Surgery – Instruments – Orthopedic instrumentation
Patent
1993-02-23
1995-02-07
Pellegrino, Stephen C.
Surgery
Instruments
Orthopedic instrumentation
606 79, 606 96, A61F 246
Patent
active
053872185
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to surgical instruments and in particular to a reaming tool for shaping bone canals for insertion of surgical implants.
BACKGROUND ART
In recent years surgical implants, e.g. for hip replacement operations, have become more routinely fitted. Current research in the design of hip replacement joints has suggested the desirability of accurate matching of the implant to the internal shape of the bone canal. Conventional practice for cutting and shaping bone canals, preparatory to introduction of a surgical implant, involves use of surgical cutting instruments consisting essentially of a variety of hand-held power drills, saws. reamers and cutters. Satisfactory use of such instruments requires a high degree of manual skill to cut and shape bone canals accurately. A particular difficulty arises where there is a requirement to cut or shape a tapered or curved surface, for example, to shape a bone canal for reception of the stem of a hip implant.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided a surgical instrument for shaping a bone or cavity in a bone which comprises a curved rod whose curvature substantially corresponds in one plane to that of a desired shaped surface, means for supporting the curved rod, a plurality of cutting teeth or heads mounted on said rod so as to be rotatable thereon, said teeth being drivably interconnected so that rotation of one of said teeth causes an adjacent tooth to rotate.
According to a second aspect of the present invention there is provided a surgical instrument, especially for shaping a bore or cavity in a bone, which comprises a curved rod whose curvature substantially corresponds in one plane to that of a desired shaped surface, means for supporting the curved rod, a plurality of cutting teeth or heads threaded on said rod so as to be rotatable thereon, said teeth being drivably interconnected so that rotation of one of said teeth causes the others to rotate.
The curved supporting rod may be mounted in a frame, said frame including a guide for location in or on a suitable reference surface, e.g. within a bore in a bone canal. Conveniently, one end of the row of cutting teeth is connected to a drive attachment for insertion in the chuck of a drill or similar driving mechanism. The tool may also include a handle for manipulating the tool with respect to the bone.
Linking of the teeth together may be achieved by gear-like recesses and projections in adjacent teeth and preferably there is a substantial degree of play in the inter-engaging gear teeth and recesses so that the cutting teeth follow a spiral-like form when they are rotated.
Preferably, the surgical instrument includes one or more depth gauges which are preferably adjustable to determine the amount by which the tool extends into the bone cavity. Preferably, the depth gauge or gauges is adjustable as appropriate for different bones and implants.
In another application of surgical instruments according to the invention, it may be desired to shape a tapered surface in or on a bony, horny or dental surface. For such wider applications, it may not be necessary to cut a surface having a curvature in two planes. In such a case the interengaging teeth may be mounted on a straight rod and the rod may constitute the frame of the tooth.
According to a further aspect of the present invention, therefore, there is provided a surgical instrument which comprises a frame, a rod supported by said frame, a plurality of cutting teeth mounted for rotation on said rod and being mutually engageable, so as to be rotatable in unison when one of said teeth is connected to driving means. Preferably, the teeth have lateral cutting surfaces so that the surface to be shaped or smoothed is contacted substantially at right angles to the direction of the rod. The frame may include a handle and/or guide means for guiding the translation of the instrument in a desired direction.
Further features and advantages of the present invention will become apparent fro
REFERENCES:
patent: 1636636 (1927-07-01), Humble
patent: 4473070 (1984-09-01), Matthews
patent: 4552136 (1985-11-01), Kenna
patent: 4706659 (1987-11-01), Matthews
patent: 4751922 (1988-06-01), DiPietropolo
patent: 4936862 (1990-06-01), Walker et al.
patent: 5169402 (1992-12-01), Elloy
Pellegrino Stephen C.
Tucker Guy V.
University College London
LandOfFree
Surgical instrument for shaping a bone does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surgical instrument for shaping a bone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surgical instrument for shaping a bone will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1107554