WO2014126913A2

WO2014126913A2 - Pressure alleviating instruments and methods

Info

Publication number: WO2014126913A2
Application number: PCT/US2014/015787
Authority: WO
Inventors: Alec Paul PORZEL; Thomas William LUX
Original assignee: Smith & Nephew, Inc.
Priority date: 2013-02-13
Filing date: 2014-02-11
Publication date: 2014-08-21
Also published as: WO2014126913A3

Abstract

Embodiments of the invention include surgical instruments and methods for preparing bones to receive orthopedic implants. In particular, some embodiments include surgical instruments and methods that provide for preparation of bones without generating some additional, unwanted forces associated with positive and negative fluidic pressures that can be created by movement of surgical instruments relative to the bones being prepared. Some embodiments provide improved control of fluid flows when surgical instruments are moved relative to the bones being prepared.

Description

PRESSURE ALLEVIATING INSTRUMENTS AND METHODS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional Application Serial No. 61/764,375 filed February 13, 2013, the contents of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

[0002] The present invention relates generally to the field of medical instruments and methods of use, and more particularly relates to surgical instruments and methods for preparing a bone to receive an orthopedic implant.

BACKGROUND

[0003] It is common when preparing a bone to receive an orthopedic implant to drill, scrape, or mill out an opening or area and then to more precisely prepare the opening or area by compacting, rasping, punching, or trialing the opening by pushing, driving, or impacting surgical instruments into the opening or area. It is also common to prepare a bone to receive an orthopedic implant by only compacting, rasping, punching, or trialing an opening or area by pushing, driving, or impacting surgical instruments into the opening or area. It can be difficult, however, to preserve optimal bone quality when compacting, rasping, punching, or trialing in a bone. Because preparation of a bone may lead to leakage of blood and other bodily fluids from the bone, there is a tendency for fluid to build up around the surgical instruments being used to prepare the bone. Irrigation water and other fluids may also be present in a bone being prepared. Any of these fluids may contribute to hydraulic pressures, both positive and negative, being generated by movement of an orthopedic instrument relative to a bone. For example, when an orthopedic instrument is advanced into a medullary canal and a tight fit or fluidic environment creates a seal between the orthopedic instrument and the bone, further advancing the orthopedic instrument will create positive pressures within the medullary canal. These positive pressures may contribute to the fracture of a bone directly or may enhance the need for greater forces to be applied to the orthopedic instrument to overcome the initial positive pressures to move the orthopedic instrument, thus leading to even higher forces and higher positive pressures being applied to and potentially damaging the bone.

[0004] Similarly, strong and damaging negative pressures may be created when an orthopedic implant is removed from a bone, such as, for example, a medullary canal of a bone. More particularly, when an orthopedic instrument is embedded tightly or in a fluidic

environment in a bone and the orthopedic instrument is removed, a vacuum or negative pressure may be generated beyond a distal end of the orthopedic instrument. Therefore, a stronger force is required to remove the instrument from the bone. This force is often so strong that a slap hammer or mallet is needed to overcome the negative pressure and remove the orthopedic instrument from the bone. This greater force is potentially damaging to the patient's bone.

[0005] Increased positive pressures may also lead to less than optimal results in an operating room with regard to control of a patient's bodily fluids. It is not uncommon when an orthopedic instrument is driven into a bone for the positive pressure created beyond the distal tip of the orthopedic instrument to cause bodily fluids to be vigorously expelled from the patient. Bodily fluids may, consequently, be propelled up to several feet across an operating room.

[0006] Improved instruments and methods may provide pressure alleviation pathways for fluid pressures resulting from movement of orthopedic instruments relative to bones. Alleviation of one or both of elevated negative and positive pressures would have the potential to lessen stresses applied to patients' bones, and consequently lead to better patient outcomes. Improved instruments and methods may also help to better manage patients' bodily fluids in the operating room by controlling the flow of bodily fluids potentially pressurized by the preparation of bones to receive implants. SUMMARY

[0007] An embodiment of the invention is a tibial punch configured to prepare a cavity in a medullary canal of a tibia, the cavity for receiving an orthopedic implant. The tibial punch may include a body with a portion configured to receive a force to drive the tibial punch into the medullary canal of the tibia and a punch tip configured to be driven into the medullary canal of the tibia. The punch tip may be of a size and shape to prepare the cavity to receive the orthopedic implant. The tibial punch may also include an opening through the punch tip configured to provide fluid communication through the punch tip with a volume outside of the tibial medullary canal such that fluid pressure within the tibial medullary canal is alleviated to a pressure approximately equivalent to a pressure in the volume outside of the tibial medullary canal as the punch tip is driven into the tibial medullary canal.

[0008] Another embodiment of the invention is a punch configured to prepare a cavity in a medullary canal, the cavity for receiving an orthopedic implant. The punch may include a body with a portion configured to receive a force to drive the punch into the medullary canal and a punch tip configured to be driven into the medullary canal. The punch tip may include a peripheral edge configured to shear material from the medullary canal in a shape that matches a cross-section of the orthopedic implant to be received within the cavity when the punch tip is driven into the medullary canal. The punch may also include an opening through the punch tip configured to provide fluid communication through the punch tip with a volume outside of the medullary canal such that fluid pressure within the medullary canal is alleviated to a pressure approximately equivalent to a pressure in the volume outside of the medullary canal as the punch tip is driven into the medullary canal.

[0009] Yet another embodiment of the invention is a method of preparing a cavity in a medullary canal for an orthopedic implant. The method may include driving a surgical instrument into the medullary canal. The driven surgical instrument may include a punch tip that forms a seal with the medullary canal such that a positive pressure is generated in the medullary canal distal of the punch tip as the surgical instrument is driven into the medullary canal, and an opening through the punch tip that provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal. The method may also include removing the surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip and implanting an orthopedic implant in the cavity in the medullary canal created by the surgical instrument.

[00010] Still another embodiment of the invention is a method of preparing a cavity in a medullary canal for an orthopedic implant. The method may include driving a surgical instrument into the medullary canal. The surgical instrument may include a punch tip that creates a positive pressure in the medullary canal distal of the punch tip as the surgical instrument is driven into the medullary canal, and an opening through the punch tip that provides a passage for fluid from within the medullary canal along a path that leads outside of the surgical instrument in a direction greater than 180 degrees from the direction of the driving of the surgical instrument. In the method, fluid may be expelled from the surgical instrument in a direction greater than 180 degrees from the direction of the driving of the surgical instrument as a result of the driving of the surgical instrument. The method may also include removing the surgical instrument from the medullary canal.

[00011] Another embodiment of the invention is a method of preparing a cavity in a medullary canal for an orthopedic implant that may include driving a surgical instrument into the medullary canal. The driven surgical instrument may include a punch tip with a cross-sectional shape that is proportional to the cross-sectional shape of the orthopedic implant. The punch tip may create an approximately constant cross-sectional shaped cavity along the entire length of the medullary canal through which the punch tip is driven, and an opening may be provided through the punch tip that provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal. The method may also include removing the surgical instrument from the medullary canal and implanting an orthopedic implant in the cavity in the medullary canal created by the surgical instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

[00012] FIG. 1 is a perspective view of an embodiment of a surgical instrument directed toward a tibia being prepared to receive a surgical implant.

[00013] FIG. 2 is a perspective view of the surgical instrument illustrated in FIG. 1 being inserted into a tibia.

[00014] FIG. 3 is a perspective view of the surgical instrument of FIG. 1. [00015] FIG. 4 is a perspective view of a distal end of the surgical instrument of FIG. 1.

[00016] FIG. 5 is an additional perspective view of the distal end of the surgical instrument of FIG. 1.

[00017] FIG. 6 is a perspective view of the surgical instrument of FIG. 1.

[00018] FIG. 7 is a perspective view of an embodiment of a surgical instrument.

[00019] FIG. 8 is a cross-sectional view of the surgical instrument of FIG. 7.

[00020] FIG. 9 is a plan view of an embodiment of a clearing device for use in combination with the surgical instrument of FIG. 7.

[00021] FIG. 10 is a plan view of an embodiment of an opening plug for use in combination with the surgical instrument of FIG. 7.

DETAILED DESCRIPTION

[00022] In an example embodiment, a surgical instrument 1 is shown in FIG. 1 directed toward a tibia 100 that is being prepared to receive a surgical implant. The surgical instrument 1 is illustrated driven into the tibia 100 in FIG. 2. In other embodiments, a surgical instrument may be driven more or less deeply into a tibia during a total knee arthroplasty procedure. By driving the surgical instrument 1 into the tibia 100, the tibia 100 can be prepared to receive a tibial component of a total knee arthroplasty surgical implant system, in this example.

[00023] One embodiment of a surgical instrument is illustrated in FIGS. 1 -6. The surgical instrument 1 that is shown is a tibial punch configured to prepare a cavity in a medullary canal of a tibia 100. In the illustrated embodiment, the cavity prepared is for receiving a tibial component of a total knee arthroplasty surgical implant system. In other embodiments of the invention, a surgical instrument may be used to prepare a cavity in a medullary canal of a femur, a humerus, or any other bone with a medullary canal or other pocket or volume of cancellous bone. In addition, in some embodiments of the invention a surgical instrument may be used to prepare a cavity in one or both of cortical and cancellous bone after the bone is initially prepared by another instrument such as, without limitation, a drill, an awl, a reamer, a needle, or a spike.

[00024] Particular details of an embodiment of the surgical instrument 1 are provided in FIGS. 3-6. The surgical instrument 1 shown has a body 10, with a portion 1 1 configured to receive a force to drive the surgical instrument 1 into the medullary canal of the tibia 100. The portion 1 1 illustrated (FIG. 3) is configured as a striking area to receive a force from a striking tool such as, without limitation, a mallet or a hammer. Other embodiments may include force receiving areas configured to ergonomically receive force from a hand or other anatomical structure of a user. Some embodiments may include force receiving areas configured for the connection of additional tools that apply forces to the surgical instrument. For example and without limitation, any force receiving area may include a connection for a slap hammer, an automated impaction tool, or any other tool or device capable of delivering a force to accomplish driving of the surgical instrument 1.

[00025] The surgical instrument 1 illustrated includes a punch tip 12 configured to be driven into the medullary canal of the tibia 100. The punch tip 12 shown includes only the far distal tip of the surgical instrument 1. However, in other embodiments a punch tip may be a greater proportion of the entire length of a surgical instrument. The illustrated punch tip 12 is of a size and shape appropriate to prepare a cavity in the tibia 100 to receive a tibial component of a total knee arthroplasty system. In the illustrated embodiment, the punch tip 12 has a round cross- sectional shape to match the shape of all or a part of the total knee arthroplasty tibial component. A punch tip of other functional shapes is also contemplated. The size of the punch tip 12 in some embodiments may be the same as the size of the orthopedic implant to be placed or may be slightly smaller than the size of the orthopedic implant to be placed when it is desirable to create a tighter, final fit between the orthopedic implant and the bone.

[00026] The punch tip 12, as more particularly illustrated in FIGS. 4-6, includes a

substantially planar surface 13 that is substantially perpendicular to a major longitudinal axis of the surgical instrument 1. In other embodiments, the substantially planar surface 13 may be given other shapes to accomplish various punching or cutting tasks. For example and without limitation, other embodiments of the punch tip may include a convex or concave curved surface, a conical surface, a serrated or rasp type surface, or any other effective shape. In the illustrated embodiment, the punch tip 12 includes a peripheral edge 14 between the substantially planar surface 13 on the outer edge of the punch tip 12. The peripheral edge 14 shown is configured to shear material from a tibial medullary canal. Material in this embodiment is sheared in a shape that matches a cross-section of at least a portion of the tibial component to be received within the cavity in the bone when the punch tip is driven into the tibial medullary canal. In some embodiments, a punch tip of the surgical instrument is the portion of the surgical instrument that is accomplishing the shaping and cutting. In other words, in some embodiments the punch tip is configured to prepare the cavity by its passage through bone, and the rest of the surgical instrument is configured to support and provide driving mechanisms for the punch tip. In other embodiments, the punch tip may extend more proximally along the surgical instrument, or other portions of the surgical instrument may work along with or separately from the punch tip to also accomplish shaping and cutting to prepare a cavity to receive an orthopedic implant.

[00027] An opening 20 through the punch tip 12 is shown in detail in FIGS. 4-6. The illustrated opening 20 is configured to provide fluid communication through the punch tip 12 with a volume beyond the punch tip 12. For example, in illustrated embodiment the opening 20 provides fluid communication through the punch tip 12 to a volume outside of the tibial medullary canal as the surgical instrument 1 is driven into the tibia 100, as in FIG. 2. As used herein, the term fluid may describe a liquid, a gas, or any combination of the two, and should be considered broadly enough to encompass liquids or gases which contain some solids mixed in with the liquids or gases. As a result of the opening 20, fluid pressure within the tibial medullary canal is alleviated to a pressure approximately equivalent to a pressure in the volume outside of the tibial medullary canal as the punch tip 12 is driven into the tibial medullary canal. In an instance where the punch tip 12 is being driven into a bone, the pressure alleviation is a reduction in the magnitude of a positive pressure. In an instance where the punch tip 12 is being pulled out of a bone, the pressure alleviation is a reduction in the magnitude of a negative pressure.

[00028] The opening 20 that is illustrated in FIGS. 4-6 includes a hole from a distal extent of the punch tip 14 into the body 10 of the surgical instrument 1. Multiple fluid pathways are shown in the illustrated embodiments. For example, a first passage 21 and a second passage 22 are shown that provide respective pathways to volumes proximal of the distal extent of the punch tip 12. A third passage 23 is shown only in FIG. 4 and provides a pathway to another volume proximal of the distal extent of the punch tip 12. The third passage 23 extends further into the body 10 of the surgical instrument 1. Passages through the surgical instrument 1 that provide pathways to other volumes proximal of the distal extent of the punch tip 12 of any other effective configuration are also contemplated.

[00029] The opening 20 illustrated in FIGS. 4-6 has a round cross-section. However, in other embodiments the opening 20 may be of any effective cross-sectional shape or size to allow a fluid pathway through the punch tip 12. For example and without limitation, an opening may have a rectangular, slotted, crosshatched, mesh, triangular, or irregular cross-sectional shape and size. In some embodiments an opening has a diameter between 1 mm and 7 mm. The term diameter is used in this cross-sectional shape description to describe an average side-to-side dimension across an opening or combination of shapes forming an opening.

[00030] In some embodiments, pathways such as the first, second, and third passages (21 , 22, 23), and any other functional passage, may serve as one or both of an entrance and an exit into or out of a surgical instrument. For example, as a surgical instrument is driven further into a bone, a pathway which was previously outside of the bone may be captured within the bone, and consequently may be connected directly to a different volume than the volume to which it was initially connected. Specifically, for example, the first passage 21 might initially serve as a pathway out of the hole extending from the opening 20, but as the surgical instrument is driven further into the medullary canal, serve as another entry point into the hole. Therefore, it is envisioned in some embodiments that a pathway, as described herein, may serve multiple functions during the use of a surgical instrument.

[00031] Some embodiments of the invention may also include a pressurization source configured to connect with an opening, such as the opening 20, to apply a pressure differential within the opening 20. Connection to the opening 20 may be accomplished through connection to other passages, holes, pathways or the like that connect with the opening 20. Application of either a positive or a negative pressure is contemplated. A nonlimiting example of a positive pressure application device is a rubber bulb placed near a proximal end of the body 10 that could be depressed to push fluid and other material distally through the surgical instrument 1 and out of the opening 20. This or another positive pressure may be used to offset a negative pressure created beyond a distal extent of a punch tip when the punch tip is being withdrawn from a bone, thereby reducing the amount of force required to remove the surgical instrument. A nonlimiting example of a negative pressure application device is operating room suction equipment which could be applied near the proximal end of the body 10 to pull fluid and other material proximally through and potentially out of the surgical instrument 1.

[00032] Another embodiment of a surgical instrument is illustrated in FIGS. 7-8. As shown, a surgical instrument 201 is essentially similar to the surgical instrument 1, but includes an extended hole 230 from a punch tip 212 all the way through the surgical instrument 201 to a portion 21 1 configured to receive a force to drive the surgical instrument 201. The extended hole 230 provides an unobstructed path and a fluid communication pathway from an opening 220 to a proximal extent of the surgical instrument 201. A proximal opening 240 is provided through the portion 21 1.

[00033] The surgical instrument 201 may be combined with various other devices to provide additional functionality to the instrument. Examples of two such devices are illustrated in FIGS. 9-10. An embodiment of a clearing device 301 is illustrated in FIG. 9. The clearing device 301 may be used to remove material from the opening 220 and the extended hole 230. The illustrated clearing device 301 includes a shaft 310, bristles 312, a proximal plug 340, and a handle 350. In operation, the clearing device 301 may be inserted, bristles 312 first, through the proximal opening 240. As the bristles 312 are moved through the extended hole 230, material can be cleared from the extended hole 230 and the opening 220. The clearing device 301 may be moved through the surgical instrument 201 after the surgical instrument 201 has been used and has captured material. In another use, the clearing device 301 may be placed into the surgical instrument 201 prior to the surgical instrument 201 being driven into a bone. In this usage, the bristles 312 may serve as a filter to prevent solid material from entering the surgical instrument 201 , but while allowing fluids to pass through the surgical instrument 201. In some

embodiments, the handle 350 may be removable from the clearing device 301 thereby allowing the proximal plug 340 to be inserted essentially flush with the distal surface of the portion 21 1. As shown in FIG. 9, the proximal plug 340 may include threads to engage with threads that may be present in the proximal opening 240. Other embodiments may not include threads in one or both of these components or may include other engagement mechanisms between the clearing device 301 and the surgical instrument 201. In other embodiments, the bristles 312 may be replaced by a mesh, a strainer, a helical lift, an auger, a solid plug, or any other configuration that provides for full or partial blockage of the opening into which it can be moved or is seated.

These other embodiments may be functional to block or move material within the surgical instrument 201.

[00034] Another example device with which the surgical instrument 201 may be combined is illustrated in the form of an opening plug 401 in FIG. 10. The opening plug 401 includes a proximal plug 440 and a distal plug 412 connected by a shaft 410. In operation, the opening plug 401 may be inserted, distal plug 412 first, through the proximal opening 240. As shown in FIG. 10, the proximal plug 440 may include threads to engage with threads that may be present in the proximal opening 240. Other embodiments may not include threads in one or both of these components or may include other engagement mechanisms between the opening plug 401 and the surgical instrument 201. The proximal plug 440 may also include a turning mechanism such as an internal hex driver receiver through its most proximal end so that the opening plug 401 may be screwed into or otherwise engaged with the surgical instrument 201. In other

embodiments, the distal plug 412 may be replaced by a mesh, a strainer, a helical lift, an auger, bristles, or any other configuration that provides for full or partial blockage of the opening into which it can be moved or is seated. The distal plug 412 may include threads or other connection mechanisms to engage with threads or other connection mechanisms that may be present in the opening 220. In other embodiments, a full or partial blockage of the opening 220 may be accomplished by mechanisms that slide fully or partially sideways across the opening 220.

[00035] Although some embodiments of a surgical instrument such as the surgical instrument 201 may be configured for placement over a guide wire, the present invention clearly includes embodiments that are not configured to be placed over a guide wire. The surgical instrument 201 is not configured to be placed over a guide wire in some of its embodiments at least because a guide wire could provide restriction of the flow of fluid through the opening 220. Additionally, embodiments intended for use with the guide wire would not function properly in combination with instruments such as the clearing device 301 or the opening plug 401.

[00036] An embodiment of the invention is a method of preparing a cavity in a medullary canal for an orthopedic implant. This method may include driving a surgical instrument into the medullary canal, such as is illustrated in FIG. 2 where the surgical instrument 1 is being driven into the medullary canal of the tibia 100. The surgical instrument 1 includes a punch tip 12 (FIG. 3) that forms a seal with the medullary canal when driven into the medullary canal. It is possible that some sizes of a surgical instrument 1 would not form a seal with the medullary canal;

however, it is contemplated that a properly fitted surgical instrument 1 may form a seal with the medullary canal. When a surgical instrument 1 does form a seal with the medullary canal, a positive pressure is generated in the medullary canal distal of the punch tip as the surgical instrument 1 is driven into the medullary canal. It is contemplated herein that reference to generation of a positive pressure includes creating a pressure that is alleviated through one or more passages. As shown in FIGS. 3-6 for example, an opening 20 through the punch tip 12 in some embodiments provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal.

[00037] In some embodiments, a surgical instrument such as the surgical instrument 1 may be removed from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip 12. This is a significant advantage because a smaller force is required to move the surgical instrument 1 absent the negative pressure, which is alleviated in this embodiment as a result of the opening 20 and fluid pathways provided. As used herein, removal without creating a negative pressure means that although some negative pressure may be immediately created, the negative pressure is quickly alleviated through the passages provided.

[00038] In some embodiments, the act of driving a surgical instrument into a medullary canal includes driving a surgical instrument with a removable opening plug in the opening. For example, as noted with reference to FIGS. 7-10 above, the surgical instrument 201 may be driven into the medullary canal with either the clearing device 301 or the opening plug 401 in the opening 220. In the cases where the clearing device 301 is in the opening 220 as the surgical instrument 201 is driven into the medullary canal, fluid and smaller pieces of material may be allowed to flow through the bristles 312 to a volume outside of the medullary canal. Likewise in embodiments of the opening plug 401 wherein the opening plug does not form a seal, fluid and smaller pieces of material may be allowed to flow through the opening plug to a volume outside of the medullary canal. Where the clearing device 301 or the opening plug 401 do form a seal, the devices may serve as a blockage to prevent clogging of material in the surgical instrument 201. In some embodiments, the opening plug or clearing device may then be removed from the surgical instrument before the surgical instrument is removed from the medullary canal. For example, removing an opening plug or clearing device in this manner would facilitate removing the surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip. With the opening 220 clear, pressure may be alleviated as a result of the fluid communication to a volume outside of the medullary canal through the pathways provided.

[00039] The method illustrated in the figures is directed toward acts of implanting a tibial orthopedic implant in a medullary canal of a tibia. However, acts of the invention may be directed to preparing a cavity in a medullary canal of a femur, a humerus, or any other bone with a medullary canal or other pocket or volume of cancellous bone. In addition, in some embodiments of the invention acts may be directed to preparing a cavity in one or both of cortical and cancellous bone after the bone is initially prepared by another instrument such as, without limitation, a drill, an awl, a reamer, a needle, or a spike. Regardless of introductory verbiage used, the invention is not necessarily limited to acts of preparation in a medullary canal.

[00040] In some embodiments, methods may also include driving one or more additional surgical instruments into a medullary canal or other bone, wherein the one or more additional surgical instruments are sequentially larger than the surgical instrument initially driven into the medullary canal or other bone. For example, where a first surgical instrument is driven into a medullary canal or other bone and is determined to be too small to adequately prepare the medullary canal or other bone to accurately or securely receive an orthopedic implant, a larger second surgical instrument may be driven into the medullary canal or other bone. Additional, sequentially larger surgical instruments may also be used until an adequate preparation is achieved.

[00041] An embodiment of the invention is a method of preparing a cavity in a medullary canal for an orthopedic implant that includes driving a surgical instrument into the medullary canal. This method may include driving a surgical instrument such as the surgical instrument 1 illustrated in FIG. 2, where the surgical instrument 1 is being driven into the medullary canal of the tibia 100. The surgical instrument 1 includes a punch tip 12 (FIG. 3) beyond which a positive pressure is created in the medullary canal as the surgical instrument 1 is driven into the medullary canal. As shown in FIGS. 3-6 for example, an opening 20 through the punch tip 12 in some embodiments provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal. In some embodiments, the passage for fluid from within the medullary canal is along a path that leads outside of the surgical instrument in a direction greater than 180 degrees from the direction of the driving of the surgical instrument.

[00042] As illustrated in FIG. 5 for example, first passage 21 and first lateral surface 28, as well as second passage 22 and second lateral surface 29, define paths that lead outside of the surgical instrument 1 in a direction greater than 180 degrees from the direction of the driving of the surgical instrument 1. Fluid may consequently be expelled from the surgical instrument 1 in a direction greater than 180 degrees from the direction of the driving of the surgical instrument 1 as a result of the driving of the surgical instrument 1. More specifically, as the surgical instrument 1 is driven into a bone, as illustrated in FIG. 2, fluid pressurized by the driving action may be expelled from the surgical instrument 1 through the first passage 21 and the second passage 22 and may be further diverted by the first lateral surface 28 and the second lateral surface 29 outwardly from the major longitudinal axis of the surgical instrument 1. This lateral expulsion is greater than 180 degrees from the proximal to distal driving direction of the surgical instrument 1. As used herein, the term greater than 180 degrees counts the reversal of the flow direction from distal to proximal and then proximal to distal as the first 180 degrees of flow direction. Subsequent lateral diversions are then counted in addition to this first 180 degrees. Consequently, in the illustrated embodiment driving the surgical instrument 1 into the medullary canal includes the act of driving a punch tip that provides a passage for fluid from within the medullary canal along a path that leads outside of the surgical instrument 1 in a direction of approximately 270 degrees from the direction of the driving of the surgical instrument 1. Under the definition for the first 180 degrees provided herein, this path would not be considered merely a 90 degree path. In another embodiment where a path was provided that directed fluid through a path that included an additional 90 degrees of turn such that fluid were directed approximately back toward a bone, the path would be defined as approximately 360 degrees from the direction of driving in the surgical instrument, or for convenience may be described as in a direction approximately the same as the direction of the driving of the surgical instrument.

[00043] Embodiments of the invention may include removing the surgical instrument from the medullary canal. Embodiments of the invention may also include implanting an orthopedic implant in the cavity in the medullary canal created by the surgical instrument.

[00044] As previously described herein, the embodiments immediately above may include removal of a surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip and may include driving a surgical instrument with a removable opening plug in the opening, along with all variations described herein. These embodiments may also be directed to preparing a cavity in any bone, and may include use of sequentially larger surgical instruments until an adequate preparation is achieved.

[00045] Another embodiment of the invention is a method of preparing a cavity in a medullary canal for an orthopedic implant that may include driving a surgical instrument into the medullary canal. This method may include driving a surgical instrument such as the surgical instrument 1 illustrated in FIG. 2, where the surgical instrument 1 is being driven into the medullary canal of the tibia 100. The driven surgical instrument 1 includes a punch tip 12 with a cross-sectional shape that is proportional to the cross-sectional shape of the orthopedic implant to be implanted. The punch tip 12 creates an approximately constant cross-sectional shaped cavity along the entire length of the medullary canal through which the punch tip 12 is driven. As shown in FIGS. 3-6 for example, an opening 20 through the punch tip 12 in some embodiments provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal.

[00046] Embodiments of the invention may include removing the surgical instrument from the medullary canal. Embodiments of the invention may also include implanting an orthopedic implant in the cavity in the medullary canal created by the surgical instrument. The act of implanting an orthopedic implant may include implanting an orthopedic implant that has an approximately constant cross-sectional shape along the portion of the orthopedic implant that is to be placed in the medullary canal.

[00047] As previously described herein, the embodiments immediately above may include removal of a surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip and may include driving a surgical instrument with a removable opening plug in the opening, along with all variations described herein. These embodiments may also be directed to preparing a cavity in any bone, and may include use of sequentially larger surgical instruments until an adequate preparation is achieved.

[00048] Various embodiments of a surgical instrument wholly or its components individually may be made from any biocompatible material. For example and without limitation,

biocompatible materials may include in whole or in part: non-reinforced polymers, reinforced polymers, metals, ceramics and combinations of these materials. Reinforcing of polymers may be accomplished with carbon, metal, or glass or any other effective material. Examples of biocompatible polymer materials include polyamide base resins, polyethylene, low density polyethylene, polymethylmethacrylate (PMMA), polyetheretherketone (PEEK),

polyetherketoneketone (PEKK), a polymeric hydroxyethylmethacrylate (PHEMA), and polyurethane, any of which may be reinforced. Example biocompatible metals include stainless steel and other steel alloys, cobalt chrome alloys, tantalum, titanium, titanium alloys, titanium- nickel alloys such as Nitinol and other superelastic or shape-memory metal alloys.

[00049] Terms such as side, outside, distal, proximal, beyond, and the like have been used relatively herein. However, such terms are not limited to specific coordinate orientations, but are used to describe relative positions referencing particular embodiments. Such terms are not generally limiting to the scope of the claims made herein. Any embodiment or feature of any section, portion, or any other component shown or particularly described in relation to various embodiments of similar sections, portions, or components herein may be interchangeably applied to any other similar embodiment or feature shown or described herein.

[00050] While embodiments of the invention have been illustrated and described in detail in the disclosure, the disclosure is to be considered as illustrative and not restrictive in character. All changes and modifications that come within the spirit of the invention are to be considered within the scope of the disclosure.

Claims

WHAT IS CLAIMED IS:

1. A tibial punch configured to prepare a cavity in a medullary canal of a tibia, the cavity for receiving an orthopedic implant, the tibial punch comprising:

a body with a portion configured to receive a force to drive the tibial punch into the medullary canal of the tibia;

a punch tip configured to be driven into the medullary canal of the tibia, wherein the punch tip is of a size and shape to prepare the cavity to receive the orthopedic implant; and an opening through the punch tip configured to provide fluid communication through the punch tip with a volume outside of the tibial medullary canal such that fluid pressure within the tibial medullary canal is alleviated to a pressure approximately equivalent to a pressure in the volume outside of the tibial medullary canal as the punch tip is driven into the tibial medullary canal.

2. The tibial punch of claim 1 wherein the body includes a striking area configured to receive a force from a striking tool, wherein the force drives the tibial punch into the medullary canal of the tibia.

3. The tibial punch of claim 1 wherein the punch tip includes a substantially planar surface substantially perpendicular to a longitudinal axis of the tibial punch.

4. The tibial punch of claim 1 wherein the punch tip includes a peripheral edge configured to shear material from the tibial medullary canal in a shape that matches a cross- section of the orthopedic implant to be received within the cavity when the punch tip is driven into the tibial medullary canal.

5. The tibial punch of claim 1 wherein the opening includes a hole from a distal extent of the punch tip into the body of the surgical instrument.

6. The tibial punch of claim 5, further comprising a passage from the hole to a volume proximal of the distal extent of the punch tip.

7. The tibial punch of claim 5, further comprising a plurality of passages from the hole to one or more volumes proximal of the distal extent of the punch tip.

8. The tibial punch of claim 1 wherein the opening has a diameter between 1mm and

7mm.

9. The tibial punch of claim 1 , further comprising a pressurization source configured to connect with the opening to apply a pressure differential within the opening.

10. The tibial punch of claim 1 , further comprising a clearing device configured to remove material from the opening.

1 1. The tibial punch of claim 1 , further comprising an opening plug configured to fit within the opening and be removable by a user.

12. A punch configured to prepare a cavity in a medullary canal, the cavity for receiving an orthopedic implant, the punch comprising:

a body with a portion configured to receive a force to drive the punch into the medullary canal;

a punch tip configured to be driven into the medullary canal, wherein the punch tip includes a peripheral edge configured to shear material from the medullary canal in a shape that matches a cross-section of the orthopedic implant to be received within the cavity when the punch tip is driven into the medullary canal; and

an opening through the punch tip configured to provide fluid communication through the punch tip with a volume outside of the medullary canal such that fluid pressure within the medullary canal is alleviated to a pressure approximately equivalent to a pressure in the volume outside of the medullary canal as the punch tip is driven into the medullary canal.

13. The punch of claim 12 wherein the body includes a striking area configured to receive a force from a striking tool, wherein the force drives the punch into the medullary canal.

14. The punch of claim 12 wherein the punch tip includes a substantially planar surface substantially perpendicular to a longitudinal axis of the punch.

15. The punch of claim 12 wherein the opening includes a hole from a distal extent of the punch tip into the body of the surgical instrument.

16. The punch of claim 15, further comprising a passage from the hole to a volume proximal of the distal extent of the punch tip.

17. The punch of claim 15, further comprising a plurality of passages from the hole to one or more volumes proximal of the distal extent of the punch tip.

18. The punch of claim 12 wherein the opening has a diameter between 1 mm and

7mm.

19. The punch of claim 12, further comprising a pressurization source configured to connect with the opening to apply a pressure differential within the opening.

20. The punch of claim 12, further comprising a clearing device configured to remove material from the opening.

21. The punch of claim 12, further comprising an opening plug configured to fit within the opening and be removable by a user.

22. The punch of claim 12 wherein the punch is configured to prepare a cavity in one or more of a tibial medullary canal, a femoral medullary canal, and a humeral medullary canal.

23. A method of preparing a cavity in a medullary canal for an orthopedic implant, comprising:

driving a surgical instrument into the medullary canal, wherein the surgical instrument includes: a punch tip that forms a seal with the medullary canal such that a positive pressure is generated in the medullary canal distal of the punch tip as the surgical instrument is driven into the medullary canal, and an opening through the punch tip that provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal;

removing the surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip; and

implanting an orthopedic implant in the cavity in the medullary canal created by the surgical instrument.

24. The method of claim 23 wherein the act of driving the surgical instrument into a medullary canal includes driving a surgical instrument with a removable opening plug in the opening.

25. The method of claim 24, further comprising removing the opening plug from the surgical instrument before removing the surgical instrument from the medullary canal.

26. The method of claim 23 wherein the act of implanting an orthopedic implant in a cavity in the medullary canal created by the surgical instrument includes implanting one of a tibial orthopedic implant, a femoral orthopedic implant, and a humeral orthopedic implant.

27. The method of claim 23, further comprising driving one or more additional surgical instruments into the medullary canal, wherein the one or more additional surgical instruments are similar to but sequentially larger than the surgical instrument initially driven into the medullary canal.

28. A method of preparing a cavity in a medullary canal for an orthopedic implant, comprising:

driving a surgical instrument into the medullary canal, wherein the surgical instrument includes: a punch tip that creates a positive pressure in the medullary canal distal of the punch tip as the surgical instrument is driven into the medullary canal, and an opening through the punch tip that provides a passage for fluid from within the medullary canal along a path that leads outside of the surgical instrument in a direction greater than 180 degrees from the direction of the driving of the surgical instrument, and wherein fluid is expelled from the surgical instrument in a direction greater than 180 degrees from the direction of the driving of the surgical instrument as a result of the driving of the surgical instrument; and

removing the surgical instrument from the medullary canal.

29. The method of claim 28 wherein driving a surgical instrument into the medullary canal includes the act of driving a punch tip that provides a passage for fluid from within the medullary canal along a path that leads outside of the surgical instrument in a direction of approximately 270 degrees from the direction of the driving of the surgical instrument.

30. The method of claim 28 wherein driving a surgical instrument into the medullary canal includes the act of driving a punch tip that provides a passage for fluid from within the medullary canal along a path that leads outside of the surgical instrument in a direction of approximately the same as the direction of the driving of the surgical instrument.

31. The method of claim 28 wherein the act of driving the surgical instrument into a medullary canal includes driving a surgical instrument with a removable opening plug in the opening.

32. The method of claim 31, further comprising removing the opening plug from the surgical instrument before removing the surgical instrument from the medullary canal.

33. The method of claim 28, further comprising driving one or more additional surgical instruments into the medullary canal, wherein the one or more additional surgical instruments are similar to but sequentially larger than the surgical instrument initially driven into the medullary canal.

34. The method of claim 28 wherein the act of removing the surgical instrument from the medullary canal includes removing the surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip.

35. The method of claim 28, further comprising implanting an orthopedic implant in a cavity in the medullary canal created by the surgical instrument.

36. The method of claim 35 wherein the act of implanting an orthopedic implant in a cavity in the medullary canal created by the surgical instrument includes implanting one of a tibial orthopedic implant, a femoral orthopedic implant, and a humeral orthopedic implant.

37. A method of preparing a cavity in a medullary canal for an orthopedic implant, comprising:

driving a surgical instrument into the medullary canal, wherein the surgical instrument includes a punch tip with a cross-sectional shape that is proportional to the cross-sectional shape of the orthopedic implant, wherein the punch tip creates an approximately constant cross- sectional shaped cavity along the entire length of the medullary canal through which the punch tip is driven, and wherein an opening is provided through the punch tip that provides a passage for fluid from within the medullary canal to a volume outside of the medullary canal;

removing the surgical instrument from the medullary canal; and

38. The method of claim 37 wherein the act of driving the surgical instrument into a medullary canal includes driving a surgical instrument with a removable opening plug in the opening.

39. The method of claim 38, further comprising removing the opening plug from the surgical instrument before removing the surgical instrument from the medullary canal.

40. The method of claim 37, further comprising driving one or more additional surgical instruments into the medullary canal, wherein the one or more additional surgical instruments are similar to but sequentially larger than the surgical instrument initially driven into the medullary canal.

41. The method of claim 37 wherein the act of removing the surgical instrument from the medullary canal includes removing the surgical instrument from the medullary canal without creating a negative pressure in the medullary canal distal of the punch tip.

42. The method of claim 37 wherein the act of implanting an orthopedic implant includes implanting an orthopedic implant that has an approximately constant cross-sectional shape along the portion of the orthopedic implant that is to be placed in the medullary canal.

43. The method of claim 37 wherein the act of implanting an orthopedic implant in a cavity in the medullary canal created by the surgical instrument includes implanting one of a tibial orthopedic implant, a femoral orthopedic implant, and a humeral orthopedic implant.