Fig. 162.—Congenital Hypertrophy of Left Lower Extremity in a boy æt. 5. The second and third toes are fused.
Supernumerary Toes (Polydactylism).—These vary from mere appendages of skin to fully developed toes ([Fig. 163]); if they interfere with the wearing of boots they should be removed.
Webbing of the Toes (Syndactylism).—This may affect two or more toes, which may be united merely by a web of skin, or so completely fused that the individual digits are only indicated by the nails; the degree of fusion is shown by means of skiagrams. Unless associated with congenital hypertrophy, no treatment is called for.
Fig. 163.—Supernumerary Great Toe.
(Photograph lent by Sir George T. Beatson.)
THE UPPER EXTREMITY
Congenital Absence of the Clavicle.—Both clavicles may be absent, and it is possible for the patient voluntarily to bring his shoulders into contact with one another in front of the chest; there is little or no impairment of function.
Displacements of the Scapula.—Congenital Elevation of the Scapula (Sprengel's shoulder, 1891).—This abnormality is rare, and is not usually recognised till several years after birth. In one variety there is a bridge of bone or fibrous tissue connecting the superior angle of the scapula with the spinous process of one of the cervical vertebræ, and there may be a false joint at one end of the bridge permitting a certain amount of movement of the scapula. Associated abnormalities in the vertebræ and in the ribs are shown in skiagrams. In the more common type, the scapula seems to be held in its elevated position by shortening of the muscles attached to its body, and it is often rotated so that its lower angle is close to the spine and its axillary border nearly horizontal, or the axillary border may lie in close to the ribs, and the vertebral border project from the chest wall. The shoulder is generally higher and farther forward on the affected side, and there is a moderate degree of scoliosis. There is a want of purchase in the movements of the shoulder and upper arm.