Alvin M. Arkin

THE MECHANISM OF ROTATION IN COMBINATION WITH LATERAL DEVIATION IN THE NORMAL SPINE

1. The intrinsic mechanism for rotation in combination with lateral deviation in the normal spine depends upon soft-tissue tensions rather than upon the arrangement of the spinal articular facets. The behavior may be summarized by stating that the structure under the greater tension will describe the straighter line. 2. Thirty-nine roentgenograms of five subjects showed a tendency to convex-side rotation in both flexion and extension of the laterally deviated living spine.

TREPHINE BIOPSY OF BONE WITH SPECIAL REFERENCE TO THE LUMBAR VERTEBRAL BODIES

The relative inaccessibility of the vertebral body for surgical biopsy makes trephine biopsy valuable in this region. By use of the needle described, excellent, adequate undistorted cores of tissue may be obtained, to aid in the differential diagnosis of many lesions.

Prophylaxis of scoliosis.

1. Gravity acting upon a growing spine which is not straight can produce structural scoliosis due to pressure-arrest of epiphyseal growth. 2. The early recognition and treatment of functional curvatures is therefore of primary importance in the prophylaxis of structural scoliosis. 3. Certain common types of functional curvatures can be corrected by tilting the pelvis by shoe and buttock lifts, thus preventing progression into structural scoliosis.

Asymmetrical Suppression of Vertebral Epiphyseal Growth with Ionizing Radiation

Summary The lumbar spines of 30 young rabbits were unilaterally irradiated with radon seeds and X-rays. Twenty-one animals died of gastro-intestinal disturbances unrelated to radiation. Five of the 9 survivors showed wedging of the vertebral bodies with the narrowing of the bodies on the more heavily irradiated side. Dosage estimates indicate that growth of the epiphyses of the vertebral bodies of baby rabbits may be suppressed with 700 to 1000 r to the epiphysis. Doses of 350 r or less have no apparent effect on the growth.