Fig. 105.—Radiogram showing Multiple partially ossified Cartilaginous Loose Bodies in Shoulder-joint. The lowest one is in the synovial prolongation along the tendon of the biceps.
Tuberculous disease is the most common and important affection ([Fig. 106]). It usually occurs in patients under twenty, but may be met with at any age; in children the age-incidence is earlier than in the other large joints, a considerable proportion being met with in the first two years of life (Stiles). When the disease is confined to the synovial membrane, its onset is insidious, there is little or no pain, and no interference with any movement except complete extension. The chief evidence of disease is a white swelling on either side of and above the olecranon, obscuring the bony landmarks. The further progress is attended with wasting of the triceps, symptoms of involvement of the articular surfaces, and with abscess formation.
Fig. 106.—Diffuse Tuberculous Thickening of Synovial Membrane of Elbow (white swelling) in a boy æt. 12.
The occurrence of articular caries without swelling of the synovial membrane is exceptional, and is associated with a good deal of pain and considerable restriction of movement. Rigidity from muscular contraction occurs late, and is rarely complete. Tuberculous foci in the bones are met with chiefly in the lower end of the diaphysis of the humerus; in children, the epiphyses are so small that the ossifying junction is intra-articular. Foci are also met with in the upper end of the ulna. The grosser osseous lesions cause enlargement of the bone, and are readily demonstrated by skiagraphy. Abscess formation most commonly occurs beneath the triceps, and the abscess points at one or other edge of that muscle. A subcutaneous abscess may form over the upper end of the ulna or over the radio-humeral joint. Tuberculous hydrops with melon-seed bodies is rare.
