may continue to cause great distress for an indefinite period.

Fractures of the costal cartilages are not as rare as might be supposed. The fracture occurs at the junction between the cartilage and the rib (see Plate 22, Fig. 2), or in the body of the cartilage itself (Plate 22, Fig. 1). The latter specimen demonstrates that a fracture of this kind may leave considerable deformity and unite with a scanty formation of callus. The fracture is predisposed to by diminished elasticity of the cartilage, due to senile changes, and is usually produced by direct violence; it occurs most frequently in those cartilages which are most exposed— namely, the fifth to the eighth.

The symptoms are the same as in fracture of the ribs, except that crepitus is of a softer character.

DISLOCATION OF THE RIBS

This extremely rare injury needs only a passing reference. It may occur in the form of a luxation of the costal cartilages at the sternal extremity or of the costo-vertebral articulations, or, finally, as a dislocation at the junction of two costal cartilages. Reduction is effected by direct pressure or movement, as, for instance, deep inspiration.

(B) FRACTURES OF THE STERNUM. (Plate 22.)

They are produced by direct violence, and are then dangerous on account of injury to the internal organs, or by indirect violence in flexion of the vertebral column or of the head so that the chin presses against the upper edge of the sternum. In the latter variety the sternum is compressed in its longitudinal axis until it snaps. Sometimes the combination of fracture of the cervical portion of the vertebral column and fracture of the sternum is produced in this way. Fracture of the sternum has also been known to occur after overextension of the trunk; that is

PLATE 22.

Fracture of the Costal Cartilages and of the Sternum.Fig. 1.—Fracture of the costal cartilages; horizontal section; marked displacement of the fragments, which are united by a scanty formation of bone. (Path.-Anat. Inst., Greifswald.)

Fig. 2.-Fracture of the costal cartilages at the bony portion of the fifth rib; horizontal section; no displacement. The union is not bony; it rather resembles a false joint. (Path.-Anat. Inst., Greifswald.)

Fig. 3.-Recent fracture of the sternum, artificially produced in the cadaver in imitation of a similar fracture observed by the author. Fig. 4. Fracture between the manubrium and gladiolus; union with displacement of the fragments. ( (After Gurlt.)

to say, by muscular action. Owing to the superficial position of the bone, the diagnosis presents no difficulties, especially when there is anterior or posterior displacement of the fragments.

Treatment. In two recent cases under my care I was able to reduce the displacement of the fragments, as is shown in the picture, by extension applied to the head with Glisson's sling; extension was maintained by supporting the thorax on a wedge-shaped cushion and the head was placed in slight overextension.

VI. FRACTURES

AND DISLOCATIONS OF THE UPPER EXTREMITY

Injuries to the upper extremity are either direct or indirect. Injuries due to direct violence present certain definite characteristics, and their presence can often be recognized by a knowledge of the cause alone; on the other hand, injuries due to indirect violence, even when produced by the same cause, present a great variety of forms. Thus, a fall on the hand may be followed by a typical fracture of the lower extremity of the radius, by an injury to the elbow-joint, the upper end of the humerus, or the