on the elbow. Direct violence may consist in a blow or a fall on the outer side of the shoulder.

Examination in these cases always presents some difficulties, and if the extravasation of blood is profuse, the diagnosis may be exceedingly difficult. After inspection, by which we determine the direction of the shaft of the bone and the alteration in the outline of the shoulder, we proceed to palpation, which is equally important. The tuberosities, the groove between them, and the region of the surgical neck can be directly palpated under normal conditions; not So, however, the region of

the anatomic neck

Fr. through the
tuberosities

Fractura colli anatomici

and head of the bone. Fr. colli chirurgici.

The parts should be felt from the outside; from in front; if necessary, from behind; and last, but not least, through the axilla.

(a) Fracture of the anatomic neck alone is a very rare

Fig. 55.-Upper extremity of the humerus, showing the possible lines of fracture.

accident. If only the articular head with its articular cartilage should break off,-in other words, a purely intracapsular fracture, the vitality of the fragment would probably be endangered. It would act like any fragment consisting of bone and cartilage, as, for example, in the knee-joint. As a rule, however, the fracture is not altogether intracapsular; the fragment is attached by portions of the capsule which convey the blood-supply, and the line of fracture includes neighboring portions of the tuberosities, of the shaft, or of the head.

The injury is produced by severe external violence to

PLATE 33.

Fractures of the Upper End of the Humerus.-Fig. 1.-Normal specimen showing the course of the epiphyseal line in a frontal section.

Fig. 2. Specimen showing fracture of the surgical neck with typical displacement. Right shoulder-joint seen partly from the side and partly from behind. The displacement of the humerus forward and inward is recognized.

Fig. 3.-Specimen of a united fracture of the left humerus. Anterior view. On the outer side, the line of fracture runs through and below the tuberosities and then curves inward toward the anatomic neck. The upper fragment (articular process) is in abduction, the lower fragment in adduction. The direction of the humerus in the region of the tuberosities can be recognized in spite of the abundant callus-formation, which is particularly marked in the diaphyseal portion. Owing to the displacement of the fragments, the base of the articular surface is in relation with the seat of fracture, which was probably impacted, and forms a right angle with the long axis of the humerus. (Path.-Anat. Inst., Greifswald.)

Fig. 4. Lateral view of a man with a fracture of the surgical neck. Typical displacement of the shaft of the humerus forward and inward, so that the alteration in the direction of the axis is at once perceptible by comparing it with a normal arm (Fig. 4 a). (The patient's name was J. Wendigorra, twenty-two years of age. July, 1895.)

the outside of the shoulder or by compression of the humerus in its long axis. The fragment from the head may be firmly impacted between the tuberosities or in the space above the lower fragment. The deformity is often very slight; but sometimes the head has been found completely turned around, so that the broken surface presented toward the glenoid fossa, and the cartilaginous surface toward the upper end of the shaft of the humerus.

The symptoms are those of a severe intra-articular injury. Direct palpation of the seat of fracture is out of the question, even under anesthesia; all that can be determined is that a fracture above the tuberosities exists. Abnormal mobility of the upper end of the humerus and

crepitation, especially during rotation, are observed. There is marked functional disturbance, and pain is elicited by compressing the bone in its long axis.

Treatment. Rest in bed with extension by means of weights; pad in the axilla; movements should be begun early. [In two cases which I have observed and diagnosed as fracture of the anatomic neck, this method of treatment by extension was most satisfactory.-ED.]

(b) Fracture of the Surgical Neck (Plate 32, Fig. 2). -This is quite common. The line of fracture is below the tuberosities or may even include them. The upper fragment is therefore partly under the influence of the muscles which are inserted in the tuberosities. The fracture occurs usually in older individuals and is produced by direct violence, as by fall on the shoulder; or indirect violence by a fall on the hand or elbow. The fragments may become impacted or they may unite with marked deformity.

Fig. 56.-Axillary pad, held in place by a short bandage to prevent slipping.

The following considerations are of prime importance both for a clear conception of the mechanism and for the treatment of these fractures: The upper end of the shaft of the humerus may be displaced inward or outward at the seat of fracture. If it is displaced inward, the arm is in abduction, but does not tend to return when the reducing force is removed; the long axis of the humerus points toward the coracoid process or the clavicle. If the shaft is displaced outward, the arm is in adduction. This posi