Low cost modular tapered and spherical hollow reamers for medical applications

A modular easy to assemble tapered hollow reamer for medical applications, comprising:

• a) a shaft portion having an elongated body with a proximal end and a distal end, said proximal end having a coupling portion appointed for attachment of said reamer to a drilling device, said distal portion having a tapered body element with a threaded central aperture and external surface taper;
• b) a disposable tapered hollow reamer portion, comprising:
• 1) a hollow reamer having an integrally attached pilot with a threaded central aperture in the distal end, a tapered central hollow reamer portion and a tapered interior aperture in the proximal end with a taper angle matching said external surface taper of said tapered body element of said shaft;
• 2) a plurality of externally protruding cutters, plurality of apertures extending through the thickness of said tapered reamer between the distal end and proximal end;
• c) a guide pin having a distal end, central portion and proximal end, said distal end and proximal end being threaded to secure said guide pin to the central aperture threads of said tapered body element of the shaft and said threaded central aperture of disposable tapered hollow reamer;
• whereby reamer assembly transmits torque from the shaft to said disposable tapered hollow reamer through two threaded connections and;
• guide pin insertion and contact between external surface taper of said tapered body element of said shaft and tapered interior aperture said reamer ensure, during assembly, substantial coincidence of centerlines, preventing reamer wobbliness, and bone and bone cement debris is collected in the space within the tapered hollow reamer portion.

A modular easy to assemble spherical hollow reamer for medical applications, comprising:

• a) a shaft portion having an elongated body with a proximal end and a distal end, said proximal end having a coupling portion appointed for attachment of said reamer to a drilling device, said distal portion having a tapered body element with a threaded central aperture and external surface taper;
• b) a disposable spherical hollow reamer portion, comprising:
• 1) a hollow reamer having a threaded central aperture in the distal end, a spherical central hollow reamer portion and a tapered interior aperture in the proximal end with a taper angle matching said external surface taper of said tapered body element of said shaft;
• 2) a plurality of externally protruding cutters, and a plurality of apertures extending through the thickness of said spherical reamer between the distal end and the proximal end;
• c) a guide pin having a distal end, a central portion and a proximal end, said distal end and said proximal end being threaded for securing said guide pin to the central aperture threads of said tapered body element of the shaft, and said threaded central aperture of said disposable spherical hollow reamer;
• whereby the reamer assembly transmits torque from the shaft to said disposable tapered hollow reamer through two threaded connections, and;
• guide pin insertion and contact between an external surface taper of said tapered body element of said shaft and the tapered interior aperture of said reamer ensure, during assembly, substantial coincidence of centerlines, preventing reamer wobbliness, and bone and bone cement debris are collected in the space within the tapered hollow reamer portion.