lacking. In Smith's, Colles's, Pirrie's, and Sarazin's cases the dislocation was not reduced, and the patients were much crippled. C. Dislocations inward. In this division are placed those cases in which, usually by adduction and inversion (supination), the foot is moved downward and to the inner side, so that the astragalus leaves the tibio-fibular mortise more or less completely. Two distinct forms are observed: in one the foot is markedly inverted and the upper surface of the astragalus can be seen and felt raising the skin under the external malleolus; in the other the inversion of the foot is less or is absent and there is marked adduction, so that sometimes the ends of the toes point directly inward; in the latter form it is thought that the displacement is secondary to a backward dislocation. Malgaigne includes in the group (which he terms tibio-tarsal dislocations outward) many cases complicated by fracture of the astragalus or of one or both bones of the leg; but of his total of 22 cases, 8 were not thus complicated, and to these I can add 4, Busch,' Nunnely," Eames,' and Carmichael. I have described under "fractures by inversion and adduction of the foot," Fractures, p. 578, the lesions and symptoms in cases in which fracture is present and the displacement is absent or slight. Excluding for the moment those cases in which the displacement is secondary to a backward dislocation, it seems probable that the cause is violent supination, or inversion, of the foot, but the histories of the cases do not positively establish this opinion. In most the cause has been a fall, usually from a height; Carmichael's patient, a woman, turned her foot while walking down hill, Nunnely's ran at night into an excavation the bottom of which was covered with loose stones and bricks, Eames's fell with a falling platform, and Busch's was injured in the overturning of a wagon. The astragalus fits so snugly and squarely into the tibio-fibular mortise that in a considerable proportion of cases it cannot be turned in it about its own antero-posterior axis without breaking the external malleolus or forcing it away from the tibia by the pressure of the upper outer edge of the astragalus. In the experiments which Hönigschmied made by fixing the foot in a vise and bending the leg directly toward the inner sidetibial flexion-the external malleolus was broken 5 times, the external lateral ligament torn from its insertion 12 times, and in 3 cases the joint remained unopened and separation took place between the astragalus and the calcaneum. These results coincide in the main with those obtained in a similar manner by Bonnet, and Hönigschmied accepts the latter's opinion that the fracture of the malleolus is effected by the direct pressure upon it of the outer upper border of the astragalus and not by traction exerted through the external lateral ligament. Bonnet frequently found the internal malleolus also broken, Hönigschmied never. 1 Busch: Lehrbuch der Chir., vol. 2, part 3, p. 327; quoted by Lossen. Eames: Idem, 1871, i. p. 503. 4 Carmichael: Idem, 1871, ii. p. 35. In one case, Busch, in which there was no fracture, the dislocation was compound and the bones of the leg protruded through the wound in front, the astragalus lay entirely to the inner side of the internal malleolus, and the foot was greatly adducted; Busch thought the dislocation had been primarily backward. In Bardy's fracture of the fibula was noted, and in Ravaton's (both quoted by Malgaigne) there was diastasis of the lower tibio-fibular joint, which gave him much trouble in the treatment. In some cases, in which the displacement inward may be assumed to have been secondary to a backward dislocation, the adduction of the foot has been very great, 90°, so that the toes pointed directly toward the other ankle; in the others the adduction is less, but the inversion is great; in Carmichael's "the plantar aspect pointed to the middle line of the body," in Eames's "the plantar aspect of the foot was completely inverted." In some the external malleolus was very prominent; in Nunnely's "there was a large and well-marked projection below the outer malleolus" over which the skin was very tense, and "there was a deep, narrow depression at the inner malleolus where the skin was also very tight." Reduction has always been easily effected by traction and eversion of the foot, and in the uncomplicated cases the recovery has been complete. D. Dislocations outward. The injuries which have been described under this head are, almost without exception, those which are now commonly known as Pott's fracture at the ankle, and which have been described in Fractures, page 581, as fractures by eversion and abduction of the foot. A few more or less doubtful cases have been reported which differ more or less from those of Pott's fracture in their mode of production and lesions, and which might be termed partial dislocations of the foot outward. such, Boyer, has been quoted in Chapter XXX., page 505, as an example of upward dislocation of the head of the fibula; another is that of Desault, quoted by Malgaigne (loc. cit., pp. 996 and 998), in which the cause appears to have been abduction of the foot without eversion. In three cases, Huguier,' Thomas, and Soubie," the foot has been so far abducted that the toes pointed directly outward. This form was first observed by Huguier and described by him as "dislocation of the foot by rotation outward." His patient was overthrown by a cask, which rolled upon his legs; Thomas's by a falling mass of straw; and Soubie's fell from a height of six feet, alighting upon his left foot, which was then engaged between a large stone and the trunk of a vine, while the body was twisted to the right, and the patient fell on his right side. In Huguier's case the external malleolus was separated from the tibia, pressed backward, and rotated outward, and the shaft of the fibula was broken in the upper third. In the other two cases no fracture was found. In Thomas's "the anterior border of the lower end of the tibia formed a Huguier: L'Union Médicale, 1848, p. 128. 2 Thomas: Revue de Chirurgie, 1887, p. 821. marked prominence in front over which the skin was tightly stretched, and below which was a transverse depression that would admit the finger.' Reduction was easily effected under anæsthesia in all three cases. Nélaton made a separate class of those rare cases of Pott's fracture in which the astragalus is forced upward between the tibia and fibula, and termed them dislocations upward. I do not see that any advantage is to be gained by separating them from the group of which they are only an extreme form. The principles of treatment are the same as in Pott's fracture. E. Compound and complicated dislocations of the foot. Dislocations of the foot may be compound, primarily or secondarily, with protrusion of the bones of the leg or of the astragalus through the wound, and they may be complicated by rupture of bloodvessels and by other fractures than those of the malleoli already referred to. In dislocations that are primarily compound the wound of the skin may be made from within outward by the projecting bone or by contact with the ground. In those that become secondarily compound the sloughing of the soft parts may be due to the pressure of the unreduced bones or to bruising of the soft parts inflicted at the time of dislocation. The statistics that have been collected come almost entirely from the period anterior to the introduction of antiseptic methods and therefore cannot be trusted to show the necessity or desirability of amputation or excision. So far as can be judged from recent experience in these dislocations and in compound dislocations of other joints, conservative treatment under antiseptic rules may properly be tried in primary compound dislocations not seriously complicated by fracture, and if suppuration is avoided a useful, movable joint may be hoped for. Particular attention must be given to drainage, and as the astragalus completely fills the space between the malleoli separate drainage must be provided for the back and front of the joint. The limb must be carefully immobilized with the foot at a right angle to the leg and without inversion or eversion, in order that if the joint should become stiff the disability will not be increased by a faulty position of the foot. In cases in which suppuration has ensued, either before or after reduction, the treatment should still be conservative with the object of obtaining ankylosis in a good position or perhaps a slightly movable joint; but if the astragalus is broken I think it would be better to remove it. It has frequently happened that suppuration of the joint has been followed by necrosis of the astragalus, presumably because of the interruption of its blood-supply consequent upon the laceration of its ligaments, and this result would of course be still more probable after its fracture. Langenbeck' even in 1874 recommended conservative treatment in compound injuries of the ankle, both in civil and military practice, although Billroth and Socin estimated the mortality after such injuries under all kinds of treatment at 34 and 38 per cent. respectively. I have had no experience with compound dislocations of the ankle, but all the compound fractures 1 Langenbeck: Arch. für klin. Chir., 1874, vol. 16, p. 484. involving the joint that have come under my care, nine or ten in number, have, with one exception, recovered without suppuration, and although the laceration of the soft parts is less in such injuries than it is in the complete dislocations I believe that primary amputation or excision should not be resorted to in the absence of exceptional conditions, such as extreme laceration or fracture, that specially indicate one or the other. 2. SUBASTRAGALOID DISLOCATIONS. DISLOCATION OF THE ASTRAGALO CALCANEOID AND THE ASTRAGALO-SCAPHOID JOINTS. For the establishment of this group in the classification of dislocations of the tarsal bones we are indebted to Broca,' who, in a remarkable paper read before the Société de Chirurgie in 1852, carefully analyzed the scattered cases that had been reported under various titles and gave a detailed and systematic description of the various forms of the injury to which little has since been added except in amplification of the statistics. His plan of subdivision recognized dislocations backward, inward, and outward of the calcaneum and scaphoid from the astragalus. Malgaigne added a fourth variety, dislocations forward, of which Broca himself subsequently saw a possible example, and changed the nomenclature by treating the astragalus as the dislocated bone and applying the terms indicative of the direction of the displacement according to its position with relation to the others. I shall here follow Broca's use of the terms, which is in harmony with that used in the other dislocations. The dislocation, then, presents four varieties: that in which the calcaneum and scaphoid are displaced inward (and somewhat backward), the head of the astragalus projecting on the outer part of the dorsum of the foot; that in which they are displaced outward; and those in which they are displaced directly forward or backward and downward. The first two are about equal in frequency and together comprise most of the reported cases; of each of the last two only one or two examples have been reported. The most notable addition to the collected statistics has been made by Poinsot.2 A. Dislocations inward, or inward and backward. The cause is forcible inversion and adduction of the foot, usually combined with violence acting in the direction of the long axis of the leg, as in a fall from a height. The displacement is rarely, if ever, directly inward, but is also somewhat backward, so that the head of the astragalus rests partly upon the cuboid. The only autopsy is one made in an old case by Quénu there was shortening of the dorsum of the foot. and elongation of the heel, and the foot was in the position of varus. The head of the astragalus lay upon the interarticular lines between the 1 Broca: Mém. de la Soc. de Chirurgie, 1852, vol. 3, p. 566, and abstract in Bull. de la Soc. de Chirurgie, 1853, vol. 3, p. 241. Poinsot: L'intervention chirurgicale dans les luxations compliqués du cou-depied, Paris, 1877, and his translation of Hamilton's Fractures and Dislocations, p 1196. calcaneum and cuboid and the cuboid and scaphoid, overlapping the former half an inch and thus resting on the cuboid. The posterior border of the astragalus lay in the groove between the anterior and posterior superior articular surfaces of the calcaneum, and its posterior lip had been broken off and remained in its normal relations with the calcaneum. There was no fracture of either malleolus. The dorsalis pedis artery and the extensor tendons lay to the inner side of the head of the astragalus; the peroneal tendons had been displaced from their groove and separated half an inch from the fibula. In other cases the displacement has been greater and the skin has been broken on the outer side of the foot; in one of Malgaigne's the head of the astragalus was almost in contact with the fifth metatarsal bone; in one of Letenneur's it corresponded to the outer border of the foot and projected entirely through a wound in the skin, and the calcaneum had been completely displaced from its inferior articular surface. The form and degree of the displacement vary with the different combinations of displacement inward, back 5 8 4 -5 Subastragaloid dislocation inward; 5, sustentaculum tali; 4, inner malleolus. (DU BOURG.) ༡ 1. The same; 1, head of astragalus; 3, 4, old cicatrices; 5, a fistula; 6, fracture of the fibula. (Du BOURG.) ward, and by adduction of the front of the foot, the latter sometimes leaving the posterior part of the calcaneum less displaced inward than its front part. With the dislocation there is sometimes associated injury to the calcaneo-cuboid joint, rupture of its ligaments and partial dislocation of the bones. The symptoms are more or less shortening of the dorsum of the foot and lengthening of the heel, adduction of the toes, and elevation of the inner border of the foot; prominence of the tip of the external malleolus and of the head of the astragalus on the outer side of the dorsum, with marked depressibility of the soft parts below each; the internal malleolus is deeply placed under the skin, and below and behind it can be felt the projecting sustentaculum tali, and in front of it the inner surface of the scaphoid. |