A pneumatic hammer was recently installed in the orthopedic operating room of the Massachusetts General Hospital, and met with such instant approval that a report of its salient features is here presented.
Shorn of technical detail, the essential features of the apparatus are:
1. An adequate supply of compressed air, preferably generated outside and piped to some convenient point in the operating room.
2. A reducing valve capable of maintaining any desired working pressure in the line distal to itself, regardless of the rate of air flow, and providing for instant adjustment under the direct supervision of the operator.
3. A satisfactory air cleaner. This is essential because the waste air is necessarily exhausted in the sterile operating field.
4. A light, compact, pneumatic hammer whose speed is controlled by a throttle conveniently situated on the pistol-grip handle. The hammer has a top speed of