Isolated dislocation of the second metatarsal upon the dorsum has been reported in one case, Brault and Belin, quoted by Hitzig; that of the third downward and backward in one, Tufnell (Dublin Quart. Journ. Med. Sci., 1855, p. 302); that of the fourth upon the dorsum in three, Malgaigne, Surmay (Bull. de la Soc. de Chir., 1876, ii. p. 579), Gosselin (Gaz. des Hôpitaux, 1876, p. 755).

The fourth and fifth metatarsals have been together dislocated upward and inward, Monteggia, and upward and backward, South; both quoted by Malgaigne. The third and fourth, Hartmann, and the first and second, Marit, have been together displaced; both quoted by Delorme.' The first, second, and third were dislocated together upon the dorsum in two cases, Laugier, quoted by Malgaigne, and Wilms, quoted by Hitzig, and downward into the sole in a case reported by Tufnell (Dublin Quart. Journ. Med. Sci., 1854, vol. 17, p. 65); in the latter case the injury was caused by the fall of a horse and was irreducible, but the patient recovered good use of the limb; the later history is recorded in the same journal, 1855, vol. 20, p. 302.

Dislocation of the second, third, and fourth together upon the dorsum was seen by Malgaigne once; the same diagnosis was made by him in another case, but at the autopsy it was found that the fifth was also partly dislocated from the cuboid and that the first together with the internal cuneiform was displaced inward.

Dislocation of the first four metatarsals has been reported in three cases, Malgaigne, Hitzig, Demarquay (Gaz. des Hôpitaux, 1865, p. 534); in Malgaigne's the first three were displaced downward, the fourth upward; in the other two the displacement was upward. Malgaigne was able to reduce the fourth, Demarquay the first, and Hitzig all; notwithstanding the persistence of part of the dislocation the two patients had good use of the limb.

All the metatarsal bones may be displaced together upward, inward, downward, or outward; of the latter two forms only one example of each has been reported. Smyly (Dublin Quart. Journ. Med. Sci., 1854, vol. 17, p. 317) saw all five bones dislocated downward by the fall of a wagon which pressed the heel forward while the toes were fixed; reduction was made. The case of dislocation inward is Kirk's, quoted by Malgaigne, who distrusts the diagnosis.

Of dislocation outward five cases have been reported, Laugier and Lacombe, quoted by Malgaigne, Tutschek, quoted by Hitzig, MignotDanton (Arch. gén. de Méd., 1866, ii. p. 405), and Desprès (Bull. de la Soc. Anatomique, 1878). The interlocking of the base of the second metatarsal between the first and third cuneiform bones must make a lateral dislocation impossible except as secondary to one upward or downward or unless accompanied by fracture; in Laugier's and Dsprès's the second metatarsal was broken at its upper end, and in Mignot-Danton's and Lacombe's the third was broken. In four cases reduction was made. Dislocation upward may be complete or incomplete, and sometimes the whole or a part of the first cuneiform remains attached to the first metatarsal and is displaced with it. Hitzig collected eleven cases. The most

1 Delorme: Dict. de Méd. et Chir. prat., vol. 27, art. Pied.

frequent cause is direct violence, but in two cases it was muscular action, the efforts of the patients to avoid falling after having slipped while carrying heavy bundles. The autopsies and the compound cases have shown rupture of the dorsal and of some of the palmar ligaments, rupture and laceration of some of the interosseous ligaments and muscles, fracture of some of the metatarsal bones and occasionally of the cuboid and first cuneiform, and sometimes separation of the first or fifth metatarsal laterally from the others. The metatarsus may remain in line with the rest of the foot or be deviated to either side, and the bases of its bones form a transverse ridge either corresponding exactly to the line of the joints or at a somewhat higher point upon the tarsus. Reduction was made more

or less completely in some of the cases; in others it failed, but the patients gradually recovered the use of the limb; in one compound case, Mazot, primary amputation was done.

DISLOCATIONS OF THE TOES.

A. Metatarso-phalangeal dislocations.

1. Dislocations of the great toe.-Of this injury Malgaigne collected 19 cases, to which Delorme added 12. The most common cause is a fall upon the toes; among the less frequent are the act of kicking, receiving the weight of the body upon the toe alone in going upstairs, and violence received upon the metatarsus. The injury is frequently compound. The dislocation has been upward, backward, and to one side, the most frequent appearing to be those to the outer side and backward, and secondly those directly backward; the former of these two is almost always compound with projection of the head of the metatarsal bone through the wound on the inner and lower aspect of the joint. Coexistent sprain or subluxation of the first tarso-metatarsal joint has been occasionally noted.

Of 14 simple cases collated by Delorme reduction was easily made in 8 and failed in 4; of the compound cases the head of the metatarsal bone was excised in 5, and the entire bone removed in 3; of 14 compound cases in which the attempt to reduce was made it was successful in 9. The means employed to reduce have been traction and direct pressure upon the base of the phalanx. Probably in the difficult cases the special procedures employed in the corresponding dislocations of the thumb would be advantageous.

2. Dislocations of the other toes.-Dislocation of the four outer, the four inner, or of all five toes together has been reported in several cases, the direction of the displacement being upward and backward or directly outward; in the latter the head of the metatarsal projected through a wound and had to be excised before reduction could be made.

B. Dislocations of the phalanges.

With one exception, the second phalanx of the third toe, in all the cases that have been reported the dislocation was of the terminal phalanx of the great toe. In one case reduction could not be made; in another, which was compound, a portion of the bone was subsequently cast off.

theories of production, 285 Foramen ovale, dislocation into, 428

isolated, of radius and ulna, 317 GLENOID fossa, fracture of, 257

Hip, dislocations of, infracotyloid, 446 Knee, injuries of vessels in, 34, 470

Humerus, fracture of anatomical neck, Metatarso-phalangeal dislocations, 534

Hyperextension in reduction at elbow, Myopathic dislocation of shoulder, 279
296

[LEO-PECTINEAL dislocation of hip, NERVES injured in dislocation, 35