WO2007053780A1 - Differential thread fixation clamp - Google Patents

Differential thread fixation clamp Download PDF

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Publication number
WO2007053780A1
WO2007053780A1 PCT/US2006/043161 US2006043161W WO2007053780A1 WO 2007053780 A1 WO2007053780 A1 WO 2007053780A1 US 2006043161 W US2006043161 W US 2006043161W WO 2007053780 A1 WO2007053780 A1 WO 2007053780A1
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WO
WIPO (PCT)
Prior art keywords
fixator
device
force
reference frame
mounting structure
Prior art date
Application number
PCT/US2006/043161
Other languages
French (fr)
Inventor
Daniel Mccombs
Original Assignee
Smith & Nephew, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US73384605P priority Critical
Priority to US60/733,846 priority
Application filed by Smith & Nephew, Inc. filed Critical Smith & Nephew, Inc.
Publication of WO2007053780A1 publication Critical patent/WO2007053780A1/en

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/50Supports for surgical instruments, e.g. articulated arms
    • A61B90/57Accessory clamps
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/50Supports for surgical instruments, e.g. articulated arms
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/39Markers, e.g. radio-opaque or breast lesions markers
    • A61B2090/3983Reference marker arrangements for use with image guided surgery

Abstract

A differential thread fixation clamp (10) securing a reference frame (50) to an item (800) in combination with a computer aided surgery navigation system (102). A differential thread fixation clamp (10) according to one embodiment applies a wedge force to two pins (20, 22) that are connected to an item. In one embodiment, a controller mechanism (18) includes an internally two-threaded surfaces (240, 260) that engages with two plungers (14, 16) having different externally threaded surfaces (140, 160), applying a pushing force to the pins (20, 22), securing the reference frame (50) in one place for the need of the computer aided surgery navigation system (102).

Description

J)Qj1 IfERENTIAL THREAD FIXATION CLAMP

[0001] This application claims priority to U.S. Application Serial No. 60/733,846 filed on November 4, 2005, the entire contents of which are hereby incorporated by this reference.

BACKGROUND

[0002] A major concern during surgical procedures as well as other medical operations is carrying out the procedures with as much precision as possible. For example, in an orthopedic procedure, less than optimum alignment of implanted prosthetic components may cause undesired wear and revision, which may eventually lead to the failure of the implanted prosthesis. Other general surgical procedures also require precision in their execution.

[0003] With orthopedic procedures, for example, previous practices have left room for precision alignment of prosthetic components. For example, in a total knee arthroplasty, previous instrument design for resection of bone limited the alignment of the femoral and tibial resections to average value for varus/valgus, flexion/extension and external/internal rotation. Additionally, surgeons conventionally often use visual landmarks or "rules of thumb" for alignment which can be misleading due to anatomical variability. Intramedullary referencing instruments can also violate the femoral and tibial canal. This intrusion can increase the risk of fat embolism and unnecessary blood loss in the patient, among other things.

[0004] Devices and processes according to various embodiments of the present invention are applicable not only for knee, hip and shoulder repair, reconstruction or replacement surgery, but also repair, reconstruction or replacement surgery in connection with any other joint of the body as well as any other surgical or other operation where it is useful to track position and orientation of body parts, non-body components and/or virtual references such as rotational axes, and to display and output data regarding positioning and orientation of them relative to each other for use in navigation and performance of the operation. UWt I

Figure imgf000003_0001
surgery systems that guide a surgeon through the application of images. In addition, there are systems and methods for accomplishing imageless computer-aided surgery, which guide surgeons through references of the objects involved, such as mechanical axes. Examples of computer-aided surgery systems are disclosed in USSN 10/364,859, filed February 11, 2003 and entitled "Image Guided Fracture Reduction," which claims priority to USSN 60/355,886, filed February 11, 2002 and entitled "Image Guided Fracture Reduction"; USSN 60/271,818, filed February 27, 2001 and entitled "Image Guided System for Arthroplasty"; USSN 10/229,372, filed August 27, 2002 and entitled "Image Computer Assisted Knee Arthroplasty Instrumentation, Systems, and Processes"; USSN 10/084,012 filed February 27, 2002 and entitled "Total Knee Arthroplasty Systems and Processes," which claims priority to provisional application entitled "Surgical Navigation Systems and Processes," Serial No. 60/355,899, filed February 11, 2002; USSN 10/084,278 filed February 27, 2002 and entitled "Surgical Navigation Systems and Processes for Unicompartmental Knee Arthroplasty," which claims priority to provisional application entitled "Surgical Navigation Systems and Processes," Serial No. 60/355,899, filed February 11, 2002; USSN 10/084,291, entitled "Surgical Navigation Systems and Processes for High Tibial Osteotomy," which claims priority to provisional application entitled "Surgical Navigation Systems and Processes," Serial No. 60/355,899, filed February 11, 2002; and provisional application entitled "Image-guided Navigated Precisions Reamers," Serial No. 60/474,178, filed May 29, 2003.

[0006] These systems and processes use position and/or orientation tracking sensors such as infrared sensors acting stereoscopically or other sensors acting in conjunction with reference structures or reference transmitters to track positions of body parts, surgery-related items such as implements, instrumentation, trial prosthetics, prosthetic components, and virtual constructs or references such as rotational axes which have been calculated and stored based as designation of bone landmarks. Processing capability such as any desired form of computer functionality, whether standalone, networked, or otherwise, takes into account the position and orientation information as to various items in the position sensing field (which may correspond generally or specifically to all or portions or more than all of the surgical field) based on sensed position and orientation of their associated reference structures such as fiducials, reference transmitters, or based on stored position and/or orientation information.

The processing functionality correlates this position and orientation information for each ation, such as a computerized fluoroscopic imaged file, a wire frame or other data file for rendering a representation of an instrument component, trial prosthesis or actual prosthesis, or a computer generated file relating to a rotational axis or other virtual construct or reference. The processing functionality then displays position and orientation of these objects on a screen or monitor, or otherwise. Thus, systems or processes, by sensing the position of indicia such as passive fiducials or active transmitters or transponders which may be located on reference frames, can display or otherwise output useful data relating to predicted or actual position and orientation of body parts, surgically related items, implants, and virtual constructs for use in navigation, assessment, and otherwise performing surgery or other operations.

[0007] Indicia according to certain aspects of the invention may emit or reflect infrared light that is then detected by an infrared camera. They may be sensed actively or passively by infrared, visual, sound, magnetic, electromagnetic, x-ray or any other desired technique. An active indicium emits energy, and a passive indicium merely reflects energy. A reference frame may have at least three, but usually four, indicia to determine the position and orientation of the associated instrument, implant component or other object to which the reference frame is attached.

[0008] In addition to reference frames with fixed indicia, modular indicia, which may be positioned independent of each other, may be used to reference points in the coordinate system. Modular indicia may include reflective elements which may be tracked by two, sometimes more sensors whose output may be processed in concert by associated processing functionality to geometrically calculate the position and orientation of the item to which the modular indicia are attached. Like fixed reference frame structures, modular reference frames and the sensors need not be confined to the infrared spectrum- any electromagnetic, electrostatic, light, sound, radio frequently or other desired technique may be used. Similarly, modular indicia may "actively" transmit reference information to a tracking system, as opposed to "passively" reflecting infrared or other forms of energy.

[0009] Some image-guided surgical navigation systems allow reference frame structures with indicia to be detected at the same time the fluoroscopy imaging is occurring. This allows the position and orientation of the reference structure to be coordinated with the |e |m|gi|ig. fjj'hfjn, after processing position and orientation data, the reference structures may be used to track the position and orientation of anatomical features that were recorded fluoroscopically. Computer-generated images of instruments, components, or other structures that are fitted with reference frame structures may be superimposed on the fluoroscopic images. The instruments, trial, implant or other structure or geometry can be displayed as 3-D models, outline models, or bone-implant interface surfaces.

[0010] Some reference frame structures also feature indicia which are arranged in particular patterns, so that the computer aided surgical navigation system can discern one reference frame from another, and thus various body parts, tools and other items from each other as they are being tracked.

[0011] The precise spatial relationship of individual indicia with respect to each other and the associated anatomy or instrument forms the basis of how an indicia-based system calculates the position and orientation of the associated items. Consequently, once the spatial relationship of the fiducials or reference transmitter with respect to each other and with respect to the associated body part or item to be tracked has been registered in the computer aided surgical navigation system, subsequent changes in the position and/or orientation of the indicia relative to each other or to the body part or item will likely cause the system to erroneously calculate the position and orientation of such parts or items. Even minor changes in orientation and/or position of the reference frames or indicia mounted on them may lead to dramatic differences in how the system detects the orientation and/or location of the associated anatomy or instruments. Such changes may require the system to be recalibrated, requiring additional fluoroscopy or other imaging to be obtained, increasing the time and the expense of the procedure. Failure to recalibrate the system may lead to imprecision in the execution of the desired surgical procedure. As such, it is critical to have the reference frame securely attached to the body part or item.

[0012] To insure that the frame is securely attached, some fixation devices use a threaded clamping mechanism. A thread provides a mechanical advantage by a means of pitch or lead. A finer pitch creates more mechanical advantage and consequent ability to fine tune the force applied to object positioning. However, as the pitch becomes finer, the strength of the thread is reduced, and thus the ultimate clamping force that the device can

Figure imgf000006_0001
use tools to further tighten these devices since the threads are limited in the amount of mechanical advantage they can provide.

[0013] In addition, surgical procedures often present challenging anatomical constraints on the size and shape of equipment that may be used during the procedure. While referencing frames are critical for certain aspects of the procedure, they can also be prohibitively cumbersome or disruptive due to their size, shape, or orientation. To further complicate the issue when using a fixation clamp, additional tools are needed to generate the mechanical advantage needed to apply the clamping force.

[0014] Because of the problems above, among others, it is desirable for a fixation clamp to be able to support a reference frame and also be able to apply the needed mechanical advantage for the required clamping force to stay securely attached to the body part or item without the use of additional tools. Existing fixation clamps that can support a reference frame do not address these problems.

SUMMARY

[0015] Embodiments of the present invention may include a device, such as fixation clamp, with mounted reference frames that can apply a wedge force to a base secured to an item. Such embodiments of the present invention may be used in image-guided computer- aided surgery as well as imageless computer-aided surgery. A fixation clamp may include a differential thread portion designed to apply a wedge force to a base secured to an item. By activating the controller mechanism of the clamp, the wedge force is created by turning two different threaded plungers. The entire assembly, the two plungers and the drive mechanism, grows in length as a result, which applies a force to an engaged base. The driving mechanism creates a mechanical advantage based upon engaging the different threads.

[0016] In these or other embodiments, the fixation clamp may include a mounting component to which a reference frame is attached.

[0017] In these or other embodiments, the reference frame may include fiducials, reference transmitters, and/or other reference devices or structures. Iϊ|.,tbje^gr Jther embodiments, the base may include pins and/or other devices connected to a human body.

[0019] In these or other embodiments, attachment devices and modular fidiucials may exhibit modularity such that they may be moved within a coordinate system without the disruption of the base secured within the coordinate system.

[0020] According to an aspect of the present invention there may be provided a device for use in computer aided surgery including a reference frame with a plurality of indicia that are adapted to be sensed by a computer aided surgical navigation system, a reference frame portion connectible to the reference frame, a fixator connectible to a mounting structure attached to an item whose position and orientation is to be tracked by the computer aided surgical navigation system, and a differentially threaded component positioned relative to the fixator, the differentially threaded component further comprises force-applying components adapted to apply a wedge force relative to the mounting structure in order to secure the fixator to the mounting structure.

[0021] According to some embodiments of the present invention, said differentially threaded component may further comprise a controller mechanism connected to the force- applying components, wherein said force-applying components further may comprise a first partially threaded plunger connected to the fixator, and a second partially threaded plunger connected to the fixator, wherein the threads on the first and second partially threaded plungers do not feature the same pitch.

[0022] According to some embodiments of the present invention, said differentially threaded component may further comprise a controller mechanism connected to the force- applying components, wherein said force-applying components may further comprise a first partially threaded plunger connected to the fixator, and a second partially threaded plunger connected to the fixator, wherein the threads on the first and second partially threaded plungers do not feature the same pitch, wherein the first and second plungers may telescope relative to one another. ,[|(|3Si3]|'"

Figure imgf000008_0001
some embodiments of the present invention, said fixator may be rotationally constrained, and said reference frame portion and said fixator may be part of the same physical body.

[0024] According to some embodiments of the present invention, said force-applying components may be rotationally constrained.

[0025] According to some embodiments of the present invention, said first and second plungers' interior geometric shape may match the exterior geometric shape of said fixator, rotationally constraining said plungers.

[0026] According to some embodiments of the present invention, said indicia may further comprise fiducials.

[0027] According to some embodiments of the present invention, said reference frame portion may further comprise a fault interface structure which is adapted to allow the reference frame to be repositioned in the same position relative to the device as it occupied before inadvertent displacement.

[0028] According to some embodiments of the present invention, said mounting structure may be connectible to an item is selected from the group consisting of a body part, a surgical implant, a surgical trial, a surgical instrument, and a surgical probe.

[0029] According to some embodiments of the present invention, said mounting structure may constitute two pins inserted into the item.

[0030] According to some embodiments of the present invention, said mounting structure may constitute two pins connected to the item.

[0031] According to some embodiments of the present invention, said mounting structure may constitute one component attached to the item. ,*,ff._^r^-11Q]f o an aspect of the present invention there may be provided a device for use in computer aided surgery characterized in that a reference frame portion connectible to a reference frame, a fixator connectible to a mounting structure attached to an item whose position and orientation is to be tracked by the computer aided surgical navigation system, and a differentially threaded component positioned relative to the fixator, the differentially threaded component adapted to apply a wedge force relative to the mounting structure in order to secure the fixator to the mounting structure.

[0033] An advantage of some of the embodiments of the invention is that there may be provided an internal mechanical advantage sufficient to generate a clamping force to attach a device without the use of tools.

[0034] An advantage of some of the embodiments of the invention is that more mechanical advantage may be derived through two threads of a different pitch, creating more clamping force than that of just one thread of a fine pitch.

[0035] An advantage of some of the embodiments of the invention is that allowance may be made for a consistent positioning of a reference frame utilized in computer-aided surgery without the need for recalibration.

[0036] Further features, aspects, and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings. Moreover, "embodiment" as used herein can be considered to mean an aspect of the invention, and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings: / 'ϊ|I<3| :! |telfs a schematic side view of a differential thread fixation clamp according to one embodiment of the present invention.

[0039] FIG. 2 shows a schematic exploded perspective view of a differential thread fixation clamp and mounting means for reference frame according to one embodiment of the present invention.

[0040] FIG. 3 shows a schematic exploded view of a differential thread fixation clamp according to one embodiment of the present invention.

[0041] FIG. 4 shows a schematic side view of the knob, coarse plunger, and fine plunger of a differential thread fixation clamp as seen in FIGS. 1-3.

[0042] FIG. 5 shows a schematic side view of the knob, coarse plunger, and fine plunger of a differential thread fixation clamp of FIGS. 1-4.

[0043] FIG. 6 shows a schematic side view of a differential thread fixation clamp with a mounted reference frame according to one embodiment of the present invention.

[0044] FIG. 7 shows a schematic bottom view of the reference frame of FIG. 6.

[0045] FIG. 8 shows a schematic top view of the differential thread fixation clamp of

FIG. 6.

[0046] FIG. 9 shows a schematic top view of a fixator of an embodiment of the present invention.

[0047] FIG. 10 shows a cross-sectional side view of an embodiment of a controller mechanism of the present invention.

[0048] FIG. 11 shows a schematic side view of a differential thread fixation clamp according to one embodiment of the present invention.

[0049] FIG. 12 shows a schematic top view of a differential thread fixation clamp of [0050] FIG. 13 shows a different schematic side view of a differential thread fixation clamp of FIGS. 11-12.

[0051] FIG. 14 shows a schematic exploded view of a differential thread fixation clamp of FIGS. 11-13.

[0052] FIG. 15 shows a schematic side view of an embodiment of a fine plunger of the differential thread fixation clamp of FIGS. 11-14.

[0053] FIG. 16 shows a schematic side view of an embodiment of a coarse plunger of the differential thread fixation clamp of FIG. 14.

[0054] FIG. 17 shows a cross-sectional side view of an embodiment of a controller mechanism of the differential thread fixation clamp of FIGS. 11-14.

[0055] FIG. 18 shows a schematic side view of an embodiment of a differential thread fixation clamp attached a bone through pins according to one embodiment of the present invention.

[0056] FIG. 19 shows a schematic view of a tracking system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0057] FIG. 1-10 illustrate a device according to one embodiment of the present invention. FIG. 1 shows a differential thread fixation clamp 10 that includes a fixator 210, two force-applying components 14 and 16, a controller mechanism 18, pins 20 and 22, an array mount 24, and a mount knob 26. FIG. 2 shows an exploded view of an embodiment of the differential thread fixation clamp 10. In addition to the elements identified in FIG. 1, the exploded view shows an optional wave spring 28 not viewable in FIG. 1. The wave spring

Figure imgf000012_0001
such that it does not easily loosen and become disengaged from the array mount 24. FIG. 2 also provides a view of the array mount 24' s ridged surface 222. Alternatively, surface 222 may be described as having radial peaks and valleys. FIG. 2 provides a view of the exteriors of the two force-applying components 14 and 16. The force-applying components 14 and 16 have an exterior threaded surface area 140 and 160 which engages in the differential controller 18. The threaded surfaces 140 and 160 of the two different force-applying components 14 and 16 may be of different pitches. The force applying components 14 and 16 in one embodiment are plungers, one plunger 16 with a fine thread 140 and one plunger 14 with a coarse thread 160 on their outer surfaces. However, the force-applying components are not limited to plungers, but can be any other device that are capable of having threaded surfaces and the capacity to engage a rotationally constrained-fixator 210. The fine plunger 16 also has a threaded exterior surface 160. The pitch of the threaded exterior 160 of the fine plunger 16 is greater than that of the pitch of the threaded exterior 140 of the coarse plunger 14. FIG. 2 also includes a stem 30 of a reference frame 50 that may be attached to the fixation clamp 10. FIG. 3 shows an exploded view of an embodiment of the differential thread fixation clamp 10 that includes optional dowels 34 that engage insets 36, 38 found on the side of the fixator 210. The dowels 34 retain the force-applying components 14, 16 and the differential controller after assembly onto the fixator 210. Fig. 3 also illustrates an optional knob pin 8. The knob pin 8 is used to retain the wave spring 28 and the mount knob 26 to the array mount 24. The knob pin 8 dowels 34 are optional and some embodiments may forego some or all of them entirely.

[0058] FIG. 18 shows one of the embodiments of the differential thread fixation device 10 with a mounted reference frame secured to an item 800. In the depicted embodiment, the item is a bone. However, the item 800 is not limited to only a bone. The item can be body parts, surgical tools, orthopedic instruments and implants, probes, and other structures and reference points.

[0059] FIG. 4 shows an embodiment of the differential thread fixation clamp 10 with the differential controller 18 fully engaged on an embodiment of one of the force-applying component, the coarse plunger 14. This illustrates the position that the controller mechanism 18 occupies before the differential thread fixation clamp 10 is mounted onto the base that is secured to an item. In FIG. 1, the base is pictured as pins 20 and 22 that are ,s^jrø||]|t|;:jj:lie||^.-|^wgver,- the base is not limited to pins, but can be other means that could be secured to an item, including a single pin, such as a staple, or any other desired structure. FIG. 5 shows an embodiment of the differential thread fixation clamp 10 with the controller mechanism 18 fully engaged on the other embodiment of the force-applying component, fine plunger 16.

[0060] FIG. 6 shows an embodiment of the differential thread fixation clamp 10 with the stem 30 of a reference frame 50 coupled to the array mount 24. The swivel joint 42 between the reference frame 50 and the stem 30 may allow the reference frame 50 to swivel in relation to the stem 30. The reference frame 50 may have several connectors 52 capable of receiving an indicium 54. The indicium 54 in this particular embodiment is a fiducial or a reflective element. However, the indicium 54 may instead be a transponder using energy within the energy spectrum as desired, or any other active or passive device which is able to impart position information to another devices so that, when that device senses position of three or more indicia 54 rigidly attached to a body part, tool, implant, trial or other thing in the operating room, the device is able to generate position and orientation information about the item. The indicium can be of any desired shape, size, structure, material, circuitry such as RFID, or any other physical instantiation. The device which senses the indicium 54 can be any conventional or unconventional computer aided surgery systems mentioned above or otherwise, which include an imager for sensing the position and location of indicium 54, computer functionality for generating position and orientation information about the thing to which the indicium 54 is attached, and a display device which can render the thing correctly located and oriented according to position of the indicia 54.

[0061] FIG. 7 shows a reference frame 50 while FIG. 8 shows an embodiment of the differential thread fixation clamp's 10 array mount 24. The array mount 24 has a fault interface 60. The reference frame 50 has a key 62 that protrudes from the lower portion of the stem 30. The fault interface 60 of the array mount 24 has a groove 64 for placement of the key 62. This key/groove arrangement allows the reference frame 50 to connect to the fault interface 60 in two possible positions. It is possible in other embodiments for the reference frame 50 to be positioned in only one orientation in order to fit correctly. However, the reference frame 50 may be attached to the differential thread fixation clamp 10 through other means, such as by the use of a fastener, by permanent fixation, like welding, or

Figure imgf000014_0001
According to some embodiments, the fault interface allows the reference frame to be repositioned at the location and orientation it previously occupied if the frame is displaced inadvertently during surgery or otherwise moved relative to the item to which it is connected for surgical purposes.

[0062] FIG. 9 shows an embodiment of a fixator 210 component of the embodiment of the differential thread fixation clamp 10 shown in FIG. 1-9. The fixator 210 has two openings 212, 214 that extend perpendicularly through it. The openings 212, 214 may engage pins 20, 22 that are attached to an item. In the depicted embodiment, the openings 212, 214 have an anticline or ogive shape, but those of ordinary skill in the art would understand that other shapes, such as circular, oblong, or rectangular, may be used. At one end of the fixator there may be a circular extension 216 that has an opening 218 through its center. The circular extension 216 on the upper surface may be ridged 220. Alternatively, the upper surface may be described as having radial peaks and valleys. The array mount 24 may also have the ridged surface 222 that corresponds with the fixator's ridged surface 220, allowing for discrete rotational positions when the array mount 24 is assembled to the fixator 210.

[0063] FIG. 10 shows a cross-section view of an embodiment of the controller mechanism 18 of one embodiment of the differential thread fixation clamp of FIG. 1. In this particular embodiment, the controller mechanism 18 is a knob. The knob 18 has a coarse- threaded interior surface 240 and a fine-threaded interior surface 260. The coarse-threaded interior surface 240 has a smaller pitch than that of the fine-threaded interior surface 260. The interior 230 of the controller mechanism 18 is hollow. The controller mechanism 18 may be a knob, but it is not limited as to such. The controller mechanism may be any device that is capable of engaging two different threaded surfaces of two separate components and is capable of threading onto and off of each surface at the same time.

[0064] In surgery the device connects a reference frame to an item to be tracked using a computer aided surgery system. To use the device, a surgeon must first attach the device to the item. In one particular application of the device, the surgeon will attach the device to a human bone 800. The surgeon may attach the fixator 210 by first connecting pins 20, 22 to the bone 800. The surgeon may do this by either attaching the pins to the bone or by /^p^^jjtijji^pilis^nloltjiβijbone. Once the pins 20, 22 are secured to the item, the fixator 210 may be mounted. However, pins are not the only way to connect the item to the differential thread fixation clamp; other connecting components can be used.

[0065] In one embodiment of the invention, the differential thread fixation clamp 10 has a reference frame 50 attached to the fixator 210 through the mounting means shown in FIGS. 6-7. In addition, the fixator 210 engages pins 20 and 22 through its openings 212, 214, which rotationally constrains the fixator 210. The fixator 210 also engages the coarse plunger 14, the controller mechanism 18, and the fine plunger 16 within the area between the fixator's openings 212 and 214, forming an assembly 90. As shown in FIG. 3, the geometrical external shape of the fixator 210 and the interior geometrical shapes of the coarse plunger 14 and the fine plunger 16 prevent the plungers 14, 16 from rotating when the controller mechanism 18 engages the coarse plunger 14 and fine plunger 16. This, however, is not the only structure for restricting rotational movement for the force-applying components 14, 16. In the depicted embodiment, the fixator 210 has a hex shape, but those skilled in the art would understand that other shapes may be used. Also, dowels 34 may be inserted into insets 36 of the fixator 210 to prevent the clamp 10 from falling apart after surgery and during storage. The controller mechanism 18 engages the coarse plunger 14 and the fine plunger 16 along the threaded surfaces 140 and 160 of the plungers along the interior surfaces 240 and 260 of the knob respectively. When the pins 20 and 22 are first engaged with the fixator 210 through its openings 212, 214, the knob 18 is fully engaged on the coarse plunger 14 as shown in FIG. 4. Once the pins 20, 22 engage the fixator 210, a rotational force is applied to the knob 18, which causes the knob 18 to thread off the coarse plunger 14 and to thread onto the fine plunger 16. As the rotational force is continued to be applied, the assembly 90 grows in length. The rate of growth is measured as the inverse of the pitch of the coarse threaded-surface 140 of the course plunger 14 minus the inverse of the pitch of the pitch of the fine threaded-surface 160 of the fine plunger 16. As the assembly grows, the fine plunger 16 and the coarse plunger 14 engage the pins 20, 22. As the assembly 90 grows in length while force is applied to the knob 18, the plungers 14, 16 apply a pushing force on the pins 20, 22. This creates a wedge force that is applied against the pins 20, 22. This force secures the clamp 10 securely with the pins. Once the pins are secured, the surgeon may mount the reference frame 50 through various structure. With the i-asssmbiwώs 9Qujfflli|patiøiil of the wedge force to the pins 20, 22, the reference frame 50 in kept in a precise location.

[0066] FIG. 11-14 show an alternative embodiment of a differential thread fixation clamp 310. FIG. 11-14 show a fixator 400, two force-applying components 314 and 316, a controller mechanism 318, an array mount 324 and its ridged surface 322, a knob pin 308 and a mount knob 326. FIG. 14 shows an exploded view of the alternative embodiment of the differential thread fixation clamp 310. This view shows an optional wave spring 328 that is not visible in FIG. 11-13. In addition, FIG. 14 shows the fixator 400 has an inset 436 that may receive a dowel 434. The fixator 400 has two openings 502, 504 that extend perpendicularly through it. The openings 502, 504 may engage pins 20, 22 as shown in FIG. 1., that are attached to an item. The openings 502, 504 are not limited to engaging only pins 20, 22, but any other secured base that is attached to an item, such as keys, extensions, and other various structures.

[0067] FIG. 15 shows a schematic side view of an embodiment of one of the force- applying components 314, 316. In this particular embodiment, the force-applying component is a fine plunger 316. One end of the fine plunger 316 has a threaded-exterior surface 616. The other end of the plunger 316 has a lip 630. The fine plunger 316 has an opening 604 that extends through it in a substantially perpendicular direction. The opening may engage a pin 20, and is capable of engaging any other secured base that is attached to an item, such as keys, extensions, and other various structures. The fine plunger 316 may have a hole 636 in one of its sides that may engage an optional dowel 434.

[0068] FIG. 16 shows a schematic side view of an embodiment of one of the force- applying components 314, 316. In this particular embodiment, the force-applying component is a coarse plunger 314. One end of the coarse plunger 314 has a threaded- exterior surface 414. The coarse plunger 314 has an opening 704 that extends through it in a substantially perpendicular direction. The opening may engage a pin 20, and is capable of engaging any other secured base that is attached to an item, such as keys, extensions, and other various structures. The coarse plunger 314 may have a hole 736 in one of its sides that may engage an optional dowel 434. Here, the threaded exterior surface 616 of the fine plunger 316 has a greater pitch than the threaded exterior surface 414 of the coarse plunger ,314rJFiadditiQa,"i3iefiii.ef)lunger 316 may have an exterior diameter of a size that is smaller than the interior diameter of the coarse plunger 314, allowing the fine plunger 316 to be inserted into the coarse plunger 314.

[0069] FIG. 17 shows a cross-section view of an embodiment of the controller mechanism 318 of the differential thread fixation clamp 310 of FIG. 11-14. In this particular embodiment, the controller mechanism 318 is a knob. The knob 318 has a coarse-threaded interior surface 440 and a fine-threaded interior surface 460. The coarse-threaded interior surface 440 has a smaller pitch than that of the fine-threaded interior surface 460. The interior 430 of the controller mechanism 318 is hollow. The controller mechanism 318 may be a knob, but it is not limited as to such. The controller mechanism may be any device that is capable of engaging two different threaded surfaces of two separate components and is capable of threading onto and off of each surface at the same time.

[0070] In this alternative embodiment of the invention, the differential thread fixation clamp 310 may have a reference frame 50 attached to the fixator 400 through the key/groove mounting means discussed in regard to the embodiment shown in FIG. 6. This key/groove arrangement allows the reference frame 50 to connect to the fault interface 60 in two possible positions. It is possible in other embodiments for the reference frame 50 to be in only one orientation in order to fit correctly. However, the reference frame 50 may be attached to the differential thread fixation clamp 310 through other means that one of ordinary skill would understand, such as by the use of a fastener, by permanent fixation, like welding, or other various means and structures.

[0071] In surgery the device connects a reference frame to an item to be tracked using a computer aided surgery system. The coarse plunger 314 may engage the controller mechanism / knob 318. The knob 318 may thread onto the threaded exterior surface 414 of the coarse plunger 314 along the interior threaded surface 440 of the knob 318. The fine plunger 316 may engage the coarse plunger 314 and the knob 318. The fine plunger 316 may be inserted into the hollow of the coarse plunger 314, where the knob 318 may thread onto the fine plunger's threaded exterior 416 along the knob's fine threaded interior surface 460. The combination of the coarse plunger 314, the fine plunger 316, and the knob 318 form an assembly 390. The fixator 400 of the differential thread fixation clamp 310 may ,.€|iga;g|"|l|| assiqp3|>lj ,,-|§0|by being inserted into the fine plunger 316. The fixator 400 may engage itself with the assembly so that the fixator's opening 504 lines up with the fine plunger's opening 604 and the coarse plunger's opening 704 while the fixator's inset 436 is in line with the fine and coarse plungers' holes 636 and 736 respectively. The force- applying components 314, 316 are rotationally constrained upon engaging the fixator 400. A dowel 434 may engage the fixator's inset 436 while engaging the coarse and fine plungers' holes 736 and 636, which prevents the fixator 400, the coarse plunger 314 and the fine plunger 316 from rotating while the knob 318 is turned, the interior threaded surfaces 440 and 460 engaging the threads 614 and 616 of the plungers. The force-applying components may be rotationally constrained through other structure as well. The dowel 434 also prevents the clamp 400 from falling apart after surgery and during storage. Pin 20 may engage the fixator 400 through opening 502, while pin 22 may engage the fixator 400 through opening 504, the fine plunger 316 through opening 604 and the coarse plunger 314 through opening 704. This also rotationally constrains the force-applying components 314, 316, in addition to rotationally constraining the fixator 400. When the knob 318 engages the fine and coarse plunger 316 and 314 along the respective threaded surfaces, the plungers move different distances because of the difference of the pitch of their respective threaded surfaces. When the pins 20, 22 are engaged with the fixator 400 and the assembly 390 and the knob 318 has a rotational force applied, the pins 20,22 have wedge force applied to them by the fine plunger 316 and the coarse plunger 314. The fine plunger's lip 360 engages one pin 22 while the openings 604, 704 of the plungers engage the other pin 20. This force secures the clamp 10 securely with the pins, keeping the reference frame 50 in one precise location.

[0072] FIG. 19 shows a tracking system 102 that may utilize modular indicium 20 attached on the differential thread fixation clamp 10 to track the orientation and/or position of desired items 104 within the tracking sensor's 106 field of vision. Modular indicium 20 attached on the differential thread fixation clamp 10 or other reference structures 8 may be placed on items 104 to be tracked such that a tracking system 102 can track the position and/or orientation of any desired item in the field of view of the tracking sensor 106. The tracking sensor 106 may relay the position and/or orientation data to a processing functionality 112 which can correlate the data with data obtained from an imaging device 108 and output that data to a suitable output device 110. / ^ceørdifϊgjp some embodiments of the present invention, there may be provided a method for connecting a reference frame to an item as part of a computer aided surgery procedure, the method including attaching a mounting structure to an item, connecting a fixator to the mounting structure, applying a wedge force to the mounting structure using a differentially threaded component positioned relative to the fixator to secure the fixator to the mounting structure, and connecting a reference frame to the fixator.

[0074] According to some embodiments of the current invention, applying the wedge force to the mounting structure using a differentially threaded component includes applying the wedge force using force-applying components and a controller mechanism.

[0075] According to some embodiments of the current invention, applying the wedge force to the mounting structure using a differentially threaded component includes applying a wedge force using force-applying components that include a first partially threaded plunger connected to the fixator and a second partially threaded plunger connected to the fixator, wherein the threads on the first and second partially threaded plungers do not feature the same pitch.

[0076] According to some embodiments of the current invention, applying the wedge force to the mounting structure using a differentially threaded component includes applying the wedge force using force-applying components that include a first partially threaded plunger connected to the fixator, and a second partially threaded plunger connected to the fixator, wherein the threads on the fist and second partially threaded plungers do not feature the same pitch, and wherein the first and second plungers telescope relative to one another.

[0077] According to some embodiments of the current invention, connecting the fixator to the mounting structure includes rotationally constraining the fixator.

[0078] According to some embodiments of the current invention, applying the wedge force to the mounting structure includes applying the wedge force using the force-applying components that are rotationally constrained. ΘJf§|; / iiAgq$d§øgj|o some embodiments of the current invention, connecting the reference rrame to the fixator includes connecting a reference frame that includes a plurality of indicia.

[0080] According to some embodiments of the current invention, connecting the reference frame to the fixator includes connecting to a reference frame that includes indicia that are fiducials.

[0081] According to some embodiments of the current invention, connecting a mounting structure to an item includes connecting the mounting structure to at least one of a body part, a surgical implant, a surgical trial, a surgical instrument, and/or a surgical probe.

[0082] According to some embodiments of the current invention, attaching a mounting structure to an item includes connecting two pins to the item.

[0083] According to some embodiments of the current invention, attaching a mounting structure to an item includes inserting two pins into the item.

[0084] According to some embodiments of the current invention, attaching a mounting structure to an item includes attaching a mounting structure that is one component.

[0085] Li view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained.

[0086] The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.

[0087] As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all

Figure imgf000021_0001
description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. For example, the instruments and techniques described herein may be used with either an image-based computer assisted surgery system or an imageless computer assisted surgery system. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.

Claims

CLAIMSWhat is claimed is:
1. A device for use in computer aided surgery characterized in that: a. a reference frame comprising a plurality of indicia which are adapted to be sensed by a computer aided surgical navigation system; b. a reference frame portion connectible to the reference frame; c. a fixator connectible to a mounting structure attached to an item whose position and orientation is to be tracked by the computer aided surgical navigation system; d. and a differentially threaded component positioned relative to the fixator, the differentially threaded component further comprises force-applying components adapted to apply a wedge force relative to the mounting structure in order to secure the fixator to the mounting structure.
2. The device as recited in claim 1, wherein said differentially threaded component further comprises: a. a controller mechanism connected to the force-applying components, wherein said force-applying components further comprise a first partially threaded plunger connected to the fixator, and a second partially threaded plunger connected to the fixator; b. wherein the threads on the first and second partially threaded plungers do not feature the same pitch.
3. The device as recited in claim 1, wherein said differentially threaded component further comprises: a. a controller mechanism connected to the force-applying components, wherein said force-applying components further comprise a first partially threaded plunger connected to the fixator, and a second partially threaded plunger connected to the fixator; b. wherein the threads on the first and second partially threaded plungers do not feature the same pitch; c. wherein the first and second plungers telescope relative to one another.
4. The device as recited in claims 1, 2, or 3, wherein; ai. iL,s3id'fixat€B: is rotationally constrained; b. and said reference frame portion and said fixator are part of the same physical body.
5. The device as recited in claims 1, 2, or 3, wherein said force-applying components are rotationally constrained.
6. The device as recited in claim 2, wherein said first and second plungers' interior geometric shape match the exterior geometric shape of said fixator, rotationally constraining said plungers.
7. The device as recited in claims 1, 2, or 3, wherein said indicia further comprise fiducials.
8. The device as recited in claims 1, 2, or 3, where said reference frame portion further comprises a fault interface structure which is adapted to allow the reference frame to be repositioned in the same position relative to the device as it occupied before inadvertent displacement.
9. The device as recited in claims 1, 2, or 3, wherein said mounting structure is connectible to an item is selected from the group consisting of a body part, a surgical implant, a surgical trial, a surgical instrument, and a surgical probe.
10. The device as recited in claim 9, wherein said mounting structure constitutes two pins inserted into the item.
11. The device as recited in claim 9, wherein said mounting structure constitutes two pins connected to the item.
12. The device as recited in claim 9, wherein said mounting structure constitutes one component attached to the item.
13. A device for use in computer aided surgery characterized in that: $3 ^aifef^rgn^ Jrame portion connectible to a reference frame; b. a fixator connectible to a mounting structure attached to an item whose position and orientation is to be tracked by the computer aided surgical navigation system; c. and a differentially threaded component positioned relative to the fixator, the differentially threaded component adapted to apply a wedge force relative to the mounting structure in order to secure the fixator to the mounting structure.
PCT/US2006/043161 2005-11-04 2006-11-06 Differential thread fixation clamp WO2007053780A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009014718A1 (en) * 2009-03-27 2010-09-30 Astrium Gmbh Device for fine adjustment of the distance between two elements

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030181918A1 (en) * 2002-02-11 2003-09-25 Crista Smothers Image-guided fracture reduction
US20040068263A1 (en) * 2002-10-04 2004-04-08 Benoit Chouinard CAS bone reference with articulated support

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030181918A1 (en) * 2002-02-11 2003-09-25 Crista Smothers Image-guided fracture reduction
US20040068263A1 (en) * 2002-10-04 2004-04-08 Benoit Chouinard CAS bone reference with articulated support

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009014718A1 (en) * 2009-03-27 2010-09-30 Astrium Gmbh Device for fine adjustment of the distance between two elements

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