d it is made on the posterior aspect by
cutting on the point of a dressing forceps introduced through the
anterior incision.

#Arthritis Deformans.#--The shoulder is seldom affected alone, except
when the arthritis is a sequel to injury, such as a fracture of the
neck of the humerus. The common type of lesion is a dry arthritis with
fibrillation and eburnation of the articular surfaces. The long tendon
of the biceps is usually destroyed, the head of the bone is drawn
upwards, and, after wearing through the capsule, rubs on the under
surface of the acromion, which also becomes eburnated. The clinical
features are pain, stiffness, and cracking on movement, and as these
symptoms may also be caused by loose bodies in the joint, an X-ray
picture should be taken to differentiate between them.

#Neuro-arthropathies# of the shoulder are met with chiefly in
syringomyelia. In some cases there is a large fluctuating and
painless swelling; in others marked and rapid wasting of the deltoid
and scapular muscles with flail-like movements of the joint associated
with disappearance of the upper end of the humerus (Fig. 104).

[Illustration: FIG. 103.--Arthropathy of Shoulder in Syringomyelia.
The upper end of the humerus has disappeared and the movements are
flail-like (cf. Fig. 104).]

[Illustration: FIG. 104.--Radiogram of specimen of Arthropathy of
Shoulder in Syringomyelia. The head of the humerus has disappeared and
masses of new bone have formed in the surrounding muscles (cf. Fig.
103).]

#Loose bodies# are rare in the shoulder; we have met with a case in
which the joint-cavity was distended with loose bodies of synovial
origin, and as most of these had undergone ossification, the X-ray
appearances were highly characteristic. They were removed through an
anterior incision.

#Ankylosis# is not so disabling at the shoulder as at other joints, as
the mobility of the scapula on the chest wall largely compensates for
the fixation of the joint.

THE ELBOW-JOINT

In disease of the elbow, the usual attitude is that of flexion with
pronation of the hand. Swelling of the joint, whether from effusion of
fluid or from thickening of the synovial membrane, is observed chiefly
on the posterior aspect, above and on either side of the olecranon,
because the synovial sac is here nearest the surface. The free
communication between the elbow and the superior radio-ulnar joint
should be borne in mind.

[Illustration: FIG. 105.--Radiogr