Abstract:
A modular portal for use with a computer-aided surgical navigation system. The modular portal is configured to receive a wide number of surgical items in either rotating or non-rotating fashions. A surgical reference associated with a base of the modular portal may be repositioned with respect to the base to facilitate a clear line of sight between a sensor of the computer-aided surgical navigation system and the surgical reference.

Description:
[0001]     This application relates to and claims the benefit on U.S. Provisional Application No. 60/509,366, filed Oct. 6, 2003 and entitled “Modular Navigated Portal,” the entire contents of which are hereby expressly incorporated by this reference. 
     
    
     BACKGROUND  
       [0002]     Many surgical procedures require a wide array of instrumentation and other surgical items. Necessary items may include, but are not limited to: sleeves to serve as entry tools, working channels, drill guides and tissue protectors; scalpels; entry awls; guide pins; reamers; reducers; distractors; guide rods; endoscopes; arthroscopes; saws; drills; screwdrivers; awls; taps; osteotomes and wrenches. In many surgical procedures, including orthopaedic procedures, it may be desirable to associate some or all of these items with a guide and/or handle incorporating a surgical reference, allowing the instrument to be used with a computer-aided surgical navigation system.  
         [0003]     Several manufacturers currently produce computer-aided surgical navigation systems. The TREON™ and ION™ systems with FLUORONAV™ software manufactured by Medtronic Surgical Navigation Technologies, Inc. are examples of such systems. The BrainLAB VECTORVISION™ system is another example of such a surgical navigation system. Systems and processes for accomplishing computer-aided surgery are also disclosed in U.S. Ser. No. 10/084,012, filed Feb. 27, 2002 and entitled “Total Knee Arthroplasty Systems and Processes”; U.S. Ser. No. 10/084,278, filed Feb. 27, 2002 and entitled “Surgical Navigation Systems and Processes for Unicompartmental Knee Arthroplasty”; U.S. Ser. No. 10/084,291, filed Feb. 27, 2002 and entitled “Surgical Navigation Systems and Processes for High Tibial Osteotomy”; International Application No. US02/05955, filed Feb. 27, 2002 and entitled “Total Knee Arthroplasty Systems and Processes”; International Application No. US02/05956, filed Feb. 27, 2002 and entitled “Surgical Navigation Systems and Processes for Unicompartmental Knee Arthroplasty”; International Application No. US02/05783 entitled “Surgical Navigation Systems and Processes for High Tibial Osteotomy”; U.S. Ser. No. 10/364,859, filed Feb. 11, 2003 and entitled “Image Guided Fracture Reduction,” which claims priority to U.S. Ser. No. 60/355,886, filed Feb. 11, 2002 and entitled “Image Guided Fracture Reduction”; U.S. Ser. No. 60/271,818, filed Feb. 27, 2001 and entitled “Image Guided System for Arthroplasty”; and U.S. Ser. No. 10/229,372, filed Aug. 27, 2002 and entitled “Image Computer Assisted Knee Arthroplasty”, the entire contents of each of which are incorporated herein by reference as are all documents incorporated by reference therein.  
         [0004]     These systems and processes use position and/or orientation tracking sensors such as infrared sensors acting stereoscopically or other sensors acting in conjunction with surgical references to track positions of body parts, surgery-related items such as implements, instrumentation, trial prosthetics, prosthetic components, and virtual constructs or references such as rotational axes which have been calculated and stored based on designation of bone landmarks. Processing capability such as any desired form of computer functionality, whether standalone, networked, or otherwise, takes into account the position and orientation information as to various items in the position sensing field (which may correspond generally or specifically to all or portions or more than all of the surgical field) based on sensed position and orientation of their associated surgical references, or based on stored position and/or orientation information. The processing functionality correlates this position and orientation information for each object with stored information, such as a computerized fluoroscopic imaged filed, a wire frame data file for rendering a representation of an instrument component, trial prosthesis or actual prosthesis, or a computer generated file relating to a rotational axis or other virtual construct or reference. The processing functionality then displays position and orientation of these objects on a rendering functionality, such as a screen, monitor, or otherwise. Thus, these systems or processes, by sensing the position of surgical references, can display or otherwise output useful data relating to predicted or actual position and orientation of surgical instruments, body parts, surgically related items, implants, and virtual constructs for use in navigation, assessment, and otherwise performing surgery or other operations.  
         [0005]     Some of the surgical references used in these systems may emit or reflect infrared light that is then detected by an infrared camera. The references may be sensed actively or passively by infrared, visual, sound, magnetic, electromagnetic, x-ray or any other desired technique. An active reference emits energy, and a passive reference merely reflects energy. Some surgical references may have at least three, but usually four, markers or fiducials that are traced by an infrared sensor to determine the position and orientation of the reference and thus the position and orientation of the associated instrument, item, implant component or other object to which the reference is attached.  
         [0006]     In addition to surgical references with fixed fiducials, modular fiducials, which may be positioned independent of each other, may be used to reference points in the coordinate system. Modular fiducials may include reflective elements which may be tracked by two, sometimes more, sensors whose output may be processed in concert by associated processing functionality to geometrically calculate the position and orientation of the item to which the modular fiducial is attached. Like fixed fiducial surgical references, modular fiducials and the sensors need not be confined to the infrared spectrum—any electromagnetic, electrostatic, light, sound, radio frequency or other desired technique may be used. Similarly, modular fiducials may “actively” transmit reference information to a tracking system, as opposed to “passively” reflecting infrared or other forms of energy.  
         [0007]     Surgical references useable with the above-identified navigation systems may be secured to any desired structure, including the above-mentioned surgical instruments and other items. The surgical references may be secured directly to the instrument or item to be referenced. However, in many instances it will not be practical or desirable to secure the surgical references to the instrument or other item. Rather, in many circumstances it will be preferred to secure the surgical references to a handle and/or a guide adapted to receive the instrument or other item. For example, drill bits and other rotating instruments cannot be tracked by securing the surgical reference directly to the rotating instrument because the reference would rotate along with the instrument. Rather, a preferred method for tracking a rotating instrument is to associate the surgical reference with the instrument or item&#39;s guide or handle.  
         [0008]     Typical guides and handles are adapted to each only support one type of instrument or item. Consequently, a guide or handle must be provided for each instrument and item to be used in the surgical procedure. This may be undesirable for several reasons. Using a unique guide or handle for each surgical item substantially increases the amount of instrumentation present in the operating room. Additionally, it requires removing and installing new guides when different instruments are to be used, increasing the time and risk of infection associated with the surgical procedure.  
       SUMMARY  
       [0009]     Various aspects and embodiments of the present invention include modular portals adapted to serve as guides or handles for a wide variety of surgical instruments and other items. The modular portals may be adapted to allow the surgical items to access interior portions of an individual. For instance, modular portals according to certain embodiments of the present invention may be used to obtain unobstructed access to desired bone structures in an individual for performance of surgical procedures, such as installation of an implant. Additionally, modular portals according to certain embodiments of the present invention may allow the surgical instruments and other items received by the modular portals to be registered in and tracked by a computer-aided surgical navigation system. Such systems may track the position and orientation of the surgical item by tracking the position and orientation of the surgical reference associated with the modular portal. Because the modular portals may be used with a wide range of surgical items for a wide range of purposes, a unique guide and/or handle does not have to be constructed for each surgical item used in any given procedure.  
         [0010]     Modular portals according to certain aspects and embodiments of the present invention may include a base and a handle. The handle may or may not be integral to the base. Modular portals may also be associated with a surgical reference such that the position and orientation of the modular portal, as well as instruments or items associated with the modular portal, may be tracked by an image guided surgical-navigation system. In certain embodiments, the surgical reference may be associated with the base. In some of these embodiments, the base may be adapted to allow the surgical reference to be repositioned with respect to the base such that the surgical reference is in a convenient location. In other embodiments where the surgical reference is not associated with the base, the surgical reference may be secured to a platform that also supports the base, or other portions of the modular portal.  
         [0011]     Bases according to certain aspects and embodiments of the present invention may include apertures or other appropriate structure allowing the modular portals to receive surgical instruments and other items of various shapes and sizes. The instruments or other items receivable by the aperture may include a number of sleeves having different lengths and diameters. The sleeves may be secured to the base in any desired manner. In one embodiment, threads on proximal ends of the sleeves interact with corresponding threads in the aperture to secure the sleeves to the modular portal.  
         [0012]     In some embodiments, tips of various sizes and shapes may be interchangeably secured onto distal ends of the sleeves. The tips may be formed in a variety of configurations. For instance, a tip may be formed such that when the tip contacts a particular bone structure, the tip assists in centering the sleeve on that bone structure. Some tips may include teeth to further stabilize the modular portal (including the sleeve) with respect to the bone. Still other tips may be adapted to perform other desired functions. In some embodiments, the sleeves may include integrally formed tips. In other embodiments, the tips may be secured to the sleeves by any appropriate and/or desired structure.  
         [0013]     Sleeves according to various aspects and embodiments of the present invention may be used for a variety of functions and purposes. Sleeves according to certain embodiments may be used as entry tools, drill guides, tissue protectors and/or working channels. In some embodiments, two or more sleeves may be used simultaneously with a modular portal. For example, in one embodiment, a sleeve with a larger diameter may be used as a working channel and a sleeve with a smaller diameter may be mounted inside the working channel for use as a drill guide.  
         [0014]     Other surgical instruments or items may be used and navigated with modular portals in accordance with certain embodiments of the present invention with or without sleeves. The surgical items may be secured, received and/or supported by the modular portal in any desired manner. In some embodiments, other surgical items may be secured to the modular portal in the same manner as the sleeves described above. In some embodiments, the modular portal may include retaining mechanisms, such as a number of spring plungers that interact with a channel or channels on the surgical item such that the item is secured to the modular portal yet able to rotate.  
         [0015]     Surgical instruments and other items receivable by modular portals of this invention may include axisymmetric or non-axisymmetric items. In some embodiments, non-axisymmetric instruments or items may be locked into a certain configuration with regard to the modular portal through the addition of a key and a keyway.  
         [0016]     In some embodiments, the modular portal may include a measuring tool. The measuring tool may measure the length and/or diameter of an instrument or other item passing through the portal such that a correct graphical representation of the length and/or width of the instrument inserted through the portal can be displayed by the computer-aided surgical navigation system. Use of such a measuring tool may obviate the need to recalibrate the computer-aided surgical navigation system when different instruments or items are used. The measuring tool may be mechanical (such as a rotating wheel), electronic, electromagnetic or optical (such as a laser).  
         [0017]     In some embodiments, the modular portal may be used to reduce or eliminate the possibility of airborne contamination of the surgical wound. In such embodiments, the modular portal may include a suction tube to provide suction through the modular portal such that any blood associated with the wound is not aerosolized.  
         [0018]     In some embodiments, interface buttons communicatively associated with the computer-aided surgical navigation system or other computer functionality may be included on the handle, or other appropriate structure, of the modular portal. The interface buttons may communicate with the image-guided surgical navigation structure or other computer functionality using either wireless or wired technology. The interface buttons may function in lieu of or in addition to a conventional footswitch, mouse, keyboard or touch-screen buttons associated with the computer-aided surgical navigation system or other computer functionality. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]      FIG. 1  shows a modular portal according to a first embodiment of the present invention in perspective view.  
         [0020]      FIG. 2  shows a schematic view of a modular portal according to another embodiment of the present invention including a suction tube.  
         [0021]      FIG. 3  shows a modular portal according to another embodiment of the present invention in perspective view including a single interface button.  
         [0022]      FIG. 4  shows a modular portal according to another embodiment of the present invention in perspective view including two interface buttons.  
         [0023]      FIG. 5  shows a modular portal according to another embodiment of the present invention in perspective view including a sleeve secured to the modular portal.  
         [0024]      FIG. 6  shows a modular portal according to another embodiment of the present invention in perspective view including two sleeves secured to the modular portal.  
         [0025]      FIG. 7  shows a modular portal according to another embodiment of the present invention in perspective view including a sleeve with an attached beveled self-centering tip.  
         [0026]      FIG. 8  shows the sleeve of  FIG. 7  disconnected from the modular portal in perspective view.  
         [0027]      FIG. 9  shows a modular portal according to another embodiment of the present invention in perspective view including a short drill guide sleeve.  
         [0028]      FIG. 10  shows a modular portal according to another embodiment of the present invention in perspective view including a long drill guide sleeve.  
         [0029]      FIG. 11  shows a modular portal according to another embodiment of the present invention in perspective view including an osteotome blade.  
         [0030]      FIG. 12  shows a modular portal according to another embodiment of the present invention in perspective view including a honeycomb drill guide.  
         [0031]      FIG. 13  shows a modular portal according to another embodiment of the present invention in schematic view including a reducer/distractor.  
         [0032]      FIG. 14  shows the reducer of  FIG. 13  with its portal securing mechanism in an exploded view.  
         [0033]      FIG. 15  shows a computer-aided surgical navigation system according to another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0034]      FIG. 1  shows a modular portal  10  according to a first embodiment of the present invention. Modular portals  10  may be used as handles and/or guides for a wide array of surgical instruments or other surgical items. In some embodiments, such as the embodiment shown in  FIG. 1 , modular portal  10  may be associated with a surgical reference  22 . Surgical reference  22  may allow modular portal  10 , as well as the surgical instruments or items received by modular portal  10 , to be tracked by a computer-aided surgical navigation system, such as the system shown in  FIG. 15 . In some embodiments, modular portal  10  may be used in conjunction with certain surgical instruments and/or items to provided unobstructed access to interior portions of an individual.  
         [0035]     The modular portal  10  shown in  FIG. 1  includes a base  12  and a handle  14 . In some embodiments, handle  14  may be formed integrally with base  12 . In other embodiments, handle  14  may be connected to base  12  by any desired and/or appropriate structure. Preferably, the handle  14  is connected to the base  12  by threaded portions on the handle  14  and base  12 . Handle  14  may be a typical instrument handle used in operating rooms. However, handle  14  may be formed in any desired shape and/or size. In the embodiment shown in  FIG. 1 , handle  14  includes a number of slots  16 . Slots  16  may make it easier for a surgeon to grip the handle and/or may allow the handle to be mounted to other desired structure.  
         [0036]     In the embodiment shown in  FIG. 1 , base  12  is secured to a surgical reference support member  20  that allows a surgical reference  22  to be rigidly mounted to modular portal  10 . In some embodiments, support  20  may be repositioned with respect to base  12  such that the surgical reference  22  can be repositioned with respect to the modular portal  10 . In the embodiment shown in  FIG. 1 , a pin (not shown) on the base  12  engages one of a plurality of notches  24  in the support  20  to orient the support  20  with respect to the base  12 . Disengagement of the pin from the notch  24  allows the support  20  to be repositioned with respect to the base  12 . Once the support  20  is oriented in a desired position, the pin can be inserted into a corresponding notch  24 , securing the support  20  in a desired orientation with respect to the base  12 . Adjusting the position of surgical reference  22  in this manner may allow the surgeon or other user to orient the surgical reference  22  in a convenient location and/or in a location that can be better visualized by the computer-aided surgical navigation system.  
         [0037]     Suitable structures other than pins and notches  24  may be used to orient surgical reference  22  with respect to modular portal  10 . In other embodiments, support  20  is fixed with respect to base  12  and cannot be repositioned. In still other embodiments, support  20  is not necessary. Rather, surgical reference  22  may be associated with modular portal  10  in any suitable and/or acceptable manner. For instance, surgical reference  22  may be secured to other portions of modular portal  10  or may be secured to other structures associated with modular portal  10 . In one embodiment, surgical reference  22  is secured to a platform that supports and stabilizes the modular portal  10  with respect to the individual being operated on.  
         [0038]     Surgical reference  22  may be any structure that can be tracked by a computer-aided surgical navigation system. For instance, as illustrated in  FIG. 1 , the surgical reference  22  may be a conventional reference structure. In other embodiments, surgical reference  22  may be a number of modular fiducials. In still other embodiments, surgical reference  22  is a reference transmitter or receiver.  FIG. 12  shows support  20  adapted to support and secure an electromagnetic reference receiver.  
         [0039]     Base  12  may include an aperture  18  extending through a longitudinal portion of the base  12 . Aperture  18  may be of a suitable diameter to allow a wide variety of items to be passed through aperture  18  and/or secured to modular portal  10 . For instance, aperture  18  may be adapted to receive sleeves  26  of various shapes and sizes. Sleeves  26  may serve as working channels (such as the working channel shown in  FIG. 5 ); drill sleeves (such as the drill sleeves shown in  FIGS. 9 and 10 ); entry tools; eccentric sleeves; tissue protectors and/or any other desired functions. Aperture  18  may also receive other surgical instruments, such as the reducers  30  shown in  FIGS. 13 and 14 ; the osteotome blade  32  shown in  FIG. 11 ; the honeycomb drill sleeve  34  shown in  FIG. 12 ; drill bits; wrenches; screwdrivers, awls, guide wires, guide rods or any other desired instrument. Aperture  18  may also allow other items, such as surgical implants (including intramedullary nails), to pass through it.  
         [0040]     According to certain embodiments, because modular portal may be associated with a surgical reference  22 , the position and/or orientation of which can be tracked by a computer-aided surgical navigation system, aperture  18  may be used as a navigated target for a variety of purposes. For example, aperture  18  may be used as a working channel to navigate the entry point for a surgical incision. Aperture  18  could also act as a navigated target entry zone indicator for passing through a scope (such as an endoscope or an arthroscope) to allow visualization and identification of structures inside the patient, such as soft tissue structures.  
         [0041]     In certain embodiments, modular portals  10 , as navigated handles or guides, may be used with surgical instruments or other items for many purposes. For instance, modular portals  10 , in conjunction with appropriate instruments or other items such as sleeves  26 , could act as navigated tissue protectors. Modular portals  10  in conjunction with appropriate sleeves  26 , could navigate an entry point into a patient&#39;s bone by aiding in the navigation of an entry awl or guide pin. Additionally, modular portals  10  may be used to aid in the preparation of bones to receive implants by navigating reamer diameters and depths. Similarly, modular portals  10 , with or without sleeves  26 , may be used to navigate reducers, distractors and/or guide rods to aid in performing fracture reductions. Additionally, modular portals  10  may be used to navigate insertion and/or placement of implants (such as an intramedullary nail).  
         [0042]     Instruments and other items useable with modular portals  10  according to certain embodiments of the present invention may be axisymmetric (such as the sleeves  26  shown in  FIGS. 5-10 ) or non-axisymmetric (such as the osteotome blade  32  shown in  FIG. 11  and the reducers  30  shown in  FIGS. 13 and 14 ). In some embodiments, aperture  18 , or another suitable portion of modular portal  10 , may include either a key or a keyway to correspond to a keyway or a key located on a non-axisymmetric instrument to orient the instrument with respect to the modular portal in a defined geometry. Because, in certain embodiments, modular portals  10  and the associated surgical references  22  are fixed in defined geometries with respect to the non-axisymmetric instruments, the position and/or orientation of the non-axisymmetric instruments can be tracked by a computer-aided surgical navigation system.  
         [0043]     Surgical instruments and items useable with modular portals  10  may be secured to and/or guided by modular portals  10  in any desired manner. For instance, in the embodiment shown in  FIG. 1 , threads  36  circumscribing a portion of the interior surface of the aperture  18  may interact with appropriately sized and shaped threads on an instrument or item to secure the instrument or item to the modular portal  10 .  FIGS. 5-7  and  9 - 10  show various sleeves secured to the modular portals  10 .  FIG. 11  shows an osteotome blade  32  secured to a modular portal  10 .  FIG. 12  shows a honeycomb drill guide  40  secured to a modular portal  10 , which may be used to navigate multiple pins simultaneously. In some embodiments, a bracket on the honeycomb drill guide  40  secures the honeycomb drill guide  40  to the modular portal  10  in such a way that the honeycomb drill guide  40  rotates with the associated surgical reference  22 .  FIGS. 13 and 14  show reducers/distractors  30  in an assembled and an exploded view respectively secured to the modular portal  10 . Reducers/distractors  30  may be used for bone segment manipulation or reduction. As illustrated by  FIG. 14 , threads do not have to be located on an interior surface of aperture  18 . In the embodiment shown in  FIGS. 13 and 14 , threads of the outside of base  12  interact with threads on a portion of reducer  30  to secure reducer  30  to the modular portal  10 . Other surgical instruments and other items may be secured to modular portal  10  simply by adding appropriately sized and shaped threads to the item.  
         [0044]     In the embodiment shown in  FIGS. 7 and 8 , the sleeve  26  includes a tip  42  secured to a distal end of the sleeve  26 . Tips  42  may be secured to sleeves  26  in any desired manner. In the embodiment shown in  FIGS. 7 and 8 , tip  42  is secured to the sleeve  26  by snap locks on the tip  42 . The snap locks may lock into a channel, ridge or any other appropriate structure on the sleeve  26 . In other embodiments, the snap locks, or other appropriate structures, may be located on the sleeve; and the ridge or other appropriate structure may be located on the tip  42 .  
         [0045]     Tips  42  may be formed in a variety of shapes and sizes for a variety of purposes. In the embodiment shown in  FIGS. 7 and 8 , tip  42  is beveled, increasing the stability of the sleeve  26  when the tip  42  is resting on certain bone structures. The beveled tip  42  may also allow the tip  42  to self-orient itself on the bone so that the desired sleeve and/or instrument orientation is automatically achieved. In other embodiments, the tip  42  may be formed in other desired geometries to assist positioning the sleeve  26  with respect to a desired bone. In some embodiments, the tip  42  may be formed with or without teeth. The teeth may further stabilize the sleeve with respect to the bone. However, because teeth may cause skiving off bones in certain circumstances, they are not desirable in every situation. Consequently, other tips  42  may be formed without teeth. In some embodiments, some or all of these tips  42  may be formed integrally with desired and/or appropriate sleeves  26 .  
         [0046]     Surgical Instruments and other items may be secured to and/or guided by modular portal  10  in a rotating or non-rotating manner. These surgical items may be secured to and/or guided by modular portal  10  in conventional or non-conventional manners. In some embodiments, retaining mechanisms may extend from interior portions of aperture  18 . The retaining mechanisms may be adapted to interact with appropriately shaped structures on the desired instrument or other item such that the item is secured to the modular portal  10 , yet able to rotate with respect to the modular portal  10 . In a preferred embodiment, retaining mechanisms are rings of spring plungers extending around an inner circumference of aperture  18 . In the preferred embodiment, the instrument or other item includes at least one channel extending around a portion of the item such that insertion into the aperture  18  causes spring plungers to engage the channel, securing the item to the modular portal  10  in a rotating manner.  
         [0047]     In some embodiments, the modular portal  10  may include a measuring tool. The measuring tool may be adapted to measure the length and/or diameter of certain instruments or other items passing through aperture  18  of the modular portal  10 . Measuring the length and/or diameter of the item passing through aperture  18  may allow the item to be properly displayed by the computer-aided surgical navigation system without requiring a surgical reference secured directly to the item. The measuring device may be any appropriate device for measuring length and/or width, including mechanical, electrical and/or optical devices. In one embodiment, the measuring device may include a wheel that is adapted to contact a portion of the instrument or item passing through the aperture  18 . As the instrument or item moves through the aperture  18 , the wheel turns. The wheel may be associated with computer functionality such that the computer functionality can calculate the length of the portion of instrument that has passed through aperture  18  based on how much the wheel has turned. Additionally, the computer functionality may relay this information to the computer-aided surgical navigation system such that the proper position and/or orientation of the instrument is displayed.  
         [0048]     In some embodiments, such as the embodiment shown in  FIG. 2 , the modular portal  10  may include suction functionality. In such embodiments, the modular portal  10  may be adapted to connect to typical suction tubes used in operating rooms. In the embodiment shown in  FIG. 2 , the handle  14  is adapted to receive a suction tube, such as the suction tubes commonly used in operating rooms. A suction pipe  44  extending through the handle  14  into the aperture  18  allows suction to be applied into the aperture  18 . The application of suction into the aperture  18 , and consequently into the surgical wound, may reduce the amount of aerosolized blood present in the wound. Reducing the amount of aerosolized blood may reduce the chances of infection and contamination.  
         [0049]     In some embodiments, such as the embodiments shown in  FIGS. 3 and 4 , the modular portal  10  may include one or more interface buttons  46 . The interface button  46  may be connected to computer functionality, including the computer-aided surgical navigation system, using wired or wireless technology. The interface button  46  may allow the surgeon or other user to interface with the computer functionality without removing his or her hands from the handle  14  or other portions of the modular portal  10 . Interface buttons  46  according to certain aspects and embodiments of the present invention may be used in much the same way as typical interface buttons used in surgical settings, including footswitches, mice and touch-screen buttons.  
         [0050]     In some embodiments, the modular nature of the portal  10  allows the above described items as well as other surgical instruments and/or items to be used in conjunction with the modular portal  10  without removing the modular portal  10  from the patient. Rather, an instrument, sleeve  26 , or other item associated with the modular portal  10  could be removed such that another desired instrument, sleeve  26  or item can be associated with the portal  10 . The removal and replacement can all be accomplished without removing the portal  10  (and other items associated with the portal  10 ) from the patient, increasing the speed of the surgical procedure and lessening the chance of infection to the patient. Also, the modular nature of portal  10  allows a number of instruments and other items to be used in conjunction with a computer-aided surgical navigation system without creating a unique handle/grip or substantially modifying the surgical items.  
         [0051]     Modular portals  10  according to various aspects and embodiments of the present invention may be used for a wide variety of surgical procedures. For instance, during the installation of an intramedullary nail into a femur, the modular portal  10  may serve a number of functions. Initially, the aperture  18  of the modular portal  10  could be used as a navigated working channel for locating the proper incision area. Subsequently, the aperture  18  could act as a navigated target entry zone indicator for passing a scope into the incision to visualize soft tissues and other structures. Subsequently, a sleeve  26  could be installed into the modular portal  10 , creating a working channel for passing through other instruments necessary to complete the surgical procedure. The sleeve  26  could also serve the purpose of protecting soft tissues and other internal structures from damage during the surgical procedure. A beveled tip  42  with teeth could be included on a distal end of the sleeve to aid in locating the sleeve proximate the proper entry point into the intramedullary canal. An entry awl, guide pin, or other suitable instrument could then be passed through the working channel such that the instrument is navigated to the proper entry point into the bone. After the entry point is identified, the modular portal could be used to navigate a reamer diameter and depth to prepare the bone to receive the intramedullary nail. If necessary or desired, the modular portal could also be used to navigate a reducer, distractor and/or guide rod through the working channel to perform a fracture reduction. The modular portal may also be used to navigate the nail implant through the portal  10 . All of these steps may be performed without removing the modular portal  10  from the patient&#39;s soft tissue.  
         [0052]     The same modular portal  10  may be used to distally lock the intramedullary nail by replacing the long sleeve  26  including the beveled tip  42  with teeth with a shorter sleeve  26  with a tip  42  that does not include teeth. Teeth are generally not preferred for performing distal locking because the teeth may cause skiving of the sleeve off of the bone during drilling.  
         [0053]     Modular portals  10 , according to certain embodiments of the present invention, may also be used (with or without sleeve  26 ) in other surgical procedures. Other uses include: navigation of endoscopes or arthroscopes; navigation of entry points and positioning of instruments and implants; navigation of osteotomes  32  to aid in resectioning bone; navigation of cutting tools such as saws, reamers, and drill bits; navigation of sleeves and injectors for the placement of biologic agents, therapeutic agents and bone cement; navigation of dowel and plug bone cutting and grafting procedures; and navigation of bone stimulation therapies. Consequently, modular portals  10  according to certain aspects and embodiments of the present invention provide a versatile tool that can not only be used as a simple drill guide, but also as a navigated handle for a wide variety of applications.  
         [0054]     Changes and modifications, additions and deletions may be made to the structures recited above and shown in the drawings without departing from the scope or spirit of the invention and the following claims.