whatever the cause of the original displacement from contact with the capitellum may have been.

Mitscherlich's patient was a girl six years old who had been born with clubfoot; both elbows were deformed, and this defect was thought also to have existed from birth. The head of the radius could be felt in front of the outer half of the coronoid process; extension was perfect, but flexion was limited on the right side to an angle of 70° and on the left to one of

110°, both hands were supinated. The elbows were more cylindrical in form than usual; the wrist and fingers were slightly flexed but could be straightened. The child was of stunted development and rather feeble intelligence. Excision of the left elbow was done by von Langenbeck with the object of increasing its range of motion, and the child died in consequence of the operation. The specimen (Fig. 94) showed that the trochlear surface of the humerus was narrowed in front by extension upon it of the exceptionally large circular surface for the head of the radius. The articular surface of the ulna was normal, but the radius was not in contact with it.

FIG. 95.

Allen's case of cognenital dislocation of the elbow.

FIG. 96.

Allen's specimen (Figs. 95 and 96) was taken from the body of an elderly man without history. Both elbows were affected; flexion was normal, extension possible only to a right angle; rotation was entirely lost, the limbs being fixed in pronation. Both radii were displaced backward, but only the left elbow is described in detail. The specimen was not presented as an example of congenital dislocation, but only to show the changes effected in the bones in consequence of unreduced dislocation in early life. These changes modified the shape of the lower end of the humerus and of the radius. The radius crossed the front of the ulna and was united with it by bony union for a distance of about three inches at their upper part; below this part the shaft of the radius was much thickened. The neck of the radius was one and a half inches long, so that the head was carried well upward behind the humerus on the inner side of the

The same.

olecranon, and this overriding was further increased by the abnormal. growth of the external condyle downward and outward, the extent downward of the growth being estimated at half an inch. The trochlear surface was deformed, mainly by the loss of much of its inner lip. The olecranon fossa was so far filled up that the septum between it and the coronoid fossa was one-third of an inch thick. The shaft of the ulna was small; its lower end was normal and preserved the usual relations with the radius. The specimen appears closely to resemble those of the earlier cases reported by Sandifort, Dubois, and Verneuil, and has as much, or as little, reason to be thought congenital as most of the others. It is of value in the interpretation of the changes observed in other specimens.

The report of Pye-Smith's case is very brief. The patient was a woman; the head of the left radius was displaced backward. She was one of a family of eleven persons, eight of whom showed abnormalities of the joints, one brother having a similar dislocation of the right radius. The father, and his father, uncle, and cousins had various deformities, clubfeet, badly developed nails, etc.

Phillips's patient was a well developed girl, seventeen years old. "The head of each radius formed a well-marked prominence behind the external condyle of the humerus. The elbow-joint could be fully extended and could be flexed to almost the normal degree, but only with the hand in the semi-pronated position. This action was produced mainly by the supinator muscle; the biceps appeared to be much atrophied. The head of the radius could be rotated to a small extent; and the various prominences of the elbow-joint, as well as the head of the radius itself, were fully developed. The mother of the child stated that the deformity was noticed almost immediately after the birth of the patient." The delivery was natural and easy.

Heele's patient was a loose-jointed, choreic boy, eight years old, of very backward intelligence. The left radius was dislocated by any slight motion and was usually out of place; it was easily reduced by flexion of the elbow or by pressure upon the bone in any position of the limb. The right radius was partly dislocated and irreducible, only one-fifth of the head remaining in contact with the humerus. Both dislocations were "backward and upward." Both condyles seemed small. All movements were possible, but rotation was weak, especially supination. The displacements were noticed shortly after birth; no history of accident.

In the last three cases the histories place the appearance of the deformity at so early a period that it is not improbable that it existed at birth, or, at least, that the structure and form of the joint were such at birth that the displacement was inevitable. In none of the older cases is a similar history found; in R. W. Smith's, which is one of those quoted by Malgaigne, the deformity had indeed existed from birth, but instead of being a dislocation it was an extreme malformation not only of the upper end of the radius but also of its lower end and of the ulna and carpus.

The arguments upon which the attribution of a congenital character

1 R. W. Smith: Fractures and Dislocations, p. 247.

was based in most of the older cases and in those of Humphrey and Hayem, and which apply equally well to Alden's, are the existence of the deformity on both sides and the changes in the shape of the articular ends of the bones; in Humphrey's and in Deville's there is in addition the lack of the lower part of the ulna.

The bilateral character, even with persistence of the ligaments, is not a proof that the displacement is not traumatic, as Bartel's case, quoted above under backward dislocations of the radius, shows, for in it both radii were gradually dislocated in a weakly lad by long-repeated efforts in pushing a cart.

The irregularities in the bones may, in part at least, be fairly attributed to the change in their relations, especially the very notable one of elongation of the neck of the radius reported in several cases. This is in keeping with similar instances of overgrowth at other points where the normal conditions of pressure have been lost, and with the coincident elongation downward of the external condyle of the humerus noted in Allen's case and in one of R. W. Smith quoted by Gurlt (loc cit., p. 320). It requires only that the displacement should occur before the growth of the skeleton is complete.

In short, although the recent clinical cases approach more nearly to the character of a demonstration, Malgaigne's conclusion that a congenital dislocation, while probable, has not yet been proved to have existed may still be repeated.

The only recorded case of dislocation of both bones of the forearm at birth is one reported by Chaussier and quoted by Pingaud.' A young woman during the ninth month of pregnancy felt her child move so vigorously that she almost lost consciousness. The movements were repeated three times in the course of ten minutes; delivery took place normally at term. The child was weak and presented a complete dislocation of the forearm backward. Malgaigne thought it probable that the lesion was produced, not by the convulsive action of the muscles, but by the striking of the limb against the wall of the uterus.

A few instances of dislocation due to pathological changes within the joint, such as fungous arthritis or relaxation of the ligaments in the course of an acute illness, have been reported.

1 Pingaud: Dict. Encyclopédique des Sc. Méd., art. coude, p. 606.

CHAPTER XXII.

DISLOCATIONS AT THE WRIST.

DISLOCATIONS OF THE LOWER RADIO-ULNAR JOINT; OF THE RADIO-CARPAL JOINT; OF THE CARPAL BONES; CARPO-METACARPAL DISLOCATIONS.

case.

A. DISLOCATIONS OF THE LOWER RADIO-ULNAR JOINT.

THESE dislocations, obscurely mentioned by the earlier writers, were first described, according to Malgaigne, in 1771, by Desault, who reported five cases and said he had observed a great number of others. He spoke of the injury as a dislocation of the radius, but Boyer and Dupuytren preferred to call it a dislocation of the ulna, and their choice has been generally accepted and followed. Both traumatic and pathological forms have been described. The reported cases are comparatively few if those cases are excluded in which the injury is a complication of a fracture of the lower end of the radius, and those injuries observed in young children which are generally thought to be a subluxation of the head of the radius, but which some consider dislocations of the lower end of the ulna; few surgeons who have reported their experience have seen more than a single Tillmanns' collected 48 cases in addition to one observed by himself, of which the dislocation was forward in 16, backward in 18, and inward in 9, and in 5 the direction was not stated; but in 3 of the first group, 8 of the second, all of the third, and 1 of the fourth, there was also fracture of the radius, and in 4 others the ulna perforated the skin and there is reason to think the radius also was fractured. Excluding the cases complicated by fracture, and including only 3 of Desault's 5, there remain 12 dislocations forward and 10 backward; to these may be added 2 backward and 3 forward seen or collected by Hamilton, and 3 forward collected by Poinsot, making a total of these two varieties of 18 forward and 12 backward. The reported dislocations inward or, more strictly speaking, downward and inward, are really dislocations of the broken end of the radius and the attached carpus upward; to these may be added also the few cases of dislocation of the head of the radius (q. v.) in which the entire bone has been displaced upward along the ulna.

In the preceding chapter mention has been made of the theory advanced by Goyrand, that the injury frequently seen in very young children and generally thought to be a subluxation of the head of the radius by elongation was a dislocation backward of the lower end of the ulna. Although the theory cannot be accepted as a correct explanation of the great majority of the cases, yet it may be true of some of them— of those few in which pain and swelling are found only at the back of the wrist-and if so the list of reported cases of the injury now under con

1 Tillmanns: Arch. der Heilkunde, 1874, vol. xv. p. 249.

sideration would have to be increased by additions to the backward variety, which would make it the more common of the two.

Dislocations backward.-The cause in most of the cases tabulated above was exaggerated pronation of the wrist; in some the mechanism is not indicated, and in others it is not clear. A few of them, Desault, Dugès, Rendu, have been included either by the surgeon himself (Rendu) or by other writers among dislocations of the upper end of the radius by elongation, and in these the injury was produced in very young children by traction upon, or forced pronation of, the hand. As above stated, several other cases, notably some of Snedden's (see Chapter XX., p. 000), presented similar symptoms and probably belong in this group. Sometimes the exaggerated pronation has been effected by external violence, as in Boyer's case, in which a lad engaged his hand between the spokes of a moving wheel; sometimes by muscular action, as in one of Desault's, a washerwoman who was wringing clothes, or in one of Rognetta's, a carpenter who was drilling a hole in a plank; Dalechamp's patient was bitten at the wrist by a horse.

The pathology has not been shown by direct examination of either recent or old cases, and the only experiments bearing upon it are those of Goyrand, quoted in Chapter XX., and they show only that by exaggerated pronation the triangular fibro-cartilage uniting the radius and ulna could be carried so far forward as to clear the end of the ulna entirely; he did not succeed in producing by this means a dislocation that would maintain itself without the aid of pressure upon the hand. It seems probable that in the clinical cases there was also rupture of the posterior radio-ulnar ligament.

Symptoms. The hand is slightly or markedly pronated; its adduction has been noted by some, and diminution of the transverse diameter of the wrist by others. Flexion and extension of the wrist are free; supination difficult.

The deformity consists in a marked projection of the lower end of the ulna on the back of the wrist, and a corresponding depression in front; the ulna may, in addition, slightly overlap the end of the radius, so that its axis if prolonged downward would pass to the middle finger.

The diagnosis appears to be easy, the exception being again noted of the possible cases occurring in young children, in which the only symptoms are pain and swelling at the back of the wrist. Malgaigne calls attention to the danger of mistaking the cause for the effect in old cases in which the dislocation follows a chronic arthritis, and also of overlooking an associated fracture of the radius.

Reduction has always been readily effected by direct pressure on the radius, aided sometimes by abduction or supination of the hand; occasionally supination alone has been sufficient, and this is the rule in the supposed cases in young children. Even in old cases-sixty daysreduction has been easily made.

Recurrence has been noted in three cases. In one of Hamilton's the dislocation had existed twenty years, but the movements of the limb were perfect.

Dislocations forward.-Dislocation of the lower end of the ulna forward appears commonly to have been caused by direct violence acting in