High Velocity Missiles Research Articles

TECHNIC FOR ARTHRODESIS OF THE HIP WHEN THE FEMORAL HEAD AND NECK ARE ABSENT

ARTHRODESIS of the hip joint when the femoral head has been removed or when there is nonunion of the femoral neck with a necrotic head presents certain difficulties not present in other circumstances. The chief of these is in maintaining the trochanter in the freshened acetabulum without placing the lower extremity in too much abduction. Another is in obtaining enough bony contact between the femur and the ilium to assure fusion without an unduly prolonged period of immobilization. Since the upper end of the trochanter is rather small, there is more difficulty placing grafts to good advantage than when the head and neck are present. In the technic to be described, these difficulties have been satisfactorily overcome. During World War II, a considerable number of patients were seen who had been struck in the hip by a high velocity missile which shattered the neck of the femur. Infection of the

CONTUSIONS OF THE LUNG FROM NONPENETRATING INJURIES TO THE THORAX

THE LUNG is subject to damage from nonpenetrating injuries to the thorax. The more severe injuries to the lung, with hemothorax and pneumothorax, have been repeatedly stressed in the literature, 1 but the minor degrees of injury resulting in contusion have received little attention. In an army hospital receiving patients with combat injuries from the army air forces all gradations of injury from contusion to rupture of the lung from nonpenetrating injuries were seen. The agents responsible for the changes in the lung were blast from high explosive shells, blows from blunt objects and nonpenetrating wounds caused by high velocity missiles. Of particular interest, and the subject of this report, were the rapidly clearing areas of pulmonary consolidation noted in some of the cases of injury to the thoracic wall. Blast injuries to the chest from high explosives have been emphasized in the past war. 2 The accepted explanation for

AN EXPERIMENTAL STUDY OF SHOCK WAVES RESULTING FROM THE IMPACT OF HIGH VELOCITY MISSILES ON ANIMAL TISSUES

The spark shadowgram method of studying shock waves is described. It has been used to investigate the properties of such waves produced by the impact of a high velocity missile on the surface of water. The method can be adapted for study of behavior of shock waves in tissue by placing the tissue on a water surface or immersing it in water. Spark shadowgrams then reveal waves passing from tissue to water or reflected from tissue surfaces. Reflection and transmission of shock waves from muscle, liver, stomach, and intestinal wall are compared with reflection from non-living surfaces such as gelatin gel, steel, plexiglas, cork, and air. Because of its heterogeneous structure, waves transmitted by tissue are dispersed and appear as a series of wavelets. When the accoustical impedance (density x wave velocity) of a medium is less than that in which the wave is moving, reflection will occur with inversion of the wave; i.e., a high pressure wave will become a low pressure wave. This inversion occurs at an air surface and is illustrated by shadowgrams of reflection from stomach wall, from a segment of colon filled with gas, and from air-filled rubber balloons. Bone (human skull and beef ribs) shows good reflection and some transmission of shock waves. When steel is directly hit by a missile, clearly visible elastic waves pass from metal to water, but a similar direct hit on bone does not result in elastic waves strong enough to be detected by a spark shadowgram.

Secondary damage in wounding due to pressure changes accompanying the passage of high velocity missiles.

Secondary damage in wounding due to pressure changes accompanying the passage of high velocity missiles.

Damage to Peripheral Nerves by High Velocity Missiles Without a Direct Hit

Damage to Peripheral Nerves by High Velocity Missiles Without a Direct Hit

Piezoelectric Crystal Measurements of Pressure Changes in the Abdomen of Deeply Anaesthetized Animals During Passage of a High-Velocity Missile

Piezoelectric Crystal Measurements of Pressure Changes in the Abdomen of Deeply Anaesthetized Animals During Passage of a High-Velocity Missile

Studies on Wounds of the Abdomen and Thorax Produced by High Velocity Missiles

Studies on Wounds of the Abdomen and Thorax Produced by High Velocity Missiles

Experiments on Head Wounding by High Velocity Missiles

Experiments on Head Wounding by High Velocity Missiles

Wounding Mechanism of High-velocity Missiles

Wounding Mechanism of High-velocity Missiles

Wounding Mechanism of High-velocity Missiles

Wounding Mechanism of High-velocity Missiles

An Experimental Study of the Wounding Mechanism of High-velocity Missiles

[he fact that' the amount of tissue destruction caused by small high-velocity bomb splinters may be out of all pro portion to their size has been recognized for some time, and was the subject of correspondence in this Journal (1940, July 13 and 27). More 6bvious explanations of the disproportion between size of wound and size of missile for example, that it is due to the irregular shape of the splinters and to their rotary movement (Wilson, 1940) appear inadequate to explain the phenomenon, and it was therefore suggested (Zuckerman, 1940) that a more reason able interpretation lies along the lines suggested by Cranz and Becker (1921) in their analysis of the effects of high velocity missiles in soft media. If the physical explanations of Cranz and Becker are applicable to splinter wounds in flesh it would appear that the destructive effect of a small splinter is due to the motion imparted to the soft medium through which it passes, as a result of which the tissue is moved away violently from the track of the missile, an effect being produced similar to that of an internal explosion. Observation also shows that splinters have little rotary effect in those media in which their effect has been studied It has been found, too, that non-spinning projectiles fired from a .mooth bore have an explosive effect in media such as mud (Cranz and Becker). It is thus improbable that the damage which occurs in the neighbourhood of the actual track of a splinter would be seriously altered by any peculiarities of shape or by any rotation. On the other hand, shape and rotation could undoubtedly have an effect on the track itself. The experiments described in this paper have been de signed to test this interpretation.