Powered surgical tool having a transmission - Patent application

Abstract

To provide: a powered surgical tool that selectively provides rotational oscillations to a tool head (effector) to effect tissue modification during a surgical procedure; and cutting tools and tissue modification tools that operate to modify a tissue when rotated in one or both directions about a longitudinal axis of the tool.SOLUTION: Tools are effective in modifying selective tissues while selectively preventing modification of other tissues. For example, a hard tissue such as a bone may be modified while a soft tissue is not modified, or a soft tissue may be modified without modification of a hard tissue.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (Related Applications and Patents) This application is a continuation of U.S. Non-Provisional Patent Application No. 17 / 893,789, filed August 23, 2022; U.S. Non-Provisional Patent Application No. 13 / 469,665, filed May 11, 2012, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly" (now U.S. Patent No. 10,194,922, issued February 5, 2019); U.S. International Application No. PCT / US2013 / 037071, filed April 18, 2013, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly"; and U.S. International Application No. PCT / US2013 / 037071, filed October 8, 2012, entitled "Cutting Tool for Bone, Cartilage, and Disk Removal Tool Assembly." U.S. Non-Provisional Patent Application No. 13 / 647,101 entitled "Cutting Tool for Bone, Cartilage, and Disk Removal" (now U.S. Patent No. 9,232,953, issued January 12, 2016); U.S. International Application No. PCT / US2013 / 063182 entitled "Cutting Tool for Bone, Cartilage, and Disk Removal," filed October 3, 2013; U.S. Provisional Patent Application No. 62 / 460,481 entitled "Surgical Rotary Tool," filed February 17, 2017; U.S. Non-Provisional Patent Application No. 15 / 895,352 entitled "Surgical Rotary Tool," filed February 13, 2018; U.S. Non-Provisional Patent Application No. 15 / 895,352 entitled "Surgical Rotary Tool," filed February 16, 2018; U.S. Non-Provisional Patent Application No. 15 / 932,361 entitled "Rotary Oscillating Surgical Tool" (now U.S. Patent No. 11,523,833, issued December 13, 2022); U.S. Provisional Patent Application No. 62 / 423,624 entitled "Rotary Oscillating Surgical Tool" filed November 17, 2016; U.S. Non-Provisional Patent Application No. 15 / 814,891 entitled "Rotary Oscillating Surgical Tool" filed November 16, 2017 (now U.S. Patent No. 10,835,263, issued November 17, 2020); U.S. Provisional Patent Application No. 62 / 423,651 entitled "Robotic Surgical System" filed November 17, 2016;U.S. Provisional Patent Application No. 62 / 423,677, entitled "Robotic Surgical System," filed November 17, 2016; U.S. Non-Provisional Patent Application No. 15 / 816,861, entitled "Robotic Surgical System," filed November 17, 2017 (now U.S. Patent No. 11,135,026, issued October 5, 2021); U.S. Non-Provisional Patent Application No. 16 / 266,802, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly," filed February 4, 2019 (now U.S. Patent No. 11,389,719, issued July 19, 2022); U.S. Non-Provisional Patent Application No. 16 / 266,802, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly," filed August 27, 2021 (now U.S. Patent No. 11,389,719, issued July 19, 2022); No. 17 / 459,754, filed June 16, 2022, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly"; and U.S. Non-Provisional Patent Application No. 17 / 842,296, filed June 16, 2022, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly." All of the above-identified references are incorporated herein by reference in their entirety.

[0002] FIELD OF THE INVENTION The present invention relates to a rotary handheld surgical tool that can be used for cutting, drilling and grinding. [Background technology]

[0003] Powered rotary tools for surgery are well known in the art. Many surgeons consider them essential for certain surgical procedures, particularly orthopedic procedures, such as drilling, cutting, and grinding. Powered rotary tools are used to modify tissue, such as bone, at a surgical site so that a surgical procedure can be performed. Such tools typically include a tool head or end effector that is rotated by an external powered motor, such as an electric motor. The tool head is a portion of an elongated shaft operably coupled to the motor rotor. The motor rotor causes rotation of the tool head and its shaft. Rotating tool heads are used to perform some surgical procedures, such as drilling, cutting, and grinding. An actuator is provided for selectively powering the motor rotor to effect rotation of the effector.

[0004] Such tools are expensive and have many parts, making them difficult and expensive to sterilize for reuse and often requiring partial or complete disassembly. Similarly, tools have separable parts, such as tissue modification tool heads. In addition to removing tissue, such powered tools are used for other surgical procedures, such as installing fasteners such as screws. If the tool cannot be easily sterilized, it will be discarded after use, adding to the cost of the surgery. Thus, when separate powered tools are used, multiple tools must be sterilized or discarded.

[0005] The prior art provides surgical tools with rotating cutters adapted to modify tissues such as bone, cartilage, and intervertebral discs in a patient. However, such tools present problems when the cutter encounters fibrous tissues such as muscle and nerves. Such fibrous tissues can wrap around the cutter and be damaged. The prior art also provides oscillating rotating tools for such surgical procedures, but the mechanism used to effect the oscillating motion of the cutter during rotation does not operate smoothly due to the mechanism used to effect the oscillating motion. Advances in such oscillating tools are disclosed in the inventor's co-pending applications: U.S. Non-Provisional Patent Application No. 13 / 469,665, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly," filed May 11, 2012 (and now U.S. Patent No. 10,194,922, issued February 5, 2019); U.S. International Application No. PCT / US2013 / 037071, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly," filed April 18, 2013; U.S. International Application No. PCT / US2013 / 037071, entitled "Rotary Oscillating Bone, Cartilage, and Disk Removal Tool Assembly," filed October 8, 2012; U.S. Non-Provisional Patent Application No. 13 / 647,101 entitled "Cutting Tool for Bone, Cartilage, and Disk Removal" (and now Patent No. 9,232,953, issued January 12, 2016); U.S. International Application No. PCT / US2013 / 063182 entitled "Cutting Tool for Bone, Cartilage, and Disk Removal," filed October 3, 2013; U.S. Provisional Patent Application No. 62 / 460,481 entitled "Surgical Rotary Tool," filed February 17, 2017; U.S. Non-Provisional Patent Application No. 15 / 895,352 entitled "Surgical Rotary Tool," filed February 13, 2018; and U.S. Non-Provisional Patent Application No. 15 / 895,352 entitled "Surgical Rotary Tool," filed February 16, 2018. U.S. Non-Provisional Patent Application No. 15 / 932,361, entitled "Rotary Oscillating Surgical Tool," filed November 17, 2016; U.S. Provisional Patent Application No. 62 / 423,624, entitled "Rotary Oscillating Surgical Tool," filed November 17, 2016;and U.S. Non-Provisional Patent Application No. 15 / 814,891, entitled "Rotary Oscillating Surgical Tool," filed November 16, 2017; U.S. Provisional Patent Application No. 62 / 423,651, entitled "Robotic Surgical System," filed November 17, 2016; U.S. Provisional Patent Application No. 62 / 423,677, entitled "Robotic Surgical System," filed November 17, 2016; and U.S. Non-Provisional Patent Application No. 15 / 816,861, entitled "Robotic Surgical System," filed November 17, 2017.

[0006] Due to the oscillation of the cutting tool, the cutting system needs to be smooth in operation with little oscillation and noise. Summary of the Invention

[0007] The present invention relates to powered surgical tools that selectively impart rotational and oscillating motion to a tool head (effector) to effect tissue modification during a surgical procedure. The present invention also relates to cutting tools and tissue modification tools that operate to modify tissue when rotated in one or both directions about the longitudinal axis of the tool. The surgical and cutting tools are effective for selective tissue modification while selectively preventing modification of other tissue. For example, hard tissue, such as bone, can be modified while soft tissue is not modified, or soft tissue can be modified without modification to hard tissue.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rotary-oscillating surgical tool having an output shaft that allows the end effector to be swapped from a hard tissue modification tool to a soft tissue modification tool.

[0009] It is a further object of the present invention to provide a rotary oscillating surgical tool that includes a transmission that provides rotary oscillating movement of the cutting tool about the longitudinal axis of the cutting tool.

[0010] It is a further object of the present invention to provide such a surgical tool that allows for the selection and interchangeability of cutting tools while utilizing the same powered surgical tool.

[0011] It is a further object of the present invention to provide a mechanism for converting rotary motion from an electric motor into oscillating rotary motion.

[0012] It is a further object of the present invention to provide a cutting tool that, when rotated and oscillated, operates to selectively modify hard or soft tissue.

[0013] It is a further object of the present invention to provide a tool change assembly that changes portions of the oscillating transmission during operation to replace portions of the transmission that have higher wear.

[0014] In one aspect of the present invention, a power-operated surgical tool is provided that includes an outer housing adapted to enclose and support various internal components, and a transmission and motor secured within the outer housing. The motor includes an output shaft, the motor output shaft connected to the transmission, the transmission including an oscillating rotary drive mechanism for rotationally oscillating the cutting tool about a longitudinal axis of the cutting tool, the oscillating rotary drive mechanism having a link that pivots about the motor offset shaft at an oscillating angle and is attached to a rotatably mounted shuttle such that a distal end of the link rotates about the motor shaft while a pivot at a front of the link is positioned to rotate at a neutral point, causing the shuttle to rotationally oscillate about an axis perpendicular to the motor output shaft.

[0015] In another aspect of the invention, the swing angle relationship can be varied relative to the motor output shaft to achieve different angular rotations of the shuttle.

[0016] In another aspect of the invention, the shuttle includes an actuation gear segment that meshes with a pinion gear that is connected to the end effector shaft to impart a rotary oscillating motion to the end effector shaft.

[0017] In another aspect of the invention, the end effector shaft includes a cutting tool.

[0018] In another aspect of the present invention, a power-operated surgical tool includes a crank assembly hub secured to a motor output shaft, the crank assembly hub including a hub bore for receiving a distal end of a link, the crank assembly hub constructed and arranged to maintain an oscillation angle.

[0019] In another embodiment of the invention, the oscillation angle is an acute angle relative to the motor output shaft. In another embodiment of the invention, the rotation of the cutting tool is 40 degrees to 180 degrees in each direction about the longitudinal axis of the cutting tool. In another embodiment of the invention, the oscillation rotation of the cutting tool is 50 degrees to 90 degrees in each direction about the longitudinal axis of the cutting tool.

[0020] In another aspect of the invention, the link is secured to the shuttle by one or more arms, each arm having a bearing that receives within it a bolt that is threadably secured in a bore in the shuttle.

[0021] In another aspect of the invention, the link is secured to the shuttle by a pair of spaced arms, each arm having a bearing received in it and receiving within it a bolt threadably secured in a bore in the shuttle.

[0022] In another aspect of the invention, the pinion gear and gear segments are constructed from a polymeric material.

[0023] In another aspect of the invention, the polymeric material is polyetheretherketone.

[0024] In another aspect of the invention, the pinion gear and gear segments are straight cut gears. In another aspect of the invention, the pinion gear and gear segments are helical cut gears.

[0025] In another aspect of the invention, the end effector is removably connected to the outer housing.

[0026] In another aspect of the invention, an end effector includes a pinion gear, an end effector shaft, and a cutting tool.

[0027] In another aspect of the invention, a power-operated surgical tool includes a tool coupler for connecting an end effector to an outer housing, the tool coupler including a ferrule secured to a first end of the end effector while a cutting tool extends from a second end of the end effector, the ferrule including a flange including a stop surface that cooperates with a front surface of a locking ring to establish a depth allowing the end effector to enter into the motor assembly, a ferrule shank adjacent the flange, the ferrule shank including one or more keys secured in a predetermined position thereon, each key including a key side and a locking surface, the locking ring configured to rotate in a first direction to allow the ferrule shank to enter an inner bore of the locking ring, and upon entry of the ferrule key, the key side engages a docking port of the outer housing to prevent rotation of the end effector relative to the outer housing.

[0028] In another aspect of the invention, the locking ring includes one or more camming surfaces that cooperate with the locking surfaces of the ferrule to pull the stop surfaces of the ferrule against the front surface of the locking ring to secure the end effector in place. In another aspect of the invention, the locking ring includes a spring lock having rounded ends that cooperate with ridges positioned on the outer surface of the docking port to provide tactile feedback when the locking ring is rotated to its locked position.

[0029] In another aspect of the invention, a power-operated surgical tool includes an oscillating cutting tool, the oscillating cutting tool including two or more flutes, the flutes extending inward from an outer diameter of the cutting tool toward a longitudinal axis to form recessed flute channels, each flute channel having a pair of opposing side walls and a cylindrical radius at the base of each flute channel, each opposing side wall forming a cutting edge surface extending along the length of each flute channel such that each flute channel presents two opposing surfaces that provide the cutting edge of a blade, allowing the cutting tool to cut in both directions when oscillated rotationally about the longitudinal axis.

[0030] In another aspect of the invention, the flute channels, and therefore the blades, extend along the cutting tool parallel to the longitudinal axis.

[0031] In another aspect of the invention, the flute channels, and therefore the blades, extend helically along the cutting tool relative to the longitudinal axis.

[0032] In another embodiment of the invention, the helix angle is 3 to 5 degrees relative to the longitudinal axis, hi another embodiment of the invention, the helix angle is greater than 5 degrees relative to the longitudinal axis.

[0033] In another aspect of the invention, each blade includes an upper corner radius that extends inwardly from the outer diameter toward the longitudinal axis, the convergence of the face and the upper corner radius providing the outermost diameter of the cutting tool.

[0034] In another aspect of the invention, the upper corner radii terminate in sharp corners proximate the longitudinal axis, such that the sharp corners are spaced apart.

[0035] In another aspect of the invention, a central point is positioned along the longitudinal axis between spaced apart sharp corners, the central point including a plurality of facets from the converging portions of the flute surfaces at the central point, the facets including sharp edges that grind and pulverize hard tissue.

[0036] In another aspect of the invention, the cutting tool includes an elongated center point that includes facets that may be flat or curved intersections at the center point to break hard tissue as the cutting tool is oscillated.

[0037] In another aspect of the present invention, a power-operated surgical tool includes a soft tissue oscillating cutter including a shank having a shaped head portion, the shaped head portion including a plurality of helically positioned shaped claws, each claw including a body curved to grasp tissue, and each claw including a cutter end.

[0038] In another aspect of the invention, the cutter edge includes both acute and obtuse cutting face clearance angles.

[0039] In another aspect of the invention, the claws are circular in cross section and include one or more bends that terminate in a generally flat cutting surface, the cutting surface being substantially parallel to the outer surface of the molded head portion. In another aspect of the invention, the bends in the claws are each about 90 degrees, and each claw includes at least two bends along its length.

[0040] In another aspect of the invention, the distal end of the soft tissue oscillating cutting tool is provided with a stop plug for limiting the proximity of the soft tissue cutting tool to the tissue surface.

[0041] Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with any accompanying drawings, in which are set forth, by way of illustration and example, certain embodiments of the invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.

[0042] Description of the Prior Art Examples of such rotary tools include those disclosed in U.S. Patent Nos. 4,646,738; 5,735,535; 7,066,940; and U.S. Publication No. 2014 / 0246047. U.S. Patent No. 4,646,738 is a highly complex, electric motor-powered tool that likely requires disassembly after use for sterilization. U.S. Patent No. 5,735,535 is also a complex, electric motor-powered tool that likely requires disassembly after use for sterilization and uses a chuck to hold the tool head. U.S. Patent No. 7,066,940, like the two previously mentioned tools, is also complex, requires disassembly for sterilization, and is a powered tool with a detachable cutting tool head. U.S. Patent Publication No. 2014 / 0246047 illustrates a different type of powered surgical tool, but is not structured to use a rotary cutting tool. Like the aforementioned tools, it requires disassembly for sterilization and is highly complex in construction.

[0043] Despite advancements made over the years, simpler surgical tools have not been provided that simplify their use and advance the art of rotary surgical tools that provide both tissue modification and screw placement functionality in a single powered tool. [Brief explanation of the drawings]

[0044] [Figure 1] 1 is an isometric view of a surgical tool that can be used for tissue modification. [Figure 2] FIG. 2 is an isometric view of the surgical tool of FIG. 1 illustrated with a removable cutting tool. [Figure 3] FIG. 1 is an isometric view of a portion of a surgical tool illustrating removal and replacement of an end effector. [Figure 4A] FIG. 10 is an isometric view illustrating the insertion of the end effector into the motor assembly. [Figure 4B] FIG. 10 is an isometric view illustrating a socket for an end effector in a motor assembly. [Figure 4C]FIG. 10 is an isometric view illustrating an end portion of an end effector engaging a motor assembly. [Figure 5A] FIG. 10 is an isometric front view of the cam ring of the motor assembly. [Figure 5B] FIG. 10 is an isometric rear view of the cam ring of the motor assembly. [Figure 6] 6 is a partial cross-sectional view taken along line 6-6 of FIG. 1 illustrating the connection between the motor assembly and the end effector. [Figure 7] 6 is a partial cross-sectional view taken along line 6-6 of FIG. 1 illustrating the connection between the motor assembly and the end effector. [Figure 8] 6 is a partial cross-sectional view taken along line 6-6 of FIG. 1 illustrating the connection between the motor assembly and the end effector. [Figure 9] 6 is a partial cross-sectional view taken along line 6-6 of FIG. 1 illustrating the connection between the motor assembly and the end effector. [Figure 10] FIG. 1 is a partial isometric view illustrating one embodiment of an assembly for converting constant rotational motion to rotary-oscillating motion. [Figure 11] 11 is a side cross-sectional view illustrating a rocking motion assembly used to convert the constant rotational motion of FIG. 10 into a rotary rocking motion. [Figure 12] 12 is a cross-sectional top view taken along line 12-12 of FIG. 1 illustrating the swing motion assembly. [Figure 13] FIG. 1 is a partial exploded view illustrating one embodiment of a swing motion assembly. [Figure 14] FIG. 1 is an isometric view illustrating the motor assembly, swing motion assembly, and end effector with a portion of the shroud removed. [Figure 15] FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly connected to a motor assembly and an end effector. [Figure 16] FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly connected to a motor assembly and an end effector. [Figure 17]FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly illustrating one position of the oscillating motion assembly when motion is imparted to the end effector. [Figure 18] FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly illustrating one position of the oscillating motion assembly when no motion is being imparted to the end effector. [Figure 19] FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly illustrating one position of the oscillating motion assembly when motion is imparted to the end effector. [Figure 20] FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly illustrating one position of the oscillating motion assembly when no motion is being imparted to the end effector. [Figure 21] FIG. 10 is a partial isometric view of an embodiment of an oscillating motion assembly illustrating the use of helical gears. [Figure 22] FIG. 10 is an isometric side view of one embodiment of an end effector. [Figure 23] FIG. 10 is a side view of one embodiment of an end effector. [Figure 24] FIG. 1 is an isometric view of a surgical tool with a position and orient assembly attached. [Figure 25] FIG. 16 is an isometric view of a tissue modifying cutting tool for an end effector. [Figure 26A] FIG. 1 is an isometric view of a bidirectional cutting tool. [Figure 26B] FIG. 26B is a side view of the bidirectional cutting tool illustrated in FIG. 26A. [Figure 26C] 26C is a partial side view of the bidirectional cutting tool taken along line 26C-26C of FIG. 26B. [Figure 26D] 26D is a cross-sectional view of the bidirectional cutting tool taken along line 26D-26D of FIG. 26C. [Figure 26E] FIG. 26E is a partial isometric view taken along line 26E-26E of FIG. 26A. [Figure 26F] FIG. 1 is an end view of a bidirectional cutting tool. [Figure 26G]FIG. 26G is a partial cross-sectional view taken along line 26G-26G of FIG. 26F. [Figure 26H] FIG. 26H is a partial isometric view taken along line 26H-26H of FIG. 26E. [Figure 26I] FIG. 1 is a partial isometric view of a bi-directional cutting tool. [Figure 26J] FIG. 1 is a partial isometric view of a bi-directional cutting tool. [Figure 27A] FIG. 1 is an isometric view of a bi-directional cutting tool having elongated flutes and a cutting surface. [Figure 27B] FIG. 27B is a side view of the bidirectional cutting tool illustrated in FIG. 27A. [Figure 27C] FIG. 27C is a partial side view of the bidirectional cutting tool taken along line 27C-27C of FIG. 27B. [Figure 27D] 27D is a cross-sectional view of the bidirectional cutting tool taken along line 27D-27D of FIG. 27C. [Figure 27E] FIG. 27E is a partial isometric cutaway view taken along line 27E-27E of FIG. 27A. [Figure 27F] FIG. 1 is a side view of a bidirectional cutting tool having extended flutes and a cutting surface. [Figure 27G] 27G is a partial side view of a bidirectional cutting tool with extended flutes and cutting surfaces taken along line 27G-27G of FIG. 27F. [Figure 27H] FIG. 1 is an end view of a bi-directional cutting tool having extended flutes and a cutting face. [Figure 27I] FIG. 27I is a partial cross-sectional view taken along line 27I-27I of FIG. 27H. [Figure 27J] FIG. 1 is a partial isometric view of a bi-directional cutting tool having extended flutes and a cutting surface. [Figure 27K] FIG. 1 is a partial isometric view of a bi-directional cutting tool having extended flutes and a cutting surface. [Figure 27L] FIG. 1 is a partial isometric view of a bi-directional cutting tool having extended flutes and a cutting surface. [Figure 28A] FIG. 1 is an isometric view of a bi-directional ball nose cutting tool. [Figure 28B]FIG. 28B is a side view of the bidirectional ball nose cutting tool illustrated in FIG. 28A. [Figure 28C] 28C is a partial side view of the bidirectional cutting tool taken along line 28C-28C of FIG. 28B. [Figure 28D] 28D is a cross-sectional view of the bidirectional cutting tool taken along line 28D-28D of FIG. 28C. [Figure 28E] FIG. 28E is a partial isometric cutaway view taken along line 28E-28E of FIG. 28A. [Figure 28F] FIG. 1 is an end view of a ball nose cutting tool. [Figure 28G] FIG. 28G is a cross-sectional view taken along line 28G-28G of FIG. 28F. [Figure 28H] FIG. 2 is a partial side view of a ball nose cutting tool. [Figure 28I] FIG. 2 is a partial side view of a ball nose cutting tool. [Figure 28J] FIG. 2 is a partial side view of a ball nose cutting tool. [Figure 28K] FIG. 1 is a partial isometric side view of a ball nose cutting tool. [Figure 28L] FIG. 10 is a partial isometric side view of a ball nose cutting tool illustrating another end configuration. [Figure 29A] FIG. 1 is an isometric view of a bidirectional cutting tool. [Figure 29B] FIG. 29B is a side view of the bidirectional cutting tool illustrated in FIG. 29A. [Figure 29C] FIG. 29C is a partial side view of the bidirectional cutting tool taken along line 29C-29C of FIG. 29B. [Figure 29D] 29D is a partial isometric view of the interactive cutting tool taken along line 29D-29D of FIG. 29A. [Figure 29E] FIG. 29C is a partial side view of the bidirectional cutting tool taken along line 29C-29C of FIG. 29B. [Figure 29F] FIG. 29F is a cross-sectional view taken along line 29F-29F of FIG. 29E. [Figure 29G] FIG. 29G is a cross-sectional view taken along line 29G-29G of FIG. 29E. [Figure 29H] FIG. 29H is a cross-sectional view taken along line 29H-29H of FIG. 29E. [Figure 29I] FIG. 2 is a partial side view of a die cutting tool. [Figure 29J] FIG. 1 is an end view of a die cutting tool. [Figure 29K] FIG. 29K is a cross-sectional view taken along line 29K-29K of FIG. 29J. [Figure 29L] FIG. 29L is a cross-sectional view taken along line 29L-29L of FIG. 29J. [Figure 29M] FIG. 2 is a partial side view of a die cutting tool. [Figure 29N] FIG. 1 is an end view of a die cutting tool. [Figure 29O] FIG. 29O is a cross-sectional view taken along line 29O-29O of FIG. 29N. [Figure 29P] FIG. 29P is a cross-sectional view taken along line 29P-29P of FIG. 29N. [Figure 29Q] FIG. 2 is a side view of a die cutting tool. [Figure 29R] FIG. 1 is an end view of a die cutting tool. [Figure 29S] FIG. 29S is a partial isometric side view of the die cutting tool taken along line 29S-29S. [Figure 29T] FIG. 29T is a cross-sectional view taken along line 29T-29T of FIG. 29R. [Figure 29U] FIG. 1 is a partial isometric view of an end and side of a mold cutting tool. [Figure 29V] FIG. 1 is a partial isometric view of an end and side of a mold cutting tool. [Figure 29W] FIG. 1 is a partial isometric view of a side of a mold cutting tool. [Figure 29X] FIG. 1 is a partial isometric view of a side of a mold cutting tool. [Figure 30] FIG. 10 is a side view of a bidirectional cutting tool self-centering point. [Figure 31A] FIG. 1 is an isometric view of an interactive tissue modification tool. [Figure 31B] FIG. 10 is a side view of an interactive tissue modification tool. [Figure 31C]FIG. 10 is an end view of a bidirectional tissue modification tool. [Figure 32A] FIG. 10 is a side view of an interactive tissue modification tool with a depth pilot. [Figure 32B] FIG. 10 is an end view of an interactive tissue modification tool illustrating a depth pilot. [Figure 32C] FIG. 10 is an isometric view of an interactive tissue modification tool with a depth pilot. [Figure 33] FIG. 10 is a side view of an alternative embodiment of a cutting tool having a very long neck relative to its diameter to increase tactile feedback during transitions between tissues of different densities, such as from cancellous bone to cortical bone. DETAILED DESCRIPTION OF THE INVENTION

[0045] Referring generally to the figures, and more particularly to FIGS. 1-24, reference numeral 10 generally designates a power-operated surgical tool having an outer housing 18 adapted to enclose and support various internal components, such as a motor 20 operably connected to a transmission, generally designated 22, which operably couples the motor 20 to the transmission 22 with a tool coupler 16. In a preferred embodiment, the motor 20 is an electric motor operably connected to a power source, for example, by a power cord 26. It should be noted that while electrical power is preferred, pressurized fluids, such as air, oil, or vacuum fluids, can be utilized to provide rotational motion to the motor without departing from the scope of the present invention. The housing 18 may be provided with an attachment handle (not shown) to be grasped by the surgeon to control the surgical tool 10. The housing 18 may be formed from a polymeric (often referred to as plastic) material and may be formed by molding. Preferably, the housing 18 is formed by assembling two halves that are suitably secured together by fasteners, adhesives, welding, spring fasteners, or the like, and suitable combinations thereof. Various controls accessible by the surgeon are provided for selecting the operating mode of the surgical tool 10 and may include a power on switch 28 and a power off switch 30 .

[0046] As shown in the embodiment of FIG. 1, surgical tool 10 operates at high cutting speeds for cutting efficiency and surgeon control. Oscillations (starting from the center, one oscillation equals moving the gear to the right, back to the center, left, and back to the center) are on the order of at least about 5,000 oscillations per minute (5,000 revolutions per minute for motor 20) and can be as high as 30,000 to 50,000 oscillations per minute or more. Oscillations refer to the movement of a tissue modification device, such as a cutter, from one extreme rotational position to the other extreme rotational position and then back to the original extreme position. Preferred are 5,000 oscillations per minute (opm) and 50,000 oscillations per minute. More preferably, the oscillation speed is between 15,000 and 30,000 oscillations per minute. Such an oscillation speed provides optimal bone cutting and disc removal speed, as well as optimal tactile feedback without component fatigue and high oscillation noise. Because there is a 1:1 ratio between rpm and opm of the motor 20, the optimal motor speed in terms of rpm is the same as the oscillation gear speed in terms of opm.

[0047] With further reference to the drawings generally, and more particularly to FIGS. 6-21, the oscillating rotary drive mechanism 35 will now be described. The oscillating rotary drive mechanism 35 is coupled to the shaft 37 of the motor 20, as by a set screw 41 or the like, as well as a crank assembly hub 39 suitably mounted on the shaft 37. The oscillating rotary drive mechanism 35 also includes a link 43 that orbits the shaft 37 and is attached to a rotatably mounted shuttle 45. The link 43 is preferably positioned within a hub bore 66 in the crank assembly hub 39 at an oscillating angle 50 (FIG. 7) relative to the motor shaft 37. In this manner, the distal end 46 of the link 43 rotates about the motor shaft 37, with the pivot axis 48 at the front of the link 43 positioned to extend through the neutral point 32. While the neutral point 32 is the point in the oscillating drive mechanism about which the shuttle 45 and link 43 rotate, the neutral point 32, and therefore the front 42 of the link 43, preferably does not have linear translation. Thus, the relationship of the oscillation angle 50 can be varied to provide different angular rotations of the shuttle 45 and gear segment 56. In this manner, a larger oscillation angle 50 provides more rotation of the shuttle 45 about the neutral point 32, while a smaller oscillation angle 50 provides less rotation for the shuttle 45 and gear segment 56. This configuration allows the amount of bidirectional oscillation provided to the shuttle 45, and therefore the end effector 12 (removable drill tip assembly), to be varied as desired. In the most preferred embodiment, the end effector rotation (the angle of rotation of its shaft) is 72.65 degrees in each direction about the longitudinal axis 104 of the end effector 12. It has been found that this amount of bidirectional rotation provides suitable hard tissue (bone) removal rates while generally not damaging soft tissues such as nerves, muscles, etc. It should be noted that bidirectional swing angles of 40 degrees to 180 degrees in each direction (more preferably between 50 degrees and 90 degrees in each direction, which provides optimal bone cutting while reducing the chance of grabbing tissue) have been successfully utilized in removing bone and tissue and are contemplated within the scope of the present invention for use in surgical procedures.While the pivot 48 of the front portion 42 of the link 34 is positioned to extend through the neutral point 32, it should again be noted that the pivot 48 may be positioned away from the neutral point 32 to provide additional rotational torque to the shuttle 45 without departing from the scope of the present invention, so long as the central portion of the link pivot 48 rotates about that point. The shuttle 45 includes an arcuate rack gear segment 56 that provides reciprocating motion of the pinion gear 58 through the shuttle's oscillating rotation. As shown, the gear ratio of the pinion gear 58 to the arcuate rack gear segment 56 is 3.125. Therefore, if the optimum oscillation of the pinion gear 58 is 72.65 degrees, the sweep angle of the shuttle 45 will be + / - 23.25 degrees. The oscillation angle 50 and sweep angle can be varied to set the oscillation angle of the pinion gear 58 to an optimum oscillation range (e.g., 40 degrees to 180 degrees, or 50 degrees and 90 degrees).

[0048] As shown, the shuttle 45 is rotatably mounted to the housing 18 via a shaft 46 secured to the shuttle 45 in a bearing 49 mounted within the housing (see FIG. 7 ). While a ball bearing 49 is shown, any suitable bearing, such as a sleeve bearing or a needle bearing, can be used. The link 43 is attached to the shuttle 45 by being rotatably mounted to a bearing 54 mounted to the shuttle 45 as well as a fastener 54, such as a nut 60 or a bolt 62. Rotation of the rotor of the motor 20 thereby causes oscillating movement of the pinion gear 58 about the end effector shaft 64. The link 43 is preferably attached to the shuttle 45 by having one or more, preferably a pair of, spaced arms 67, each having a bearing 49 received in a bearing 69 and secured therein by a bolt 62 threadably secured to the shuttle 45 via a threaded bore 68.

[0049] FIGS. 6-21 illustrate further details of the transmission device 22, which is operable to provide oscillating rotational drive of the end effector shaft 64 at high speeds, such as 10,000 orbits per minute or greater. The transmission device 22, like the cutting tool 100, is configured to selectively convert rotation of the shaft 37 of the rotor 70 of the motor 20 into oscillating rotation of the end effector shaft 64 for tissue modification. A pinion gear 58, such as a bevel gear or helical bevel gear 59, meshes with the gear segments 56 or helical gear segments 57, such that oscillating motion of the gear segments 56, 57 induced by rotation of the hub 39, as well as bearings 49, induces oscillating motion in the end effector shaft 64, which is rotatably mounted within the end effector housing 72 (see FIGS. 14 and 22). The pinion gear and gear segments are preferably constructed from materials that provide quiet operation and high wear resistance. In a most preferred embodiment, the gears are constructed from a polymeric material such as polyetheretherketone (PEEK) or other members of the polyarletherketone family of high-performance polymers. The polymer may be compression molded or injection molded and may contain fibers or fillers to provide additional wear, strength, or lubricity to the gears. It should also be noted that metals or combinations of metals and polymers may be utilized for the gears without departing from the scope of the present invention. Note that motor 20 may be an electric motor or a compressed or vacuum air-operated motor, with an electric motor being preferred. Motor 20 is operably connected to a power source via power cord 26, and switches 28 and 30 are operable to selectively effect operation of motor 15.

[0050] Although shaft 102 is shown as being at an angle to the longitudinal axis of the motor, it is possible, and in some cases desirable, to have the shaft aligned or parallel to the longitudinal axis of the motor.

[0051] The use of helical gears (non-linear) in the pinion gear 58 and gear segments 56 is especially important in high speed drills because they substantially reduce wobble and increase gear strength by engaging 30 percent or more more teeth in the gear meshing area. The extra strength provided by helical gears allows the pinion gear 58 of the disposable drill tip assembly 12 to use a low inertia material such as PEEK (molded PEEK material) rather than a high inertia material such as steel.

[0052] Referring generally to the drawings, and more specifically to Figures 1-12, 14, 22-24, an end effector 12 and its connection to the motor 14 and transmission assembly 22 are illustrated. Generally, the end effector 12 is removably connected to the outer housing 18, including the pinion gear 58 portion of the transmission assembly 22 and the cutting tool 100. In this manner, portions of the device that cannot be cleaned in an autoclave, as well as high-wear parts such as the pinion gear 58 and cutting tool 100, can be replaced between procedures. This configuration also allows the surgeon to easily change from one type of end effector to another if the need arises during a procedure. Figure 9 shows the distal end of the output shaft 19. The output shaft 19 includes a tool coupler 16 assembly that removably mounts different end effectors 12 to the motor shaft 37 and is operable to prevent relative rotation between the end effector 12 and the output shaft 19 during operation. As shown, the end effector 12 is operable to remove hard tissue, such as bone, and may be attached to the motor assembly 14 via a tool coupler 16. The tool coupler assembly 16 includes a ferrule 74 secured to a first end 76 of the end effector housing 72, while a cutting tool 100 extends from a second end 78 of the end effector housing 72. The ferrule 74 includes a flange 80 including a stop surface 81 that cooperates with a front surface 90 of a locking ring 92 to establish the depth at which the end effector 12 can be inserted into the motor assembly 14. A ferrule shank 82 resides adjacent to the flange 80. The shank 82 includes one or more keys 84, with a preferred embodiment including three keys 84. The key 84 is fixed in place on the ferrule shank 82 and includes a key side 86 and a locking surface 88. The locking ring 92 is configured to rotate in a first direction to allow the ferrule shank 82 to enter the inner bore 94 of the locking ring 92, the ferrule key 84 to enter, and the key side 86 to engage the docking port 96 of the outer housing 18 to prevent the end effector 12 from rotating relative to the outer housing 18.Similarly, during insertion of the end effector 12, the pinion gear 58 engages the gear segment 56. To maintain proper clearance between the gear segment 56 and the pinion gear 58, the locking ring 92 includes one or more camming surfaces 98 that cooperate with the locking surfaces 88 of the ferrule 74 to pull the stop surfaces 81 of the ferrule 74 against the front surface 90 of the locking ring 92, securing the end effector 12 in place. The end effector 12 is thus prevented from rotating and moving in or out relative to the motor assembly 14. This structure maintains proper positioning and clearance for high-speed operation of the transmission 22, and therefore the end effector 12. A spring lock 97 may be provided within the locking ring 92 and includes a rounded end 95 that cooperates with a ridge 93 positioned on the exterior surface of the docking port 96 to provide tactile feedback when the locking ring 92 is rotated to its locked position. This configuration also provides resistance to inadvertent rotation of the locking ring 92 to the disengaged position during use of the surgical tool 10. Disengagement and removal of the end effector 12 is achieved by grasping the locking ring 92 and rotating it to the disengaged position, at which point the end effector 12 can be withdrawn from the motor assembly 14. In this manner, the same motor assembly 14 can be utilized with multiple surgical tools, which can be interchanged by the surgeon as needed.

[0053] 26-30, a bidirectional cutting tool 100 is illustrated. With general reference to FIGS. 1-18, a bidirectional (oscillating) cutting tool 100 for cutting bone and tissue is illustrated. The cutting tool 100 includes a shank 102 having a longitudinal axis 104, a first end 108, and a second end 110. The shank 102 has a peripheral surface 106 extending about the longitudinal axis 104, the peripheral surface 106 being symmetrically shaped to allow at least the second end 110 of the peripheral surface 106 to be gripped for rotation about the longitudinal axis 104 and sized to cooperate with the bearings 49 to support rotation of the cutting tool 100. Thus, the longitudinal axis 104 is also the axis of rotation. In a preferred embodiment, the second end of the shank 110 is rounded to cooperate with the inner bore of the pinion gear 58. In at least one embodiment, the second end of the shank 110 includes one or more indexing keys 112 constructed and arranged to cooperate with a keyway (not shown) or the like positioned within the bore of the pinion gear 58 to ensure that the surgical cutting tool 100 oscillates at the same speed and through the same arc of rotation as the transmission 22 that drives the surgical cutting tool 100. The first end 108 of the shank 102 includes a cutter 114, the cutter 114 including an outer diameter 116, the cutter 114 including two or more flutes 118, each extending parallel to the longitudinal axis 104 (FIGS. 28A-28K) or helically (FIGS. 26A-26J, 27A-27L, 29A-29X, 30, 31A-31B, and 32A-32C). The flutes 118 extend inward from the outer diameter 116 toward the longitudinal axis 104, forming recessed flute channels 120, each having a pair of opposing sidewalls 122, 124 and a cylindrical radius 125 at the base of each flute channel 120. Each sidewall 122, 124 forms a face 126 of a cutting edge 142 that extends along the length of each flute channel 120, such that each flute channel 120 presents two opposing faces 126 that provide the cutting edge 142 of the blade 132, allowing cutting in both directions when the cutter 114 is rotationally oscillated about the longitudinal axis 104.In a most preferred embodiment, the flute channels 120, and thus the blades 132, are positioned helically along the shank 102, e.g., at a helix angle 144, to allow the faces 126 to engage bone at an angle that reduces cutting loads. A preferred helix angle is between 4 and 10 degrees, with a 5-degree angle being used in the illustrated embodiment. It should also be noted that a high helix angle 144 facilitates two or more cutting faces 126 simultaneously contacting bone, reducing rocking and increasing removal rates. To enhance cutting and reduce pressure on the cutter 114, each face 126 includes a rake angle 128 that converges relative to the central face 130, which extends through the longitudinal / rotational axis 104, when the blade 132 is centered relative to the central face 130. A rake angle 128 is also provided between each face 126 extending from the outermost surface of the blade 132. Thus, each cutting edge preferably includes a positive rake angle to reduce loads on the cutting edge when cutting hard materials such as bone. Flutes 118 separate blades 132, each including a cutting edge 142, and each blade 132 preferably includes an upper corner radius 134 that extends inward from the outer diameter 116 toward the axis of rotation 104, such that convergence of the face 126 and the upper corner radius 134 creates the outermost diameter of the cutter 114. In at least some embodiments, the upper corner radius 134 is structured to provide relief behind the face 126 as the cutter 114 oscillates. The upper corner radius 134 preferably terminates in sharp corners 136 closer to the axis of rotation 104, with the sharp corners spaced apart. Between the spaced sharp corners 136 is a center point 138 that is an extremely sharp point.

[0054] The top corner radii 134 of all four blades 132 define a central recessed region about a center point 138. The center point 138 is configured and positioned at a central point where a plurality of facets 140 converge. The flutes 118 also converge toward the plurality of facets 140. The convergence of the facets 140 creates a sharp edge that functions to grind and crush the bone, while the top corner radii 134 cut the bone around the center point 138 and the flutes 118 convey the cut and crushed bone away from the cutting tool 100. An additional benefit of the center point 138 is that the tendency of the cutting tool 100 to move across the bone surface when the distal end of the cutting tool 100 contacts the bone is significantly reduced.

[0055] 26A-26H, the center point 138 is located slightly below (proximal to) the edge 134 of the blade 132. The center point 138 is a zero angular velocity point, and thus cutting with the upper corner radius 134 is not effective and a different cutting mode (e.g., the crushing method described above) is used.

[0056] The transition between the sharp corners 136 and 138 defines a concavely curved edge that results in a positive milling shape that defines a central recessed region. This is an important feature because the central recessed region has such low angular velocities that conventional cutting shapes are ineffective. This region and milling cutting shapes such as center point 138 therefore allow cutting tip 102 to penetrate bone more effectively.

[0057] In at least some embodiments, the face 126 and upper corner radius 134 may include notches or waves (not shown) suitable for breaking the face 126 into shorter segments, thereby reducing the load on the face 126 of the cutter 114. These notches or waves may be aligned, or more preferably, offset relative to one another, to eliminate ribs on the cutting surface. The cutter 114 may be formed with an even or odd number of flutes 118 without departing from the scope of the present invention. In general, a cutter 114 having a greater number of flutes 118 and blades 132 will remove material faster than a cutter 114 having a fewer number of flutes 118 and blades 132. The cutter 114 may be formed from the same material or may be integrally formed with the shank 102. Alternatively, the shank 102 and cutter 114 may be constructed from different materials, and the cutter 114 may be bonded to the shank 102 using a suitable silver solder or the like to secure the cutter 114 to the shank 102. Thus, materials such as high-speed steel and / or carbides may be utilized as desired without departing from the scope of the present invention. Coatings known in the art, such as, but not limited to, titanium nitride, titanium carbonitride, and vanadium carbide, which have a higher hardness than the base material, may be utilized to extend the useful life of the cutting tool 100. The cutting tool 100 may be fabricated in any desired diameter suitable for a surgical procedure, with some of the most desirable diameters being 1.5 millimeters, 2.0 millimeters, 2.4 millimeters, 3 millimeters, and 4 millimeters. It should also be noted that the cutting tool 100 may include depth markings 146 to provide a visual indicator to the person using the tool. The depth markings 146 may be colored for more clarity.

[0058] In at least some embodiments, the cutting tool 100 includes a shank 102 that is intentionally undersized to provide tactile feedback to the surgeon when the surgeon applies a significant load to the cutter 100. As shown in FIG. 33, the cutting tool 100 includes a cutter 190 that includes a neck portion 192 having a constant diameter, followed by a cutter 114. The cutter 190 extends distally from the first end 108 of the shank 102 and is made of stainless steel, although other shafts may be used. In this embodiment, the neck portion has a diameter D2, and the cutter 114 has a diameter D1. By way of example, D1 is 2-4 mm, D2 is 2 mm, and the illustrated L1 is approximately 50 mm. The first end 108 extends slightly distally of the second end 78 of the end effector housing 72.

[0059] The small diameter of neck portion 192 allows cutter 190 to rock if the load on cutter 100 is too high, particularly as the tip of cutter 114 transitions from one region to another of different density (e.g., cancellous bone to cortical bone). Neck portion 192 can include a length of approximately 30-120 millimeters. In this manner, rocking is induced within neck portion 192 to provide tactile feedback to the surgeon when a different type of bone is encountered or if the load on cutter 100 is too high. It should be noted that the length and diameter of the neck portion can be varied to achieve the same function without departing from the scope of the present invention.

[0060] The ratio of L1 to D2 is important for cutter 190. Preferably, this ratio is between 15 and 60, inclusive, with a minimum L1 of 30 mm and a maximum L1 of 120 mm. More preferably, this ratio is between 25 and 35, inclusive, which provides sufficient tactile feedback without being too flexible, which would cause cutter 190 to wobble.

[0061] Referring generally to the figures, and more specifically to FIGS. 28A-28K, an embodiment of a cutting tool 100 is illustrated that is ball-shaped. Accordingly, the blade 132 includes an outermost surface that is curved relative to the longitudinal centerline of the cutter while maintaining a positive rake angle 128 on the flute sidewalls 122, 124, as well as a positive rake angle on the outer surface of the blade 132. FIG. 28L illustrates a ball-shaped cutter 156 that has a division point 148 instead of a center point 138. The division point 148 includes the flutes 118 cut across the tip of the ball-shaped cutter 156. Thus, a surface 126 with a positive rake angle 128 is provided on each side 122, 124 of the flute 118. This configuration tends to shift the surface when the end is applied to bone, but remains suitable for cutting bone and other tissue when rotated and rocked.

[0062] Referring generally to the drawings, and more specifically to FIGS. 29A-29X, a bidirectional cutting tool 100 is illustrated that includes a shaped side surface 150. The side surface 150 may be tapered or include any number of different diameters, with a transition surface 152 extending between the diameters. In this manner, the cutter 100 is suitable for penetrating bone to form a machined gap. The cutter 100 can also be used to cut along the side of bone and create stepped or notched surfaces. The shaped cutter 100, as described above, includes a positive rake angle and flutes that allow the shaped cutter to cut when swung in both directions. The shaped cutter 100 can also be constructed to provide a pilot bore with a minimum diameter portion of the cutter 100, while a smaller diameter for threading or the like is followed by a larger diameter. Additionally, a third diameter of the shaped cutter 100 may be used, by way of non-limiting example, as a countersink or for clearance or the like.

[0063] Referring generally to the drawings, and more particularly to FIG. 30 , a bidirectional cutting tool 100 is illustrated that includes an elongated center point 154. The elongated center point 154 is configured to provide a center point that resists movement across hard surfaces or irregularities, such as bone. The elongated center point 154 includes facets 140 that may be flat or curved and intersect at point 154, capable of breaking up hard bone into small particles as the cutting tool 100 is oscillated.

[0064] 25, 31A-31B, and 32A-32C, a bidirectional soft tissue cutter 160 is illustrated. Generally, the soft tissue cutter 160 includes a substantially rigid shank 102 having a shaped head portion 172. The shaped head portion 172 includes a plurality of helically mounted, shaped claws 162, each including a curved body 164 for gripping tissue, and each claw 162 including a cutting end 166. The cutting end 166 includes both acute 168 and obtuse 170 cutting face clearance angles for versatile cutting action on hard and soft tissue. The claws 162 are generally constructed and arranged to cut and grasp tissue, such as a disc material held against the shaped head portion 172 and the distal end of the claws 162. This configuration allows disc material to be removed from the surgical site by removing the tool with entangled soft tissue attached. The configuration of the claw 162 also allows the soft tissue cutter 160 to self-clean once detached by high-speed rocking or spinning. This allows the tool to be quickly cleaned for reuse in removing more disc material, eliminating the need to replace the tool each time it becomes filled with disc material. Once the disc material is removed, the claw 162 can be used to decorticate the bone. Thus, the same tool can be used to remove disc material, decorticate the bone, and shape it. To facilitate widespread use, the claw 162 includes a unique configuration. In a preferred embodiment, the claw 162 is circular in cross section and includes one or more bends 174 that terminate in a generally flat cutting surface 176 that is substantially parallel to the plane of the shaping head portion 172. The bends 174 provide rigidity and controlled flexibility to the claw 162. Additionally, one of the bends 174 in the claw 162 is located adjacent to the outer cutting surface 176 so that the cutting surface 176 is oriented parallel to the forming head 172, and various clearance angles 168, 170 are provided around the periphery of the cutting surface 176.This configuration allows the same claw 162 to cut, scrape, and smooth the surface being cut, while claws 162 rotationally oriented at different angles around and along the bidirectional cutting surface 176 contact the bone surface. Sides of the claw 162 with higher clearance angles reduce the load on the claw 162, allowing for greater material removal at the same load, while lower clearance angles scrape and / or polish the surface, leaving a relatively smooth surface finish. This configuration allows the same tool to be used for roughing and finishing the bone surface, achieving a suitable surface for supporting an implant and promoting bone growth. The claw bends 174 are preferably approximately 90 degrees, and each claw 162 preferably includes two bends 174 along its length. However, it should be noted that other bend angles, as well as bends as few as one and as many as six, can be utilized without departing from the scope of the present invention. The bends 174 may be axially aligned with one another along the length of each claw 162, or there may be rotation between the bends 174 to provide more or less bending of the claw 162 during operation for a smoother surface finish or faster material removal, respectively. The claws 162 may also be arranged at a helical angle relative to one another along the shank 102 or aligned to give the tool different operating characteristics. The preferred material for the soft tissue cutting tool 160 is printed titanium. However, other materials, including high-speed steel, stainless steel, carbides, and the like, may be utilized without departing from the scope of the present invention. A suitable coating may also be utilized on the exterior surface of the bidirectional cutter to reduce friction and increase surface hardness. Such coatings may include, but are not limited to, titanium nitride, titanium carbide, chromium carbide, titanium carbonitride, and the like. In some embodiments 32A-32C, the distal end 178 of the soft tissue cutting tool 160 is provided with a suitable stop plug 180 to prevent the tool from moving into the surface or to limit the access of the soft tissue cutting tool 160 to the side.In this manner, once the soft tissue cutting tool 160 is within a desired proximity to the bottom or side, the stop plug 180 scrapes against the bone surface, preventing further movement of the tool toward the bone. This configuration is particularly useful in bone decortication procedures, reducing the opportunity for the surgeon to remove excess material from the bone surface.

[0065] Referring generally to the figures, and more particularly to FIG. 24 , the present surgical tool 100 is illustrated having a plurality of spheres 182 positioned for use with a surgical tracking system known in the art. Surgical tracking systems typically utilize a camera to monitor the position of the spheres 182, which can be shown on a display screen to confirm position and movement. In a preferred embodiment, the tracking system is removable from the motor assembly 14 without disassembly of the surgical tool 100.

[0066] All features of the cutting tool 100 may be symmetrical to balance the cutting action so as to minimize inadvertent axial and lateral translation of the cutting tool 100. A favorable cutting action can also be obtained with asymmetric shapes.

[0067] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which this invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

[0068] While particular forms of the present invention have been exemplified, it should be understood that the invention should not be limited to the specific forms or configurations described and illustrated herein. It will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the invention and that the invention should not be considered as limited to that shown and described in this specification and any figures / figures contained herein.

[0069] Those skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures, and techniques described herein are presently representative of preferred embodiments and are intended to be illustrative, not limiting in scope. Modifications thereof and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and defined by the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

Claims

1. A power-operated surgical tool, comprising: an outer housing adapted to surround and support the various internal components; A transmission device; a motor secured within the outer housing, the motor including a motor output shaft connected to the transmission, the transmission including an oscillating rotary drive mechanism for rotationally oscillating the cutting tool about a longitudinal axis of the cutting tool, the oscillating rotary drive mechanism having a link that pivots about the motor output shaft at an oscillating angle and is attached to a rotatably mounted shuttle such that a distal end of the link rotates about the motor output shaft while a pivot at a front of the link is positioned to rotate at a neutral point, causing the shuttle to rotationally oscillate about an axis transverse to the motor output shaft; a crank assembly hub fixed to the motor output shaft, the crank assembly hub including a hub bore for receiving the distal end of the link, the crank assembly hub configured and arranged to maintain the swing angle; a power-operated surgical tool, wherein the link is secured to the shuttle by one or more arms, each arm having a bearing that receives within it a bolt that is threadably secured in a bore in the shuttle.

2. A power-operated surgical tool, comprising: an outer housing adapted to surround and support the various internal components; A transmission device; a motor secured within the outer housing, the motor including a motor output shaft connected to the transmission, the transmission including an oscillating rotary drive mechanism for rotationally oscillating the cutting tool about a longitudinal axis of the cutting tool, the oscillating rotary drive mechanism having a link that pivots about the motor output shaft at an oscillating angle and is attached to a rotatably mounted shuttle such that a distal end of the link rotates about the motor output shaft while a pivot at a front of the link is positioned to rotate at a neutral point, causing the shuttle to rotationally oscillate about an axis transverse to the motor output shaft; a crank assembly hub fixed to the motor output shaft, the crank assembly hub including a hub bore for receiving the distal end of the link, the crank assembly hub configured and arranged to maintain the swing angle; a power-operated surgical tool, wherein the link is secured to the shuttle by a pair of spaced arms, each arm having a bearing received therein for receiving a bolt threadably secured in a bore in the shuttle;

3. 3. The power-operated surgical tool of claim 1, wherein the pivot angle relationship can be varied relative to the motor output shaft to achieve different angular rotations of the shuttle.

4. 3. The power-operated surgical tool of claim 1, wherein the shuttle includes an arcuate gear segment that meshes with a pinion gear that is connected to the end effector shaft to impart a rotary-oscillating motion to the end effector shaft.

5. The power-operated surgical tool of claim 4 , wherein the end effector shaft includes the cutting tool.

6. The power-operated surgical tool of claim 1 or 2, wherein the pivot angle is an acute angle relative to the motor output shaft.

7. The power-operated surgical tool of claim 5, wherein the rotation of the cutting tool is between 40 degrees and 180 degrees in each direction about the longitudinal axis of the cutting tool.

8. The power-operated surgical tool of claim 7, wherein the rotation of the cutting tool is between 50 degrees and 90 degrees in each direction about the longitudinal axis of the cutting tool.

9. The power-operated surgical tool of claim 4 , wherein the pinion gear and the arcuate gear segments are constructed from a polymeric material.

10. The power-operated surgical tool of claim 9, wherein the polymeric material is polyetheretherketone.

11. The power-operated surgical tool of claim 4 , wherein the pinion gear and the arcuate gear segment are straight cut gears.

12. The power-operated surgical tool of claim 4 , wherein the pinion gear and the arcuate gear segment are helical cut gears.

13. The power-operated surgical tool of claim 4 , wherein an end effector including the end effector shaft is removably connected to the outer housing.

14. The power-operated surgical tool of claim 13 , wherein the end effector includes the pinion gear, the end effector shaft, and the cutting tool.

15. 14. The power-operated surgical tool of claim 13, further comprising a tool coupler for coupling the end effector to the outer housing, the tool coupler including a ferrule secured to a first end of the end effector while the cutting tool extends from a second end of the end effector, the ferrule including a flange including a stop surface that cooperates with a front surface of a locking ring to establish a depth that allows the end effector to enter into a motor assembly, a ferrule shank adjacent the flange, the ferrule shank including one or more keys fixed in place on the ferrule shank, each key including a key side and a locking surface, the locking ring configured to rotate in a first direction to allow the ferrule shank to enter an inner bore of the locking ring and for the ferrule keys to enter and for the key side to engage a docking port of the outer housing to prevent the end effector from rotating relative to the outer housing.

16. 16. The power-operated surgical tool of claim 15, wherein the locking ring includes one or more cam surfaces that cooperate with the locking surface of the ferrule to pull the stop surface of the ferrule against a front surface of the locking ring to secure the end effector in place.

17. 17. The power-operated surgical tool of claim 16, wherein the locking ring includes a spring lock having rounded ends that cooperate with ridges positioned on an outer surface of the docking port to provide tactile feedback when the locking ring is rotated to its locked position.

18. The power-operated surgical tool of claim 12 , wherein the arcuate gear segment comprises an inclined gear having a helical tooth profile.

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