CONGENITAL ELEVATION OF THE SCAPULA.—SPRENGEL'S DEFORMITY

1. The scapula in its development is a cervical, not a dorsal appendage. It retains that position throughout fetal life. In its development the scapula, as well as the entire system, passes through the different stages of lower forms and repeats the history of its species.

2. In the scapula of congenital elevation alterations in shape are found, coinciding with the conditions normally seen in the scapula of lower mammals. These consist of an increase in width and a diminution in length, rounding of the superior median angle, and articulations with the vertebral column. Willet and Walshamclaim these articulations (found in 25 percent of our collected cases) to be of suprascapular origin. Dr. Minot is of the opinion that they are due to centres of ossification appearing within the sheet of development of the scapula. This sheet is continuous with that of the vertræ. If these articulations were of secondary growth due to attrition they would be bony throughout, whereas, the union at either or both ends is by means of cartilage.

3. The affected scapula is situated 1 to 12 cm. (two to four vertebral bodies) higher than its fellow, with an average of 3 to 5 cm., and rotated upon its frontal or sagittal axis. This rotation is due in part to the weight of the arm and in part to the retracted muscles.

4. Scoliosis existed in sixty-five cases (47.5 percent). This is usually of a mild character, excepting that seen in cases one, two and three of our series. It is cervical and high dorsal with a compensatory low dorsal or lumbar curve. The convexity of the curve is found toward the elevated scapula in 223 percent, and away from it in 15 percent. This curve must be regarded as of congenital origin, parallel with defective ribs and vertebræ, also with other evidences of arrested development elsewhere in the body, cleft palate, spina bifida, congenital dislocations, undeveloped limbs, etc., all due to the same mechanical pressure causes. The undeveloped scapula is not to be regarded as a deformity due to these same causes, but as of another type. The scoliosis is neither primary nor secondary to the elevated scapula.

Torticollis is seen in 10 percent and facial and cranial asymmetry without torticollis in 11 percent. These deformities are therefore not dependent upon each other nor upon the elevated scapula.

5. Both sexes are equally prone to this deformity, sixty-four existing in males and sixty-three in females. It is more frequent on the left side, left sixty-nine, right forty-nine, bilateral 14. In the bilateral cases the left scapula is always higher. Kolliker believes this predilection for the left side to be due to the left occipito-anterior position of the fetus in utero, in which the left shoulder lies posteriorly.

Sixty-seven percent (ninety-two cases) showed some attendant defect in other parts of the body. Among these are seen missing and defective ribs and vertebræ, dislocations, defective limbs, etc. Heredity plays no part in this deformity.

6. Sprengel regarded this deformity as an upward displacement due to pressure exerted in utero through lack of amniotic fluid. We believe that pressure is a factor and that this retains the scapula in its original high position.

Rager believes that through certain disturbances, alterations in the shape of the superior border takes place which prevent the descent of the scapula.

Kausch advocates the theory that the elevation is due to the defect of the trapezius muscle. This was seen in 33 percent of the cases in our tabulation. We believe that the caudal migration of the scapula depends upon muscular traction. This traction may be insufficient where the intrauterine pressure is excessive, where abnormal articulations exist, or where the musculature is per se defective.

7. The maldevelopment of the scapula is due to improper muscular tension. The scapular muscles, by their traction, shape the bone to its normal adult contour. Where this muscular influence is lacking or diminished, or where the weight of the arm is lessened, either by maldevelopment or by abnormal position, or where the power of the normal muscle is unable to draw a scapula abnormally fixed, the bone remains undeveloped.

This muscular defect must precede the defect in the bone and is caused by some disturbance, nervous or mechanical.

8. Congenital elevation must be differentiated from the acquired form due to rickets, osteomalacia, paralysis, scoliosis, empyema and cervical Pott's disease. The history, symptoms and radiogram will be sufficient to establish the diagnosis.

9. Treatment consists of operative procedure or gymnastics. The results in operative cases, where an articulation existed, were good. A degree of improvement is offered by stretching and gymnastics.

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