Abstract: The present invention relates to an orthopedic tool made of a plastic material (M) comprising at least one semi-aromatic polyamide (P) comprising more than 50 mole % of recurring units obtained by the polycondensation reaction between at least one aliphatic diacid or derivative thereof and at least one aromatic diamine. In particular, hip rasp consisting essentially of at least one plastic material comprising at least one PMXDA polymer.

Abstract: Rasps for preparing bones of various patients to receive a prosthetic implant and a method for using the same. Multiple rasps may be provided as a set. Within the set, the rasps generally correspond to the size and shape of a single prosthetic implant, such as a prosthetic femoral hip stem, and have a range of bone removal and bone compression capabilities to account for unique bone characteristics of the various patients. A surgeon may select a desired rasp from the set provided depending on the patient's unique bone characteristics.

Abstract: Two self-clearing radial rasp systems for automatic milling material disclosed. In addition, as examples two automatic apparatuses utilizing said rasp systems for milling material disclosed. The rasp system may include a rasp and a trimming member. The radial rasp may include a base surface that may include cutting teeth with apertures of predetermined sizes disposed adjacent the cutting teeth. The revolving radial trimming member may include radial channels which may independently partitioned for confining and directing material toward the base surface of the rasp as the material move by centrifugal force in a radial direction. The rasp may have different sizes of cutting teeth associating with the individual radial channels of the radial trimming member.

Abstract: The invention to which this application relates is to the provision of medical devices such as implants for use in hips, knees or the like and also tools which may be used in surgery or for medical treatment. At least a portion of the external surface of the device is provided with a particular external surface texture which in accordance with the invention is formed by exposing said portions to at least one power beam. The exposure and relative movement between the device and the beam cause specific controlled configurations of the surface to be created without the need to add additional material and therefore allow the formation of the surfaces to the required configuration while maintaining the integrity of the device.

Abstract: A broaching system is disclosed for creating a cavity in a bone such that the cavity has a cross section which has a generally triangular profile having a first side generally parallel with an axis of the bone and a second side forming an acute angle with the first side and such that the cavity is contiguous with a pre-existing conical cavity in the bone. The apparatus comprises a shaft and a broach. The shaft has a longitudinal axis. The broach is mounted to the shaft and has a first cutting side mounted at the acute angle relative to the longitudinal axis of the shaft. The first cutting side is formed to include teeth. The shaft and broach are configured so that when the longitudinal axis of the shaft is advanced into the bone along the axis of the bone, the teeth of the broach form the triangular cavity. A method for cutting a triangular cavity in bone is also described. The method comprises a providing a shaft step, an incising step and a cutting step.

Abstract: A method of reconditioning a medical device may include removing a portion of the medical device, and attaching to the medical device a replacement piece formed from nickel carbide and sized, shaped, and positioned to replace the portion removed.

Abstract: An intramedullary femoral broach aligns two instruments. A femoral neck resector guide slides over the broach and centers on the patient's femoral head to determine the height and angular rotation of resection. A circular ring of the head and cutting arms assure the system will fit any femur. A template is applied to the femoral broach and seats itself against the buttress of the broach locking it into place. The broach is then reinserted into the intramedullary canal. When the template reaches the greater trochanter the sizer is adjusted to the rotational anteversion of the canal. The handle of the femoral broach is struck with a mallet until the template is imbedded into the proximal femoral neck intramedullary bone. A retractor facilitates reaming of the acetabulum through a small anterior incision. A proximal portion digs into the bone of the superior acetabulum to allow for retraction of soft tissues.

Abstract: A slotted bone rasp for reciprocal planing of opposed bone surfaces joined by a fixation pin so that the bone surfaces are made congruous and parallel to each other preparatory to bone fusion irrespective of pin orientation includes a shank with a pair of legs defining a slot for accommodating the pin and the legs having a flat side and an opposed abrasive side for remodeling the bone surfaces. Each leg includes an inner opposed convex surface whereupon the slot is narrowest at its midline so that the rasp is laterally pivotal transverse to the pin axis providing oblique angulations of the plane of bone removal relative to the pin axis; and the rasp also being rotatable to at least 90 degrees arc of rotation about the pin for 360 degree coverage of the bone surface creating two parallel bone surfaces in maximal end-to-end contact for successful bone fusion.

Abstract: The present invention relates in certain embodiments to components of a hip-joint prosthesis. More particularly, embodiments of the invention relate to a leaf-like femoral shaft for use as part of a hip-joint prosthesis, and instruments (e.g., a rasp) and methods for implanting the shaft. The shaft includes an anchoring section extending between a proximal region and a distal end of the shaft. The shaft has a cross-sectional contour that defines a lateral side, a medial side, an anterior side and a posterior side. A corresponding rasp is preferably provided for each femoral shaft. The rasp is inserted into the femur to form a cavity having generally the same configuration as the rasp. The shaft is configured to be over-dimensioned in at least one of the anterior-posterior direction and medial-lateral direction relative to the rasped femur cavity.

Abstract: This invention relates to devices and instruments for implant insertion through a posterior lateral opening to the disc space. The instruments include an implant inserter, and the devices include a spinal fusion implant engageable by the implant inserter. The implant provides bilateral support of the adjacent vertebrae when inserted into the disc space from a postero-lateral approach.

Abstract: Tools and methods for spinal fusion are provided. The tool is configured to cut openings into first and second vertebrae to receive a spinal implant between the vertebrae. The tool includes a proximal handle connected to an elongate shaft that extends to a distal end. The distal end includes a first non-cutting portion through which the shaft extends, a cutting portion fixed to the shaft to rotate with rotation of the shaft, and a second non-cutting portion fixed to the cutting portion.

Abstract: A method of reducing the surface roughness of articulating surfaces of orthopaedic implants is provided. The method includes the steps of providing an abrasive particle providing a chemical including at least one of an oxidant, a corrosion inhibitor, a complexing agent and a surfactant, combining the chemical with the abrasive particle to form a slurry, and polishing the implant with the slurry.

Abstract: Instruments and methods are provided for inserting a rasp into an intervertebral space of a spine and using the rasp to decorticate the adjacent vertebra. More particularly, one embodiment provides an instrument that actively changes the angle of the rasp relative to the instrument. The delivery instrument may use a gear portion to articulate the rasp. A second gear on the rasp may mate with a corresponding gear on the instrument. As the instrument gear rotates relative to the instrument, the instrument gear drives the rasp gear, thereby rotating the rasp to decorticate the vertebra. Trial inserts and methods are also provided to determine an appropriate size of a rasp for decortication.

Abstract: Disclosed herein is a femoral broaching apparatus for use in preparing a femoral cavity for implantation of a prosthetic joint in surgical orthopedic artificial hip joint replacement arthroplasty procedures. The apparatus comprises a fixing guide unit fixed in the femoral cavity by an interference fit, a cavity preparing broach coupled to the fixing guide unit in a longitudinally movable manner, and a vibration-generating unit coupled to the cavity preparing broach for allowing the cavity preparing broach to perform the preparing of the femoral cavity under operation of the fixing guide unit. According to the present invention, a femoral cavity having an intended accurate shape can be easily prepared using mechanical vibration rather than a manual operation, thereby ensuring operational convenience.

Abstract: A method of treating spinal stenosis, in which a rasp is brought through a part of a spinal channel and then axially moved so that the rasp removes a stenosis in the spinal channel. Optionally, a shield protects a spinal cord or other sensitive tissues in the spinal channel.

Abstract: An apparatus for the preparation of a cement-free implantation of a prosthesis is provided. The prosthesis has a distal part corresponding to a diaphysial region of the femur, a proximal part corresponding to a metaphysial region of the femur, and an intermediate region which corresponds to a metaphysial-diaphysial region. The apparatus includes a rasp of modular design including a conical distal part and first and second proximal parts of substantially different basic shapes and heights. The apparatus also includes a releasable connection means at the distal part for connecting a proximal part to at least one distal part. The apparatus also includes a neutral intermediate element mountable on the distal part of the rasp for driving it and for measuring its degree of recessing on a graduated scale.

Abstract: This invention relates to devices and instruments for implant insertion through a posterior lateral opening to the disc space. The instruments include an implant inserter, and the devices include a spinal fusion implant engageable by the implant inserter. The implant provides bilateral support of the adjacent vertebrae when inserted into the disc space from a postero-lateral approach.

Abstract: A device and method for use in a human spine to prepare a space between adjacent vertebral bodies and into the vertebral end plates to receive an implantable insert. The device includes a handle, a shaft, and a mounting member at one end of the shaft. An abrading element is mounted on the mounting member and is coupled to a drive mechanism. The drive mechanism is operable to move the abrading element in at least one degree of freedom to create surfaces having predetermined contours in the end plates of the adjacent vertebral bodies.

Abstract: An elongated cutting tool (10, 110) intended to plunge cut a blind form in a bone using a plurality of teeth (30, 130) arranged on the tool. At least one of the teeth is an undercut tooth (30, 130) having a cutting edge (470, 570). The undercut tooth (30, 130) has a profile defined substantially along a primary relief angle (480, 580) measured from a vertical reference plane (477, 577) passing though the cutting edge (470, 570) and by a positive rake angle (485, 585) measured from a horizontal reference plane (472, 572) passing through the cutting edge (470, 570). The undercut tooth (30, 130) has a parabolic, non-circular relief (490, 590) along which bone chips are guided substantially away from the bone being cut, thereby avoiding capturing debris in the teeth and, consequently, avoiding overstressing the bone during cutting.

Abstract: A compacting broach comprises an elongate body and a distal tip at a forward end of the body. The body plurality of corner edges corresponding to the corner edges of a prosthetic component, cutting teeth along the corner edges and side walls between the cutting teeth of adjacent corner edges. The side walls extend inwardly from the cutting teeth of adjacent corner edges and compact cancellous bone as the cutting teeth penetrate cortical bone during advancement of the broach in the intramedullary canal. The distal tip comprises a plurality of fins radial to a central longitudinal axis of the broach and extending longitudinally, distally from the body. The fins contact the side of the canal at locations about a central axis of the canal to center the broach in the canal prior to the cutting teeth engaging cortical bone as the broach is advanced therein.

Abstract: This invention relates to methods and instruments for performing disc space preparation and implant insertion from a unilateral approach to the spine through a posterior lateral opening to the disc space. The instruments include spreaders, distractors, reamers, scrapers, cutters, chisels, rasps, pushers and implant inserters. A surgical procedure is provided that allows bilateral support of the adjacent vertebrae with at least one interbody fusion device inserted into the disc space via a unilateral approach. Implants for insertion into the disc space are also provided.

Abstract: A high-speed, hand-held attachment for flex rotor shafts of power rotary tools, and also for direct attachment to power rotary tools without flex rotor shafts, that converts rotary motion to reciprocating motion for precision control of cutting, carving, sawing, chiseling, filing, sanding, and engraving on delicate work pieces. The attachment is one assembly comprising a one-piece front one-piece enclosure (20), a rear one-piece enclosure (30), a high-speed bearing (22), a one-piece rotating piece (40) with integral cam groove, a one-piece reciprocating piece (50) with an integral cam follower on one end and with its other, exposed end accomodating the attachment of a chuck or collet and with geometry to prevent rotation, and a thumbscrew (32). Rotating piece (40) attaches directly to the rotary power source and provides the cam action drive to reciprocating piece (50). Bearing (22) provides rotative support for the other end of rotating piece (40).

Abstract: An elongated cutting tool (10, 110) intended to plunge cut a blind form in a bone using a plurality of teeth (30, 130) arranged on the tool. At least one of the teeth is an undercut tooth (30, 130) having a cutting edge (470, 570). The undercut tooth (30, 130) has a profile defined substantially along a primary relief angle (480, 580) measured from a vertical reference plane (477, 577) passing though the cutting edge (470, 570) and by a positive rake angle (485, 585) measured from a horizontal reference plane (472, 572) passing through the cutting edge (470, 570). The undercut tooth (30, 130) has a parabolic, non-circular relief (490, 590) along which bone chips are guided substantially away from the bone being cut, thereby avoiding capturing debris in the teeth and, consequently, avoiding overstressing the bone during cutting.

Abstract: An intervertebral distractor possesses a scissors-like mechanism for actuating its distal portion for the spreading of adjacent vertebrae. The distal portion of the distractor possesses a pair of extension members laterally offset therefrom with each extension member possessing a vertebral endplate-engaging member.

Abstract: Device for withdrawing flakes or shavings from a donor bone by scraping, comprising an internally hollow handle (M) composed of a hollow body (1) with a cavity (11) and of slidable means for closing and respectively rendering accessible the cavity (11), and scraper means (20) positioned at the front end of said slidable means and comprising a gap for passage of the bone flakes or shavings into the cavity (11); said slidable means comprise an upper plate (6) positioned on the upper side of the hollow body (1) to close the cavity (11) and slidable on this latter, its front portion (7) being not joined to the hollow body (1) and being elastically deformable to move away from the front edge of this latter when under load. Said scraper means comprise a blade (20) positioned at the front end of said slidable plate (6), and having an active surface (21) perpendicular or nearly perpendicular to the longitudinal axis of the front portion of the handle (M).

Abstract: An Apparatus for the preparation of a femur bone for the cement-free implantation of a prosthesis having a so-called press-fit-effect, the prosthesis having a distal part (2, 2A) corresponding to a diaphysial region of the femur (1, 1A), a proximal part (3, 3A) corresponding to a metaphysial region of the femur and an intermediate region (4, 4A) in which the press-fit-effect is preferably provided and which corresponds to a metaphysial-diaphysial region, with the height of the prosthesis being variable depending on the morpho-type and degree of bone damage is described which is characterized in that the apparatus consists of a modulatable rasp (10) including a plurality of parts, at least one of which has a conical distal part (10A) of a single size and of a single shape, there being at least first and second proximal parts (10B) of substantially different basic shapes, each of said first and second proximal parts being provided in a plurality of increasing heights (H), there being releasable connection means

Abstract: A femur rasp fastener has a frame and a linkage. The frame has a chamber for housing the linkage. When a femur rasp is engaged with the frame and a handle of the linkage is moved, an arched and elastic suspension bar will be driven to pull a bucking hear which is engaged with a front end of the suspension bar so that the bucking head will clamp a strut in an indented recess located at one end of the femur rasp. The femur rasp thus will be held securely and continuously by the frame of the fastener.

Abstract: The invention relates to a hollow rasp for preparing a tubular bone in which a post-shaped endoprosthesis is inserted. A manipulating instrument can be proximally coupled to the rasp. The rasp comprises a metal grid network and a plurality of metal rasp elements. The metal rasp elements are studded at least at junctions of the metal grid network and are an integral part of a material forming the grid network.

Abstract: To provide a surgical ribbon file that can rapidly grind a projecting bone on a curved surface of a bone to an even face without skill and easily and safely grind a projecting bone in an opening between bones. The surgical ribbon file according to the present invention comprises a ribbon-shaped resilient main body with prescribed hardness and flexibility and file teeth on a surface of the main body. The ribbon-shaped main body may be made from alloy with high resiliency, synthetic resin or fiber-reinforced resin. Striking the ribbon-shaped main body from one face to the other face such that notches are formed and triangular portions project from the one face to the other face can form the file teeth, or the file teeth may be hemispherical projections standing on one face of the main body.

Abstract: A tool (10) for preparation of a cavity (12) in a long bone (14) for receiving a joint prosthesis (16) for use in arthroplasty is provided. The tool (10) includes a body (20) having an outer periphery (22) of the body (20). The outer periphery (22) is adapted to have a first shape (24) and a second shape (26) thereof of the body (20). The second shape (26) has dimensions different than the first shape (24), whereby the tool (10), when in the first shape (24), is capable of forming a first cavity (30) in the long bone (14) and whereby the tool (10), when in the second shape (26), is capable of forming a second cavity (32) in the long bone (14). The second cavity (32) is different than the first cavity (30).

Abstract: A surgical handpiece adapter for converting rotary motion of a powered surgical handpiece into reciprocating motion to drive a cutting member includes a rear drive shaft for being removably coupled to a rotatable drive shaft of the handpiece, a front drive shaft for being removably coupled to the cutting member and a motion converting mechanism causing reciprocation of the front drive shaft and, therefore, the cutting member coupled thereto, in response to rotation of the rear drive shaft by the drive shaft of the handpiece. A handpiece adapter assembly is formed by an adapter and a cutting member coupled thereto, and a powered surgical handpiece assembly is formed by an adapter, a cutting member coupled to the adapter and a powered surgical handpiece coupled to the adapter.

Abstract: A method of making a cut in the nasal bone of a patient includes the steps of reciprocating a distal end of an osteotome via a powered surgical handpiece and moving the distal end of the osteotome, while it is being reciprocated, forwardly along the nasal bone of a patient in a predetermined path with a cutting edge of the osteotome in contact with the nasal bone to make a cut of desired length in the nasal bone along the predetermined path. The distal end of the osteotome may be moved so as to produce a straight cut and/or a curved cut in the nasal bone. The distal end of the osteotome may be reciprocated by converting rotary motion of the handpiece into reciprocating motion of the osteotome.

Abstract: The present invention relates to a machining method for obtaining a teeth following a helical curve on the surface of any shape whatsoever, this method being able to be applied to the manufacture of a broach, intended to prepare the intramedullary canal of a bone. The machining method on the surface of any shape whatsoever by a tool provided with a head, following at least one geometrical curve with the shape of a helix is characterised in that it comprises the following stages: tracing the surface normal at a plurality of points taken along the helix, making the helix follow the head of the tool, by orienting the head in such a way that it follows the orientation of the defined normals.

Abstract: A surgical osteotome for being reciprocatively driven to cut anatomical tissue includes an elongate shaft having a proximal end and a distal end presenting a cutting element. The cutting element comprises an upper part and a lower part, with the lower part having inwardly angled lateral surfaces merging at a cutting edge. The upper part forms a blunt tip disposed distally of the cutting edge. A handpiece adapter assembly includes the osteotome removably coupled to a handpiece adapter. The handpiece adapter includes a motion converting mechanism for converting rotary motion of a powered surgical handpiece into reciprocating motion of the osteotome. A powered surgical handpiece assembly includes the osteotome, the handpiece adapter and a powered surgical handpiece having a rotatable drive shaft.

Abstract: A device and method for use in a human spine to prepare a space between adjacent vertebral bodies and into the vertebral end plates to receive an implantable insert. The device includes a handle, a shaft, and a mounting member at one end of the shaft. An abrading element is mounted on the mounting member and is coupled to a drive mechanism. The drive mechanism is operable to move the abrading element in at least one degree of freedom to create surfaces having predetermined contours in the end plates of the adjacent vertebral bodies.

Abstract: A prosthesis system consisting of an endoprosthesis with a shank which is to be introduced into the medullary canal of a bone, and of a rasp (20) which is similar in shape to the shank and is used to prepare a cavity for receiving the shank. Along much of its length, the rasp has an untoothed profile part (25) which, instead of excavating the spongy bone substance, compacts the latter and thus ensures a secure fit of the prosthesis. In the area corresponding to the untoothed area of the rasp (20), the prosthesis shank preferably has a rib which cuts like a wedge into the compacted spongy substance.

Abstract: This invention relates to devices and instruments for implant insertion through a posterior lateral opening to the disc space. The instruments include an implant inserter, and the devices include a spinal fusion implant engageable by the implant inserter. The implant provides bilateral support of the adjacent vertebrae when inserted into the disc space from a postero-lateral approach.

Abstract: A system and method to facilitate bone grafting, the system including a rasp configured to prepare the grafting surfaces of a recipient, a sizer configured to determine the dimensions of a graft for abutment with the grafting surfaces, a cutting guide configured to receive bone stock and to facilitate producing the graft in proportion to the sizer, a measuring pan configured to determine the amount of grafting substance required to fill the void in the graft, and a holding device configured to stabilize the graft as the grafting substance is placed in the graft.

Abstract: A surgical handpiece adapter for converting rotary motion of a powered surgical handpiece into reciprocating motion to drive a cutting member includes a rear drive shaft for being removably coupled to a rotatable drive shaft of the handpiece, a front drive shaft for being removably coupled to the cutting member and a motion converting mechanism causing reciprocation of the front drive shaft and, therefore, the cutting member coupled thereto, in response to rotation of the rear drive shaft by the drive shaft of the handpiece. A handpiece adapter assembly is formed by an adapter and a cutting member coupled thereto, and a powered surgical handpiece assembly is formed by an adapter, a cutting member coupled to the adapter and a powered surgical handpiece coupled to the adapter.

Abstract: The system and method of the invention includes surgical instrumentation to enable a spine fusion procedure to proceed more accurately, efficiently and safely by allowing precision placement of an intervertebral implant, precision preparation of the area into which the bone graft is placed, and pre-selection of a pre-specified known shape of bone graft. In the order in which they are used, improvements in a distractor, box chisel, curette, an anterior or anterolateral type intervertebral cylindrically directed or peripheral rasp, intervertebrally operated vertebral bone plate shaping rasp, or roughing combination rasp, and an intervertebral sizing tool; any combination of which may be anatomically shaped.

Abstract: A bur-abrading tool for use with a rotating or oscillating drive unit. The unit includes a base abrader bit unit comprising a bit rod and bit substrate shape having a surface of revolution. A very large number of particles, comprised of a plurality of shapes having sharp edges, are brazed to the substrate shape utilizing a brazing material which binds the particles to the substrate shape creating burs. The brazing material at least partially coats the particles. In preferred embodiments the particles are comprised of small cut pieces of wire. Tools having various surfaces of revolution and various cut wire shapes are described.

Abstract: A surgical handpiece adapter for converting rotary motion of a powered surgical handpiece into reciprocating motion to drive a cutting member includes a rear drive shaft for being removably coupled to a rotatable drive shaft of the handpiece, a front drive shaft for being removably coupled to the cutting member and a motion converting mechanism causing reciprocation of the front drive shaft and, therefore, the cutting member coupled thereto, in response to rotation of the rear drive shaft by the drive shaft of the handpiece. A handpiece adapter assembly is formed by an adapter and a cutting member coupled thereto, and a powered surgical handpiece assembly is formed by an adapter, a cutting member coupled to the adapter and a powered surgical handpiece coupled to the adapter.

Abstract: The present invention relates to a machining method for obtaining a teeth following a helical curve on the surface of any shape whatsoever, this method being able to be applied to the manufacture of a broach, intended to prepare the intramedullary canal of a bone.

Abstract: This invention relates to methods and instruments for performing disc space preparation and implant insertion from a unilateral approach to the spine through a posterior lateral opening to the disc space. The instruments include spreaders, distractors, reamers, scrapers, cutters, chisels, rasps, pushers and implant inserters. A surgical procedure is provided that allows bilateral support of the adjacent vertebrae with at least one interbody fusion device inserted into the disc space via a unilateral approach. Implants for insertion into the disc space are also provided.

Abstract: A bone rasp has an elongate body which tapers in the distal direction with first cutting ribs which extend transversely to the longitudinal axis of the body and are arranged in parallel graduations at a first spacing along the longitudinal axis and with second cutting ribs which are formed in parallel graduations at a second spacing at the body. The first and second cutting ribs have a different depth of cut in order to ablate different amounts.

Abstract: A surgical handpiece adapter for converting rotary motion of a powered surgical handpiece into reciprocating motion to drive a cutting member includes a rear drive shaft for being removably coupled to a rotatable drive shaft of the handpiece, a front drive shaft for being removably coupled to the cutting member and a motion converting mechanism causing reciprocation of the front drive shaft and, therefore, the cutting member coupled thereto, in response to rotation of the rear drive shaft by the drive shaft of the handpiece. A handpiece adapter assembly is formed by an adapter and a cutting member coupled thereto, and a powered surgical handpiece assembly is formed by an adapter, a cutting member coupled to the adapter and a powered surgical handpiece coupled to the adapter.

Abstract: A prosthesis system consisting of an endoprosthesis with a shank which is to be introduced into the medullary canal of a bone, and of a rasp (20) which is similar in shape to the shank and is used to prepare a cavity for receiving the shank. Along much of its length, the rasp has an untoothed profile part (25) which, instead of excavating the spongy bone substance, compacts the latter and thus ensures a secure fit of the prosthesis. In the area corresponding to the untoothed area of the rasp (20), the prosthesis shank preferably has a rib which cuts like a wedge into the compacted spongy substance.

Abstract: A bone mill comprising a vessel and a rotatable grinding tool to produce ground autologous bone particles for surgical bone reconstruction use, wherein the vessel includes a wall defining a circular cylindrical chamber having a concentric axis. The vessel further includes a bottom wall at right angle to the axis and a lid adapted to be removably connected to the vessel. The lid includes an opening coincident with the axis. The grinding tool includes an elongated shaft extending through the opening in the lid along the axis with a cutting blade mounted to the shaft within the chamber whereby the cutting blade can be rotated by motive device, such as a dental drill, engaging the shaft exterior of the vessel to cut bone, placed in the vessel, into said bone particles.

Abstract: The invention provides a cutter head that reduces the cutting force and number of reamers required by increasing the depth of cut or cutting length. The cutting head uses at least one tooth placed along the length of flutes formed within the body of the cutting head. The grooves forming the flutes can follow a first helical path along the body length, maintaining a substantially constant path over a major portion of the entire length in relation to the axes or, alternatively, have a constantly changing path. A second pattern can follow a second, contiguous helical path that has a second radial orientation to the axis. The teeth can be formed from a sinusoidal wave form comprised of a continuous radius going from convex to concave, with each of the teeth having a predetermined pitch from the crest to the base. In another embodiment the crest of the teeth on the first flute is offset axially by a predetermined distance from the teeth on the adjacent flutes.

Abstract: An instrument for seating taper junctions of modular implants engages two components and provides a sustained assembly force along the junction axis with great mechanical advantage. In one embodiment the instrument comprises a lever mechanism for generating the mechanical advantage. In another embodiment, the instrument provides for an indicator of the amount of force being applied to the junction. In another embodiment, the instrument engages the components for such that both assembly and disassembly can be accomplished.