Abstract: The present invention relates to an interspinous spacer (10, 10?, 10?, 10??, 10??, 10???) for implantation between adjacent spinous process (SP) to treat spinal stenosis. The interspinous spacer preferably includes a W-shaped or S-shaped leaf spring body member (21) for insertion between adjacent spinous processes and one or more wire straps (42) extending from the body to attach the spacer to the adjacent spinous processes. The wire straps are preferably sized and configured to extend from one side of the leaf spring, along one side of a spinous process, over or under the spinous process to the other side wherein the wire strap can be coupled to the leaf spring. Alternatively, the spacer may include one or more hooks (60) for engaging one or both of the adjacent spinous processes.

Abstract: In order to optimize the handling of a rotating surgical tool for producing a depression in bone material, provision is made for an ultrasonic transducer which is capable of emitting and receiving ultrasonic waves to be arranged in the tool, and for the ultrasonic transducer to be connectable to an ultrasonic generator and to a receiver which generates signals in dependence upon the strength of the ultrasonic radiation received by the ultrasonic transducer and upon the length of time between the emission of ultrasonic radiation and the reception of reflected ultrasonic radiation, which are a measure of the condition of the bone material in the direction of emission.