Acetabular cup remover assembly

Abstract

To provide a cup remover instrument assembly for removing an acetabular cup in a revision hip procedure.SOLUTION: A cup remover instrument assembly for removing an acetabular cup in a revision hip procedure includes: a positioning member 100 supporting a cutting assembly 350 having a cutting blade 380 and a detachable drive member 200 for selectively rotating the cutting assembly to cut around a cup to detach the cup from a patient's natural acetabulum. In some embodiments, the positioning member is sized and configured to operate in a main incision, while the drive member is sized and configured to operate in a portal incision. In some embodiments, the cutting blade is detachable for use in selecting blades for cup sizes. In some embodiments, the cutting blade is selectively extendable from the cutting assembly. In other embodiments, the cutting blade is hemispherical and is rotated by a power driver.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] (Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 267,618, filed Feb. 7, 2022. The disclosure of this related application is incorporated herein by reference in its entirety.

[0002] (Field of the Invention) The present disclosure relates to instruments and methods for orthopedic surgery, and more particularly, to instruments and methods for removing an acetabular hip cup implant in total hip arthroplasty.

Background Art

[0003] In total hip arthroplasty (“THA”), deteriorated cartilage within the acetabulum is replaced with an artificial hip cup. This artificial hip cup interacts with the ball head of an artificial hip stem to provide an artificial hip joint. In some hip implant designs, the cup consists of a single-shell cup that is fixed within the acetabulum by means such as press-fit, bone cement, or screws. In other hip implant designs, the cup comprises an outer shell fixed within the acetabulum in the aforementioned manner, and a separate cup liner that is inserted within a shell between the outer shell and the ball head of the artificial hip stem.

[0004] Primary or “primary” hip implants typically last in a patient for about 10 to 20 years. When a primary hip implant wears out, it is often useful to “revise” the primary hip implant by replacing it with new components. Revision typically involves removal and replacement of the primary acetabular cup. Further, when a revision cup wears out, it is typically desirable to remove and replace it.

[0005] Conventional cup removers that use a cutting blade to loosen the hip cup from the acetabulum include the cup removers disclosed in International Publication No. 2015 / 155657 (by Giardiello et al.) and U.S. Patent No. 6,565,575 (by Lewis). However, these designs are intended for use in traditional total hip arthroplasty (THA). THA is typically performed through a relatively large incision (e.g., 8–12 inches) to provide sufficient access to the joint. This large incision also allows for the introduction and manipulation of instruments within the joint. Large incisions increase surgical time, cause substantial blood loss to the patient, inflict significant trauma to surrounding tissues (e.g., nerves and muscles), increase the risk of infection, and may require a longer recovery period.

[0006] Furthermore, Giardiello and Lewis devices have modular cutting blades of different lengths and curvatures. A short, thick blade may be used to begin at the opening between the hip cup and the acetabulum, while a longer, gradually curving blade may be used to extend the opening and remove the hip cup. These devices require partial disassembly of the cup remover before replacing the modular cutting blade. This practice increases the duration of the procedure and therefore inevitably increases the secondary risks of the surgical procedure, including the risk of infection and potential complications resulting from the increased time under anesthesia.

[0007] In recent years, efforts have been made to develop "minimally invasive" techniques that reduce the length of the incision required in THA, with the aim of reducing blood loss, trauma, infection risk, and recovery time. Refer to U.S. Patent No. 6,905,502 (by Brad Penenberg, MD) and its family of literature (e.g., U.S. Patents No. 6,997,928, 7,833,229, and 6,997,928), each of which is incorporated herein by reference in whole. These patents describe the earliest achievements using a posterior approach, employing a smaller entry incision in conjunction with a larger main incision to prepare the acetabulum and receive a hip implant. Improvements to these instruments and methods are described in U.S. Patent No. 7,651,501 (by Brad Penenberg, MD) and related patents (e.g., U.S. Patents No. 8,439,928, 9,180,023, and 9,539,113), each of which is incorporated herein by reference in whole. In these methods, a specially constructed guide is positioned in the main incision. A portion of the guide is positioned in the acetabulum to provide a reference point. A protruding support structure extends from the guide outside the main incision. The outer portion of this protruding support includes a guide for guiding instruments such as trocars and cannulas to align with the acetabulum. This guide is used to form a small posterior inlet incision to align with the acetabulum and to hold the cannula and guide the instrument during acetabular preparation. By using a posterior incision in conjunction with the main incision, the length of the main incision can be reduced to approximately the size of the acetabular cup, for example, 2-3 inches.

[0008] However, when it comes to corrective procedures, cup removal devices remain stuck in the concept of a simple incision. There is a need for a cup removal device that can be used in minimally invasive two-incision techniques. Thus, there is a need for the technique described below herein, which enables reduced incision, better visualization, and other benefits not available in traditional corrective procedures. [Overview of the project]

[0009] Problems associated with the long procedure duration and large incision in corrective hip arthroplasty include, but are not limited to, an increased risk of patient infection, significant blood loss, trauma to surrounding tissues, increased healing time, and complications arising from prolonged anesthesia. These problems can be mitigated by the assemblies or methods, or combinations of assemblies and methods, provided in this disclosure. One exemplary medical device assembly may comprise: an orientation bearing having an inner surface defining a bore; a positioning member engaged with the orientation bearing, the positioning member having a longitudinal body extending between a tip and a terminal; and a cutting assembly having a fitting portion configured to be rotatably disposed within the bore of the orientation bearing, the cutting assembly including a cutting blade; and a drive member having a drive member body extending between a drive member tip and a drive member terminal, the drive member terminal being configured to engage with the cutting assembly to rotatably drive the cutting assembly.

[0010] Certain exemplary embodiments of this disclosure may provide an acetabular cup removal device assembly for use in a corrective hip arthroplasty procedure.

[0011] Certain exemplary embodiments of this disclosure may provide a cup remover assembly configured for use in minimally invasive hip joint procedures performed through a primary incision and an entrance incision.

[0012] Certain exemplary embodiments of this disclosure may further provide an acetabular cup remover assembly configured for use with a cannula in a hip arthroplasty procedure.

[0013] The method of using the instrument assembly and presenting the parts of the exemplary assembly included in the kit is also described.

[0014] The aforementioned and other features, embodiments, and advantages of the present invention will become more apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0015] [Figure 1] This is a front side perspective view of one exemplary embodiment of an acetabular cup remover assembly in an assembly configuration featuring a single, fixed cutting blade. [Figure 2A] This is a front perspective view of one exemplary embodiment of an acetabular cup remover assembly in an assembly configuration featuring an extendable cutting blade. [Figure 2B] Figure 2A is an exploded perspective view of an exemplary acetabular cup remover assembly in its disassembled configuration. [Figure 2C] Figures 2A and 2B show exemplary cutting assemblies and exemplary cutting assembly supports, as well as detailed perspective views of acetabular implants. [Figure 3] This is a front side perspective view of an exemplary embodiment of an acetabular cup remover assembly in an assembly configuration featuring an extendable cutting blade, the extension of which is synchronized with the rotation of the handle. [Figure 4A] This is a side perspective view of an exemplary embodiment of a cup remover assembly in a partial assembly configuration featuring a hemispherical cutting blade. [Figure 4B] Figure 4A is a side perspective view of the hemispherical cutting blade, showing the hemispherical cutting blade positioned above the upper part of the acetabular implant (i.e., the hip cup). [Figure 4C] Figure 4A is a perspective side view of the hemispherical cutting blade, showing the hemispherical cutting blade positioned to cut around the side of the acetabular implant. [Figure 4D] Figure 4A is an enlarged perspective view of the hemispherical cutting blade, and the sawtooth-like teeth extending from the periphery of the hemispherical cutting blade are described in more detail. [Figure 4E]To further illustrate the outer angle, it is an enlarged side sectional view of the hemispherical cutting blade of FIG. 4A that further details the cross-section of a single serrated tooth. [Figure 5] It is a perspective side view of another exemplary embodiment of a cup remover assembly in an assembled configuration, characterized by a hemispherical cutting blade, an orientation bearing integrally engaged with the tip of a positioning member, and a cutting assembly support rotatably engaged with a drive member via a flexible joint. [Figure 6] It is a side perspective view of an exemplary embodiment of a cup remover assembly in an assembled configuration, further comprising a gimbal clamp including a first arm and a second arm configured to indirectly engage an orientation bearing. [Figure 7] It is a side perspective view of an exemplary embodiment of a cup remover assembly in an assembled configuration similar to the embodiment of FIG. 6 but having a more ergonomic handle.

Embodiments for Carrying Out the Invention

[0016] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof and which illustrate specific embodiments by which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the invention.

[0017] The following detailed description of the preferred embodiments is presented for illustrative purposes only to aid understanding and is not intended to be exhaustive or to limit the scope and spirit of the invention. The embodiments have been selected and described to best illustrate the principles of the invention and its practical applications. Those skilled in the art will recognize that many variations can be made to the invention disclosed herein without departing from the scope and spirit of the invention.

[0018] Unless otherwise specified, like reference numerals indicate corresponding parts throughout the several views. The drawings represent embodiments of various features and components according to the present disclosure, but the drawings are not necessarily to scale, and certain features may be exaggerated to better illustrate embodiments of the present disclosure, and such illustrations should not be construed as limiting the scope of the present disclosure.

[0019] Except as otherwise expressly stated herein, the following rules of interpretation apply to this specification. (a) All terms used in this specification shall be construed to be of such gender or number (singular or plural) as may be required in such context. (b) The singular terms “a,” “an,” and “the” used in this specification and the appended claims shall include plural references unless the context clearly indicates otherwise. (c) The prefix “about” applied to a recited range or value indicates an approximation having a deviation from the range or value that is known in the art or expected from the measurement. (d) Unless otherwise specified, the terms “herein,” “hereby,” “hereto,” “hereinbefore,” and “hereinafter,” and words of similar import refer to the entire specification rather than to any particular paragraph, claim, or other item. (e) Headings are for convenience only and control neither the meaning nor the effect of any part of this specification. (f) “Or” and “any” are not exclusive, and “include,” “including” are not limiting. Further, “comprising,” “having,” “including,” and “containing” should be construed as open-ended terms (i.e., meaning “including, but not limited to”).

[0020] References in this specification such as "one embodiment" or "an embodiment" indicate that the described embodiments may include certain features, structures, or characteristics, but not all embodiments may necessarily include such features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, where certain features, structures, or characteristics are described in relation to an embodiment, it is implied that any influence on such features, structures, or characteristics in relation to other embodiments, whether explicitly stated or not, is within the knowledge of those skilled in the art.

[0021] To the extent necessary to provide descriptive support, the subject matter and / or text of the attached claims are incorporated herein by reference in their entirety.

[0022] The enumeration of value ranges in this specification is merely intended to serve as a simple means of individually referring to each distinct value within any subrange between them, unless otherwise explicitly indicated herein. Each distinct value within an enumerated range is incorporated herein or into the claims as if each distinct value were individually enumerated herein. Where a particular range of values ​​is provided, each intervening value up to one-tenth of the lower limit between the upper and lower limits of that range, and any other stated or intervening values ​​within the described range of that subrange, are understood to be included herein unless the context explicitly indicates otherwise. All subranges are also included. The upper and lower limits of these smaller ranges are also included therein, subject to any specific and explicitly excluded limitations within the described ranges.

[0023] It should be noted that some of the terms used herein are relative. For example, the terms “upper” and “lower,” and “top” and “bottom” are spatially relative to each other; that is, the upper component is located higher than the lower component in the orientation shown or described, but these terms may change if the orientation is reversed.

[0024] The terms "horizontal" and "vertical" are used to indicate an absolute standard, i.e., direction relative to the ground. However, these terms should not be interpreted as requiring structures to be absolutely parallel or absolutely perpendicular to each other. For example, a first vertical structure and a second vertical structure are not necessarily parallel to each other.

[0025] As shown in Figures 1 to 7, an exemplary embodiment of the removable acetabular cup removal device assembly 1 is configured for use in a modified hip joint procedure to remove the primary acetabular cup or cup and shell 400 (Figure 2A) (collectively, the “primary cup”). Although the device 1 is described herein for removing the primary cup, if a modification cup is present, the device can be used to remove the modification cup.

[0026] An exemplary cup removal tool assembly 1 described herein has an assembled configuration (e.g., Figure 2A), a disassembled configuration (Figure 2B), and a partially assembled configuration.

[0027] An exemplary cup removal tool assembly 1 generally includes a positioning member 100 comprising a longitudinal body 110, a tip 111, and a terminal 112. The longitudinal body 110 extends between the tip 111 and the terminal 112. The positioning member engages with an orientation bearing 115 having an inner surface 143 (Figure 2B) defining a through hole 145 (Figure 2B). A cutting assembly 350 having a mating portion 363 (Figure 2B) is configured to be rotatably disposed within the through hole 145 of the orientation bearing 115. Briefly referring to Figure 2C, the mating portion 363 may have an outer circumferential surface. Briefly referring to Figures 2A and 2B, the orientation inner surface 143 is arranged concentrically and in close proximity around the outer circumferential surface of the mating portion 363 when the cup removal tool 1 is in assembly configuration. Thus, it can be said that the mating portion 363 is "configured to be rotatably disposed within the through hole 145 of the orientation bearing 115."

[0028] The cutting assembly 350 comprises a cutting blade 380. A drive member 200, having a drive member body 210 (Figure 2B), extends between a drive member tip 211 and a drive member rear end 212. The tip 211 of the drive member 200 engages with the cutting assembly 350 to rotatably drive the cutting assembly 350, cutting around the acetabular cup implant 400, and thus removing the acetabular cup implant 400 from the patient's natural acetabulum. The positioning member 100, drive member 200, orientation bearing 115, and cutting assembly 350 may be fabricated from medical-grade stainless steel, titanium, or any other biocompatible material having similar strength and durability properties.

[0029] Various configurations of cutting devices and drive mechanisms for operating various cutting devices will be described herein. In certain exemplary embodiments, the positioning member 100 is sized and configured to operate within or through the main cut, while the drive member 200 is sized and configured to operate within or through the entrance cut.

[0030] Fixed blade In the embodiment shown in Figure 1, the exemplary cup remover assembly 1 includes a single, fixed cutting blade 380 that can rotate around the outer edge of the acetabular cup implant 400 (see Figure 2A). The positioning member 100 includes a longitudinal body 110, such as a main shaft or extension, extending between a tip or lower end 111 and a terminal or upper end 112. The orientation bearing 115 may be attached to the tip 111 or integral with the tip. In the exemplary embodiment, the orientation bearing 115 is a ring member configured to rotatably receive and support the cutting assembly 350. In some embodiments, a handgrip 120 is provided on or adjacent to the terminal 112 of the longitudinal body 110. The handgrip 120 may be in the form of a T-handle, as shown in Figure 1. The handgrip 120 is configured to be used when inserting the positioning member 100 and the cutting assembly 350 into the main incision that is positioned in the patient's hip joint. Using a partial engagement configuration in which the positioning member 100 engages with the cutting assembly 350, the cutting assembly 350 can be positioned on the patient's acetabulum, and the femoral head bearing 330 can be seated in the acetabular cup implant 400 that is to be removed.

[0031] The cutting assembly 350 is rotatably mounted adjacent to the tip 111 of the positioning member 100 via an orientation bearing 115. In the embodiment described, the cutting assembly 350 comprises a blade support portion 360 rotatably connected to the orientation bearing 115 in an assembled or partially assembled configuration, a cutting blade 380 extending distally from the blade support portion 360, and a femoral head bearing 330. The femoral head bearing 330 is positioned below the blade support portion 360. The femoral head bearing 330 is typically hemispherical and is typically sized for use in orienting the cup remover assembly 1 within the primary acetabular cup 400 (see Figure 2A). The femoral head bearing 330 can be rotatably connected below the blade support portion 360, so that the blade support portion 360 rotates independently around the femoral head bearing 330. As shown in Figure 1, the cutting blade 380, exemplary, extends distally from the blade support portion 360 and has a curved or arc-shaped cross-section that substantially matches the outer diameter of the acetabular cup implant 400 to be removed. Positioned at a selected distance from the outer diameter of the femoral head bearing 330, the cutting blade 380 cuts bone or bone cement adjacent to the outer diameter of the acetabular cup implant 400 to be removed. The driver base 361 (Figure 2C) extension of the blade support portion 360 can be rotatably positioned within the orientation bearing 115 for use when rotating the blade support portion 360 and the cutting blade 380, as described herein.

[0032] A separate drive member 200 is provided for use in rotating the cutting assembly 350. The drive member 200 (see also Figure 2B) has a drive member body 210 extending between a drive member tip or lower end 211 and a drive member end or upper end 212. In the embodiment of Figure 1, the drive member body 210 is inserted through an inlet guide assembly 250. The inlet guide assembly 250 may include an inlet guide 235 which can be inserted through an inlet incision in the patient's leg, if desired. In other exemplary embodiments, the inlet guide assembly 250 can be inserted through a cannula 500 (Figure 4A). The inlet guide assembly 250 may optionally include a drive handle 230 extending from the inlet guide 235 adjacent to the drive member end 212 in the assembly configuration. The drive handle 230 is preferably positioned and configured to be used to rotate the drive member 200 for rotating the blade support portion 360 and the mounted cutting blade 380 via the drive base 161 when engaged. The drive handle 230 engages with the rear end 212 of the drive member in any manner recognizable to those skilled in the art, but preferably by a mechanical projection-receiving engagement mechanism, as described below with reference to the front end 211 of the drive member 200. Thus, it can be said that the drive handle 230 is "configured" to engage with the end 212 of the drive member and thereby rotate the drive member body 210 and the front end 211 of the drive member.

[0033] The tip 211 of the drive member 200 is configured to engage with the drive base 361 of the blade support member 360 via a male hexagon on the tip 211 and a female hexagon on the drive base 361, or vice versa. All projections and tightly fitting receiving engagement mechanisms known to those skilled in the art are considered to be within the scope of this disclosure. Thus, the tip 211 of the drive member can be said to be "configured to engage with the cutting assembly 350 and to rotatably drive the cutting assembly 350." A handle 220 is provided on or thereof of the end 212 of the drive member 200 for use in holding, inserting, removing, and manipulating the drive member 200 within the entrance guide assembly 250 to engage with the drive base 361 located within the orientation bearing 115 of the positioning member 100.

[0034] Using the configuration described herein, a surgeon can selectively position the positioning member 100 at the main incision and the drive member 200 at the entrance incision, and selectively rotate the drive member 200 to rotate the cutting blade 380 around the acetabular cup implant 400 to be removed.

[0035] To accommodate and remove acetabular cup implants (i.e., hip cups) of various sizes, the fixed cutting blade 380 is configured to be removable so that differently sized cutting blades 380 can be selected for use when removing cups of different sizes. In exemplary embodiments, multiple sized blade support portions 360, cutting blades 380, and femoral head bearings 330 may be provided in the form of an instrument kit arranged in a surgical tray, for example.

[0036] For example, the blade support portion 360 may have a length dimension that can be sized in cooperation with the cutting blade 380 so that the cutting blade 380 is positioned just outside the outer diameter of the acetabular cup implant 400 to be removed. The acetabular cup implant 400 is preferably known before surgery (e.g., through patient records or preoperative radiographs), so that the blade support portion 360 and the cutting blade 380 can be sized to adapt to the removal of the acetabular cup implant 400. However, it is also conceivable that more than one blade support portion 360 or cutting blade 380 having different size dimensions may be provided at the time of surgery to give the surgeon a choice when faced with the actual acetabular cup implant 400 during the procedure.

[0037] It is also conceivable that fixed cutting blades 380 having different blade lengths may be provided. The surgeon can use a shorter cutting blade 380 to begin the removal of the acetabular cup implant 400. For example, a shorter cutter blade 380 can create a useful opening between the natural acetabulum and the acetabular cup implant 400 around the outer periphery of the acetabular cup implant 400. A longer cutting blade 380 positioned within the initial opening can then be used to extend the opening between the acetabular cup implant 400 and the natural acetabulum, thereby separating the acetabular cup implant 400 from the natural acetabulum.

[0038] Various sizes of femoral head bearings 330 can be used to seat various sizes of acetabular cup implants 400. In exemplary embodiments, the various sizes are integrated with their respective positioning members 100. In other embodiments, the components may be removable and detachable from the positioning member 100, thereby reducing the inventory of the instrument.

[0039] Extendable blade In the embodiments of Figures 2A–C, the cup remover assembly 1 is similar to the exemplary embodiment described with reference to Figure 1. However, the cutting blade 380 is selectively extendable from the blade support portion 360 (see Figure 2C). In the embodiments of Figures 2A–C, this is achieved by providing a hollow inlet guide 235 that houses the drive member body 210. The adjustment handle 220A is provided on the end 212, rather than the fixed handle 220 in the embodiment of Figure 1. The selectively extendable cutting blade 380A is operably connected to the drive member 200 (Figure 2B), so that rotation of the adjustment handle 220A selectively extends the cutting blade 380A, for example, clockwise. Once the desired cutting blade length is set, the surgeon can disengage the drive member 200 from the cutting assembly 350 to define a partially engaged position (i.e., the orientation bearing 115 of the positioning member 100 is still positioned around the mating portion 363 of the cutting assembly 350). Next, the surgeon uses the handle 120 of the positioning member 100 to selectively move the cutting assembly and, by extension, move the selectively extendable cutting blade 380A around the outer surface of the acetabular cup implant 400, thereby allowing the acetabular cup implant 400 to be removed from the patient's natural acetabulum. The length of the selectively extendable cutting blade 380A can be adjusted as needed during the procedure relative to the bottom 351 of the cutting assembly support 360.

[0040] Figure 2C provides an enlarged view of an exemplary operable connection of the cutting blade 380 to the drive member 200. In its assembled configuration, the tip 211 of the drive member 200 includes a male keyed shape, such as a hexagon. The male keyed shape is positioned on the side of a complementary keyed shape, such as a female hexagon, on the drive base 361 and engages with that side. Thus, it can be said that the drive base member 361 has a proximal end having a keyed interface that is "configured to mate" with the complementary keyed inner surface of the drive member tip 211.

[0041] The drive base 361 is disposed within the mating portion 363 of the cutting assembly 350. In the assembly configuration, the mating portion 363 is disposed within a hole 145 of the orientation bearing 115, preferably an annular inner surface 143. Thus, it can be said that the mating portion 363 is "configured to be rotatably positioned" within the hole 145 of the orientation bearing 115. The annular inner surface 143 includes preferred embodiments, but any mechanical engagement that enables the mating portion 363 to be positioned relative to the movement of the engaged positioning member 100 is considered to be within the scope of this disclosure.

[0042] The drive base 361 engages with a spline shaft 347 having distal spline teeth 348 and shares a rotation axis with the spline shaft. The distal spline teeth 348 then selectively engage with geared teeth 349 of the extendable cutting blade 380. The geared teeth 349 can be positioned opposite the ungeared blade support side 346. In this way, rotation of the adjustment handle 220A selectively extends the cutting blade 380A relative to the bottom 351 of the blade support portion 360, for example, in a clockwise direction. The above description is an example of how the blade support portion 360 may have a drive base configured to "communicate" with the cutting blade 380.

[0043] In certain exemplary embodiments, a sleeve may be positioned close to the spline shaft 347 and the inner wall of the drive base 361. Such a sleeve provides a frictional force that, when the frictional force cannot overcome the rotational motion of the engaged drive member 200, prevents the spline shaft 347 from rotating. In this way, the sleeve can lock the spline shaft 347 and, by extension, the selectively extendable cutting blade 380A at a desired position, the desired position may correspond to a desired length of the selectively extendable cutting blade 380A relative to the bottom 351 of the cutting assembly support 360.

[0044] It will be understood that a light-touch projection and receiving locking mechanism, or a similar mechanical or electromechanical locking structure, for preventing rotational movement of the spline shaft 347 when the engaged drive member 200 is not rotating is within the scope of this disclosure. In exemplary embodiments, the spline shaft 347 may be arranged in a generally cylindrical and annular manner around a fixed femoral head bearing support 331. The fixed femoral head bearing support 331 extends beyond the spline shaft 347 and preferably supports a femoral head engagement mechanism 332. This femoral head engagement mechanism is configured to removably engage with a femoral head bearing 330. The exemplary femoral head engagement mechanism 332 may include threads, ball bearings in complementary sockets, clamps, projections, recesses, and other known means for selectively mechanically engaging and disengaging one component from another.

[0045] Figure 3 shows an alternative embodiment of the selectively extendable cutting blade 380A, in which the extension of the blade 380 is timed with the rotation of the drive handle 230. In this embodiment, the blade 380 extends only slightly relative to the bottom 351 of the cutting assembly support 360 with each rotation of the drive handle 230. In this way, the cutting blade 380 cuts deeper with each rotation. In the embodiment of Figure 3, this is achieved by providing the drive member 200 via the inlet guide 235 of the inlet guide assembly 250 (see Figure 2B). The inlet guide assembly 250 may optionally further comprise a handle 240 fixed to the upper portion of the inlet guide 235 for use in holding and manipulating the diving member 200. As with the embodiments depicted in Figures 1 and 2A-C, the inlet guide assembly 250 can be inserted through an inlet incision in the patient's leg, if desired. In other exemplary embodiments, the inlet guide assembly 250 can be inserted through a cannula 500 (Figure 4A). The cutting blade 380 is operably connected to the internal drive member 200, and as a result, rotation of the drive handle 230 selectively extends the cutting blade 380, for example, in a clockwise direction. In the embodiment described, the cutting blade 380 is operably connected to the drive member 200 and can be selectively locked in the same manner as described with reference to Figure 2C above.

[0046] Powered blade In the embodiment of Figure 4A, the removable cup remover assembly 1 of the present disclosure includes a powered hemispherical cutting blade 380B. In the embodiment of Figure 4A, the hemispherical cutting blade 380B has a hollow hemispherical interior and an annular rim on its lower end. The hemispherical cutting blade 380B is provided with a cutting edge end (see 383) along the annular bottom rim, such as a serrated edge end or a serrated portion like that of a saw blade. The hemispherical cutting blade 380B preferably includes one or more discharge holes 385 extending through the blade body of the hemispherical cutting blade 380B. The discharge holes 385 allow the removed bone cement, bone, bone marrow, or other tissue to exit the excavation area without interfering with the cutting process unnecessarily.

[0047] In some embodiments, various sizes of the hemispherical blade 380B are provided, so that the blade 380B can be selectively fitted to the size of the primary or modified acetabular cup implant 400 to be removed. The annular rim is selectively sized to extend the cutting end of the hemispherical cutting blade 380B around the fixed primary or modified acetabular cup implant 400. The hemispherical cutting blade 380B may be power-driven by a drive member 200, which in this embodiment takes the form of an inlet drive shaft 200A. The end 212 of the inlet drive shaft 200A is provided with a standard configuration for engagement by an electric drill or other power-driven mechanism, such as an engagement flat or flat section.

[0048] As shown in Figures 4B and 4C (see also Figure 4A), the T-handle 120 of the positioning member 100 can be used to move the hemispherical blade 380B around the outer diameter of the primary or modified acetabular cup implant 400 during cutting. Figure 4B shows the hemispherical cutting blade 380B oriented directly over the acetabular cup implant 400 in the starting position. Figure 4C shows the hemispherical cutting blade 380B rotating around the side of the acetabular cup implant 400 to assist in cutting deeper areas of adjacent bone or bone cement.

[0049] The powered hemispherical cutting blade 380B is powerful but presents some design limitations. Depending on the size of the inner diameter of the acetabular cup implant 400, a liner insert 401 may be required to maintain the hemispherical cutting blade 380B in a concentric orientation with respect to the outer diameter of the primary or modified acetabular cup implant 400. A liner insert 401 can be provided to accommodate acetabular cup implants 400 and hemispherical cutting blades 380B of various sizes. Furthermore, it is thought that the use of an inlet drive shaft 200A having a ball end, a universal joint (209, see Figure 5), or a gimbal connection (not shown) would improve the maneuverability of any of the blades 380 around the acetabular cup implant 400 during cutting, as is considered to be within the scope of this disclosure.

[0050] As can be seen more clearly in Figures 4D and 4E, the serrated edge includes serrated teeth 383 extending from the periphery C of the hemispherical cutting blade 380B. In the embodiments depicted, the serrated teeth 383 have an outer surface angle θ defined by the intersection of the normal N to the periphery C of the hemispherical cutting blade 380B and the plane defined by the outer surface S of the individual serrated teeth 383A of the serrated teeth 383. In certain exemplary embodiments, the outer surface angle θ is preferably less than 10 degrees. In other exemplary embodiments, the outer surface angle θ may be a composite angle including the sum of multiple angles, for example, a combination of the outer surface angle and the normal angle. In yet another exemplary embodiment, the outer surface S of the individual serrated teeth 383A may include multiple outer surface angles θ, where a second angle positioned below an initial angle positioned closest to the periphery C and any subsequent angles are greater than the preceding outer surface angle θ with respect to the normal N. In yet another exemplary embodiment, the serrated teeth 383 may have the same space as the normal N and be inclined with respect to a line coplanar with the normal plane for defining the normal angle. In yet another exemplary embodiment, the outer surface S of a single serrated tooth 383A may include multiple normal angles, where the second angle and any subsequent angles are greater than the preceding normal angle with respect to a line coplanar with the normal plane. Any combination of normal angle and outer surface angle θ is considered to be within the scope of the disclosure. Any configuration of teeth 383 that closely fits the outer curve of the acetabular cup implant 400 in such a way as to pull the acetabular cup implant 400 toward the cutting assembly support 360 during surgery is considered to be within the scope of the disclosure.

[0051] While not bound by theory, a hemispherical cutting blade 380B having serrated teeth 383 with an external angle θ of preferably less than 10 degrees could be used in an active state to apply tensile force to the acetabular cup implant 400. That is, the hemispherical cutting blade 380B having serrated teeth 383 described herein could facilitate the removal of the acetabular cup implant 400 by pulling it toward the bottom 351 of the cutting assembly support 360 during normal use. As a result, it is thought that surgeons could reduce the time spent removing previously implanted acetabular cup implants 400, thereby potentially reducing procedure time and its secondary risks.

[0052] The components of cup removal instrument assembly 1, including components of different sizes, would typically be arranged in a kit format, in a convenient form such as a surgical tray or case. However, given that the kit components are to be assembled or combined together in the operating room for use during surgery, the components do not need to be packaged together or delivered together.

[0053] Figure 5 is a side perspective view of another exemplary embodiment of the present disclosure, in which the orientation bearing 115 is directly integrally engaged with the tip 111 of the positioning member 100, and the annular inner surface 143 of the orientation bearing 115 further includes a ball bearing 118 disposed within the orientation bearing 115 and extending into the bore 145 of the orientation bearing 115. In an assembled configuration, or in a partially assembled configuration in which the cutting assembly 360 is rotatably disposed within the bore 145 of the orientation bearing 115, the ball bearing 118 is disposed in close proximity to the track within the cutting assembly support 360 to facilitate the rotational movement of the cutting assembly support 360 relative to the orientation bearing 115.

[0054] In the embodiment described, the drive member 200 includes a universal joint 209 at the drive member tip 211. In practice, as in the embodiment described, the drive member 200, which is an inlet drive shaft, can be inserted through an inlet incision in the patient's leg, which aligns with an exposed surgical area. This exposed surgical area can be defined by positioning the main surgical incision on the patient's joint capsule with respect to the surgeon's viewpoint. The surgeon can position a cutting assembly 350, comprising a cutting assembly support 360 and a hemispherical cutting blade 380, within the main incision. The cutting assembly 350 may be rotatably engaged with an orientation bearing 115, which then directly or indirectly engages with a positioning member 100 while inserted within the main incision. The drive member 200 can be inserted through the inlet incision. A cannula 500 or other tube may be inserted through the inlet incision before the drive member 200 is inserted. The cannula 500 or other liner may be desirable to protect the patient tissue surrounding the inlet in terms of the rotational motion of the drive member 200. Once both the cutting assembly 350 and the drive member tip 211 are within the main surgical area, the surgeon then engages the drive member tip 211 with the drive base 361 of the cutting assembly 350. In the depicted embodiment, the drive base 361 of the cutting assembly 350 is positioned on the end (see 111) of a universal joint 209 (see Figure 6). The depicted universal joint 209 may be part of the cutting assembly support 360. The cutting assembly support 360 then supports the cutting blade 380, which in the depicted embodiment is a hemispherical cutting blade 380B.

[0055] While not bound by theory, the presence of a universal joint 209 or a similar omnidirectional joint would allow the surgeon to adjust the position of the hemispherical cutting blade 380B in an arc shape relative to the acetabular cup implant 400 (see Figures 4B and 4C) while maintaining the rotational motion of the hemispherical cutting blade 380B around a central rotation axis R via a drive member 200, using a positioning member 100. Such embodiments could allow the surgeon to remove a previously placed acetabular cup implant 400 using minimally invasive techniques for the entrance and main incisions in a modified hip arthroplasty procedure. The speed at which this can be achieved would reduce the overall time the patient is under anesthesia, thus reducing procedure time and, consequently, the risk of infection, while maintaining the enhanced recovery period associated with minimally invasive procedures.

[0056] Although a universal joint 209 is depicted, all joints that allow for alignment or distance variations between the drive member 200 and the cutting assembly support 360 are considered to be within the scope of this disclosure and include, for example, jaw couplers, lug couplers, spline couplers, ball end and gimbal type connections, and prism couplers.

[0057] Figure 6 is a side perspective view of an exemplary cup removal tool assembly 1, which is similar to the embodiment described with reference to Figure 5, except that the positioning member 100 further comprises an articulation clamp 119 at its tip 111. The articulation clamp 119 comprises a first arm 117a and a second arm 117b disposed opposite and distal to the first arm 117a. Pins 113a, 113b extend through aligned pin holes in the orientation bearing 115 and in the first arm 117a and the second arm 117b, indirectly engaging the orientation bearing 115 with the tip 111 of the positioning member 100. Thus, the positioning member 100 can be said to "indirectly engage" with the orientation bearing 115. In the embodiment depicted, the T-handle 120 of the positioning member 100 engages with the end of the driven portion 106. The surgeon can apply a reaction force when pushing the T-handle 120 and the driven part 106 toward the tip 111 of the positioning member 100. The driven part 106 extends along the length of the positioning member 100, generally within the positioning member 100, until the driven part 106 reaches the articular movement clamp 119. The surgeon can push the driven part 106 toward the tip 111, extending the first arm 117a and the second arm 117b toward each other and releasing the orientation bearing 115.

[0058] The exemplary embodiment in Figure 7 is similar to the exemplary embodiment in Figure 6, except that the body 110 of the positioning member 100 is provided with a grip 121 that extends substantially in the longitudinal direction along the length of the body 110 of the positioning member 100. The driven portion 106 may engage with a T-handle 120 as shown in Figure 6, a different type of handle, or may not engage with a handle at all.

[0059] An instrument comprising an exemplary cup removal instrument assembly 1 may be provided in the form of a kit. The components of the kit are preferably arranged in a convenient form, such as a surgical tray or case. However, given that the kit components are to be assembled or aggregated together in the operating room for use during surgery, they do not need to be packaged together or delivered together. An exemplary kit may include any preferred embodiment of the cup removal instrument assembly 1, variations of the cup removal instrument assembly 1 described herein, and any other cup removal instrument assembly 1 according to certain embodiments. An exemplary kit may further include one or more cutting assemblies 350, one or more cutting blades 380, one or more types of cutting blades 380 (e.g., selectively extendable cutting blades 380A, or hemispherical cutting blades 380B), one or more drive members 200, one or more cutting assembly supports 360, one or more orientation bearings 115, and one or more positioning members 100, although it will be understood that a particular kit may lack some or all of these elements. Any preferred embodiment of any other cutting assembly 350, any variation of the cutting assembly 350 described herein, and any other cutting assembly 350 according to a particular embodiment are considered to be within the scope of this disclosure. Modifications of 380, and any preferred embodiment of any other cutting blade 380 according to certain embodiments, are considered to be within the scope of this disclosure. Drive members 200, modifications of the drive members 200 described herein, and any preferred embodiment of any other drive members 200 according to certain embodiments, are considered to be within the scope of this disclosure. Cutting assembly supports 360, modifications of the cutting assembly supports 360 described herein, and any preferred embodiment of any other cutting assembly supports 360 according to certain embodiments, are considered to be within the scope of this disclosure. Orientation bearings 115, modifications of the orientation bearings 115 described herein, and any preferred embodiment of any other orientation bearings 115 according to certain embodiments, are considered to be within the scope of this disclosure.Positioning member 100, variations of positioning member 100 described herein, and any preferred embodiment of any other positioning member 100 according to a particular embodiment are considered to be within the scope of this disclosure.

[0060] The selection of a suitable number or type of cup removal tool assembly 1, cutting assembly 350, cutting blade 380, drive member 200, cutting assembly support 360, orientation bearing 115, and positioning member 100 included in a kit according to a particular embodiment may be based on various considerations, such as the procedure intended to be performed using the components included in that kit.

[0061] How to use During surgery, the cup remover 1 is configured for use in two-incision hip joint procedures, such as those described in the background art section, which are incorporated herein by reference in their entirety. In two-incision hip joint procedures, the primary incision provides access to the hip joint, while the adjacent entrance incision communicates with the hip joint. Relatively large instruments are inserted into the hip joint through the primary incision, while the entrance incision is used to drive or otherwise operate instruments placed within the hip joint. Two-incision hip joint procedures have traditionally been used for primary hip joint procedures. However, the cup remover 1 of the present invention is designed for use in two-incision modification procedures. As described above, the positioning member 100 is sized and configured to operate within or through the primary incision, while the drive member 200 is sized and configured to operate within or through the entrance incision. The positioning member can be operated within the main incision via the handgrip 120 and the upper portion of the extension 120. The configuration of the drive member 200 allows it to be inserted through the entrance incision and operated via the handle 220 and the drive handle 230. When the cannula 500 is used within the entrance incision, the entrance drive shaft 200 can be inserted into the cannula 500 and used to drive the cutting blade 380.

[0062] An exemplary medical device assembly comprises an orientation bearing having an inner surface defining a hole; a positioning member engaged with the orientation bearing, having a longitudinal direction extending between a tip and a terminal; a cutting assembly having a fitting portion configured to be rotatably disposed within the hole of the orientation bearing, including a cutting blade; and a drive member having a drive member body extending between a drive member tip and a drive member terminal, the drive member tip being configured to engage with the cutting assembly to rotatably drive the cutting assembly.

[0063] In an exemplary embodiment, the medical device assembly may further include a femoral head bearing disposed below the blade support portion.

[0064] In exemplary embodiments, the cutting assembly may further comprise a blade support portion rotatably connected to a cutting assembly support. In even more exemplary embodiments, the blade support portion is a drive base configured to communicate with a cutting blade, the cutting blade extending distally from the blade support portion, and the tip of the drive member configured to engage with the drive base.

[0065] In an exemplary embodiment, the orientation bearing is integrally engaged with the tip of the positioning member. In another exemplary embodiment, the orientation bearing is indirectly engaged with the tip of the positioning member.

[0066] In exemplary embodiments, the cutting blade is a hemispherical cutting blade. In such embodiments, the hemispherical cutting blade may further include serrated teeth extending from the distal periphery of the hemispherical cutting blade. In such embodiments, the serrated teeth may further have an outer surface angle defined by the angle between the normal to the distal periphery of the hemispherical cutting blade and the outer surface of the individual serrated teeth of the serrated teeth. In such embodiments, the outer surface angle may be less than 10 degrees.

[0067] In exemplary embodiments including a hemispherical cutting blade, the hemispherical cutting blade further defines discharge holes extending through the blade body of the hemispherical cutting blade. In such exemplary embodiments, the hemispherical cutting blade may further define a plurality of discharge holes extending through the blade body of the hemispherical cutting blade.

[0068] In exemplary embodiments, the cutting assembly further comprises a cutting assembly support, the cutting assembly support having a fitting portion configured to be rotatably disposed within a hole in an orientation bearing. In such exemplary embodiments, including the cutting assembly support, the medical device assembly may further include a drive base member disposed between the cutting assembly support and the drive member in the assembly configuration. In such exemplary embodiments, including the cutting assembly support, the cutting assembly support may have a drive base member configured to communicate with a cutting blade, the cutting blade may extend distally from the cutting assembly support, and the tip of the drive member may be configured to engage with the drive base.

[0069] In exemplary embodiments including a drive base member, the drive base member may include a proximal end having a keyed interface configured to engage with a complementary keyed inner surface of the drive member tip.

[0070] In an exemplary embodiment having a keyed interface, the cutting blade is a curved cutting blade, and the spline shaft extends distally from the keyed interface, with geared teeth on the distal end of the spline shaft engaging with complementary geared teeth of the curved cutting blade disposed within the cutting assembly support, thereby converting the rotational motion of the spline shaft into the arc motion of the curved cutting blade.

[0071] In exemplary embodiments, the positioning member may further include an articulated clamp at its tip, the articulated clamp may include a first arm and a second arm, and a pin may extend through aligned pinholes in the orientation bearing and in the first arm and the second arm to indirectly engage the orientation bearing with the positioning member.

[0072] In exemplary embodiments, the medical device assembly may further include a handle disposed at the end of the positioning member.

[0073] In exemplary embodiments, the medical device assembly may further include a drive handle configured to engage with the end of the drive member, thereby rotating the drive member body and the drive member tip.

[0074] In an exemplary embodiment, the cutting assembly is rotatably engaged with the cutting assembly support.

[0075] In exemplary embodiments, the medical device assembly may further include a cannula, the drive member being disposed within the cannula.

[0076] An exemplary medical device assembly may comprise a cutting assembly support having a drive base configured to communicate with a curved cutting blade, the cutting assembly support having a drive member having a drive member body extending between a drive member tip and a drive member end, the drive member being configured to engage with the drive base to extend the curved cutting blade in an arc shape.

[0077] An exemplary medical device assembly may include: an orientation bearing having an inner surface defining a hole; a positioning member engaged with the orientation bearing, having a longitudinal body extending between a tip and a terminal; a cutting assembly support having a fitting portion configured to be rotatably disposed within the hole of the orientation bearing; a cutting assembly engaged with the cutting assembly support, including a cutting blade; and a drive member having a drive member body extending between a drive member tip and a drive member terminal, the drive member terminal being configured to engage with the cutting assembly support to rotatably drive the cutting assembly.

[0078] Although the present invention has been described in relation to specific embodiments, it is expected that alternative and modified examples will be obvious to those skilled in the art. Therefore, the following claims are intended to be interpreted as covering all alternative and modified examples that fall within the true spirit and scope of the present invention.

Claims

1. 1. A medical device assembly comprising: an oriented bearing having an inner surface defining a bore and an outer surface; a positioning member engaged with the orientation bearing, the positioning member having a first longitudinal body extending between a leading end and a trailing end, the longitudinal body defining a first longitudinal body axis, the leading end physically engaging the outer surface of the orientation bearing; a cutting assembly comprising a blade, a blade support engaged with the blade, and a mating portion tube extending from the blade support, the mating portion tube configured to be rotatably disposed within the bore of the orientation bearing, the mating portion tube including an outer sidewall and an inner sidewall, the outer sidewall being in physical contact with the bore defined by the inner surface of the orientation bearing for engaging the positioning member with the cutting assembly, the inner sidewall configured to provide a drive seat having the shape of a first keyed surface; a drive member having a drive member body, the drive member body having a second longitudinal body extending between a drive member tip and a drive member terminal end and defining a second longitudinal body axis, the drive member body configured for rotatable driving about the second longitudinal body axis, the drive member tip having a second keyed surface that engages with the first keyed surface of the drive seat disposed on the inner sidewall of the mating portion tube of the cutting assembly, and physical contact between the second keyed surface of the drive member tip and the first keyed surface providing the drive seat on the inner sidewall of the mating portion is within an opening defined by the inner surface of the orientation bearing.

2. The medical device assembly of claim 1 , further comprising a femoral head bearing disposed below the blade support portion.

3. A medical device assembly comprising: an oriented bearing having an inner surface defining a bore and an outer surface; a positioning member physically engaged with the orientation bearing, the positioning member having a first longitudinal body extending between a leading end and a trailing end, the longitudinal body defining a first longitudinal body axis; a cutting assembly having a mating portion configured to be rotatably disposed within the bore of the orientation bearing, the cutting assembly further including an extendable cutting blade assembly and a splined shaft, the extendable blade assembly including a first cutting edge having a cutting blade and a second cutting edge having first geared teeth, the splined shaft including a first axial end having a first keyed surface disposed in the mating portion and a second axial end having second geared teeth engaged with the first geared teeth of the extendable blade assembly, the mating portion including an outer sidewall and an inner sidewall, the outer sidewall physically contacting the bore defined by the inner surface of the orientation bearing for engaging the positioning member to the cutting assembly, the inner sidewall configured to be disposed around a periphery of a drive base including the first keyed surface; a drive member having a drive member body including a second longitudinal body extending between a drive member distal end and a drive member proximal end and defining a second longitudinal body axis, the drive member body configured to rotate about the second longitudinal body axis, the drive member distal end including a second keyed surface for engaging a first keyed surface of a drive seat of a mating portion of the cutting assembly, the splined shaft extending distally from a keyed interface between the first keyed surface and the second keyed surface, second geared teeth on a distal end of the splined shaft configured to rotate the splined shaft to engage the first keyed surface of a drive seat of a mating portion of the cutting assembly; a drive member that engages the complementary second geared teeth of the cutting blade disposed within the cutting assembly support to translate arcuate motion of the cutting blade, the second longitudinal body axis of the drive member engaging the cutting assembly at an angle different from the angle at which the first longitudinal body axis of the positioning member engages the cutting assembly via the orientation bearing, whereby the positioning member is configured to be inserted through a main incision in a two-incision surgical procedure and the drive member is configured to be inserted through another portal incision in the two-incision surgical procedure; A medical device assembly comprising:

4. The medical device assembly of claim 1 , further comprising a handle disposed at the terminal end of the positioning member.

5. The medical device assembly of claim 1 , further comprising a drive handle configured to engage the drive member terminal end, thereby rotating the drive member body and the drive member tip.

6. The medical device assembly of claim 1 , further comprising a cannula, the drive member being disposed within the cannula.

7. A medical device assembly as described in claim 1, wherein the second longitudinal body axis of the drive member is engaged with the cutting assembly at an angle different from the angle at which the first longitudinal body axis of the positioning member is engaged with the cutting assembly via the orientation bearing.

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