Surgical Navigation Systems for Unicompartmental Knee - DocsLib

sign in sign up

<<

(19) &

(11) EP 1 372 516 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention (51) Int Cl.: of the grant of the patent: A61B 19/00 (2006.01) 13.05.2009 Bulletin 2009/20 (86) International application number: (21) Application number: 02715006.9 PCT/US2002/005956

(22) Date of filing: 27.02.2002 (87) International publication number: WO 2002/067784 (06.09.2002 Gazette 2002/36)

(54) SURGICAL NAVIGATION SYSTEMS FOR UNICOMPARTMENTAL KNEE CHIRURGISCHES NAVIGATIONSSYSTEM ZUR TEILWEISEN KNIEGELENKREKONSTRUKTION SYSTEMES DE NAVIGATION CHIRURGICALE POUR PROTHESE UNICOMPARTIMENTALE DE GENOU

(84) Designated Contracting States: (72) Inventor: CARSON, Christopher, P. AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU Memphis, TN 38103 (US) MC NL PT SE TR (74) Representative: Drysdale, Douglas Standen et al (30) Priority: 27.02.2001 US 271818 P Murgitroyd & Company 11.02.2002 US 355899 P Scotland House 165-169 Scotland Street (43) Date of publication of application: Glasgow G5 8PL (GB) 02.01.2004 Bulletin 2004/01 (56) References cited: (73) Proprietor: SMITH & NEPHEW, INC. EP-A- 0 676 178 DE-A- 19 709 960 Memphis, Tennessee 38116 (US) DE-C- 4 225 112 US-A- 5 682 886 US-A- 5 871 018 US-A- 6 167 296

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 1 372 516 B1

Printed by Jouve, 75001 PARIS (FR) 1 EP 1 372 516 B1 2

Description formed when arthritis or trauma has affected two or more of the three compartments of the knee: medial compart- RELATED APPLICATION DATA ment (toward the body’s central axis), lateral compartment (away from the body’s central axis), and patello- [0001] This document claims the benefit of USSN 5 femoral compartment (toward the front of the knee). 60/271818, filed February 27, 2001 entitled "Image Guid- [0005] The remaining knee arthroplasties are unicom- ed System for Arthroplasty" and USSN 60/355,899, fled partmental knee arthroplasties ("UKA"). UKA involves February 11, 2002 entitled "Surgical Navigation Systems the replacement of the articular surfaces of only one knee and Processes,". compartment, usually the medial compartment. UKA is 10 an attractive surgical treatment for patients with arthritis FIELD OF THE INVENTION in only one compartment and with a healthy patella. [0006] UKA has several advantages over TKA. UKA [0002] This invention generally relates to unicompart- allows the preservation of both cruciate ligaments, while mental knee arthroplasty surgical operations using sys- the anterior cruciate ligament is usually removed in TKA. tems and processes for tracking anatomy, implements, 15 Preservation of the ligaments provides greater stability instrumentation, trial implants, implant components and to the joint after surgery. UKA also allows for preservation virtual constructs or references, and rendering images of more bone stock at the joint, which will be beneficial and data related to them. Anatomical structures and such if revision components must be placed. Finally, UKA is items may be attached to or otherwise associated with less invasive than TKA because UKA requires smaller fiducial functionality, and constructs may be registered 20 resections and components. in position using fiducial functionality whose position and [0007] In spite of these advantages, there continue to orientation can be sensed and tracked by systems of the be problems in UKA performance. A leading cause of present invention in three dimensions in order to perform wear and revision in prosthetics such as knee implants, unicompartmental knee arthroplasty. Such structures, hip implants and shoulder implants is less than optimum items and constructs can be rendered onscreen properly 25 implant alignment. In a UKA, for example, current instru- positioned and oriented relative to each other using as- ment design for resection of bone limits the alignment of sociated image files, data files, image input, other sen- the femoral and tibial resections to average values for sory input, based on the tracking. Such systems and varus/valgus flexion/extension, and external/internal ro- processes, among other things, allow surgeons to navi- tation. Additionally, surgeons often use visual landmarks gate and perform unicompartmental knee arthroplasty 30 or "rules of thumb" for alignment which can be misleading using images that reveal interior portions of the body due to anatomical variability. Intramedullary referencing combined with computer generated or transmitted imag- instruments also violate the femoral and tibial canal. This es that show surgical implements, instruments, trials, im- intrusion increases the risk of fat embolism and unnec- plants, and/or other devices located and oriented prop- essary blood loss in the patient. Surgeons also rely on erly relative to the body part. Such systems and process- 35 instrumentation to predict the appropriate implant size es allow, among other things, more accurate and effec- for the femur and tibia instead of the ability to intraoper- tive resection of bone, placement and assessment of trial atively template the appropriate size of the implants for implants and joint performance, and placement and as- optimal performance. Another challenge for surgeons is sessment of performance of actual implants and joint per- soft tissue or ligament balancing after the bone resec- formance. 40 tions have been made. Releasing some of the soft tissue points can change the balance of the knee; however, the BACKGROUND multiple options can be confusing for many surgeons. Although much of the bone stock remains after UKA, if [0003] Knee arthroplasty is a surgical procedure in a revision is necessary, many of the visual landmarks which the articular surfaces of the femur, tibia and patella 45 are no longer present, making alignment and restoration are cut away and replaced by metal and/or plastic pros- of the joint line difficult. thetic components. The goals of knee arthroplasty in- [0008] Document US-A-5 682 886 discloses a system clude resurfacing the bones in the knee joint and repo- for performing unicompartmental knee arthroplasty sur- sitioning the joint center on the mechanical axis of the gical operations on portions of a knee joint comprising leg. Knee arthroplasty is generally recommended for pa- 50 an imager for obtaining an image of at least portions of tients with severe knee pain and disability caused by the knee joint, wherein the at least one bone forming part damage to cartilage from rheumatoid arthritis, osteoar- of the knee joint is attached to a fiducial capable of being thritis or trauma. It can be highly successful in relieving tracked by a position sensor; at least one position sensor pain and restoring joint function. adapted to track position of said fiducial; a computer [0004] More than 95% of knee arthroplasties per- 55 adapted to store at least one image of at least portions formed in the United States are tricompartmental knee of the knee joint and to receive information from said at arthroplasties ("TKA"), which involves the replacement least one sensor in order to track position and orientation of all the articular surfaces of the knee joint. TKA is per- of said fiducial and thus the knee joint; a unicompartmen-

2 3 EP 1 372 516 B1 4 tal knee arthroplasty surgical instrument component or images showing internal aspects of the femur and tibia implant component adapted to be attached to bone form- can be displayed on the monitor in combination with ac- ing part of the knee joint using a tool, whereby the position tual or predicted shape, position and orientation of sur- of the component is capable of being tracked by said gical implements, instrumentation components, trial im- sensor and the position and orientation of the component 5 plants, actual prosthetic components, and rotational axes is capable of being tracked by said computer; a monitor in order to allow the surgeon to properly position and adapted to receive information from the computer in order assess performance of various aspects of the knee joint ta display at least one image of the component, posi- being repaired, reconstructed or replaced. The surgeon tioned and oriented relative to the knee joint for navigation may navigate tools, instrumentation, trial prostheses, ac- and positioning of the component relative to the knee 10 tual prostheses and other items relative to the femur and joint. tibia in order to perform UKA’s more accurately, efficiently, and with better alignment and stability. SUMMARY [0012] Systems according to the present invention can also use the position tracking information and, if desired, [0009] The present invention is applicable not only for 15 data relating to shape and configuration of surgical relat- knee repair, reconstruction or replacement surgery, but ed items and virtual constructs or references in order to also repair, reconstruction or replacement surgery in con- produce numerical data which may be used with or with- nection with any other joint of the body as well as any out graphic imaging to perform tasks such as assessing other surgical or other operation where it is useful to track performance of trial prosthetics statically and throughout position and orientation of body parts, non-body compo- 20 a range of motion, appropriately modifying tissue such nents and/or virtual references such as rotational axes, as ligaments to improve such performance and similarly and to display and output data regarding positioning and assessing performance of actual prosthetic components orientation of them relative to each other for use in nav- which have been placed in the patient for alignment and igation and performance of the operation. stability. [0010] Systems according to one embodiment of the 25 [0013] Systems according to the present invention can present invention use position and/or orientation tracking also generate data based on position tracking and, if de- sensors such as infrared sensors acting stereoscopically sired, other information to provide cues on screen, aurally or otherwise to track positions of body parts, surgery- or as otherwise desired to assist in the surgery such as related items such as implements, instrumentation, trial suggesting certain bone modification steps or measures prosthetics, prosthetic components, and virtual con- 30 which may be taken to release certain ligaments or por- structs or references such as rotational axes which have tions of them based on performance of components as been calculated and stored based on designation of bone sensed by systems according to the present invention. landmarks. Processing capability such as any desired [0014] According to a preferred embodiment of sys- form of computer functionality, whether standalone, net- tems according to the present invention, at least the fol- worked, or otherwise, takes into account the position and 35 lowing steps are involved: orientation information as to various items in the position sensing field (which may correspond generally or specif- 1. Obtain appropriate images such as fluoroscopy ically to all or portions or more than all of the surgical images of appropriate body parts such as femur and field) based on sensed position and orientation of their tibia, the imager being tracked in position via an as- associated fiducials or based on stored position and/or 40 sociated fiducial whose position and orientation is orientation information. The processing functionality cor- tracked by position/orientation sensors such as ster- relates this position and orientation information for each eoscopic infrared (active or passive) sensors ac- object with stored information regarding the items, such cording to the present invention. as a computerized fluoroscopic imaged fib of a femur or 2. Register tools, instrumentation, trial components, tibia, a wire frame data file for rendering a representation 45 prosthetic components, and other items to be used of an instrumentation component, trial prosthesis or ac- in surgery, each of which corresponds to a fiducial tual prosthesis, or a computer generated file relating to whose position and orientation can be tracked by the a rotational axis or other virtual construct or reference. position/orientation sensors. The processing functionality then displays position and 3. Locating and registering body structure such as orientation of these objects on a screen or monitor, or 50 designating points on the femur and tibia using a otherwise. Thus, systems and processes according to probe associated with a fiducial in order to provide one embodiment of the invention can display and other- the processing functionality information relating to wise output useful data relating to predicted or actual the body part such as rotational axes. position and orientation of body parts, surgically related 4. Navigating and positioning instrumentation such items, implants, and virtual constructs for use in naviga- 55 as cutting instrumentation in order to modify bone, tion, assessment, and otherwise performing surgery or at least partially using images generated by the other operations. processing functionality corresponding to what is be- [0011] As one example, images such as fluoroscopy ing tracked and/or has been tracked, and/or is pre-

3 5 EP 1 372 516 B1 6

dicted by the system, and thereby resecting bone ankle. This requires placement of reference frames at effectively, efficiently and accurately. the iliac crest of the pelvis and in or on the ankle. This 5. Navigating and positioning trial components such calculation is also time consuming and the system must as femoral components and tibial components, find multiple points in different planes in order to find the some or all of which may be installed using impactors 5 center of rotation. This is also problematic in patients with with a fiducial and, if desired, at the appropriate time pathologic conditions. Ligaments and soft tissues in the discontinuing tracking the position and orientation of arthritic patient are not normal and thus will give a center the trial component using the impactor fiducial and of rotation that is not desirable for normal knees. Robotic starting to track that position and orientation using systems require expensive CT or MRI scans and also the body part fiducial on which the component is in- 10 require pre-operative placement of reference frames, stalled. usually the day before surgery. These systems are also 6. Assessing alignment and stability of the trial com- much slower, almost doubling operating room time and ponents and joint, both statically and dynamically as expense. desired, using images of the body parts in combina- [0017] None of these systems can effectively track tion with images of the trial components while con- 15 femoral and/or tibial trials during a range of motion and ducting appropriate rotation, anterior-posterior calculate the relative positions of the articular surfaces, drawer and flexion/extension tests and automatically among other things. Also, none of them currently make storing and calculating results to present data or in- suggestions on ligament balancing, display ligament bal- formation which allows the surgeon to assess align- ancing techniques, or surgical techniques. Additionally, ment and stability. 20 none of these systems currently track the patella. 7. Releasing tissue such as ligaments if necessary [0018] An object of certain aspects of the present in- and adjusting trial components as desired for accept- vention is to use computer processing functionality in able alignment and stability. combination with imaging and position and/or orientation 8. Installing implant components whose positions tracking sensors to present to the surgeon during surgical may be tracked at first via fiducials associated with 25 operations visual and data information useful to navigate, impactors for the components and then tracked via track and/or position implements, instrumentation, trial fiducials on the body parts in which the components components, prosthetic components and other items and are installed. virtual constructs relative to the human body in order to 9. Assessing alignment and stability of the implant improve performance of a repaired, replaced or recon- components and joint by use of some or all tests 30 structed knee joint. mentioned above and/or other tests as desired, re- [0019] Another object of certain aspects of the present leasing tissue if desired, adjusting if desired, and oth- invention is to use computer processing functionality in erwise verifying acceptable alignment, stability and combination with imaging and position and/or orientation performance of the prosthesis, both statically and tracking sensors to present to the surgeon during surgical dynamically. 35 operations visual and data information useful to assess performance of a knee and certain items positioned [0015] This process, or processes including it or some therein, including components such as trial components of it may be used in any total or partial joint repair, recon- and prosthetic components, for stability, alignment and struction or replacement, including knees, hips, shoul- other factors, and to adjust tissue and body and nonbody ders, elbows, ankles and any other desired joint in the 40 structure in order to improve such performance of a re- body. paired, reconstructed or replaced knee joint. [0016] Systems according to the present invention rep- [0020] Another object of certain aspects of the present resent significant improvement over other previous sys- invention is to use computer processing functionality in tems and processes. For instance, systems which use combination with imaging and position and/or orientation CT and MRI data generally require the placement of ref- 45 tracking sensors to present to the surgeon during surgical erence frames pre-operatively which can lead to infection operations visual and data information useful to show at the pin site. The resulting 3D images must then be any or all of predicted position and movement of imple- registered, or calibrated, to the patient anatomy intraop- ments, instrumentation, trial components, prosthetic eratively. Current registration methods are less accurate components and other items and virtual constructs rela- than the fluoroscopic system. These imaging modalities 50 tive to the human body in order to select appropriate com- are also more expensive. Some "imageless" systems, or ponents, resect bone accurately, effectively and efficient- non-imaging systems, require digitizing a large number ly, and thereby improve performance of a repaired, re- of points to define the complex anatomical geometries placed or reconstructed knee joint. of the knee at each desired site. This can be very time [0021] Other objects, features and advantages of the intensive resulting in longer operating room time. Other 55 present invention are apparent with respect to the re- imageless systems determine the mechanical axis of the mainder of this document. knee by performing an intraoperative kinematic motion to determine the center of rotation at the hip, knee, and

4 7 EP 1 372 516 B1 8

BRIEF DESCRIPTION OF THE DRAWINGS according one embodiment of the present invention. Fig. 17 is another view of a probe according to one [0022] embodiment of the present invention being used to designate landmarks on bone structure for tracking Fig. 1 is a schematic view of a particular embodiment 5 according one embodiment of the present invention. of systems according to the present invention. Fig. 18 is a screen face produced according to one Fig. 2 is a view of a knee prepared for surgery, in- embodiment of the present invention during desig- cluding a femur and a tibia to which fiducials accord- nation of landmarks to determine a femoral mechan- ing to one embodiment of the present invention have ical axis. been attached. 10 Fig. 19 is a view produced according to one embod- Fig. 3 is a view of a portion of a leg prepared for iment of the present invention during designation of surgery with a C-arm for obtaining fluoroscopic im- landmarks to determine a tibial mechanical axis. ages associated with a fiducial according to one em- Fig. 20 is a screen face produced according to one bodiment of the present invention. embodiment of the present invention during desig- Fig. 4 is a fluoroscopic image of free space rendered 15 nation of landmarks to determine an epicondylar ax- on a monitor according to one embodiment of the is. present invention. Fig. 21 is a screen face produced according to one Fig. 5 is a fluoroscopic image of femoral head ob- embodiment of the present invention during desig- tained and rendered according one embodiment of nation of landmarks to determine an anterior-poste- the present invention. 20 rior axis. Fig. 6 is a fluoroscopic image of a knee obtained and Fig. 22 is a screen face produced according to one rendered according to one embodiment of the embodiment of the present invention during desig- present invention. nation of landmarks to determine a posterior condy- Fig. 7 is a fluoroscopic image of a tibia distal end lar axis. obtained and rendered according to one embodi- 25 Fig. 23 is a screen face according to one embodiment ment of the present invention. of the present invention which presents graphic in- Fig. 8 is a fluoroscopic image of a lateral view of a dicia which may be employed to help determine ref- knee obtained and rendered according to one em- erence locations within bone structure. bodiment of the present invention. Fig. 24 is a screen face according to one embodiment Fig. 9 is a fluoroscopic image of a lateral view of a 30 of the present invention showing mechanical and knee obtained and rendered according to one em- other axes which have been established according bodiment of the present invention to one embodiment of the present invention. Fig. 10 is a fluoroscopic image of a lateral view of a Fig. 25 is another screen face according to one em- tibia distal end obtained and rendered according to bodiment of the present invention showing mechan- one embodiment of the present invention. 35 ical and other axes which have been established ac- Fig. 11 shows a probe according to one embodiment cording to one embodiment of the present invention. of the present invention being used to register a sur- Fig. 26 is another screen face according to one em- gically related component for tracking according to bodiment of the present invention showing mechan- one embodiment of the present invention. ical and other axes which have been established ac- Fig. 12 shows a probe according to one embodiment 40 cording to one embodiment of the present invention. of the present invention being used to register a cut- Fig. 27 shows navigation and placement of an ex- ting block for tracking according to one embodiment tramedullary rod according to one embodiment of of the present invention. the present invention. Fig. 13 shows a probe according to one embodiment Fig. 28 is another view showing navigation and of the present invention being used to register a tibial 45 placement of an extramedullary rod according to one cutting block for tracking according to one embodi- embodiment of the present invention. ment of the present invention. Fig. 29 is a screen face produced according to one Fig. 14 shows a probe according to one embodiment embodiment of the present invention which assists of the present invention being used to register an in navigation and/or placement of an extramedullary alignment guide for tracking according to one em- 50 rod. bodiment of the present invention. Fig. 30 is another view of a screen face produced Fig. 15 shows a probe according to one embodiment according to one embodiment of the present inven- of the present invention being used to designate tion which assists in navigation and/or placement of landmarks on bone structure for tracking according an extramedullary rod. one embodiment of the present invention. 55 Fig. 31 is a view which shows navigation and place- Fig. 16 is another view of a probe according to one ment of an alignment guide according to one em- embodiment of the present invention being used to bodiment of the present invention. designate landmarks on bone structure for tracking Fig. 32 is another view which shows navigation and

5 9 EP 1 372 516 B1 10

placement of an alignment guide according to one entation sensing functionality and communications link embodiment of the present invention. such as spread spectrum RF link, in order to report po- Fig. 33 is a view showing placement of an alignment sition and orientation of the item. Such active fiducials, guide according to one embodiment of the present or hybrid active/passive fiducials such as transponders invention. 5 can be implanted in the body parts or in any of the sur- Fig. 34 is another view showing placement of a cut- gically related devices mentioned above, or conveniently ting block according to one embodiment of the located at their surface or otherwise as desired. Fiducials present invention. may also take the form of conventional structures such Fig. 35 is a view showing navigation and placement as a screw driven into a bone, or any other three dimen- of the cutting block of Fig. 45. 10 sional item attached to another item, position and orien- Fig. 36 is another view showing navigation and tation of such three dimensional item able to be tracked placement of a cutting block according to one em- in order to track position and orientation of body parts bodiment of the present invention. and surgically related items. Hybrid fiducials may be part- Fig. 37 is a view showing navigation and placement ly passive, partly active such as inductive components of a tibial cutting block according to one embodiment 15 or transponders which respond with a certain signal or of the present invention. data set when queried by sensors according to the Fig. 38 is a view showing the UKA femoral and tibial present invention. implant components. [0026] Systems and processes according to a pre- Fig. 39 is a view showing the UKA femoral and tibial ferred embodiment of the present invention employ a implant components attached at the knee joint. 20 computer to calculate and store reference axes of body components such as in a UKA, for example, the mechan- DETAILED DESCRIPTION ical axis of the femur and tibia. From these axes such systems track the position of the instrumentation and os- [0023] Systems according to a preferred embodiment teotomy guides so that bone resections will locate the of the present invention use computer capacity, including 25 implant position optimally, usually aligned with the me- standalone and/or networked, to store data regarding chanical axis. Furthermore, during trial reduction of the spatial aspects of surgically related items and virtual con- knee, the systems provide feedback on the balancing of structs or references including body parts, implements, the ligaments in a range of motion and under varus/val- instrumentation, trial components, prosthetic compo- gus, anterior/posterior and rotary stresses and can sug- nents and rotational axes of body parts. Any or all of these 30 gest or at least provide more accurate information than may be physically or virtually connected to or incorporate in the past about which ligaments the surgeon should any desired form of mark, structure, component, or other release in order to obtain correct balancing, alignment fiducial or reference device or technique which allows and stability. Systems according to the present invention position and/or orientation of the item to which it is at- can also suggest modifications to implant size, position- tached to be sensed and tracked, preferably in three di- 35 ing, and other techniques to achieve optimal kinematics. mensions of translation and three degrees of rotation as Systems according to the present invention can also in- well as in time if desired. clude databases of information regarding tasks such as [0024] In a preferred embodiment, orientation of the ligament balancing, in order to provide suggestions to elements ona particular fiducial varies from one fiducial the surgeon based on performance of test results as au- to the next so that sensors according to the present in- 40 tomatically calculated by such systems and processes. vention may distinguish between various components to [0027] FIG. 1 is a schematic view showing one em- which the fiducials are attached in order to correlate for bodiment of a system according to the present invention display and other purposes data files or images of the and one version of a setting according to the present components. In a preferred embodiment of the present invention in which surgery on a knee, in this case a Uni- invention, some fiducials use reflective elements and 45 compartmental Knee Arthroplasty, may be performed. some use active elements, both of which may be tracked Systems according to the present invention can track var- by preferably two, sometimes more infrared sensors ious body parts such as tibia 10 and femur 12 to which whose output may be processed in concert to geometri- fiducials of the sort described above or any other sort cally calculate position and orientation of the item to may be implanted, attached, or otherwise associated which the fiducial is attached. 50 physically, virtually, or otherwise. In the embodiment [0025] Position/orientation tracking sensors and fidu- shown in FIG. 1, fiducials 14 are structural frames some cials need not be confined to the infrared spectrum. Any of which contain reflective elements, some of which con- electromagnetic, electrostatic, light sound, radiofrequen- tain LED active elements, some of which can contain cy or other desired technique may be used. Alternatively, both, for tracking using stereoscopic infrared sensors each item such as a surgical implement, instrumentation 55 suitable, at least operating in concert, for sensing, stor- component, trial component, implant component or other ing, processing and/or outputting data relating to ("track- device may contain its own "active" fiducial such as a ing") position and orientation of fiducials 14 and thus com- microchip with appropriate field sensing or position/ori- ponents such as 10 and 12 to which they are attached

6 11 EP 1 372 516 B1 12 or otherwise associated. Position sensor 16, as men- such items may be moved, or the on screen image oth- tioned above, may be any sort of sensor functionality for erwise presented to suit the preferences of the surgeon sensing position and orientation of fiducials 14 and there- or others and carry out the imaging that is desired. Sim- fore items with which they are associated, according to ilarly, when an item 22, such as an extramedullary rod, whatever desired electrical, magnetic, electromagnetic, 5 intramedullar rod, or any other type of rod, that is being sound, physical, radio frequency, or other active or pas- tracked moves, its image moves on monitor 24 so that sive technique. In the preferred embodiment, position the monitor shows the item 22 in proper position and sensor 16 is a pair of infrared sensors disposed on the orientation on monitor 24 relative to the femur 12: The order of a meter, sometimes more, sometimes less, apart rod 22 can thus appear on the monitor 24 in proper or and whose output can be processed in concert to provide 10 improper alignment with respect to the mechanical axis position and orientation information regarding fiducials and other features of the femur 12, as if the surgeon were 14. able to see into the body in order to navigate and position [0028] In the embodiment shown in FIG. 1, computing rod 22 properly. functionality 18 can include processing functionality, [0030] The computer functionality 18 can also store memory functionality, input/output functionality whether 15 data relating to configuration, size and other properties on a standalone or distributed basis, via any desired of items 22 such as implements, instrumentation, trial standard, architecture, interface and/or network topolo- components, implant components and other items used gy. In this embodiment, computing functionality 18 is con- in surgery. When those are introduced into the field of nected to a monitor on which graphics and data may be position/orientation sensor 16, computer functionality 18 presented to the surgeon during surgery. The screen 20 can generate and display overlain or in combination with preferably has a tactile interface so that the surgeon may the fluoroscopic images of the body parts 10 and 12, point and click on screen for tactile screen input in addi- computer generated images of implements, instrumen- tion to or instead of, if desired, keyboard and mouse con- tation components, trial components, implant compo- ventional interfaces. Additionally, a foot pedal 20 or other nents and other items 22 for navigation, positioning, as- convenient interface may be coupled to functionality 18 25 sessment and other uses. as can any other wireless or wireline interface to allow [0031] Additionally, computer functionality 18 can the surgeon, nurse or other desired user to control or track any point in the position/orientation sensor 16 field direct functionality 18 in order to, among other things, such as by using a designator or a probe 26. The probe capture position/orientation information when certain also can contain or be attached to a fiducial 14. The sur- components are oriented or aligned properly. Items 22 30 geon, nurse, or other user touches the tip of probe 26 to such as trial components, instrumentation components a point such as a landmark on bone structure and actu- may be tracked in position and orientation relative to body ates the foot pedal 20 or otherwise instructs the computer parts 10 and 12 using fiducials 14. 18 to note the landmark position. The position/orientation [0029] Computing functionality 18 can process, store sensor 16 "sees" the position and orientation of fiducial and output on monitor 24 and otherwise various forms 35 14 "knows" where the tip of probe 26 is relative to that of data which correspond in whole or part to body parts fiducial 14 and thus calculates and stores, and can dis- 10 and 12 and other components for item 22. For exam- play on monitor 24 whenever desired and in whatever ple, in the embodiment shown in FIG. 1, body parts 10 form or fashion or color, the point or other position des- and 12 are shown in cross-section or at least various ignated by probe 26when the foot pedal 20 is hit or other internal aspects of them such as bone canalsand surface 40 command is given. Thus, probe 26 can be used to des- structure are shown using fluoroscopic images. These ignate landmarks on bone structure in order to allow the images are obtained using a C-arm attached to a fiducial computer 18 to store and track, relative to movement of 14. The body parts, for example, tibia 10 and femur 12, the bone fiducial 14, virtual or logical information such also have fiducials attached. When the fluoroscopy im- as mechanical axis 28, medial lateral axis 30 and anterior/ ages are obtained using the C-arm with fiducial 14, a 45 posterior axis 32 of femur 12, tibia 10 and other body position/orientation sensor 16 "sees" and tracks the po- parts in addition to any other virtual or actual construct sition of the fluoroscopy head as well as the positions or reference. and orientations of the tibia 10 and femur 12. The com- [0032] Systems and processes according to an em- puter stores the fluoroscopic images with this position/ bodiment of the present invention such as the subject of orientation information, thus correlating position and ori- 50 Figs. 2-36, can use the so-called FluoroNAV system and entation of the fluoroscopic image relative to the relevant software provided by Medtronic Sofamor Danek Tech- body part or parts. Thus, when the tibia 10 and corre- nologies. Such systems or aspects of them are disclosed sponding fiducial 14 move, the computer automatically in USPNs 5,383,454; 5,871,445; 6,146,390; 6,165,81; and correspondingly senses the new position of tibia 10 6,235,038 and 6,236,875. Any other desired systems can in space and can correspondingly move implements, in- 55 be used as mentioned above for imaging, storage of data, struments, references, trials and/or implants on the mon- tracking of body parts and items and for other purposes. itor 24 relative to the image of tibia 10. Similarly, the image [0033] The FluoroNav system requires the use of ref- of the body part can be moved, both the body part and erence frame type fiducials 14 which have four and in

7 13 EP 1 372 516 B1 14 some cases five elements tracked by infrared sensors tioned. Such center of rotation can be established by ar- for position/orientation of the fiducials and thus of the ticulating the femur within the acetabulum or a prosthesis body part, implement, instrumentation, trial component, to capture a number of samples of position and orienta- implant component, or other device or structure being tion information and thus in turn to allow the computer to tracked. Such systems also use at least one probe 26 5 calculate the average center of rotation. The center of which the surgeon can use to select, designate, register, rotation can be established by using the probe and des- or otherwise make known to the system a point or points ignating a number of points on the femoral head and thus on the anatomy or other locations by placing the probe allowing the computer to calculate the geometrical center as appropriate and signaling or commanding the com- or a center which corresponds to the geometry of points puter to note the location of, for instance, the tip of the 10 collected. Additionally, graphical representations such as probe. The FluoroNav system also tracks position and controllably sized circles displayed on the monitor can orientation of a Carm used to obtain fluoroscopic images be fitted by the surgeon to the shape of the femoral head of body parts to which fiducials have been attached for on planar images using tactile input on screen to desig- capturing and storage of fluoroscopic images keyed to nate the centers according to that graphic, such as are position/orientation information as tracked by the sen- 15 represented by the computer as intersection of axes of sors 16. Thus, the monitor 24 can render fluoroscopic the circles. Other techniques for determining, calculating images of bones in combination with computer generated or establishing points or constructs in space, whether or images of virtual constructs and references together with not corresponding to bone structure, can be used in ac- implements, instrumentation components, trial compo- cordance with the present invention. nents, implant components and other items used in con- 20 [0037] FIG. 5 shows a fluoroscopic image of the fem- nection with surgery for navigation, resection of bone, oral head while FIG. 6 shows an anterior/posterior view assessment and other purposes. of the knee which can be used to designate landmarks [0034] FIGS. 2 - 39 are various views associated with and establish axes or constructs such as the mechanical Unicompartmental Knee Arthroplasty surgery processes axis or other rotational axes. FIG. 7 shows the distal end according to one particular embodiment and version of 25 of the tibia and FIG. 8 shows a lateral view of the knee. the present invention being carried out with the Fluoro- FIG. 9 shows another lateral view of the knee while FIG. Nav system referred to above. FIG. 2 shows a human 10 shows a lateral view of the distal end of the tibia. knee in the surgical field, as well as the corresponding femur and tibia to which fiducials 14 have been rigidly Registration of Surgically Related Items attached in accordance with this embodiment of the in- 30 vention. Attachment of fiducials 14 preferably is accom- [0038] FIGS. 11-14 show designation or registration plished using structure that withstands vibration of sur- of items 22 which will be used in surgery. Registration gical saws and other phenomenon which occur during simply means, however it is accomplished, ensuring that surgery without allowing any substantial movement of the computer knows which body part, item or construct fiducial 14 relative to body part being tracked by the sys- 35 corresponds to which fiducial or fiducials, and how the tem. position and orientation of the body part, item or construct [0035] FIG. 3 shows fluoroscopy images being ob- is related to the position and orientation of its correspond- tained of the body parts with fiducials 14 attached. The ing fiducial or a fiducial attached to an impactor or other fiducial 14 on the fluoroscopy head in this embodiment other component which is in turn attached to an item. is a cylindrically shaped cage which contains LEDs or 40 Such registration or designation can be done before or "active" emitters for tracking by the sensors 16. Fiducials after registering bone or body parts as discussed with 14 attached to tibia 10 and femur 12 can also be seen. respect to FIGS. 4 - 10. FIG. 11 shows a technician des- The fiducial 14 attached to the femur 12 uses LEDs in- ignating with probe 26 an item 22 such as an instrument stead of reflective spheres and is thus active, fed power component to which fiducial 14 is attached. The sensor by the wire seen extending into the bottom of the image. 45 16 "sees" the position and orientation of the fiducial 14 [0036] FIGS. 4-10 are fluoroscopic images shown on attached to the item 22 and also the position and orien- monitor 24 obtained with position and/or orientation in- tation of the fiducial 14 attached to the probe 26 whose formation received by, noted and stored within computer tip is touching a landmark on the item 22. The technician 18. FIG. 4 is an open field with no body part image, but designates onscreen or otherwise the identification of the which shows the optical indicia which may be used to 50 item and then activates the foot pedal or otherwise in- normalize the image obtained using a spherical fluoros- structs the computer to correlate the data corresponding copy wave front with the substantially flat surface of the to such identification, such as data needed to represent monitor 24. FIG. 5 shows an image of the femur 12 head. a particular cutting block component for a particular knee This image is taken in order to allow the surgeon to des- implant product, with the particularly shaped fiducial 14 ignate the center of rotation of the femoral head for pur- 55 attached to the component 22. The computer has then poses of establishing the mechanical axis and other rel- stored identification, position and orientation information evant constructs relating to of the femur according to relating to the fiducial for component 22 correlated with which the prosthetic components will ultimately be posi- the data such as configuration and shape data for the

8 15 EP 1 372 516 B1 16 item 22 so that upon registration, when sensor 16 tracks ignated points for determining the epicondylar axis, both the item 22 fiducial 14 in the infrared field, monitor 24 in the anterior/posterior and lateral planes while FIG. 21 can show the cutting block component 22 moving and shows such determination of the anterior-posterior axis turning, and properly positioned and oriented relative to as rendered onscreen. The posterior condylar axis is also the body part which is also being tracked. FIGS. 12-14 5 determined by designating points or as otherwise de- show similar registration for other instrumentation com- sired, as rendered on the computer generated geometric ponents 22. images overlain or displayed in combination with the fluoroscopic images, all of which are keyed to fiducials Registration of Anatomy and Constructs 14 being tracked by sensors 16. 10 [0041] FIG. 23 shows an adjustable circle graphic [0039] Similarly, the mechanical axis and other axes which can be generated and presented in combination or constructs of body parts 10 and 12 can also be "reg- with orthogonal fluoroscopic images of the femoral head, istered" for tracking by the system. Again, the system and tracked by the computer 18 when the surgeon moves has employed a fluoroscope to obtain images of the fem- it on screen in order to establish the centers of the femoral oral head, knee and ankle of the sort shown in FIGS. 15 head in both the anterior-posterior and lateral planes. 4-10. The system correlates such images with the posi- [0042] FIG. 24 is an onscreen image showing the an- tion and orientation of the Garm and the patient anatomy terior-posterior axis, epicondylar axis and posterior con- in real time as discussed above with the use of fiducials dylar axis from points which have been designated as 14 placed on the body parts before image acquisition and described above. These constructs are generated by the which remain in position during the surgical procedure. 20 computer 18 and presented on monitor 24 in combination Using these images and/or the probe, the surgeon can with the fluoroscopic images of the femur 12, correctly select and register in the computer 18 the center of the positioned and oriented relative thereto as tracked by the femoral head and ankle in orthogonal views, usually an- system. In the fluoroscopic/computer generated image terior/posterior and lateral, on a touch screen. The sur- combination shown at left bottom of FIG. 24, a "saw- geon uses the probe to select any desired anatomical 25 bones" knee as shown in certain drawings above which landmarks or references at the operative site of the knee contains radio opaque materials is represented fluoro- or on the skin or surgical draping over the skin, as on the scopically and tracked using sensor 16 while the com- ankle. These points are registered in three dimensional puter generates and displays the mechanical axis of the space by the system and are tracked relative to the fidu- femur 12 which runs generally horizontally. The epi- cials on the patient anatomy which are preferably placed 30 condylar axis runs generally vertically, and the anterior/ intraoperatively. FIG. 15 shows the surgeon using probe posterior axis runs generally diagonally. The image at 26 to designate or register landmarks on the condylar bottom right shows similar information in a lateral view. portion of femur 12 using probe 26 in order to feed to the Here, the anterior-posterior axis runs generally horizon- computer 18 the position of one point needed to deter- tally while the epicondylar axis runs generally diagonally, mine, store, and display the epicondylar axis. (See FIG. 35 and the mechanical axis generally vertically. 20 which shows the epicondylar axis and the anterior- [0043] FIG. 24, as is the case with a number of screen posterior plane and for lateral plane.) Although register- presentations generated and presented by the system ing points using actual bone structure such as in FIG. 15 of FIGS. 4- 39, also shows at center a list of landmarks is one preferred way to establish the axis, a cloud of points to be registered in order to generate relevant axes and approach by which the probe 26 is used to designate 40 constructs useful in navigation, positioning and assess- multiple points on the surface of the bone structure can ment during surgery. Textural cues may also be present- be employed, as can moving the body part and tracking ed which suggest to the surgeon next steps in the process movement to establish a center of rotation as discussed of registering landmarks and establishing relevant axes. above. Once the center of rotation for the femoral head Such instructions may be generated as the computer 18 and the condylar component have been registered, the 45 tracks, from one step b the next, registration of items 22 computer is able to calculate, store, and render, and oth- and bone locations as well as other measures being tak- erwise use data for, the mechanical axis of the femur 12. en by the surgeon during the surgical operation. FIG. 17 once again shows the probe 26 being used to [0044] FIG. 25 shows mechanical, lateral, anterior- designate points on the condylar component of the femur posterior axes for the tibia according to points are regis- 12. 50 tered by the surgeon. [0040] FIG. 18 shows the onscreen images being ob- [0045] FIG. 26 is another onscreen image showing the tained when the surgeon registers certain points on the axes for the femur 12. bone surface using the probe 26 in order to establish the [0046] Any desired axes or other constructs can be femoral mechanical axis. The tibial mechanical axis is created, tracked and displayed, in order to model and then established by designating points to determine the 55 generate images and data showing any desired static or centers of the proximal and distal ends of the tibia so that kinematic function of the knee for any purposes related the mechanical axis can be calculated, stored, and sub- to a UKA. sequently used by the computer 18. FIG. 20 shows des-

9 17 EP 1 372 516 B1 18

Modifying Bone tion can be used to navigate and position the rod relative to the femur. At a point in time during or after placement [0047] After the mechanical axis and other rotation ax- of the rod, its tracking may be "handed off" from the im- es and constructs relating to the femur and tibia are es- pactor fiducial14 to the femur fiducal 14 as discussed tablished, instrumentation can be properly oriented to re- 5 below. sect or modify bone in order to fit trial components and [0051] Once the extramedullary rod, intramedullary implant components properly according to the embodi- rod, or any other type of rod has been placed, instrumen- ment of the invention shown in FIGS. 4 - 39. Instrumen- tation can be positioned as tracked in position and ori- tation such as, for instance, cutting blocks, to which fidu- entation by sensor 16 and displayed on screen face 24. cials 14 are mounted, can be employed. The system can 10 Thus, a cutting block of the sort used to establish the then track instrumentation as the surgeon manipulates condylar anterior cut, with its fiducial 14 attached, is in- it for optimum positioning. In other words, the surgeon troduced into the field and positioned on the rod. Because can "navigate" the instrumentation for optimum position- the cutting block corresponds to a particular implant prod- ing using the system and the monitor. In this manner, uct and can be adjusted and designated on screen to instrumentation may be positioned according to the sys- 15 correspond to a particular implant size of that product, tem of this embodiment in order to align the ostetomies the computer 18 can generate and display a graphic of to the mechanical and rotational axes or reference axes the cutting block and the femoral component overlain on on an extramedullary rod that does not violate the canal, the fluoroscopic image. The surgeon can thus navigate on an intramedullary rod, or on any other type of rod. The and position the cutting block on screen using not only touchscreen 24 can then also display the instrument such 20 images of the cutting block on the bone, but also images as the cutting block and/or the implant relative to the in- of the corresponding femoral component which will be strument and the rod during this process, in order, among ultimately installed. The surgeon can thus adjust the po- other things, properly to select size of implant and per- sitioning of the physical cutting block component, and haps implant type. As the instrument moves, the varus/ secure it to the rod in order to resect the anterior of the valgus, flexion/extension and internal/external rotation of 25 condylar portion of the femur in order to optimally fit and the relative component position can be calculated and position the ultimate femoral component being shown on shown with respect to the referenced axes; in the pre- the screen. Other cutting blocks and other resections ferred embodiment, this can be done at a rate of six cycles may be positioned and made similarly on the condylar per second or faster. The instrument position is then fixed component. in the computer and physically and the bone resections 30 [0052] In a similar fashion, instrumentation may be are made. navigated and positioned on the proximal portion of the [0048] FIG. 27 shows orientation of an extramedullary tibia 10 and as tracked by sensor 16 and on screen by rod to which a fiducial 14 is attached via impactor 22. images of the cutting block and the implant component. The surgeon views the screen 24 which has an image [0053] FIGS. 33-37 show instrumentation being posi- as shown in FIG. 29 of the rod overlain on or in combi- 35 tioned relative to femur 12 as tracked by the system for nation with the femur 12 fluoroscopic image as the two resection of the condylar component in order to receive are actually positioned and oriented relative to one an- a particular size of implant component. Various cutting other in space. The surgeon then navigates the rod into blocks and their attached fiducials can be seen in these place preferably along the mechanical axis of the femur views. and drives it home with appropriate mallet or other device. 40 The present invention thus avoids the need to bore a hole Navigation, Placement and Assessment of Trials in the metaphysis of the femur and place a reamer or and Implants other rod into the medullary canal which can cause fat embolism, hemorrhaging, infection and other untoward [0054] Once resection and modification of bone has and undesired effects. 45 been accomplished, implant trials can then be installed [0049] FIG. 28 also shows the extramedullary rod be- and tracked by the system in a manner similar to navi- ing located. FIG. 29 shows fluoroscopic images, both an- gating and positioning the instrumentation, as displayed terior-posterior and lateral, with axes, and with a compu- on the screen 24. Thus, a femoral component trial, a tibial ter generated and tracked image of the rod superposed plateau trial, and a bearing plate trial may be placed as or in combination with the fluoroscopic images of the fe- 50 navigated on screen using computer generated overlays mur and tibia. FIG. 30 shows the rod superimposed on corresponding to the trials. the femoral fluoroscopic image similar to what is shown [0055] During the trial installation process, and also in FIG. 29. during the implant component installation process, in- [0050] FIG. 29 also shows other information relevant strument positioning process or at any other desired point to the surgeon such as the name of the component being 55 in surgical or other operations according to the present overlain on the femur image, suggestions or instructions invention, the system can transition or segue from track- at the lower left, and angle of the rod in varus/valgus and ing a component according to a first fiducial to tracking extension relative to the axes. Any or all of this informa- the component according to a second fiducial. Thus, the

10 19 EP 1 372 516 B1 20 trial femoral component is mounted on an impactor to calculate and display the drawer and whether it is ac- which is attached a fiducial 14. The trial component is ceptable for the patient and the product involved. If not, installed and positioned using the impactor. The compu- the computer can apply rules in order to generate and ter 18 "knows" the position and orientation of the trial display suggestions for releasing ligaments or other tis- relative to the fiducial on the impactor (such as by prior 5 sue, or using other component sizes or types. Once the registration of the component attached to the impactor) proper tissue releases have been made, if necessary, so that it can generate and display the image of the fem- and alignment and stability are acceptable as noted oral component trial on screen 24 overlaid on the fluor- quantitatively on screen about all axes, the trial compo- oscopic image of the condylar component. At any desired nents may be removed and actual components navigat- point in time, before, during or after the trial component 10 ed, installed, and assessed in performance in a manner is properly placed on the condylar component of the fe- similar to that in which the trial components were navi- mur to align with mechanical axis and according to proper gated, installed, and assessed. orientation relative to other axes, the system can be in- [0059] At the end of the case, all alignment information structed by foot pedal or otherwise to begin tracking the can be saved for the patient file. This is of great assist- position of the trial component using the fiducial attached 15 ance to the surgeon due to the fact that the outcome of to the femur rather than the one attached to the impactor. implant positioning can be seen before any resectioning According to the preferred embodiment, the sensor 16 has been done on the bone. The system is also capable "sees" at his point in time both the fiducials on the im- of tracking the patella and resulting placement of cutting pactor and the femur 12 so that it already "knows" the guides and the patellar trial position. The system then position and orientation of the trial component relative to 20 tracks alignment of the patella with the patellar femoral the fiducial on the impactor and is thus able to calculate groove and will give feedback on issues, such as, patellar and store for later use the position and orientation of the tilt. trial component relative to the femur 12 fiducial. Once [0060] The tracking and image information provided this "handoff’ happens, the impactor can be removed and by systems and processes according to the present in- the trial component tracked with the femur fiducial 14 as 25 vention facilitate telemedical techniques, because they part of or moving in concert with the femur 12. Similar provide useful images for distribution to distant geo- handoff procedures may be used in any other instance graphic locations where expert surgical or medical spe- as desired in accordance with the present invention. cialists may collaborate during surgery. Thus, systems [0056] Alternatively, the tibial trial can be placed on the and processes according to the present invention can be proximal tibia and then registered using the probe 26. 30 used in connection with computing functionality 18 which Probe 26 is used to designate preferably at least three is networked o otherwise in communication with comput- features on the tibial trial of known coordinates, such as ing functionality in other locations, whether by PSTN, in- bone spike holes. As the probe is placed onto each fea- formation exchange infrastructures such as packet ture, the system is prompted to save that coordinate po- switched networks including the Internet, or as otherwise sition so that the system can match the tibial trial’s fea- 35 desire. Such remote imaging may occur on computers, ture’s coordinates to the saved coordinates. The system wireless devices, videoconferencing devices or in any then tracks the tibial trial relative to the tibial anatomical other mode or on any other platform which is now or may reference frame. in the future be capable of rending images or parts of [0057] Once the trial components are installed, the sur- them produced in accordance with the present invention. geon can assess alignment and stability of the compo- 40 Parallel communication links such as switched or un- nents and the joint. During such assessment, in trial re- switched telephone call connections may also accompa- duction, the computer can display on monitor 24 the rel- ny or form part of such telemedical techniques. Distant ative motion between the trial components to allow the databases such as online catalogs of implant suppliers surgeon to make soft tissue releases and changes in or prosthetics buyers or distributors may form part of or order to improve the kinematics of the knee. The system 45 be networked with functionality 18 to give the surgeon in can also apply rules and/or intelligence to make sugges- real time access to additional options for implants which tions based on the information such as what soft tissue could be procured and used during the surgical opera- releases to make if the surgeon desires. The system can tion. also display how the soft tissue releases are to be made. [0058] During this assessment, the surgeon may con- 50 duct certain assessment processes such as external/in- Claims ternal rotation or rotary laxity testing, varus/valgus tests, and anterior-posterior drawer at 0 and 90 degrees and 1. A system for performing unicompartmental knee ar- mid range. Thus, in the AP drawer test, the surgeon can throplasty surgical operations on portions of a knee position the tibia at the first location and press the foot 55 joint comprising: pedal. He then positions the tibia at the second location and once again presses the foot pedal so that the com- (a) an imager for obtaining an image of at least puter has registered and stored two locations in order to portions of the knee joint, wherein the imager

11 21 EP 1 372 516 B1 22

and at least one bone forming part of the knee quency sensors. joint are each attached to a fiducial (14) capable of being tracked by a position sensor; (b) at least one position sensor (16) adapted to Patentansprüche track position of said fiducials; 5 (c) a computer adapted to store at least one im- 1. Ein System zum Durchführen von chirurgischen, uni- age of at least portions of the knee joint and to kompartimentellen Kniearthroplastik-Operationen receive information from said at least one sensor an Abschnitten eines Kniegelenks, das Folgendes in order to track position and orientation of said beinhaltet: fiducials and thus the knee joint; 10 (d) a unicompartmental knee arthroplasty surgi- (a) ein Bildgerät zum Erhalten eines Bildes von cal instrument component, implant trial compo- wenigstens Abschnitten des Kniegelenks, wo- nent or implant component adapted to be at- bei das Bildgerät und mindestens ein Knochen, tached to the bone forming part of the knee joint der einen Teil des Kniegelenks bildet, jeweils an using a tool, said tool attached to a fiducial, 15 einer Bezugsmarke (14), die von einem Positi- whereby the position of the component is capa- onssensor verfolgt werden kann, angebracht ble of being tracked by said sensor and the po- sind; sition and orientation of the component is capa- (b) mindestens einen Positionssensor (16), der ble of being tracked by said computer; angepasst ist, um die Position der Bezugsmar- (e) a monitor (24) adapted to receive information 20 ken zu verfolgen; from the computer in order to display at least (c) einen Computer, der angepasst ist, um min- one image of the component, positioned and ori- destens ein Bild von wenigstens Abschnitten ented relative to the knee joint for navigation and des Kniegelenks zu speichern und um Informa- positioning of the component relative to the knee tionen von dem mindestens einen Sensor zu joint. 25 empfangen, um die Position und die Ausrich- tung der Bezugsmarken und somit des Kniege- 2. A system according to claim 1 in which the instrument lenks zu verfolgen; component is a rod. (d) eine Komponente eines chirurgischen Instru- ments, Komponente eines Probeimplantats 3. A system according to claim 1 in which the instrument 30 oder Komponente eines Implantats zur unikom- component is a cutting block. partimentellen Kniearthroplastik, die angepasst sind, um unter Verwendung eines Werkzeugs 4. A system according to claim 2 in which the rod is an an dem Knochen, der einen Teil des Kniege- intramedullary rod. lenks bildet, angebracht zu werden, wobei das 35 Werkzeug an einer Bezugsmarke angebracht 5. A system according to claim 2 in which the rod is an ist, wodurch die Position der Komponente mit- extramedullary rod. tels des Sensors verfolgt werden kann, und wobei die Position und die Ausrichtung der Kom- 6. A system according to any one of claims 1 to 5 in ponente mittels des Computers verfolgt werden which the component is adapted to interact with the 40 können; femur. (e) einen Monitor (24), der angepasst ist, um Informationen aus dem Computer zu empfan- 7. A system according to any one of claims 1 to 5 in gen, um mindestens ein Bild der Komponente, which the component is adapted to interact with the die relativ zu dem Kniegelenk positioniert und tibia. 45 ausgerichtet ist, zur Navigation und zum Posi- tionieren der Komponente relativ zu dem Knie- 8. A system according to any one of claims 1 to 7 in gelenk anzuzeigen. which the imager comprises one of a C-arm fluoroscope, a CT scanner, and an MRI machine. 2. System gemäß Anspruch 1, wobei die Komponente 50 des Instruments ein Stab ist. 9. A system according to any one of claims 1 to 8 in which the fiducials comprise one of active fiducials, 3. System gemäß Anspruch 1, wobei die Komponente passive fiducials and hybrid active/passive fiducials. des Instruments ein Schneideblock ist.

10. A system according to any of claims 1 to 9 in which 55 4. System gemäß Anspruch 2, wobei der Stab ein in- the position sensors comprise one of infrared sen- tramedullärer Stab ist. sors, electromagnetic sensors, electrostatic sensors, light sensors, sound sensors, and radiofre- 5. System gemäß Anspruch 2, wobei der Stab ein ex-

12 23 EP 1 372 516 B1 24

tramedullärer Stab ist. par ledit capteur et la position et l’orientation du composant sont à même d’être suivies par ledit 6. System gemäß einem der Ansprüche 1 bis 5, wobei ordinateur ; die Komponente angepasst ist, um mit dem Femur (e) un moniteur (24) adapté pour recevoir des zusammenzuwirken. 5 informations provenant de l’ordinateur afin d’af- ficher au moins une image du composant, posi- 7. System gemäß einem der Ansprüche 1 bis 5, wobei tionné et orienté relativement à l’articulation de die Komponente angepasst ist, um mit der Tibia zu- genou pour la navigation et le positionnement sammenzuwirken. du composant relativement à l’articulation de 10 genou. 8. System gemäß einem der Ansprüche 1 bis 7, wobei das Bildgerät eines von einem C-Bogen-Fluoroskop, 2. Un système selon la revendication 1 dans lequel le einem Computertomographen und einem MRT-Ge- composant formant instrument est une tige. rät beinhaltet. 15 3. Un système selon la revendication 1 dans lequel le 9. System gemäß einem der Ansprüche 1 bis 8, wobei composant formant instrument est un billot. die Bezugsmarken eines von aktiven Bezugsmar- ken, passiven Bezugsmarken und hybriden aktiven/ 4. Un système selon la revendication 2 dans lequel la passiven Bezugsmarken beinhalten. tige est une tige intramédullaire. 20 10. System gemäß einem der Ansprüche 1 bis 9, wobei 5. Un système selon la revendication 2 dans lequel la die Positionssensoren eines von Infrarotsensoren, tige est une tige extramédullaire. elektromagnetischen Sensoren, elektrostatischen Sensoren, Lichtsensoren, Schallsensoren und 6. Un système selon une quelconque des revendica- Hochfrequenzsensoren beinhalten. 25 tions 1 à 5 dans lequel le composant est adapté pour interagir avec le fémur.

Revendications 7. Un système selon une quelconque des revendications 1 à 5 dans lequel le composant est adapté pour 1. Un système pour réaliser des opérations chirurgica- 30 interagir avec le tibia. les d’arthroplastie unicompartimentale du genou sur des portions d’une articulation de genou 8. Un système selon une quelconque des revendica- comprenant : tions 1 à 7 dans lequel l’imageur comprend soit un fluoroscope à bras en C, soit un tomodensitomètre, (a) un imageur destiné à obtenir une image d’au 35 soit une machine IRM. moins des portions de l’articulation de genou, dans lequel l’imageur et au moins un os qui fait 9. Un système selon une quelconque des revendica- partie de l’articulation de genou sont chacun rat- tions 1 à 8 dans lequel les repères de centrage com- tachés à un repère de centrage (14) à même prennent soit des repères de centrage actifs, soit d’être suivi par un capteur de position ; 40 des repères de centrage passifs, soit des repères (b) au moins un capteur de position (16) adapté de centrage hybrides actifs / passifs. pour suivre la position desdits repères de centrage ; 10. Un système selon une quelconque des revendica- (c) un ordinateur adapté pour stocker en mémoi- tions 1 à 9 dans lequel les capteurs de position com- re au moins une image d’au moins des portions 45 prennent soit des capteurs d’infrarouge, soit des de l’articulation de genou et pour recevoir des capteurs électromagnétiques, soit des capteurs informations provenant dudit au moins un cap- électrostatiques, soit des capteurs optiques, soit des teur afin de suivre la position et l’orientation des- capteurs de sons, soit des capteurs à radiofréquen- dits repères de centrage et donc de l’articulation ce. de genou ; 50 (d) un composant formant instrument chirurgi- cal, un composant formant implant d’essai ou un composant formant implant pour l’arthroplastie unicompartimentale du genou adapté pour être rattaché à l’os qui fait partie de l’articulation 55 de genou à l’aide d’un outil, ledit outil étant rat- taché à un repère de centrage, grâce à quoi la position du composant est à même d’être suivie

13 EP 1 372 516 B1

14 EP 1 372 516 B1

15 EP 1 372 516 B1

16 EP 1 372 516 B1

17 EP 1 372 516 B1

18 EP 1 372 516 B1

19 EP 1 372 516 B1

20 EP 1 372 516 B1

21 EP 1 372 516 B1

22 EP 1 372 516 B1

23 EP 1 372 516 B1

24 EP 1 372 516 B1

25 EP 1 372 516 B1

26 EP 1 372 516 B1

27 EP 1 372 516 B1

28 EP 1 372 516 B1

29 EP 1 372 516 B1

30 EP 1 372 516 B1

31 EP 1 372 516 B1

32 EP 1 372 516 B1

33 EP 1 372 516 B1

34 EP 1 372 516 B1

35 EP 1 372 516 B1

36 EP 1 372 516 B1

37 EP 1 372 516 B1

38 EP 1 372 516 B1

39 EP 1 372 516 B1

40 EP 1 372 516 B1

41 EP 1 372 516 B1

42 EP 1 372 516 B1

43 EP 1 372 516 B1

44 EP 1 372 516 B1

45 EP 1 372 516 B1

46 EP 1 372 516 B1

47 EP 1 372 516 B1

48 EP 1 372 516 B1

49 EP 1 372 516 B1

50 EP 1 372 516 B1

51 EP 1 372 516 B1

52 EP 1 372 516 B1

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description

• US SN60271818 P [0001] • US 5682886 A [0008] • US SN60355899 P [0001]

53

Web Analytics