US20060069324A1 - Method and apparatus for performing a computer-assisted orthopaedic procedure - Google Patents

Abstract

A method of performing a computer-assisted orthopaedic procedure includes securing a sensor support instrument to the patient's bone. A number of sensors are secured to the support instrument. A computer-assisted orthopaedic surgical instrument is also disclosed.

Description

CROSS REFERENCE TO RELATED U.S. PATENT APPLICATION
• This application is a Continuation-in-Part of co-pending U.S. patent application Ser. No. 10/956,181 filed Sep. 30, 2004, and titled METHOD AND APPARATUS FOR PERFORMING A COMPUTER-ASSISTED ORTHOPAEDIC PROCEDURE, the disclosure of which is expressly incorporated herein by reference.
FIELD OF THE DISCLOSURE
• The present disclosure relates generally to a computer-assisted surgical instrument for use in the performance of an orthopaedic procedure.
BACKGROUND
• Many computer guided orthopaedic surgical procedures are based on determining the position of bones, and relating this position to the computer via some type of ultrasonic, magnetic resonance, or optical sensor. In such cases, a first sensor may be secured to the patient's bone, with a second sensor being secured to the surgical instrument so that the instrument may be subsequently guided via a computer into the desired position within the patient's bone. U.S. Patents and Patent Publications relating to computer guided surgery include U.S. Pat. No. 5,520,694 and U.S. patent application Publication Nos. 2003/0153978 A1 and 2003/01538829 A1, each of which is hereby incorporated by reference. Similar computer-assisted navigation systems are disclosed in U.S. Pat. Nos. 6,514,259; 6,434,507; 6,428,547; 6,424,856; 6,351,659; 6,223,067; 6,187,018; 6,178,345; 5,889,834; 5,769,861; 5,702,406; 5,643,268; and 5,628,315, along with U.S. patent application Publication No. 2002/0038118 A1, each of which is hereby incorporated by reference.
SUMMARY
• According to one aspect of the disclosure, a method of performing a computer-assisted orthopaedic hip procedure includes securing a sensor support instrument to the lesser trochanter of the patient's femur. The sensor support instrument has a number of sensors secured thereto.
• In one exemplary implementation, the sensor support instrument includes a screw that is screwed into the lesser trochanter. The screw may be a Shanz screw. The screw may be cannulated. The screw may be a cannulated Shanz screw.
• The sensor support instrument may also include a sensor support having a number of support arms. Each of the support arms may have a sensor secured thereto.
• The sensor support instrument may also include a support sleeve through which the screw extends.
• According to another aspect of the disclosure, a method of performing a computer-assisted orthopaedic procedure includes securing a cannulated screw to a patient's bone. A sensor may be secured to the cannulated screw.
• The tip of the cannulated screw may be positioned in the medullary canal of the patient's bone. The other end of the cannulated screw is positioned outside of the patient's body.
• The cannulated screw may be coupled to a negative pressure source via a suction tube thereby placing the medullary canal of the patient's bone in fluid communication with the negative pressure source.
• According to another aspect of the disclosure, a computer-assisted orthopaedic surgical instrument includes a cannulated screw having a sensor support coupled thereto. A number of sensors may be secured to the sensor support.
• The sensor support may be configured with a number of support arms. Each of the support arms may have a sensor secured thereto.
• The surgical instrument may also include a support sleeve through which the cannulated screw extends.
• According to another aspect of the present disclosure, a method of performing computer-assisted hip surgery includes securing a sensor support instrument to a proximal, posterior region of a patient's femur, and securing a sensor to the sensor support instrument. Illustratively, the proximal, posterior region includes the lesser trochanter, the greater trochanter, the intertrochanteric crest and any portions of the patient's femur therebetween.
• The step of securing the sensor support instrument to the proximal, posterior region may comprise screwing a screw into the proximal, posterior of the patient's femur.
• Further, the step of securing the sensor to the sensor support instrument comprises (i) coupling a sensor support to the screw, and (ii) coupling the sensor to the sensor support. Alternatively, the step of securing the sensor to the sensor support instrument may comprise (i) coupling a sensor support having three support arms to the screw, and (ii) coupling a sensor to each of the three support arms.
• The method may further include the step of securing a support sleeve to the patient's femur such that a portion of the screw is positioned in the support sleeve. Illustratively, the step of securing the sensor to the sensor support instrument may include securing the sensor to the support sleeve. Further, securing the sensor to the support sleeve may include (i) coupling a sensor support to the support sleeve, and (ii) coupling the sensor to the sensor support.
• According to one aspect of this disclosure, the step of securing the sensor support instrument to the proximal, posterior region may include screwing a screw into the proximal, posterior region of the patient's femur such that a tip of the screw is positioned in the medullary canal of the patient's femur. Further illustratively, screwing a screw into the proximal, posterior region comprises screwing a cannulated screw into the proximal, posterior region of the patient's femur. The method may further include the step of coupling the cannulated screw to a negative pressure source thereby placing the medullary canal of the patient's femur in fluid communication with the negative pressure source.
• According to another aspect of the present disclosure, a method of performing computer-assisted hip surgery includes locating one or more of the greater trochanter, the lesser trochanter, and the intertrochanteric crest of a patient's femur, measuring a pre-determined distance from one or more of the greater trochanter, the lesser trochanter, and the intertrochanteric crest to a second location, securing a sensor support instrument to the second location, and securing a sensor to the sensor support instrument.
• The above and other features of the present disclosure will become apparent from the following description and the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• The detailed description particularly refers to the accompanying figures in which:
• FIG. 1 is an exploded perspective view of the cannulated screw and the sensor support sleeve;
• FIG. 2 is a perspective view of the sensor support and the adjustable linkage;
• FIG. 3 is a fragmentary cross sectional view showing the cannulated screw positioned in the sensor support sleeve;
• FIG. 4 is a fragmentary perspective view showing the sensor support instrument ofFIGS. 1-3 secured to the lesser trochanter of a patient's femur;
• FIG. 5 is a posterior perspective view of a left femur showing a particular region of the femur defined by a dotted line; and
• FIG. 6 shows the femur ofFIG. 5 as well as multiple cannulated screws (some shown in phantom) secured to femur within the proximal, posterior region defined inFIG. 5.
DETAILED DESCRIPTION OF THE DRAWINGS
• Referring now toFIGS. 1-3, there is shown asurgical instrument10 for use in a computer-assisted orthopaedic procedure. Thesurgical instrument10 is used to support a number of sensors12 (seeFIG. 4). The location of thesensors12 is tracked or otherwise monitored by a computer (not shown) of a computer-assisted surgical system. Thesensors12 may be embodied as ultrasonic, magnetic resonance, or optical sensors, for example. Sensors which are suitable for use as thesensors12 are commercially available from BrainLAB AG of Heimstetten, Germany.
• Thesurgical instrument10 includes ascrew14 which may be screwed into the patient's bone during a surgical procedure. In an exemplary implementation, thescrew14 is embodied as a Shanz screw. Thescrew14 is cannulated, and, as such, has anelongated bore16 extending therethrough. Thecannulated screw14 has atrocar tip18 defined in oneend portion20 thereof. Other tip configurations, such as a self-tapping drill bit tip, may also be used. A series ofthreads22 extend from thetip18 in the direction toward theother end portion24 of thescrew14.
• Thesurgical instrument10 also includes asensor support sleeve26. Thesensor support sleeve26 has an elongated bore28 extending therethrough. Oneend30 of thesensor support sleeve26 has a number ofbone engaging tips32 defined therein which engage the outer surface of the patient's bone. Aset screw34 is located on theother end36 of thesensor support sleeve26. When tightened, theset screw34 engages the cannulatedscrew14 thereby preventing relative rotation between thescrew14 and thesupport sleeve26.
• A mountingflange38 extends outwardly from theouter end36 of thesensor support sleeve26. A corresponding mountingflange40 of anadjustable linkage42 is removably coupled to the sleeve's mountingflange38. Thelinkage42 couples thesupport sleeve26 to asensor support44. Thesensor support44 includes threesupport arms46, each of which has a threadedshaft48 extending outwardly therefrom. Illustratively, each of thesensors12 has a threaded bore (not shown) formed therein. The sensors are threaded onto theshafts48 of thesupport arms46. Although thesensor support44 is herein described as having three support arms46 (for supporting three sensors12), it should be appreciated that thesensor support44 may be configured with any number of support arms46 (to support any number of sensors12). Further, it should be appreciated that although eachsupport arm46 of thesensor support44 includes a threadedshaft48 and eachsensor12 includes a threaded bore for attachment onto one of the threadedshafts48, thesensors12 may include non-threaded bores and may be snap-fit or press-fit onto non-threaded shafts or posts (not shown) of eachsupport arm46.
• Theadjustable linkage42 includes atensioning knob50. By loosening theknob50, thesensor support44 may be pivoted or otherwise moved relative to thesensor support sleeve26 thereby allowing a surgeon to adjust the position of thesensors12. Once the surgeon has positioned thesensor support44 in a desired position, theknob50 may be tightened thereby retaining thesupport44 in such a position.
• Use of thesurgical instrument10 is shown inFIG. 4, and will now be described in greater detail in regard to an orthopaedic hip replacement procedure. However, it should be appreciated that use of thesurgical instrument10 is not limited to hip procedures, with the following discussion being exemplary in nature.
• As shown inFIG. 4, thesurgical instrument10 is secured to thelesser trochanter52 of the patient'sfemur54. Thelesser trochanter52 provides a convenient anatomical landmark which is readily accessible during most hip procedures. It allows thesensors12 to be positioned in a desirable location with respect to the surgeon and the computer/camera/detector of the computer-assisted surgical system (not shown).
• The cannulatedscrew14 is advanced through thelesser trochanter52 such that itstip18 extends into themedullary canal56 of the patient'sfemur54. Theouter end portion24 of the cannulatedscrew14 extends out of the patient's body. The cannulatedscrew14 may be inserted in any desirable angle. By inserting the cannulatedscrew14 into thefemur54, a fluid path for venting the proximal femur is created. Such venting of the proximal femur removes blood, fat, intramedullary marrow, or other substances which could be the source of embolic material during, for example, the preparation and cementation process.
• Moreover, a negative pressure source, such as avacuum source58 may be fluidly coupled to theouter end24 of the cannulatedscrew14 via asuction tube60. In such a way, theintramedullary canal56 of the patient'sfemur54 is placed in fluid communication with thevacuum source58 via a fluid path that includes the elongated bore16 of the cannulatedscrew14 and thesuction tube60. Use of thevacuum source58 facilitates venting of the proximal femur. Moreover, during cementation, the negative pressure assists interdigitation of the bone cement to the bone surface. The negative pressure also helps draw down the femoral component (e.g., femoral articular surface component) thereby reducing the need for impaction.
• Thesensor support sleeve26 is then advanced over the cannulatedscrew14 such that thescrew14 is received into the elongated bore28 of thesleeve26. Thesupport sleeve26 is advanced to a position in which itstips32 engage the outer surface of the patient'sfemur54. If need be, the rotational position of thesupport sleeve26 relative to thescrew14 may then (or at anytime) be adjusted by loosening theset screw34 and thereafter rotating the sleeve relative to thescrew14. Once thesleeve26 is positioned in a desired rotational position relative to thescrew14, theset screw34 is tightened thereby preventing relative rotation between thescrew14 and thesupport sleeve26.
• If not already installed (e.g., prior to installation of the support sleeve26), the adjustable linkage42 (and hence the sensor support44) is then secured to thesensor support sleeve26. To do so, the mountingflange38 of thesensor support sleeve26 is mated with or otherwise secured to the corresponding mountingflange40 of theadjustable linkage42. If not already installed, thesensors12 are then installed onto the threadedshafts48 of thesupport arms46. The location of thesensors12 may then be adjusted (if need be) by use of the adjustment knob50 (to pivot the sensor support44) and/or the set screw34 (to rotate thesupport sleeve26 and hence the sensor support44).
• Once thesensors12 are in place, the computer-assisted orthopaedic hip procedure may continue. During the conclusion of the procedure, the support sleeve26 (with or without theadjustment linkage42 having been previously removed) is removed from the patient, and the cannulatedscrew14 is reversed out of the patient'sfemur54.
• Although thesensor support44 and thesensor support sleeve26 are shown as two separate components, as shown inFIGS. 1 and 2, which may be secured to one another, as shown inFIG. 4, it should be appreciated that thesensor support44 and thesensor support sleeve26 may form a common, one-piece component or may still be embodied as multiple components which are not removable from one another.
• It should be appreciated that thelesser trochanter52 may be used as an insertion site for any type of sensor support instrument. In particular, although insertion into thelesser trochanter52 is herein described in regard to thesurgical instrument10, it is contemplated that thelesser trochanter52 may serve as a beneficial insertion site for any type of instrument for supporting thesensors12. It is also contemplated that thesurgical instrument10 may be inserted into bone sites other than the lesser trochanter (including sites on bones other than the femur).
• While it is described that thesensor support instrument26 is secured to thelesser trochanter52, it is contemplated that thelesser trochanter52 may serve as an anatomical landmark or location for allowing the surgical team to measure and position the sensor support instrument26 a particular distance in any direction from thelesser trochanter52. In other words, it is contemplated that the computer-assisted hip surgery may include locating thelesser trochanter52 and then positioning thesensor support instrument26 some distance in any direction from the lesser trochanter52 (i.e., but not on thelesser trochanter52 itself). Once thesensor support instrument26 is secured to the patient's femur in the desired location, the sensor(s)12 may be secured to thesensor support instrument26 and thescrew14 may be inserted through thesensor support instrument26 and screwed into the patient's bone.
• Looking now toFIGS. 5 and 6, a posterior view of the proximal end of a patient'sleft femur154 showing aposterior side155 of thefemur154 is provided. Thefemur154 includes thehead156 andneck158 portions of thefemur154. Further, aposterior region160 of the proximal end of thefemur154 adjacent theneck158 is defined by the dashed line shown in bothFIGS. 5 and 6. Generally, thisposterior region160 extends between and includes thegreater trochanter162, thelesser trochanter52, the posteriorintertrochanteric crest164, and any areas of theposterior side155 of thefemur154 therebetween. More specifically, an exemplary area of thisposterior region160 includes portions of the surface of thefemur154 defined by a line drawn from the lateral-most point orportion170 of the posterior side orsurface155 of thefemur154, to the superior-most point orportion172 of thegreater trochanter162, along theintertrochanteric crest164 to thelesser trochanter52, around to the medial-most point or portion174 of thelesser trochanter52 to the distal-most point orportion176 of thelesser trochanter52, and along aproximal edge178 of theshaft180 of thefemur154 back to thelateral-most point170 of theposterior side155 of thefemur154.
• Illustratively, thesurgical instrument10 discussed above in regards toFIGS. 1-4 may be secured to thefemur154 anywhere within theposterior region160 of thefemur154 as defined above and outlined inFIGS. 5 and 6. For example,FIG. 6 illustratively shows the cannulatedscrew14 of thesurgical instrument10 having been advanced through a portion of thegreater trochanter162 within theposterior region160. Further,FIG. 6 illustrates, in phantom, the cannulatedscrew14 of thesurgical instrument10 having been advanced through a portion of thelesser trochanter52 as well through a portion of thefemur154 near theintertrochanteric crest164 of theposterior region160. In other words, thesurgical instrument10 may be secured to any portion of theposterior region160 of the patient'sfemur154 as defined above and specifically outlined withinFIGS. 5 and 6.
• Theposterior region160 of the patient'sfemur154 provides a convenient anatomical landmark which is readily accessible during most hip procedures. It allows thesensors12 of thesurgical instrument10 to be positioned in a desirable location with respect to the surgeon and the computer/camera/detector of the computer-assisted surgical system. Illustratively, the use of thesurgical instrument10 and its attachment to theposterior region160 of the patient's femur is the same as or similar to that discussed above with respect toFIGS. 1-4. In other words, thesurgical instrument10 is attached to theposterior region160 of the patient's femur in the same way thesurgical instrument10 is attached to thelesser trochanter52, as shown inFIG. 4.
• Further, it should be appreciated that theposterior region160 may be used as an insertion site for any type of sensor support instrument. In particular, although insertion into thefemur154 within theposterior region160 of thefemur154 is herein described in regard to thesurgical instrument10, it is contemplated that theposterior region160 may serve as a beneficial insertion site for any type of instrument for supporting thesensors12. It is also contemplated that thesurgical instrument10 may be inserted into bone sites other than theposterior region160 of thefemur154 including sites on bones other than the femur.
• Further, while it is described that thesensor support instrument26 is secured to theposterior region160, it is contemplated that theposterior region160 of the patient'sfemur154 may serve as an anatomical landmark or location for allowing the surgical team to measure and position of the sensor support instrument26 a particular distance in any direction from theposterior region160 or from any particular anatomical landmark within the posterior region160 (such as thegreater trochanter162, thelesser trochanter52, and theintertrochanteric crest164, for example). In other words, it is contemplated that the computer-assisted hip surgery may include locating theposterior region160, or any particular anatomical landmark within theposterior region160, and then positioning thesensor support instrument26 some distance in any direction from theposterior region160 or the particular landmark within theregion160. Once thesensor support instrument26 is secured to the patient's femur in the desired location, the sensor(s)12 may be secured to thesensor support instrument26 and thescrew14 may be inserted through thesensor support instrument26 and screwed into the patient's bone.
• While the disclosure is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and has herein be described in detail. It should be understood, however, that there is no intent to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.
• There are a plurality of advantages of the present disclosure arising from the various features of the apparatus and methods described herein. It will be noted that alternative embodiments of the apparatus and methods of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of an apparatus and method that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the present disclosure.

Claims (15)

1. A method of performing computer-assisted hip surgery, the method comprising the steps of:

securing a sensor support instrument to the posterior surface of a patient's proximal femur, and

securing a sensor to the sensor support instrument.

2. The method ofclaim 1, wherein the step of securing the sensor support instrument to the posterior surface comprises securing the sensor support instrument to a region of the posterior surface of the proximal femur consisting of the lesser trochanter, the greater trochanter, the intertrochanteric crest and any portions of the patient's femur therebetween.

3. The method ofclaim 1, wherein the step of securing the sensor support instrument to the posterior surface comprises securing the sensor support instrument to a region of the posterior surface of the proximal femur defined by a line drawn from the lateral-most portion of the posterior surface of the proximal femur, to the superior-most portion of the greater trochanter, along the intertrochanteric crest to the lesser trochanter, around to the medial-most portion of the lesser trochanter to the distal-most portion of the lesser trochanter, and along a proximal edge of the shaft of the femur to the lateral-most portion of the posterior surface of the femur.

4. The method ofclaim 1, wherein the step of securing the sensor support instrument to the posterior surface of the patient's proximal femur comprises screwing a screw into the posterior surface of the patient's proximal femur.

5. The method ofclaim 4, wherein the step of securing the sensor to the sensor support instrument comprises (i) coupling a sensor support to the screw, and (ii) coupling the sensor to the sensor support.

6. The method ofclaim 4, wherein the step of securing the sensor to the sensor support instrument comprises (i) coupling a sensor support having three support arms to the screw, and (ii) coupling a sensor to each of the three support arms.

7. The method ofclaim 4, further comprising the step of securing a support sleeve to the patient's proximal femur such that a portion of the screw is positioned in the support sleeve.

8. The method ofclaim 7, wherein the step of securing the sensor to the sensor support instrument comprises securing the sensor to the support sleeve.

9. The method ofclaim 8, wherein securing the sensor to the support sleeve comprises (i) coupling a sensor support to the support sleeve, and (ii) coupling the sensor to the sensor support.

10. The method ofclaim 1, wherein the step of securing the sensor support instrument to the posterior surface of the patient's proximal femur comprises screwing a screw into the posterior surface of the patient's proximal femur such that a tip of the screw is positioned in the medullary canal of the patient's proximal femur.

11. The method ofclaim 10, wherein screwing a screw into the posterior surface of the patient's proximal femur comprises screwing a cannulated screw into the posterior surface of the patient's proximal femur.

12. The method ofclaim 11, further comprising the step of coupling the cannulated screw to a negative pressure source thereby placing the medullary canal of the patient's femur in fluid communication with the negative pressure source.

13. A method of performing computer-assisted hip surgery, the method comprising the steps of:

locating one or more of the greater trochanter, the lesser trochanter, and the intertrochanteric crest of a patient's femur,

measuring a pre-determined distance from one or more of the greater trochanter, the lesser trochanter, and the intertrochanteric crest to a second location,

securing a sensor support instrument to the second location, and

securing a sensor to the sensor support instrument.

14. The method ofclaim 13, wherein the step of securing the sensor support instrument to the second location comprises screwing a screw into the second location of the patient's femur.

15. The method ofclaim 14, wherein the step of securing the sensor to the sensor support instrument comprises (i) coupling a sensor support to the screw, and (ii) coupling the sensor to the sensor support.

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