Orthopedic instrument and method of use for extracting femoral stem components in hip replacement surgery.

Abstract

An orthopedic instrument (10) for extracting an implanted femoral stem component includes a clamping jaw (40) configured to clamp the femoral component within an extraction loop (18) of the instrument. A leaf spring (66) applies spring bias to the clamped femoral component. A method of using the orthopedic instrument to extract an implanted femoral component is also disclosed.

Description

Technical Field

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[0001] The present disclosure generally relates to orthopedic instruments for use in performing orthopedic joint replacement surgery, and more specifically to orthopedic instruments for use in hip joint replacement surgery.

Background Art

[0002] Arthroplasty is a well-known surgical procedure in which a diseased and / or damaged living joint is replaced with an artificial joint. The artificial joint may include a prosthesis implanted into one or more of the patient's bones. Many hip prostheses include a femoral prosthesis implanted into the patient's femur. The femoral prosthesis typically includes an elongated stem component disposed within the intramedullary canal of the patient's femur and a spherical head component that abuts the patient's acetabulum or an artificial replacement acetabular cup.

[0003] Typical arthroplasty surgical procedures include the insertion of surgical instruments (e.g., insertion / extraction instruments, broaches, or other cutting tools) and / or artificial implants into the patient's bone. In some surgical procedures, such as revision surgery, it is necessary to remove a previously implanted femoral stem component. In such cases, the surgeon applies an insertion force to an extraction instrument and applies an extraction force to the femoral stem component to extract the femoral stem component from the patient's femur. Historically, insertion has been performed by the orthopedic surgeon manually striking the surgical instrument using a surgical mallet or hammer.

[0004] Certain automated surgical impacters can perform a series of impact insertions that each provide a controlled amount of insertion force. The automated surgical impacter may be used with one or more adapters for connecting to various surgical instruments and / or implants.

Summary of the Invention

Means for Solving the Problems

[0005] According to one embodiment, an orthopedic instrument for extracting a femoral stem component during an orthopedic hip replacement surgery on a patient's femur includes an elongated body having a connector formed at the proximal end of the elongated body, the connector configured to engage with the chuck of an automated surgical impactor. The elongated body also has an extraction loop formed at its distal end. The extraction loop has a hole extending through the elongated body and is configured to receive the neck of a femoral stem component. The instrument also includes both a locking lever having a pivot end and a latch end on the opposite side, pivotably connected to the elongated body, and a clamping jaw slidably connected to the elongated body. The clamping jaw is movable between a clamped position in which the clamping jaw extends toward the extraction loop and a released position in which the clamping jaw retracts away from the extraction loop. A threaded drive assembly is operably connected to the clamping jaw and is operable to move the clamping jaw between its clamped position and its released position. The leaf spring of the device has a first end pivotably connected to a locking lever and a second end connected to a clamping jaw.

[0006] In one embodiment, a threaded drive assembly includes a drive screw rotatably connected to an elongated body and a drive link slidably connected to the elongated body. The drive link is operably connected to a clamping jaw. The drive screw has a socket defined at its proximal end and a threaded shaft extending distally away from the socket. The drive link has a threaded hole formed therein, and the threaded shaft of the drive screw is positioned within the threaded hole. Rotation of the drive screw in a first direction moves the drive link toward the extraction loop, and rotation of the drive screw in a second opposite direction moves the drive link toward away from the extraction loop.

[0007] The device may also include a push-button fastener connected to an elongated body. In such an embodiment, the locking lever is movable between an unlocked position in which the latch end is separated from the elongated body and a locked position in which the latch end is captured by the push-button fastener.

[0008] The device may also include a compression spring positioned between the locking lever and the elongated body. The compression spring biases the locking lever to its unlocked position.

[0009] In one embodiment, a leaf spring applies spring bias to the neck of the femoral component when the neck of the femoral component is positioned within the extraction loop and the locking lever is in its locked position.

[0010] In one embodiment, the clamping jaws apply a clamping force to the neck of the femoral component when the neck of the femoral component is positioned within the extraction loop and the clamping jaws are positioned in their clamping position.

[0011] The second end of the leaf spring may be pivotably connected to the clamping jaw. Alternatively, the device may include a knuckle link pivotably connected to an elongated body, with the second end of the leaf spring pivotably connected to the first end of the knuckle link. In such an embodiment, the second end of the knuckle link is connected to the clamping jaw.

[0012] In another embodiment, an orthopedic instrument for extracting a femoral stem component during an orthopedic hip replacement surgery on a patient's femur includes an elongated body having a connector formed at the proximal end of the elongated body, the connector configured to engage with the chuck of an automated surgical impactor. The elongated body also has an extraction loop formed at its distal end. The extraction loop has a hole extending through the elongated body, configured to receive the neck of the femoral stem component. The instrument also includes both a locking lever having a pivot end and a latching end on the opposite side, pivotably connected to the elongated body, and a drive link slidably connected to the elongated body. The drive link is movable within the elongated body in a direction toward and away from the extraction loop. The connecting link has a first end pivotably connected to the locking lever and a second end pivotably connected to the drive link. A clamping jaw is slidably connected to the elongated body. The clamping jaw is movable between a clamped position, where it extends toward the extraction loop, and a released position, where it retracts away from the extraction loop. The leaf spring has a first end pivotably connected to a locking lever and a second end connected to the clamping jaw. In this configuration, movement of the drive link toward the extraction loop positions the clamping jaw in its clamped position, and movement of the drive link toward the extraction loop positions the clamping jaw in its released position.

[0013] The device may also include a drive screw rotatably connected to an elongated body. The drive screw has a socket defined at its proximal end and a threaded shaft extending distally away from the socket. The drive link has a threaded hole formed therein, and the threaded shaft of the drive screw is positioned within the threaded hole. Rotation of the drive screw in a first direction moves the drive link toward the extraction loop, and rotation of the drive screw in a second opposite direction moves the drive link away from the extraction loop.

[0014] In one embodiment, the locking lever has a slot formed therein. The first end of the leaf spring and the first end of the connecting link are connected to each other by a pivot pin that translates within the slot of the locking lever.

[0015] The device may also include a push-button fastener connected to an elongated body. In such an embodiment, the locking lever is movable between an unlocked position in which the latch end is separated from the elongated body and a locked position in which the latch end is captured by the push-button fastener.

[0016] The device may also include a compression spring positioned between the locking lever and the elongated body. The compression spring biases the locking lever to its unlocked position.

[0017] In one embodiment, a leaf spring applies spring bias to the neck of the femoral component when the neck of the femoral component is positioned within the extraction loop and the locking lever is in its locked position.

[0018] In one embodiment, the clamping jaws apply a clamping force to the neck of the femoral component when the neck of the femoral component is positioned within the extraction loop and the clamping jaws are positioned in their clamping position.

[0019] The second end of the leaf spring may be pivotably connected to the clamping jaw. Alternatively, the device may include a knuckle link pivotably connected to an elongated body, with the second end of the leaf spring pivotably connected to the first end of the knuckle link. In such an embodiment, the second end of the knuckle link is connected to the clamping jaw.

[0020] In another embodiment, a method for extracting an implanted femoral stem component during the performance of an orthopedic hip replacement surgery on a patient's femur includes positioning an extraction loop of an orthopedic instrument around the neck of the femoral stem component. Next, the threaded drive assembly of the orthopedic instrument is operated to move the clamping jaws into contact with the neck of the femoral stem component. Subsequently, the locking lever of the orthopedic instrument is moved to the locked position to apply spring bias to the neck of the femoral stem component by a leaf spring. The connector of the orthopedic instrument is connected to the chuck of an automated surgical impactor, which is then operated to apply extraction force to the femoral stem component.

[0021] In one embodiment, the drive screw of the threaded drive assembly is rotated to move the clamping jaws into contact with the neck of the femoral stem component.

[0022] In one embodiment, the latch end of the locking lever is captured by a push-button fastener to hold the locking lever in its locked position. [Brief explanation of the drawing]

[0023] For a detailed explanation, please refer in particular to the following drawings. [Figure 1] This is a side view of a femoral stem extraction device for use in orthopedic hip replacement surgery on a patient's femur. [Figure 2] This is a cross-sectional view of the femoral stem extraction device in Figure 1, along line 2-2 in Figure 1, when viewed in the direction of the arrow. [Figure 3] This figure is similar to Figure 2, but shows a femoral stem extraction device fixed to the neck of the femoral stem component. [Figure 4] This is a cross-sectional view of the femoral stem extraction device in Figure 1, along line 4-4 in Figure 1, when viewed in the direction of the arrow. [Figure 5]A cross-sectional view of a patient's femur during a hip replacement surgical procedure, showing a surgeon preparing to remove an implanted femoral stem component using the stem removal instruments of FIGS. 1-4. [Figure 6] A view similar to FIG. 5, showing a stem removal instrument that is fully fixed to the implanted femoral stem component and connected to an automated surgical impacter. [Figure 7] A view similar to FIG. 1, showing another embodiment of the stem removal instrument. [Figure 8] A view similar to FIG. 2, showing another embodiment of the stem removal instrument. [Figure 9] A view similar to FIG. 1, showing yet another embodiment of the stem removal instrument. [Figure 10] A perspective view of another embodiment of the stem removal instrument [Figure 11] A cross-sectional view of the femoral stem removal instrument of FIG. 10 along line 11-11 of FIG. 10 as viewed in the direction of the arrow, and note that in FIG. 11, the femoral stem removal instrument is shown fixed to the neck of the femoral stem component.

Best Mode for Carrying Out the Invention

[0024] The concepts of the present disclosure are subject to various modifications and alternative forms, but specific exemplary embodiments thereof are shown in the drawings and described in detail herein. However, it is not intended to limit the concepts of the present disclosure to the specific forms disclosed, but rather to cover all modifications, equivalents, and alternatives encompassed by the spirit and scope of the invention as defined by the appended claims.

[0025] Terms such as anterior, posterior, medial, lateral, superior, and inferior, which represent anatomical reference points, may be used throughout this specification in relation to the orthopedic implants and orthopedic instruments described herein, as well as in relation to the vivisection of the patient. Such terms have well-understood meanings in both the study of anatomy and the field of orthopedic surgery. The use of such anatomical reference terms in the descriptions and claims described herein is intended to be consistent with their well-understood meanings unless otherwise specified. In addition, terms such as “apex,” “base,” “anterior,” “posterior,” “lateral,” “height,” “length,” “width,” “upper,” and “lower,” which may be used herein, are merely descriptive of reference points and should not necessarily limit embodiments of this disclosure to any particular orientation or configuration.

[0026] Referring here to Figures 1-4, an adapter for use with an automated surgical impactor in the form of the femoral stem extraction instrument 10 is shown. The stem extraction instrument 10 is an orthopedic instrument. That is, it is a surgical instrument used by a surgeon when performing an orthopedic procedure. Therefore, as used herein, the terms “orthopedic instrument (singular)” and “orthopedic instrument (plural)” should be understood to be different from orthopedic implants or prostheses that are surgically implanted in a patient’s body. As will be further described below, the stem extraction instrument 10 is used with an automated surgical impactor to extract a previously implanted femoral stem component from the patient’s femur.

[0027] As shown in Figures 1 to 4, the stem extraction instrument 10 includes an elongated body 12 having a connector 14 formed at its proximal end 16. The connector 14 is configured to engage with the chuck of an automated surgical impactor (see Figure 6). As best shown in Figures 2 and 3, an extraction loop 18 is formed at the end 20 of the elongated body 12 of the instrument. The extraction loop 18 has a lateral opening 22 that penetrates the elongated body 12 and extends from its upper surface 24 to its lower surface 26. As shown in Figure 3, the extraction loop 18 is configured to receive and then capture the neck 152 of a femoral stem component 150.

[0028] The stem extraction tool 10 further includes an elongated locking lever 30 extending outward from the internal cavity of the elongated body 12 through an opening 32 formed in the upper surface 24 of the elongated body 12. The locking lever 30 includes a pivot end 34 pivotably connected to the elongated body 12 via a pivot pin 36. As described below, the latch end 38 on the opposite side of the locking lever 30 is selectively captured by a push-button latch to hold the locking lever 30 in its locked position.

[0029] As shown in Figures 2 and 3, the clamping jaw 40 is slidably connected to the elongated body 12. The clamping jaw 40 includes a number of serrated edges 42 at its distal end 44. The serrated edges 42 facilitate a secure connection to the outer surface of the neck 152 of the femoral stem component 150. It should be understood that the surface of the extraction loop 18 defining the hole 22 may also have similar serrated edges or other textured structures formed therein. The clamping jaw 40 is configured to slide back and forth in the direction toward and away from the extraction loop 18. Specifically, the clamping jaw 40 is movable between a clamped position in which the clamping jaw extends toward the extraction loop 18 and a released position in which the clamping jaw 40 retracts away from the extraction loop 18. When the clamping jaw 40 is positioned in its clamped position, its serrated distal end 44 is biased to contact the neck 152 of the femoral stem component 150, thereby applying a clamping force thereto. This clamping force traps the neck 152 of the femoral stem component 150 within the extraction loop 18 by clamping the neck 152 of the stem between the clamping jaw 40 and the extraction loop 18. Conversely, when the clamping jaw 40 is positioned in its release position, it retracts away from the extraction loop 18, thereby releasing the neck 152 of the femoral stem component 150.

[0030] As shown in Figures 2 and 3, the threaded drive assembly 46 is operably connected to the clamping jaw 40 and is operable to move the clamping jaw 40 between its clamped position and its released position. Specifically, as seen in Figures 2 and 3, the threaded drive assembly 46 includes a drive screw 48 and a drive link 50. The drive screw 48 is rotatably connected to an elongated body 12 and includes a socket 52 defined at its proximal end 54. The threaded shaft 56 extends distally away from the socket 52. The drive link 50 is slidably connected to the elongated body 12 so as to be movable within the elongated body 12 in the direction toward and away from the extraction loop 18. A threaded hole 58 is formed in the drive link 50. The threaded shaft 56 of the drive screw 48 is screwed into and received in the threaded hole 58 of the drive link 50. The rotation of the threaded shaft 56 of the drive screw 48 within the threaded hole 58 of the drive link 50 causes the linear movement of the drive link 50 within the elongated body 12.

[0031] As seen in Figures 2, 3, and 5, the socket 52 is configured as a hexagonal socket that is set to receive a manual or electric ball-end hex driver 60. When a surgeon or other person rotates the drive screw 48, the threaded shaft 56 of the drive screw is also rotated, thereby causing linear movement of the drive link 50. Rotation in one direction (e.g., clockwise) moves the drive link 50, and therefore the clamping jaw 40, toward the extraction loop 18, thereby moving the clamping jaw 40 to a clamped position where the neck 152 of the femoral stem component 150 is captured within the extraction loop 18. Rotation in the opposite direction (e.g., counterclockwise) moves the drive link 50, and therefore the clamping jaw 40, toward the extraction loop 18, thereby moving the clamping jaw 40 to a released position where the neck 152 of the femoral stem component 150 is released from the extraction loop 18.

[0032] As shown in Figures 2 and 3, the drive link 50 is connected to the clamping jaw 40 by a linkage including a connecting link 64 and a leaf spring 66. Specifically, the distal end 68 of the drive link 50 is pivotably connected to the proximal end 70 of the connecting link 64, and the opposite distal end 72 of the connecting link is connected to the proximal end 74 of the leaf spring 66. The opposite distal end 76 of the leaf spring 66 is pivotally connected to the proximal end 78 of the clamping jaw 40. As shown in Figures 2 and 3, both the connecting link 64 and the leaf spring 66 are connected to a locking lever 30. Specifically, the pivot pin 80 connecting the distal end 72 of the connecting link to the proximal end 74 of the leaf spring is captured in an arc-shaped slot 82 formed in the locking lever 30. When the drive link 50 is driven within the elongated body 12 in a direction toward and away from the extraction loop 18, the pivot pin 80 translates in the same direction within the slot 82 of the locking lever.

[0033] The leaf spring 66 is used to apply a fixed load in the form of spring bias to the neck 152 of the femoral stem component 150, thereby creating a rigid structure during the extraction of the stem component 150. This fixed load is applied and removed using a locking lever 30. In particular, the locking lever 30 is movable between an unlocked position (shown in Figures 1 and 2) in which the latch end 38 of the locking lever 30 extends away from the elongated body 12, and a locked position (shown in Figure 3) in which the latch end 38 is positioned close to the elongated body 12 and is captured by a push-button fastener 88. When the locking lever 30 is in its unlocked position, the leaf spring 66 relaxes and therefore does not exert spring bias on the clamping jaw 40 (and thus the neck 152 of the femoral stem component 150). However, when the locking lever 30 is moved to its locked position, the leaf spring 66 is compressed, thereby applying spring bias to the clamping jaw 40 (and thus to the neck 152 of the femoral stem component 150).

[0034] As described above, the push-button fastener 88 can be used to selectively hold the locking lever 30 in the locked position shown in Figures 3 and 6. The push-button fastener 88 includes a button surface 90 that is substantially coplanar with the outer surface of the elongated body 12. The button surface 90 is configured to be pressed by a surgeon and may be grooved or otherwise textured to provide an improved grip.

[0035] As shown in Figure 4, the push-button fastener 88 also includes a locking claw 92 having a ramp-shaped upper cam surface 94 and a lower surface 96. A guide post 98 extends from the rear surface of the locking claw 92 toward the inner surface of the elongated body 12. A compression spring 102 is trapped around the guide post 98 and is thus held between the inner surface of the elongated body 12 and the rear surface of the locking claw 92. The spring 102 biases the push-button fastener 88 toward the outer surface of the elongated body 12 and the rear surface of the locking claw 92 (i.e., the compression spring 102 biases the push-button fastener 88 to the right, as seen in the orientation of Figure 4).

[0036] As shown in Figure 4, a latch 104 extending downward is formed at the latch end 38 of the locking lever 30. The latch 104 has a ramp-shaped lower cam surface 106 and an upper surface 108 formed therein. When the locking lever 30 is in the locked position, the upper surface 108 of the latch 104 engages with the lower surface 96 of the locking claw 92, thereby holding the latch 104. When a surgeon or other person presses down the button surface 90, the push-button fastener 88 slides toward the opposite inner surface of the elongated body 12 (i.e., slides to the left when viewed in the orientation of Figure 4), and the lower surface 96 of the locking claw 92 slides away from the upper surface 108 of the latch 104, thereby releasing the locking lever 30. As seen in Figure 2, a compression spring 112 biases the locking lever 30 to its unlocked position. Therefore, when the latch 104 is released by pressing the push-button fastener 88, the latch end 38 of the locking lever 30 is biased toward its unlocked position by the spring bias of the compression spring 112, releasing the tension of the leaf spring 66.

[0037] When a surgeon or other user moves the lever 30 from its unlocked position to its locked position without pressing the push-button fastener 88, the lower cam surface 106 of the latch 104 engages with the upper cam surface 94 of the locking claw 92. This engagement of the cam surfaces 94, 106 overcomes the spring bias of the compression spring 102, causing the push-button fastener 88 to slide toward the opposite inner surface of the elongated body 12 (i.e., sliding to the left when viewed in the orientation of Figure 4). When the latch 104 passes the claw 90 and the cam surfaces 94, 106 disengage, the spring 102 slides the push-button fastener 88 backward toward its original position (i.e., the compression spring 102 biases the push-button fastener 88 to the right when viewed in the orientation of Figure 4), causing the upper surface 108 of the latch 104 to engage with the lower surface 96 of the locking claw 92, thereby holding the latch 104.

[0038] As described above, the use of the push-button fastener 88 provides secure locking to the locking lever 30, thereby preventing accidental release of the locking lever 30 during use of the stem extraction instrument 10. Furthermore, the position of the push-button fastener 88 on the elongated body 12 allows the locking lever 30 to be opened and / or closed by the surgeon using one hand.

[0039] As shown in Figures 2 and 3, the lower end of the compression spring 112 that biases the locking lever 30 to its unlocked position is captured on a post 114 formed in a plate 116 defined within the elongated body 12, and the upper end opposite the compression spring 112 is captured on a similarly shaped post 118 formed on the lower surface of the locking lever 30. The distal edge 120 of the plate 116 functions as a built-in stopper that prevents overtightening and thereby prevents damage to the leaf spring 66.

[0040] In exemplary embodiments, the stem extractor 10 is formed from a metal material such as stainless steel. In particular, the elongated body 12, the locking lever 30, and various internal components form the assembled metal instrument. The stem extractor 10 may be formed by conventional machining techniques, or alternatively by the use of 3D printing techniques. In the case of 3D printing, the stem extractor 10 is formed layer by layer.

[0041] When in use, the femoral resection instrument 10 may be used by a surgeon to remove a femoral stem component 150 implanted from the intramedullary canal 162 of the patient's femur 160 during hip replacement surgery, such as revision hip replacement surgery. Prior to the removal of the femoral stem component 150, the surgeon performs several intraoperative surgical steps to gain access to the implanted femoral stem component 150. The surgeon also removes the femoral head component (not shown) from the trunnion 154 of the implanted femoral stem component. Then, as shown in Figures 5 and 6, the surgeon advances the stem resection instrument 10 into the surgical site and positions the instrument's resection loop 18 around the neck 152 of the femoral stem component 150, between its trunnion 154 and its proximal body 156.

[0042] Subsequently, the surgeon uses a manual or electric ball-end hex driver 60 to operate the threaded drive assembly 46 and clamp the neck 152 of the femoral stem component 150 into the extraction loop 18. Specifically, the surgeon rotates the drive screw 48 in a direction (e.g., clockwise) that moves the drive link 50 and, by extension, the clamping jaw 40 toward the extraction loop 18, thereby moving the clamping jaw 40 to a clamping position where the neck 152 of the femoral stem component 150 is securely captured (i.e., clamped) within the extraction loop 18.

[0043] As shown in Figure 6, once the neck 152 of the femoral stem component 150 is secured within the extraction loop 18, the surgeon moves the locking lever 30 to its locked position to apply a fixing load to the clamped femoral stem component 150. Specifically, the surgeon grips the stem extraction instrument 10 to bias the locking lever 30 to its locked position, in which the latch 104 is captured and held by a push-button fastener 88. In doing so, the leaf spring 66 that applies a fixing load to the neck 152 of the femoral stem component 150 in the form of spring bias is compressed, thereby forming a rigid structure for the instrument 10 and the stem component 150.

[0044] Subsequently, the instrument's connector 14 is connected to the chuck 172 of the automated surgical impactor 170 (see Figure 6). The automated surgical impactor 170 may be embodied as the Kinese® automated surgical system, commercially available from DePuy Synthes (Warsaw, Indiana). In an exemplary embodiment, the automated surgical impactor 170 includes a chuck 172 in the form of a twist-locking collar. The automated surgical impactor 170 also includes a primary handgrip 174, a secondary handgrip 176, and a trigger 178. Once the chuck 172 is connected to the connector 14 of the stem extraction instrument 10, the surgeon presses down the trigger 178, thereby causing the automated surgical impactor 170 to generate extraction forces in the form of a series of controlled impacts against the stem extraction instrument 10. The stem extraction instrument 10 transmits the extraction force from their impact insertion to the implanted femoral stem component 150, thereby enabling the component 150 to be extracted from the intramedullary canal 162 of the patient's femur 160. During such extraction, a push-button fastener 88 holds the locking lever 30 in its locked position, allowing the surgeon's hand to remain on the automated surgical impactor 170. In addition, a leaf spring 66 holds the femoral stem component 150, which is firmly fixed to the stem extraction instrument 10 during insertion. Unlike adapters using typical rigid drive row mounting mechanisms, the compliant flexible leaf spring 66 of the stem extraction instrument 10 does not retract during insertion, nor does it loosen otherwise, even when subjected to frequent low-amplitude insertions caused by the automated surgical impactor 170.

[0045] Once the surgeon has extracted the femoral stem component 150 from the intramedullary canal 162 of the patient's femur 160, the connector 14 of the stem insertion instrument 10 may be separated from the chuck 172 of the automated surgical impactor 170. The surgeon or other personnel may then press the button surface 90 of the push-button fastener 88 to release the locking lever 30, thereby automatically moving the locking lever 30 to its unlocked position (by spring biasing exerted thereon). The surgeon or other personnel then rotate the drive screw 48 in a direction (e.g., counterclockwise) that moves the drive link 50, and therefore the clamping jaw 40, away from the extraction loop 18, thereby moving the clamping jaw 40 to its released position, where the neck 152 of the femoral stem component 150 is released from the extraction loop 18. The surgeon then performs the remaining steps in the surgical procedure.

[0046] Referring now to Figures 7 and 8, another embodiment of the stem extraction instrument 10 is shown. The stem extraction instrument 10 in Figures 7 and 8 is essentially the same as the instrument in Figures 1 to 6, except for certain features that have been modified to improve the use of the instrument in direct anterior approach hip replacement surgery. Specifically, when using a direct anterior approach, the surgeon does not have line-of-sight access to the intramedullary canal of the patient's femur. This limited access and visibility makes it difficult for the surgeon to navigate "around the corner" of the proximal end of the patient's femur 160. Therefore, the distal end 20 of the elongated body 12 of the stem extraction instrument 10 in Figures 7 and 8 has been modified to have a curved outer surface that offsets the extraction loop 18 inward compared to the instrument 10 in Figures 1 to 6.

[0047] As shown in Figure 8, to accommodate the modified shape of its elongated body 12, the stem extraction tool 10 in Figures 7 and 8 includes a knuckle link 130 pivotally connected to the elongated body 12. The knuckle link 130 converts the linear movement generated by the threaded drive assembly 46 and the spring bias generated by the leaf spring 66 around the curved shape of the elongated body 12. Specifically, the distal end 76 of the leaf spring 66 is pivotally connected to the proximal end 132 of the knuckle link 130, and the distal end 134 of the knuckle link 130 is connected to the proximal end 78 of the clamping jaw 40 by capturing a pin formed in the clamping jaw 40 within a slot formed in the distal end 134 of the knuckle link. Thus, the movement of the leaf spring 66 by the threaded drive assembly 46 is converted to the clamping jaw 40 via the knuckle link 130. Similarly, the spring biasing force generated by the leaf spring 66 is transmitted to the clamping jaw 40 via the knuckle link 130.

[0048] Referring next to Figures 9 to 11, additional embodiments of the stem extraction instrument 10 are shown. For example, the stem extraction instrument 10 in Figure 9 is essentially the same as the instrument in Figures 1 to 6, except that the window of the elongated body 12 has been removed. With respect to the embodiments in Figures 10 and 11, certain structural elements of the instrument 10 have been removed to result in a somewhat "reduced-size" design. In particular, the stem extraction instruments in Figures 10 and 11 do not include the leaf spring 66 and locking lever 30 for applying a fixed load to the neck 152 of the femoral stem component 150. Instead, the distal end 68 of the drive link 50 has been modified to directly clamp the neck 152 of the femoral stem component 150. Thus, the operation of the threaded drive assembly 46 biases the drive link 50 to and from contact with the neck 152 of the femoral stem component 150 in order to selectively capture the femoral stem component 150 within the extraction loop 18 of the instrument.

[0049] While the drawings and the above description have illustrated and illustrated the present disclosure in detail, such illustrations and descriptions are by their nature illustrative and should not be considered limiting, and merely illustrate illustrative embodiments. It is understood that all changes and modifications that fall within the spirit of the present disclosure should be protected.

[0050] For example, the concepts of this disclosure are described in relation to orthopedic instruments for use with automated surgical impactors, thereby offering significant advantages, some of which may be recognized in other instrument designs. For instance, the concepts of this disclosure may be used in the design of orthopedic instruments for manual implantation using a surgical mallet or hammer.

[0051] This disclosure offers several advantages based on various features of the methods, apparatus, and systems described herein. It should be noted that alternative embodiments of the methods, apparatus, and systems of this disclosure do not include all of the features described, but still benefit from at least some of the advantages of such features. Those skilled in the art can easily independently implement methods, apparatus, and systems encompassing the spirit and scope of this disclosure as defined by the appended claims, incorporating one or more features of the present invention.

[0052] [Implementation Method] (1) An orthopedic instrument for extracting a femoral stem component during an orthopedic hip replacement surgery on a patient's femur, wherein the orthopedic instrument is An elongated body comprising: (i) a connector formed at the proximal end of the elongated body, the connector being configured to engage with the chuck of an automated surgical impactor; and (ii) an extraction loop formed at the distal end of the elongated body, the extraction loop extending through the elongated body and having a hole configured to receive the neck of the femoral stem component inside; A locking lever having a pivot end pivotably connected to the elongated body and a latch end on the opposite side, A clamping jaw slidably connected to the elongated body, wherein the clamping jaw is movable between (i) a clamping position in which the clamping jaw extends toward the extraction loop and (ii) a release position in which the clamping jaw retracts away from the extraction loop. A threaded drive assembly operably connected to the clamping jaw, wherein the threaded drive assembly is operable to move the clamping jaw between its clamped position and its released position, An orthopedic instrument comprising a leaf spring having a first end pivotably connected to the locking lever and a second end connected to the clamping jaw. (2) The screw drive assembly comprises a drive screw rotatably connected to the elongated body and a drive link slidably connected to the elongated body, The drive link is operably connected to the clamping jaw, The drive screw has a socket defined at its proximal end and a threaded shaft extending distally away from the socket. The drive link has a threaded hole formed therein, The threaded shaft of the drive screw is positioned within the threaded hole of the drive link. The rotation of the drive screw in the first direction moves the drive link toward the extraction loop, The orthopedic instrument according to Embodiment 1, wherein a second rotation of the drive screw in the opposite direction moves the drive link away from the extraction loop. (3) The orthopedic instrument according to Embodiment 1, further comprising a push-button fastener connected to the elongated body, wherein the locking lever is movable between an unlocked position in which the latch end is separated from the elongated body and a locked position in which the latch end is captured by the push-button fastener. (4) The orthopedic instrument according to Embodiment 3, further comprising a compression spring disposed between the locking lever and the elongated body, wherein the compression spring biases the locking lever to its unlocked position. (5) The orthopedic instrument according to Embodiment 1, wherein the leaf spring applies spring bias to the neck of the femoral component when the neck of the femoral component is positioned within the extraction loop and the locking lever is in its locked position.

[0053] (6) The orthopedic instrument according to Embodiment 1, wherein when the neck of the femoral component is positioned within the extraction loop and the clamping jaw is positioned in its clamping position, the clamping jaw applies a clamping force to the neck of the femoral component. (7) The orthopedic instrument according to Embodiment 1, wherein the second end of the leaf spring is pivotably connected to the clamping jaw. (8) Further comprising a knuckle link pivotably connected to the elongated body, The second end of the leaf spring is pivotably connected to the first end of the knuckle link, The orthopedic instrument according to Embodiment 1, wherein the second end of the knuckle link is connected to the clamping jaw. (9) An orthopedic instrument for extracting a femoral stem component during an orthopedic hip replacement surgery on a patient's femur, wherein the orthopedic instrument is An elongated body comprising: (i) a connector formed at the proximal end of the elongated body, the connector being configured to engage with the chuck of an automated surgical impactor; and (ii) an extraction loop formed at the distal end of the elongated body, the extraction loop extending through the elongated body and having a hole configured to receive the neck of the femoral stem component inside; A locking lever having a pivot end pivotably connected to the elongated body and a latch end on the opposite side, A drive link slidably connected to the elongated body, wherein the drive link is movable within the elongated body in a direction toward the extraction loop and in a direction toward the extraction loop, A connecting link having a first end pivotably connected to the locking lever and a second end pivotably connected to the drive link, A clamping jaw slidably connected to the elongated body, wherein the clamping jaw is movable between (i) a clamping position in which the clamping jaw extends toward the extraction loop and (ii) a release position in which the clamping jaw retracts away from the extraction loop. A leaf spring having a first end pivotably connected to the locking lever and a second end connected to the clamping jaw, An orthopedic instrument wherein (i) the drive link moves in the direction toward the extraction loop, thereby positioning the clamping jaws in a clamped position, and (ii) the drive link moves in the direction away from the extraction loop, thereby positioning the clamping jaws in a released position. (10) The elongated body is further provided with a drive screw that is rotatably connected to it, The drive screw has a socket defined at its proximal end and a threaded shaft extending distally away from the socket. The drive link has a threaded hole formed therein, The threaded shaft of the drive screw is positioned within the threaded hole of the drive link. The rotation of the drive screw in the first direction moves the drive link toward the extraction loop, The orthopedic instrument according to Embodiment 9, wherein a second rotation of the drive screw in the opposite direction moves the drive link away from the extraction loop.

[0054] (11) The locking lever has a slot formed therein, The orthopedic instrument according to Embodiment 9, wherein the first end of the leaf spring and the first end of the connecting link are connected to each other by a pivot pin that translates within the slot of the locking lever. (12) The orthopedic instrument according to Embodiment 9, further comprising a push-button fastener connected to the elongated body, wherein the locking lever is movable between an unlocked position in which the latch end is separated from the elongated body and a locked position in which the latch end is captured by the push-button fastener. (13) The orthopedic instrument according to embodiment 12, further comprising a compression spring disposed between the locking lever and the elongated body, wherein the compression spring biases the locking lever to its unlocked position. (14) The orthopedic instrument according to Embodiment 9, wherein the leaf spring applies spring bias to the neck of the femoral component when the neck of the femoral component is positioned within the extraction loop and the locking lever is in its locked position. (15) The orthopedic instrument according to Embodiment 9, wherein when the neck of the femoral component is positioned within the extraction loop and the clamping jaw is positioned in its clamping position, the clamping jaw applies a clamping force to the neck of the femoral component.

[0055] (16) The orthopedic instrument according to Embodiment 9, wherein the second end of the leaf spring is pivotably connected to the clamping jaw. (17) Further comprising a knuckle link pivotably connected to the elongated body, The second end of the leaf spring is pivotably connected to the first end of the knuckle link, The orthopedic instrument according to Embodiment 1, wherein the second end of the knuckle link is connected to the clamping jaw. (18) A method for removing an implanted femoral stem component during the performance of an orthopedic hip replacement surgery on a patient's femur, The extraction loop for the orthopedic instrument is positioned around the neck of the femoral stem component, The screw-type drive assembly of the orthopedic instrument is operated to move the clamping jaws to contact the neck of the femoral stem component, The locking lever of the orthopedic instrument is moved to the locked position, and a spring bias is applied to the neck of the femoral stem component by the leaf spring, Connecting the connector of the orthopedic instrument to the chuck of the automated surgical impactor, A method comprising operating the automated surgical impactor to apply an excision force to the femoral stem component. (19) The method according to embodiment 18, wherein operating the threaded drive assembly of the orthopedic instrument includes rotating the drive screw of the threaded drive assembly to move the clamping jaws to contact the neck of the femoral stem component. (20) The method according to embodiment 18, wherein moving the locking lever of the orthopedic instrument to the locked position includes capturing the latch end of the locking lever in a push-button fastener so as to hold the locking lever in the locked position.

Claims

1. An orthopedic instrument for extracting a femoral stem component during an orthopedic hip replacement surgery on a patient's femur, wherein the orthopedic instrument is An elongated body comprising: (i) a connector formed at the proximal end of the elongated body, the connector being configured to engage with the chuck of an automated surgical impactor; and (ii) an extraction loop formed at the distal end of the elongated body, the extraction loop extending through the elongated body and having a hole configured to receive the neck of the femoral stem component inside; A locking lever having a pivot end pivotably connected to the elongated body and a latch end on the opposite side, A clamping jaw slidably connected to the elongated body, wherein the clamping jaw is movable between (i) a clamping position in which the clamping jaw extends toward the extraction loop and (ii) a release position in which the clamping jaw retracts away from the extraction loop. A threaded drive assembly operably connected to the clamping jaw, wherein the threaded drive assembly is operable to move the clamping jaw between its clamped position and its released position, An orthopedic instrument comprising a leaf spring having a first end pivotably connected to the locking lever and a second end connected to the clamping jaw.

2. The screw-type drive assembly comprises a drive screw rotatably connected to the elongated body and a drive link slidably connected to the elongated body, The drive link is operably connected to the clamping jaw, The drive screw has a socket defined at its proximal end and a threaded shaft extending distally away from the socket. The drive link has a threaded hole formed therein, The threaded shaft of the drive screw is positioned within the threaded hole of the drive link. The rotation of the drive screw in the first direction moves the drive link toward the extraction loop, The orthopedic instrument according to claim 1, wherein a second rotation of the drive screw in the opposite direction moves the drive link away from the extraction loop.

3. The orthopedic instrument according to claim 1, further comprising a push-button fastener connected to the elongated body, wherein the locking lever is movable between an unlocked position in which the latch end is separated from the elongated body and a locked position in which the latch end is captured by the push-button fastener.

4. The orthopedic instrument according to claim 3, further comprising a compression spring disposed between the locking lever and the elongated body, wherein the compression spring biases the locking lever to its unlocked position.

5. The orthopedic instrument according to claim 1, wherein the neck of the femoral component is positioned within the extraction loop and the locking lever is positioned in its locked position, the leaf spring applies spring bias to the neck of the femoral component.

6. The orthopedic instrument according to claim 1, wherein the neck of the femoral component is positioned within the extraction loop and the clamping jaws are positioned in their clamping position, the clamping jaws apply a clamping force to the neck of the femoral component.

7. The orthopedic instrument according to claim 1, wherein the second end of the leaf spring is pivotably connected to the clamping jaw.

8. The aforementioned elongated body is further equipped with a knuckle link pivotably connected to it, The second end of the leaf spring is pivotably connected to the first end of the knuckle link, The orthopedic instrument according to claim 1, wherein the second end of the knuckle link is connected to the clamping jaw.

9. An orthopedic instrument for extracting a femoral stem component during an orthopedic hip replacement surgery on a patient's femur, wherein the orthopedic instrument is An elongated body comprising: (i) a connector formed at the proximal end of the elongated body, the connector being configured to engage with the chuck of an automated surgical impactor; and (ii) an extraction loop formed at the distal end of the elongated body, the extraction loop extending through the elongated body and having a hole configured to receive the neck of the femoral stem component inside; A locking lever having a pivot end pivotably connected to the elongated body and a latch end on the opposite side, A drive link slidably connected to the elongated body, wherein the drive link is movable within the elongated body in a direction toward the extraction loop and in a direction toward the extraction loop, A connecting link having a first end pivotably connected to the locking lever and a second end pivotably connected to the drive link, A clamping jaw slidably connected to the elongated body, wherein the clamping jaw is movable between (i) a clamping position in which the clamping jaw extends toward the extraction loop and (ii) a release position in which the clamping jaw retracts away from the extraction loop. A leaf spring having a first end pivotably connected to the locking lever and a second end connected to the clamping jaw, An orthopedic instrument wherein (i) the drive link moves in the direction toward the extraction loop, thereby positioning the clamping jaws in a clamped position, and (ii) the drive link moves in the direction toward the extraction loop, thereby positioning the clamping jaws in a released position.

10. The aforementioned elongated body is further equipped with a drive screw that is rotatably connected to it, The drive screw has a socket defined at its proximal end and a threaded shaft extending distally away from the socket. The drive link has a threaded hole formed therein, The threaded shaft of the drive screw is positioned within the threaded hole of the drive link. The rotation of the drive screw in the first direction moves the drive link toward the extraction loop, The orthopedic instrument according to claim 9, wherein the second rotation of the drive screw in the opposite direction moves the drive link away from the extraction loop in the direction described above.

11. The locking lever has a slot formed therein, The orthopedic instrument according to claim 9, wherein the first end of the leaf spring and the first end of the connecting link are connected to each other by a pivot pin that translates within the slot of the locking lever.

12. The orthopedic instrument according to claim 9, further comprising a push-button fastener connected to the elongated body, wherein the locking lever is movable between an unlocked position in which the latch end is separated from the elongated body and a locked position in which the latch end is captured by the push-button fastener.

13. The orthopedic instrument according to claim 12, further comprising a compression spring disposed between the locking lever and the elongated body, wherein the compression spring biases the locking lever to its unlocked position.

14. The orthopedic instrument according to claim 9, wherein the neck of the femoral component is positioned within the extraction loop and the locking lever is positioned in its locked position, the leaf spring applies spring bias to the neck of the femoral component.

15. The orthopedic instrument according to claim 9, wherein the neck of the femoral component is positioned within the extraction loop and the clamping jaws are positioned in their clamping position, the clamping jaws apply a clamping force to the neck of the femoral component.

16. The orthopedic instrument according to claim 9, wherein the second end of the leaf spring is pivotably connected to the clamping jaw.

17. The aforementioned elongated body is further equipped with a knuckle link pivotably connected to it, The second end of the leaf spring is pivotably connected to the first end of the knuckle link, The orthopedic instrument according to claim 1, wherein the second end of the knuckle link is connected to the clamping jaw.

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