinks that there is an actual building up of new bone about its rim.

The external and visible anatomical changes, are largely those of figure. It has been stated above that the mobility of the head of the femur upon the dorsum of the ilium, results in a waddling gait. When the affection is unilateral, this waddling appears as a lameness or limp, with prominence of the hip of the affected side, and a twist of the pelvis. In bilateral cases, there is always lordosis, produced by the tilting forward of the pelvis and its vertical suspension from the heads of the femora and the elongated capsular ligaments. This peculiar and unstable sling-like support, is tolerated in infancy and early childhood, because the superincumbent weight of the trunk is comparatively slight, and the patient, up to puberty and youth walks about with remarkably little embarrassment. With increasing weight, however, especially if the case be bilateral, the pelvis tips farther and farther forward until an extreme compensatory curvature of the lumbar spine develops. At each step the head of the femur slides up and down on the dorsum of the ilium; finally the area of friction becomes bare and eburnated. With advancing years and increasing weight of the trunk. locomotion becomes more and more difficult and limited.

TREATMENT OF CONGENITAL HIP DISLOCATION.

The treatment of this deformity has been a surgical stumbling block up to the time of Lorenz's teachings. Treatment by splints, and by extension have proven unavailing be

cause of the impossibility of reducing the head of the femur to the acetabulum by such means, and furthermore, the failure to keep it there, if it by any chance reduction was effected.

To Hoffa, belongs the credit of initiating the first great advance in the surgical treatment of congenital hip dislocation. He recognized that success must depend on complete restoration of the head of the femur and its maintenance there. This he accomplished by a cutting operation, exposing the acetabulum, and in case of its inadequacy he chiseled it out sufficiently to receive the articular head and keep it there. This was a step in advance, but the results were not satisfactory for an ankylosis was almost sure to occur, with nearly as great disability in locomotion as accompanies untreated

cases.

Nearly simultaneously, Pacci, of Italy, and Lorenz, of Austria, essayed to effect reduction by manipulation and postural fixation. Unfortunately for Pacci, his case was a youth, and the anatomical changes offered such obstacles that his efforts were unavailing. Lorenz's case was a young child, and he succeeded.

The Lorenz method then in brief, is reduction by manipulation, and retention of the articular head in the acetabulum by postural fixation. The latter is really the important feature of the Lorenz method. His system of manipulation does not differ materially from that of the late Dr. Henry J. Bigelow, of Boston, for reduction of accidental hip dislocation. Dr. Lorenz has shown that reduction of congenital hip dislocation can be done in the same way, and the steps differ in nowise from those which anyone would follow in reduction of a neglected accidental hip dislocation.

In congenital hip dislocation the adductor muscles become much contracted and shortened, and offer greater resistance to reduction and retention than any other structure involved. Dr. Lorenz breaks this down at the outset, by strong adduction of the leg and forcible kneading of the muscles at their tendonous attachment to the pelvis. The next step is extreme flexion of the whole limb, then extreme extension limited only by the integrity of the tissues-all this time the pelvis is fixed by the hand of an assistant. After all the tissues about the joint have been stretched or torn, sufficiently to permit the head of the femur to be brought down to the acetabulum, the leg is again abducted, and with the aid of a wedge-shaped block as a fulcrum, the head of the femur is slipped over the edge of the