US20080319491A1 - Patient-matched surgical component and methods of use - Google Patents

Abstract

A method of automatically registering a surgical navigation system to a patient's anatomy is provided. The method comprises programming a surgical navigation system with a first spatial relationship between a surgical component and a reference array connected to the surgical component, programming the surgical navigation system with a second spatial relationship between an anatomical feature of a patient and the surgical component, installing the surgical component on the patient such that the surgical component engages the anatomical feature in the second spatial relationship, and locating the reference array with the surgical navigation system. The navigation system automatically recognizes the position of the reference array relative to the patient's anatomy.

Description

RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/944,817, filed Jun. 19, 2007, the complete disclosure of which is expressly incorporated herein by this reference.
FIELD OF THE INVENTION
• The present teachings relate generally to surgical navigation, and more particularly to patient-matched surgical components that are adapted to conform to a patient's anatomy, as well as to methods for using such surgical components during a surgical navigation procedure.
BACKGROUND
• Surgical navigation systems, also known as computer assisted surgery systems and image guided surgery systems, aid surgeons in locating patient anatomical structures, guiding surgical instruments, and implanting medical devices with a high degree of accuracy. Surgical navigation has been compared to a global positioning system that aids vehicle operators to navigate the earth. A surgical navigation system typically includes a computer, a tracking system, and patient anatomical information. The patient anatomical information can be obtained by using an imaging mode such as fluoroscopy, magnetic resonance imaging (MRI), computer tomography (CT) or by simply defining the location of patient anatomy with the surgical navigation system. Surgical navigation systems can be used for a wide variety of surgeries to improve patient outcomes.
• To successfully implant a medical device, surgical navigation systems often employ various forms of computing technology, as well as utilize intelligent instruments, digital touch devices, and advanced 3-D visualization software programs. All of these components enable surgeons to perform a wide variety of standard and minimally invasive surgical procedures and techniques. Moreover, these systems allow surgeons to more accurately plan, track and navigate the placement of instruments and implants relative to a patient's body, as well as conduct preoperative and intra-operative body imaging.
• To accomplish the accurate planning, tracking and navigation of surgical instruments, tools and/or medical devices during a surgical procedure utilizing surgical navigation, surgeons often couple “tracking arrays” to the surgical components. These tracking arrays allow the surgeons to track the physical location of these surgical components, as well as the patient's bones during the surgery. By knowing the physical location of the tracking array, software associated with the tracking system can accurately calculate the position of the tracked component relative to a surgical plan image.
• It is known to use surgical navigation instruments to measure the size and general contour of a bone before selecting and/or manufacturing a prosthetic implant. This process allows the surgeon to choose a prosthetic component that generally resembles the shape and size of the patient's anatomy, thereby achieving a more customized fit during the implantation process. Despite such customization efforts, most orthopaedic procedures still require the use of adjustable components or guides during the surgical procedure, particularly as such instruments are needed to fit the prosthetic components to the patient's anatomy. However, this process is time consuming, as well as subject to error during the placement and registration of the surgical components. As such, it would be desirable to improve this process to reduce surgery time and improve prosthetic fit and/or function.
SUMMARY OF THE INVENTION
• The present teachings provide a patient matched surgical component that is custom manufactured to fit a patient's anatomy in a precise manner. To achieve such customization, the patient's anatomy is preoperatively scanned and uploaded to a software program, which then recreates a three-dimensional model of the patient's anatomy from the scanned image. The three-dimensional model is then used by the software program to identify and locate on the image specific known anatomical landmarks of the patient's anatomy. Planning software then analyzes the identified anatomical landmarks together with any specific surgical instructions needed to develop and plan a surgical protocol for the patient. Once the surgical protocol has been approved by the surgeon, the protocol is presented to a software program, which then uses the protocol, as well as the preoperative scan images, to create a virtual patient matched surgical component. The virtual component is then sent to a rapid prototyping machine or a standard machining process, which in turn manufactures the surgical component for use during the surgical procedure. Because the surgical component is custom manufactured to fit the patient's anatomy relative to specific anatomical landmarks, it can be manufactured with a reference array positioned on its surface in a predefined spatial relationship with respect to the patient's anatomy. By having a predefined spatial relationship between the reference array and the patient's anatomy, the need for intra-operative registration during the surgical procedure is minimized or even eliminated altogether. Furthermore, since the patient matched component is fixable to the patient's anatomy with pins, the reference array can act as an automatically registered rigid bone reference marker that can be used throughout the surgical navigation procedure.
• According to one aspect of the present teachings, a method of automatically registering a surgical navigation system to a patient's anatomy is provided. The method comprises programming a surgical navigation system with a first spatial relationship between a surgical component and a reference array connected to the surgical component, programming the surgical navigation system with a second spatial relationship between an anatomical feature of a patient and the surgical component, installing the surgical component on the patient such that the surgical component engages the anatomical feature in the second spatial relationship, and locating the reference array with the surgical navigation system. The navigation system automatically recognizes the position of the reference array relative to the patient's anatomy.
• According to another exemplary embodiment herein, a method of performing a surgical procedure aided by a surgical navigation system is provided. The method comprises generating a representative model of an anatomical feature from an image of a patient's anatomy, using the model to make a surgical component, installing the surgical component on the anatomical feature by mating the surface of the component with the anatomical feature in the predefined spatial relationship, and tracking movement of the anatomical feature with a tracking system when the installed surgical component is moved within a measurement field of the tracking system. According to this embodiment, the surgical component has a surface that is shaped to substantially mate with the anatomical feature in a predefined spatial relationship.
• According to yet another exemplary embodiment herein, a patient matched surgical component is provided. The surgical component comprises a body having a surface that is shaped to substantially mate with the shape of an anatomical feature of a patient in a predefined spatial relationship, and a reference array connected to the body, the reference array being trackable by a tracking system when exposed to a measurement field of the tracking system.
• In still another exemplary embodiment, a method of performing a surgical procedure aided by a surgical navigation system is provided. According to this exemplary embodiment, the method comprises generating a representative model of an anatomical feature from an image of a patient's anatomy, using the model to make a surgical component, the surgical component having a reference array associated therewith and a surface that is shaped to substantially mate with an anatomical feature in a predefined spatial relationship, installing the surgical component on the anatomical feature by mating the surface of the component with the anatomical feature in the predefined spatial relationship, tracking movement of the anatomical feature with the tracking system when the installed surgical component is moved within a measurement field of the tracking system, removing a portion of the anatomical feature, the removed portion also including a portion of the installed surgical component, and tracking a remaining portion of the anatomical feature with the tracking system, the remaining portion of the anatomical feature including a portion of the installed surgical component, the remaining portion of the installed surgical component including the reference array.
BRIEF DESCRIPTION OF THE DRAWINGS
• The above-mentioned aspects of the present teachings and the manner of obtaining them will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
• FIG. 1 is a perspective view of an exemplary operating room setup in a surgical navigation embodiment in accordance with the present teachings;
• FIG. 2 is a patient-matched surgical component created from a preoperative scan image of the patient's bone;
• FIG. 3A is a fragmentary perspective view of a surgeon aligning the patient-matched surgical component ofFIG. 2 with a bone;
• FIG. 3B is a fragmentary perspective view of the backside of the surgical component ofFIG. 3A, the component being shown aligned with a bone;
• FIG. 4 is a fragmentary perspective view of the patient-matched surgical component ofFIG. 2 being attached to the bone by the surgeon;
• FIG. 5 is a fragmentary perspective view of the patient-matched surgical component ofFIG. 4 attached to the bone and its corresponding reference array, which is connectable thereto;
• FIGS. 6 and 7 are fragmentary perspective views illustrating the bone ofFIG. 5 undergoing an exemplary resection process in accordance with the present teachings;
• FIG. 8 is a fragmentary perspective view of a surgeon aligning a patient-matched surgical component with a patient's pelvis in accordance with the present teachings;
• FIG. 9 is a fragmentary perspective view of the patient-matched surgical component ofFIG. 8 being attached to the pelvis by the surgeon; and
• FIG. 10 is a fragmentary perspective view of the patient-matched surgical component ofFIG. 8 and its corresponding reference array connected thereto.
• Corresponding reference characters indicate corresponding parts throughout the several views.
DETAILED DESCRIPTION
• The embodiments of the present teachings described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present teachings.
• FIG. 1 shows a perspective view of an operating room withsurgical navigation system20.Surgeon21 is aided bysurgical navigation system20 in performing knee arthroplasty, also known as knee replacement surgery, onpatient22 shown lying on operating table24.Surgical navigation system20 has a tracking system that locates arrays and tracks them in real-time. To accomplish this, the surgical navigation system includesoptical locator23, which has two CCD (charge couple device)cameras25 that detect the positions of the arrays in space by using triangulation methods. The relative location of the tracked arrays, including the patient's anatomy, can then be shown on a computer display (such ascomputer display27 for instance) to assist the surgeon during the surgical procedure. The arrays that are typically used include probe arrays, instrument arrays, reference arrays, and calibrator arrays. The tracking system also detects the location ofreference array36, which is attached to patient matched surgical component34. The relative location of patient matched surgical component34 with respect to the patient's anatomy can then be shown oncomputer display image38 ofcomputer monitor42. The operating room also includesinstrument cart45 havingtray44 for holding a variety of surgical instruments andarrays46.Instrument cart45 is also draped insterile cover48 to eliminate contamination risks within the sterile field.
• The surgery is performed within a sterile field, adhering to the principles of asepsis by all scrubbed persons in the operating room.Patient22,surgeon21 and assistingclinician50 are prepared for the sterile field through appropriate scrubbing and clothing. The sterile field will typically extend from operating table24 upward in the operating room. Typically, the computer display is located outside of the sterile field.
• A representation of the patient'sanatomy52 can be acquired with an imaging system, a virtual image, a morphed image, or a combination of imaging techniques. The imaging system can be any system capable of producing images that represent the patient's anatomy such as a fluoroscope producing x-ray two-dimensional images, computer tomography (CT) producing a three-dimensional image, magnetic resonance imaging (MRI) producing a three-dimensional image, ultrasound imaging producing a two-dimensional image, and the like. A virtual image of the patient's anatomy can be created by defining anatomical points with thesurgical navigation system20 or by applying a statistical anatomical model. A morphed image of the patient's anatomy can be created by combining an image of the patient's anatomy with a data set, such as a virtual image of the patient's anatomy.
• The tracking system of the present invention can be any system that can determine the three-dimensional location of devices carrying or incorporating markers that serve as tracking indicia. More particularly, the tracking system may be an active tracking system that has a collection of infrared light emitting diode (ILEDs) illuminators surrounding the position sensor lenses to flood a measurement field of view with infrared light. Alternatively, the system may be a passive tracking system, which incorporates retro-reflective markers that reflect infrared light back to the position sensor, and the system triangulates the real-time position (x, y, and z location) and orientation (rotation around x, y, and z axes). In yet other embodiments, the tracking system may be a hybrid tracking system that detects active and active wireless markers in addition to passive markers. Active marker based instruments enable automatic tool identification, program control of visible LEDs, and input via tool buttons. Finally, in yet other exemplary embodiments, the tracking system may utilize electromagnetic tracking techniques. These systems locate and track devices and produce a real-time, three-dimensional video display of the surgical procedure by using electromagnetic field transmitters that generate a local magnetic field around the patient's anatomy.
• The present teachings enhancesurgical navigation system20 by incorporating into the system a process for custom manufacturing patient-matched surgical component34 so that it fits the anatomy ofpatient22 in a precise manner. Particularly, in addition to tracking surgical components, the navigation system can also generate preoperative images of the patient's anatomy and then use such images to manufacture a surgical component that is custom matched to the patient's anatomy. More specifically, the patient's anatomy is preoperatively scanned and uploaded to a software program, which then recreates a three-dimensional virtual model of the patient's anatomy from the scanned image. The virtual model is then used by the software program to identify and locate known bony anatomical landmarks or predefined points of the patient's anatomy. For a further description about the acquisition and registration of bony landmarks, see U.S. patent application Ser. No. 11/689,711, entitled “Modeling Method and Apparatus for use in Surgical Navigation,” filed Mar. 22, 2007, which is incorporated by reference herein in its entirety.
• As is appreciated by those of skill within the art, bony anatomical landmarks are visible points or locations on a patient's anatomy, which are identifiable by referencing known locations on the surface of the bone. For instance, known bony landmarks on the femur include, but are not limited to, a femoral head landmark, a central knee landmark, a medial femoral condyle landmark, a lateral femoral condyle landmark, a medial epicondyle landmark, a lateral epicondyle landmark, a medial posterior condyle landmark, a lateral posterior condyle landmark and an anterior cortex point landmark. Similar bony landmarks are also found on other bones (such as the tibia, fibula, patella and pelvis, for instance), however, for simplicity purposes, the exemplary illustrations provided here are specifically directed to the femur. As the present teachings are not intended to be limiting, it should be understood and appreciated that these teachings are also applicable to bony landmark structures other than the femur.
• Planning software analyzes the identified anatomical landmarks together with any specific surgical instructions received from the surgeon and develops a surgical procedure or protocol for the patient. After its approval, the protocol is then entered into a software program, which uses the protocol together with the preoperative scan images to create a virtual representation of a patient matched surgical component. The virtual representation of the surgical component is then sent to a rapid prototyping machine or a standard machining process, which in turn manufactures a physical prototype of the surgical component. Because the surgical component is custom manufactured to fit the patient's anatomy relative to known anatomical landmarks, it can be manufactured to include a reference array that extends from its surface in a predefined manner. By having the reference array positioned in a predefined spatial orientation with respect to the patient's anatomy, the need to further register the component intraoperatively is unnecessary; particularly as the registration of the reference array is completed preoperatively during the surgical planning stages. Furthermore, since the patient matched component can be secured to the patient's anatomy, the reference array can also function as an automatically registered and trackable bone reference array during the surgical procedure.
• The principles upon which exemplary embodiments of the present invention rely can be understood with reference toFIG. 2, which illustrates three-dimensional bone model301 on surgical display image oruser interface screen303 ofmonitor305.Model301 is based on an image of the patient's anatomy, which was obtained from a preoperative diagnostic imaging procedure, such as by magnetic resonance imaging (MRI), computer assisted tomography (CT), fluoroscopy, ultrasound or positron emission tomography (PET). It should be understood thatmodel301 is intended to illustrate general principles of the present teachings and is not representative of any particular screen shot that a surgeon may observe during a surgical navigation procedure. Moreover, it should be understood and appreciated herein that processes for generating three-dimensional models from preoperative images of anatomical features are well known by those within the surgical navigation field and therefore not discussed in detail herein.
• Once three-dimensional model301 has been created, it is then used by the software program to identify and locate specific known anatomical landmarks characteristic of the anatomical feature. The number of anatomical landmarks identified on the model will depend on the bony anatomy that is being characterized, as well as what type of surgical procedure is being performed on the patient undergoing the operation. In some exemplary embodiments, however, less than about ten anatomical landmarks are identified by the software program and represented on the three-dimensional model. In other exemplary embodiments, less than about seven anatomical landmarks are identified, while in still other exemplary embodiments, less than about three landmarks are identified.
• InFIG. 2,model301 depicts five bony anatomical landmarks common to a typical femur. These bony landmarks include the distal most point of the medialfemoral condyle307, the distal most point of the lateralfemoral condyle309, themedial epicondyle311, thelateral epicondyle313 and the anterior cortex point of thefemur315. By acquiring such bony landmarks, the surgeon can use such information to assist in planning the surgical protocol to be performed on the patient. For instance, by acquiring the epicondyles (311,313), the transepicondylar axis of the femur can be determined to assist with the rotation and positioning of a femoral implant component. Moreover, by acquiring the anterior cortex point of thefemur315, proper implant sizing techniques can be utilized.
• Oncemodel301 has been created and the bony anatomical landmarks identified, the surgeon can use the model as a visual aid and manipulate it to gather important surgical information, such as gap analysis data, resection plane details and bone alignment angles. Furthermore, if the surgeon desires, he can rotate or manipulatemodel301 so that he can visually appreciate the general shape and characteristics of the patient's femur, particularly as the acquired bony anatomical landmark points shown on the model remain accurate as it is manipulated by the surgeon. In addition to displaying the acquired femoral landmark points (i.e. points307,309,311,313 and315),model301 can also depict a representation of the implant component that will be implanted onto the patient during the surgical procedure. By displaying a representation of the implant on the bone model, the system can gather additional information useful for finalizing the surgical protocol, particularly implant sizing and rotation information. The representation of the implant can also be rotated and aligned preoperatively, particularly so that the navigation system can calculate the location of necessary bone cuts and/or resection planes to be used during the surgical procedure. Some resection planes that can be determined preoperatively include, but are not limited to, the tibial proximal cut, the femoral distal cut, the femoral anterior cut, as well as the chamfer cuts made by a 4-in-1 resection block.
• After the surgical protocol has been planned and is approved, the software then creates a virtual surgical component that is custom-shaped to effect implementation of the surgical specifications (e.g., bone cuts, resection planes, drill holes, etc.) that were determined by the planning software. In some exemplary embodiments, the surgical component may function as a patient-matched reference array and not include any cut slots in its body design. More particularly, in certain embodiments, the surgical component may replace one or more rigid bone reference arrays or markers typically attached to the patient's anatomy during a surgical procedure. By eliminating the use of such rigid bone reference arrays, the surgical procedure can be performed in a minimally invasive manner, particularly as fewer incisions would be required of the patient's anatomy. Reducing the number of required incisions during a surgical procedure is advantageous, particularly in terms of reducing associated scarring and/or complications typically caused from such incisions.
• Once the component has been virtually designed, the virtual representation is then sent to a rapid prototyping machine or a standard machining process, which in turn manufactures a physical component that corresponds to the dimensional parameters of the virtual component. For instance, as shown inFIGS. 2,3A and3B,surgical component320 has been created having aninterior surface322, which matches the topography ofmodel301.Surgical component320 also includes one or more cutting slots or guides324, which are specifically designed to accommodate cutting devices (e.g., saw blades) during a bone resection process. It should be understood and appreciated herein that the position, shape and directional orientation of the cutting slot(s) on the surgical component will depend particularly on the surgical procedure that is to be performed on the given patient. For instance, if the surgeon will be performing a total knee arthroplasty, a cutting slot to accommodate the distal femur cut, such asslot324 shown inFIG. 2, may be included.Surgical component320 may also include one ormore holes328 to accommodate drilling into the patient's bone and/or attaching the component to the patient's bone during a surgical procedure.
• FIGS. 3A and3B show surgeon402 positioningsurgical component320 relative tobone404 during a surgical procedure. As the interior surface of the surgical component is shaped to substantially match the general topographic landscape and contour ofbone404, the surgeon is able to align the component with the bone in such a manner that the component mates with the bone in a position predefined by the software. In other words,surgeon402 is able to pressinner surface322 ofsurgical component320 againstouter surface406 ofbone404 until a tactile sensation is felt by the surgeon indicating that the component has mated with or “matched” its corresponding surface of the bone. Becausesurgical component320 is patient-matched to the shape ofbone404,surgeon402 can positionsurgical component320 by feel with a high degree of precision. More particularly, the body of the surgical component is shaped in such a manner that it interfits or interlocks to the shape of the anatomical feature during installation. This interfitting or interlocking relationship allows the surgeon to achieve the tactile sensation when the surgical component is correctly installed onto the anatomical feature. When thesurgical component320 is properly or correctly installed, it sits substantially flush against the surface ofbone404, i.e., there will not be significant gaps around the edge of the component as it sits against the patient's anatomical feature or bone.
• As explained above,surgical component320 further includes one ormore holes328 for drilling into the bone and/or for attaching the component to the bone's surface during a surgical procedure, as well as one ormore cutting slots324 to accommodate cutting devices during a bone resection process. According to one exemplary embodiment, holes328 are configured to function as anchoring holes, which can be used for inserting temporary pins or screws into the bone to hold the surgical component into place during a surgical procedure.Holes328 may also be configured into various dimensional patterns and arrangements to accommodate the surgical plan and/or to accommodate the anatomical shape of the bony structure or anatomical feature to which the component is to be affixed. Moreover, in certain exemplary embodiments, the same surgical component may be used in multiple resection procedures, whereby the holes are arranged such that the remaining portion ofsurgical component320 remains securely fastened to the bone after the initial resection is completed.Holes328 may also be configured to use previously placed reference markers or anchors already attached to the surface of the bone. More particularly, according to this embodiment, the arrangement of the holes can be positioned such that the surgeon places the surgical component over one or more reference markers or anchor devices previously placed into the bone. Such reference markers or anchor devices may have been placed during prior diagnostic or therapeutic surgeries, or may have been placed preoperatively for use in future diagnostic or therapeutic procedures.
• FIG. 4 showssurgical component320 aligned with and positioned substantially flush againstbone404. Once positioned,surgical component320 can be affixed tobone404 by inserting one ormore pins502 into the bone throughholes328. Affixingsurgical component320 tobone404 with pins, screws, or other attachment means insures that the surgical component is securely held in place during the surgical procedure. InFIG. 4,surgeon402 is shown using apin insertion device504 to insertpin502 intobone404 through one ofholes328. Such surgical pin insertion techniques and instrumentation are known by those of skill within the art and therefore not discussed in detail herein.
• FIG. 5 showssurgical component320 positioned againstbone404 and secured into place with attachment pins502.Surgical component320 also includes aquick connect receptacle602, which is configured to connect to a tracking device, such as a reference array. According to this embodiment, tracking orreference array604 is provided with aquick connect base606 that dimensionally corresponds withreceptacle602 such that a removable snap-fit connection can be achieved between the two components. WhileFIG. 5 illustrates a snap-fit attachment means between the reference array and the component, it should be understood that in other embodiments,reference array604 may be “pre-installed” ontosurgical component320, whereby no additional attachment means is required after the component is attached to the bone. It should also be understood and appreciated that any attachment means known within the art may be used to securereference array604 tosurgical component320. Such attachment means include, but are not limited to, welding, fusing, molding, gluing, threading, snap-connections, quick disconnect connections and the like.
• Oncereference array604 is attached tosurgical component320,navigation system20 is able to locate and track its position in real-time and display its tracked position on a surgical plan image. In other words, once the navigation system locates the array, the system automatically knows its position with respect to the landmarks identified on the model image, as well as where it has been pre-registered with respect to the image. To accomplish this, and with reference toFIG. 6,cameras702 ofoptical locator704 detect in space the position ofmarkers706, which extend from the surface ofreference array604. It should be understood and appreciated herein that while this embodiment shows fourmarkers706 attached to the frame ofreference array604, in other embodiments less than four markers may be used, while in yet other embodiments, more than four markers may be used. For instance, in some embodiments using electromagnetic tracking technology, only one marker is needed to track the position of the surgical component in space. In yet other embodiments, three markers may be used to triangulate the position of the surgical component in space. As such, it should be fully appreciated that the present teachings are not intended to be limited herein.
• To detect the position of the markers in space, known triangulation methods are used. These triangulation methods allow the navigation system to determine the relative location of the reference array and its markers with respect to the patient's anatomy, and then display the same on a surgical plan image. Asreference array604 is trackable in real-time, the position ofbone404 can also be tracked in real-time, particularly sincereference array604 is fixably attached to its surface by way ofsurgical component320. As explained above, by havingreference array604 positioned relative to thesurgical component320 in a predefined spatial manner, the need for intra-operative registration during the surgical procedure is substantially minimized.
• As used herein, “predefined” refers to a preoperatively planned spatial relationship between the surgical component and the anatomical feature of the patient to which the component is to be attached. In other words, once the component is installed onto the anatomical feature in its predefined spatial orientation, it is automatically registered with the system and can be tracked by the navigation system for the remainder of the procedure without further registration techniques. Moreover, since the patient matched component is fixably secured to the patient's anatomy throughout the surgical procedure,reference array604 is able to function as a rigid reference bone marker to trackbone404 during the surgical procedure. Such rigid bone reference arrays are commonly used in orthopaedic surgical procedures and are able to track a patient's bones with respect to various surgical instruments during a surgical navigation procedure. Because the presently disclosed reference arrays are preoperatively registered with the navigation system in a predefined manner with respect to the patient's anatomy, these components can be used to track the patient's anatomy without the need to insert additional rigid array markers into the patient during the procedure. Moreover, because such surgical components are registered with the navigation system during the preoperative planning steps of the surgical procedure, timely intraoperative registration processes are also unnecessary.
• An exemplary illustration of a bone undergoing a resection process in accordance with the present teachings is depicted inFIGS. 6-7.Surgical instrument714 may optionally include amarker array715, which can be further identified and tracked bycameras702 ofoptical locator704. However, sincesurgical component320 was custom designed to match and mate with the specific shape ofbone404, the surgeon does not need to track the position of the surgical instrument relative to the bone during the surgical procedure. More particularly, the position of cuttingslot324 onsurgical component320 was previously registered with the tracking system during the preoperative planning stages of the surgical procedure. As such, once the surgeon attaches the component to the bone in its predetermined position, he can proceed directly to resecting the bone with the surgical instrument without further tracking or registering of the surgical instrument. As such, it should be understood that the depiction ofmarker array715 onsurgical instrument714 is optional and is not intended to limit the scope of the present teachings.
• Referring still toFIGS. 6 and 7, assurgeon716 movesinstrument714 relative tobone404, the tracking system locates and tracksmarker array715 in real-time. The relative location ofmarker array715 is then shown onsurgical plan image708 ofcomputer display710. The tracking system detects the location ofsurgical instrument714 relative tobone404 by referencing the position ofmarker array715 as it moves with respect toreference array604, which is fixably attached tobone404 by way ofsurgical component320. The position ofsaw blade712 ofsurgical instrument714 is displayed onsurgical plan image708 as cutplane713. By viewing cutplane713 onsurgical plan image708,surgeon716 can confirm that the surgical component is positioned properly, although as just noted, this step is optional since the component can be properly positioned by the surgeon by feel alone.
• FIG. 7 shows a portion ofbone404 removed aftersurgeon716 has insertedsaw blade712 intocut slot324 ofsurgical component320. A portion of the surgical component321 remains affixed to the removed bone byattachment pin329. Becausereference array604 is still attached tobone404 by way ofsurgical component320, the surgical navigation system continues to recognize and track the position ofbone404 and the remaining portion of the attachedsurgical component320 in real-time throughout the remainder of the surgical procedure. As such, the remaining portion ofsurgical component320, and itsreference array604, can be used for additional steps in the surgical procedure, such as the removal or modification of a second predefined part of the bone after the initial resection, or the placement and use of additional surgical components. The tracked remaining portion ofsurgical component320 can also be used to perform other surgical procedures that require tracking, such as ligament balancing, range of motion and impingement analyses.
• It should be understood and appreciated herein that whileFIG. 7 depicts portion321 ofsurgical component320 being removed withsaw blade712, in other exemplary embodiments, portion321 may be removed by being snapped, broken or cleaved away fromsurgical component320. For instance, cutslot324 could be replaced by a groove or cleave that is designed to be physically broken or torn away from the surgical component after it has been attached to the patient's anatomy. As such, the attachment means useful for the present teachings are not intended to be limited herein.
• While the above-described embodiments illustrate the presently disclosed surgical components as being useful for knee related applications, it should be appreciated and understood herein that the exemplary components disclosed herein may also be used together with any other anatomical features without straying from the present teachings. For instance, in certain exemplary embodiments, the surgical components may also be used together with hip-related navigation applications. More particularly, as is known within the surgical navigation field, registration processes for the hip can be quite challenging, particularly as the surgeon must register both sides of the patient's pelvis, including rolling the patient onto their side to collect data points and then re-draping and re-scrubbing the patient between such registration steps. By using the presently disclosed surgical components, navigating the hip during a surgical procedure is significantly simplified, particularly as the need to register the hip intraoperatively is eliminated.
• Further principles upon which exemplary embodiments of the present invention rely can be understood with reference toFIG. 8.FIG. 8 depictssurgical component802, which has been created by a rapid prototyping machine or a standard machining process to match the dimensional parameters of a virtual representation of a patient's pelvis according to the process described above. More particularly,surgical component802 has an interior surface that matches the topographic landscape ofpelvis803. According to this embodiment,surgeon806 positionssurgical component802 relative topelvis803 during a hip procedure. As the interior surface of the surgical component is shaped to substantially match the general topographic landscape and contour ofpelvis803, the surgeon is able to align the component with the pelvis in such a manner that the component mates with the pelvis in a position predefined by the software. In other words,surgeon806 is able to press the inner surface ofsurgical component802 againstouter surface804 ofpelvis803 until a tactile sensation is felt by the surgeon indicating that the component has mated with or “matched” its corresponding surface of the pelvis. Becausesurgical component802 is patient-matched to the shape ofpelvis803,surgeon806 can positionsurgical component802 by feel with a high degree of precision. When properly positioned,surgical component802 will sit substantially flush against the surface ofpelvis803, i.e., there will not be significant gaps around the edge of the component as it sits against the patient's pelvic bone.
• Surgical component802 also includes one ormore holes808 for drilling into the pelvis and/or for attaching the component to the pelvis's surface during a hip procedure. According to one exemplary embodiment, holes808 are configured to function as anchoring holes, which can be used for inserting temporary pins or screws into the pelvis, thereby holding the surgical component into place during a surgical procedure. For instance,FIG. 9 showssurgical component802 aligned with and positioned substantially flush againstpelvis803. Once positioned,surgical component802 can be affixed topelvis803 by inserting one ormore pins810 into the pelvis throughholes808. Affixingsurgical component802 topelvis803 with pins, screws, or other attachment means insures that the surgical component is securely held in place during the surgical procedure. InFIG. 9,surgeon806 is shown using apin insertion device812 to insertpin810 intopelvis803 through one ofholes808.
• FIG. 10 showssurgical component802 positioned againstpelvis803 and secured into place with attachment pins810.Surgical component802 also includes aquick connect receptacle814, which is configured to connect to a tracking device, such asreference array816. Oncereference array816 is attached tosurgical component802,navigation system20 is able to locate and track its position in real-time and display its tracked position on a surgical plan image. In other words, once the navigation system locates the array, the system automatically knows its position with respect to the landmarks identified on the model image, as well as where it has been pre-registered with respect to the image. To accomplish this,cameras818 ofoptical locator820 detect in space the position ofmarkers817, which extend from the surface ofreference array816. To detect the position of the markers in space, known triangulation methods are used. These triangulation methods allow the navigation system to determine the relative location of the reference array and its markers with respect to the patient's anatomy, and then display the same on a surgical plan image. Asreference array816 is trackable in real-time, the position ofpelvis803 can also be tracked in real-time, particularly sincereference array816 is fixably attached to its surface by way ofsurgical component802. As explained above, by havingreference array816 positioned relative to thesurgical component802 in a predefined spatial manner, the need for intra-operative registration during the surgical procedure is substantially minimized.
• In additional to navigating knees and hips, the present teachings can also be used with surgical procedures involving the shoulder, spine, ankle, elbow, skull or any other type of bony structure found within the human anatomy. As such, the present teachings are not intended to be limited herein.
• While an exemplary embodiment incorporating the principles of the present invention has been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Claims (28)

1. A method of automatically registering a surgical navigation system to a patient's anatomy, comprising:

programming the surgical navigation system with a first spatial relationship between a surgical component and a reference array connected to the surgical component;

programming the surgical navigation system with a second spatial relationship between an anatomical feature of a patient and the surgical component;

installing the surgical component on the patient such that the surgical component engages the anatomical feature in the second spatial relationship; and

locating the reference array with the surgical navigation system, wherein the navigation system automatically recognizes the position of the reference array relative to the patient's anatomy.

2. The method ofclaim 1, wherein installing the surgical component onto the patient comprises mating a surface of the surgical component with a corresponding surface on the anatomical feature, the corresponding surface on the anatomical feature being shaped to substantially correspond to the shape of the surgical component's surface.

3. The method ofclaim 2, wherein installing the surgical component on the patient comprises adjusting the position of the surgical component relative to the anatomical feature until a tactile sensation of correct placement is achieved.

4. The method ofclaim 2, wherein mating the surface of the surgical component with the corresponding surface on the anatomical feature comprises attaching the surgical component to the anatomical feature with at least one of pins and screws.

5. The method ofclaim 1, further comprising identifying a finite number of predefined points on a representative model of the anatomical feature, the model being generated from a preoperative image of the patient's anatomy.

6. The method ofclaim 5, wherein at least one of the predefined points is a bony anatomical landmark selected from at least one of a femoral head landmark, a central knee landmark, a medial femoral condyle landmark, a lateral femoral condyle landmark, a medial epicondyle landmark, a lateral epicondyle landmark, a medial posterior condyle landmark, a lateral posterior condyle landmark and an anterior cortex point landmark.

7. The method ofclaim 5, further comprising using the surgical navigation system to calculate a bone cut by analyzing the predefined points on the model.

8. The method ofclaim 1, further comprising removing a portion of the anatomical feature and a portion of the installed surgical component.

9. The method ofclaim 8, further comprising tracking a remaining portion of the anatomical feature with the surgical navigation system, the remaining portion of the anatomical feature including a portion of the installed surgical component, the remaining portion of the installed surgical component including the reference array.

10. A method of performing a surgical procedure aided by a surgical navigation system, comprising:

generating a representative model of an anatomical feature from an image of a patient's anatomy;

using the model to make a surgical component, the surgical component having a surface that is shaped to substantially mate with the anatomical feature in a predefined spatial relationship;

installing the surgical component on the anatomical feature by mating the surface of the component with the anatomical feature in the predefined spatial relationship; and

tracking movement of the anatomical feature with a tracking system when the installed surgical component is moved within a measurement field of the tracking system.

11. The method ofclaim 10, wherein installing the surgical component on the anatomical feature comprises adjusting the position of the surgical component relative to the anatomical feature until a tactile sensation of correct placement is achieved.

12. The method ofclaim 10, wherein tracking movement of the anatomical feature with the tracking system comprises tracking movement of a reference array attached to the surgical component.

13. The method ofclaim 10, further comprising identifying a finite number of predefined points on the anatomical feature, the predefined points being shown on the model to assist in making the surgical component.

14. The method ofclaim 13, wherein at least one of the predefined points is a bony anatomical landmark selected from at least one of a femoral head landmark, a central knee landmark, a medial femoral condyle landmark, a lateral femoral condyle landmark, a medial epicondyle landmark, a lateral epicondyle landmark, a medial posterior condyle landmark, a lateral posterior condyle landmark and an anterior cortex point landmark.

15. The method ofclaim 10, further comprising removing a portion of the anatomical feature and a portion of the installed surgical component.

16. The method ofclaim 15, further comprising tracking a remaining portion of the anatomical feature with the surgical navigation system, the remaining portion of the anatomical feature including a portion of the installed surgical component, the remaining portion of the installed surgical component including the reference array.

17. A patient matched surgical component, comprising:

a body having a surface that is shaped to substantially mate with the shape of an anatomical feature of a patient in a predefined spatial relationship; and

a reference array connected to the body, the reference array being trackable by a tracking system when exposed to a measurement field of the tracking system.

18. The patient matched surgical component ofclaim 17, wherein the surface of the body and a surface of the anatomical feature have interfitting shapes, the interfitting shapes being configured to allow a surgeon to achieve a tactile sensation when correctly placing the surgical component relative to the anatomical feature during a surgical procedure.

19. The patient matched surgical component ofclaim 17, wherein a first portion of the surgical component is adapted to be removed during a surgical procedure and a second portion is adapted to remain attached to the anatomical feature, the remaining portion being trackable by the tracking system during a remainder of the surgical procedure.

20. The patient matched surgical component ofclaim 17, wherein the reference array comprises a frame and at least one marker attached to the frame and detectable by the tracking system during a surgical procedure.

21. The patient matched surgical component ofclaim 17, wherein the surgical component further comprises a coupler adapted to releasably attach the reference array thereto.

22. The patient matched surgical component ofclaim 21, further comprising an attachment means for attaching the reference array to the surgical component, the attachment means being selected from at least one of welding, fusing, molding, gluing, threading, snap-connecting and quick disconnecting.

23. A method of performing a surgical procedure aided by a surgical navigation system, comprising:

generating a representative model of an anatomical feature from an image of a patient's anatomy;

using the model to make a surgical component, the surgical component having a reference array associated therewith and a surface that is shaped to substantially mate with an anatomical feature in a predefined spatial relationship;

installing the surgical component on the anatomical feature by mating the surface of the component with the anatomical feature in the predefined spatial relationship;

tracking movement of the anatomical feature with the tracking system when the installed surgical component is moved within a measurement field of the tracking system;

removing a portion of the anatomical feature, the removed portion also including a portion of the installed surgical component; and

tracking a remaining portion of the anatomical feature with the tracking system, the remaining portion of the anatomical feature including a portion of the installed surgical component, the remaining portion of the installed surgical component including the reference array.

24. The method ofclaim 23, wherein installing the surgical component on the anatomical feature comprises adjusting the position of the surgical component relative to the anatomical feature until a tactile sensation of correct placement is achieved.

25. The method ofclaim 23, further comprising identifying a finite number of predefined points on the anatomical feature, the predefined points being shown on the model to assist in making the surgical component.

26. The method ofclaim 25, wherein at least one of the predefined points is a bony anatomical landmark selected from at least one of a femoral head landmark, a central knee landmark, a medial femoral condyle landmark, a lateral femoral condyle landmark, a medial epicondyle landmark, a lateral epicondyle landmark, a medial posterior condyle landmark, a lateral posterior condyle landmark and an anterior cortex point landmark.

27. The method ofclaim 23, wherein removing a portion of the anatomical feature comprises resecting bone with a saw blade through a cut slot of the surgical component.

28. The method ofclaim 23, wherein mating the surface of the component with the anatomical feature in the predefined spatial relationship comprises attaching the surgical component to the anatomical feature with at least one of pins and screws.

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