Abstract: To remove a damaged acetabular cup attached to the hipbone, applicant positions the cutting surface of a curved cutting blade at the acetabular cup/hipbone interface. The blade mounts to a head. The powered drive shaft of a motor rotates the blade and head. A linkage, part of which may be around the drive shaft, moves longitudinally relative to the drive shaft under surgeon control. The linkage pivots the head and urges the blade into the interface. As the power tool rotates the curved blade and the linkage pivots the blade into the interface, the blade follows the hemispherical contour of the interface. Continued powered rotation of the drive shaft and blade and further pivoting of the blade cuts the cup from the hipbone.

Abstract: To remove a damaged acetabular cup attached to the hipbone, applicant positions the cutting surface of a curved cutting blade at the acetabular cup/hipbone interface. The blade mounts to a head. The powered drive shaft of a motor rotates the blade and head. A linkage, part of which may be around the drive shaft, moves longitudinally relative to the drive shaft under surgeon control. The linkage pivots the head and urges the blade into the interface. As the power tool rotates the curved blade and the linkage pivots the blade into the interface, the blade follows the hemispherical contour of the interface. Continued powered rotation of the drive shaft and blade and further pivoting of the blade cuts the cup from the hipbone.

Abstract: The reciprocating saw has two, superimposed, blades having a common axis and arcuate cutting surfaces adjacent each other. Part of one blade extends through an opening in the other blade so that the cutting edge of an upper blade is under the cutting edge of a lower blade. The blades' cutting edges extend around the blade or along a smaller arc. A linkage in the saw converts rotary motion of a motor into synchronous, counter-reciprocating motion of the blades about the axis. Counter-reciprocation minimizes action/reaction forces, which occur when a single reciprocating saw blade changes directions.

Abstract: The reciprocating saw has two, superimposed, blades having a common axis and arcuate cutting surfaces adjacent each other. Part of one blade extends through an opening in the other blade so that the cutting edge of an upper blade is under the cutting edge of a lower blade. The blades' cutting edges extend around the blade or along a smaller arc. A linkage in the saw converts rotary motion of a motor into synchronous, counter-reciprocating motion of the blades about the axis. Counter-reciprocation minimizes action/reaction forces, which occur when a single reciprocating saw blade changes directions.

Abstract: The reciprocating saw has two, superimposed, blades having a common axis and arcuate cutting surfaces adjacent each other. Part of one blade extends through an opening in the other blade so that the cutting edge of an upper blade is under the cutting edge of a lower blade. The blades' cutting edges extend around the blade or along a smaller arc. A linkage in the saw converts rotary motion of a motor into synchronous, counter-reciprocating motion of the blades about the axis. Counter-reciprocation minimizes action/reaction forces, which occur when a single reciprocating saw blade changes directions.

Abstract: The process uses micro-machining for forming a prosthetic spinal disc in which one of more springs bias adjacent vertebrae apart and absorb shock. Instead of using conventionally wound springs, the entire prosthesis including the springs are formed by micro-machining a block of material. Imaging, load and other patient data provide the parameters for the prosthesis.

Abstract: A prosthetic spinal disc uses a stiff spring or springs for resiliency between two plates that attach to adjacent vertebrae. When the disc has multiple springs, they may be adjacent, concentric or nested. Multiple springs may be spaced around the periphery of the plates. A foil metal bellows may surround the plates to prevent material from entering or exiting the space between the plates. Alternatively, the ends of the spring(s) may be machined with spikes to engage the vertebrae directly without plates.