Patent Application
20240058136
The present disclosure relates generally to bone screws, spinal implants, and instruments useful in spinal implant procedures, including inserters, trial inserters, screw drivers, and removal drivers for bone screws.
The spine is critical in human physiology for mobility, support, and balance. Spinal injuries can be debilitating or catastrophic to patients. Even small irregularities in the spine can cause devastating pain and loss of coordination.
Surgical procedures are commonly performed to correct problems with displaced, damaged, or degenerated intervertebral discs. Generally, spinal fusion procedures involve removing some or all of the diseased or damaged disc, and inserting one or more intervertebral implants into the resulting disc space. Successful replacement of injured or deteriorated spinal bone with artificial implants can involve consideration and understanding of the inherent stresses on the spine, as well as the biological properties of the body in response to the devices.
In one aspect, disclosed herein is a spinal implant comprising: an upper endplate comprising a first plurality of micropores; a lower endplate comprising a second plurality of micropores; a central body fixedly placed between the upper and lower endplates, the central body comprising a plurality of pores formed by struts, a first and second end opposing each other, and two sides; and a plurality of fixation apertures, each of said plurality of fixation apertures defined by a solid wall and extending from the second end of the central body to one of the upper endplate or the lower endplate, wherein one or more of the solid walls includes a retaining feature configured to retain a bone screw within one or more of the plurality of fixation aperture and a confirmation feature configured to provide tactile feedback to a user when the bone screw has been fully inserted into the corresponding fixation aperture.
In some embodiments, the retaining feature is a passive retaining feature. In some embodiments, the retaining feature is a deflectable latch having a lip at a proximal end thereof and configured to allow passage of a bone screw in a first direction through the corresponding fixation aperture and retain the bone screw within the corresponding fixation aperture after a proximal portion of the bone screw has passed the lip. In some embodiments, the confirmation feature is a thread formed integrally as part of the solid wall and the bone screw further comprises a ridge on a proximal portion of the bone screw and wherein contact between the ridge and the thread provides tactile feedback to the user. In some embodiments, the solid wall defining each of the plurality of fixation apertures are not in contact with each other. In some embodiments, at least one of the solid walls defining a fixation aperture is in contact with at least one other solid wall defining a different fixation aperture. In some embodiments, at least one solid wall defining a fixation aperture is in contact with at least one of the struts in the central body. In some embodiments, the spinal implant further comprises an insertion tool engagement feature on the second end. In some embodiments, the insertion tool engagement feature is in contact with at least one of the solid walls defining a fixation aperture. In some embodiments, the insertion tool engagement feature is located between and in contact with at least two solid walls defining a fixation aperture. In some embodiments, one or more of the plurality of the fixation apertures extend from the second end to the upper endplate. In some embodiments, the lip of the deflectable latch extends at least towards the upper endplate. In some embodiments, one or more of the plurality of the fixation apertures extend from the second end to the lower endplate. In some embodiments, the lip of the deflectable latch extends at least towards the lower endplate. In some embodiments, the deflectable latch is integral to or fixedly attached to the solid wall. In some embodiments, the deflectable latch is fixedly attached to or integral to the central body. In some embodiments, the deflectable latch is solid. In some embodiments, the bone screw is configured to extend beyond the upper endplate and anchor in a first vertebral bone or extend beyond the lower endplate and anchor in a second vertebral bone. In some embodiments, the lip is configured to contact and hold the head of the bone screw in place thereby retaining the bone screw in the fully seated position. In some embodiments, the thread is at a distal portion of a corresponding fixation aperture. In some embodiments, the thread is a triple-lead thread. In some embodiments, the thread is configured to engage with a single ridge on the bone screw. In some embodiments, at least a portion of the spinal implant is 3D printed. In some embodiments, the spinal implant is 3D printed. In some embodiments, the spinal implant is made of titanium. In some embodiments, the plurality of pores of the central body comprises a first average pore size that is greater than an average pore size of the first plurality of micropores or an average pore size of the second plurality of micropores. In some embodiments, the insertion tool engagement feature is configured to engage a corresponding engagement feature of an inserter. In some embodiments, the engagement feature is not in contact with the solid walls of the plurality of fixation apertures. In some embodiments, the spinal implant further comprises a fusion aperture extending from the upper endplate to the lower endplate. In some embodiments, one or more of the plurality of fixation apertures extend in a first direction that is angled from the lower endplate by a first acute angle. In some embodiments, one or more the plurality of fixation apertures extends in a second direction that is angled from the lower endplate by a second acute angle. In some embodiments, the first end comprises a first height shorter than a second height of the second end.
In another aspect, disclosed herein is an inserter for inserting a spinal implant, the inserter comprising: an outer shaft comprising an elongate body containing a cavity therewithin and two opposing pins near a distal end of the elongate body, the two opposing pins extending inwardly from an inner surface of the elongate body; an inner shaft configured to be received in the cavity of the outer shaft, the inner shaft comprising a distal tip configured to be received in an engagement aperture of the spinal implant, and a barrel cam element near the distal tip, wherein the barrel cam element is configured to mate with the two opposing pins of the outer shaft; and a thumbwheel threadedly coupled to a proximal end of the inner shaft, wherein the thumbwheel is configured to rotate and cause rotation of the barrel cam element, thereby simultaneously rotating and translating the inner shaft relative to the outer shaft and the spinal implant.
In some embodiments, the simultaneous rotation and translation of the inner shaft is configured to couple the distal tip with the engagement aperture thereby locking or unlocking the inserter to the spinal implant. In some embodiments, the outer shaft further comprises two posts at the distal end of the elongate body, each of the two posts configured to mate with a side engagement slot of the spinal implant. In some embodiments, the two opposing pins are at or near a distal end of the barrel cam element in an unlocked position. In some embodiments, the two opposing pins are at or near a proximal end of the barrel cam element in a locked position.
In yet another aspect, disclosed herein is a driver for removing a bone screw from a spinal implant, the driver comprising: an outer sleeve containing a cavity therewithin; an inner shaft comprising a threaded distal end, the threaded distal end configured to couple with a threaded head of a bone screw thereby unthreading the bone screw from a spinal implant. The inner shaft is translatable at least distally relative to the outer sleeve through the cavity of the outer sleeve, and the outer sleeve is configured to deflect a deflectable latch latching on the thread head of the bone screw.
In some embodiments, the outer sleeve comprises a cannulated hexalobe drive feature at or near a distal end of the outer sleeve. In some embodiments, the threaded distal end of the inner shaft is disposed distally relative to a distal end of the outer sleeve. In some embodiments, the hexalobe drive feature is configured to couple to a corresponding feature of the threaded head of the bone screw to facilitate engagement to the bone screw. In some embodiments, the driver is configured to unlock the bone screw when a longitudinal axis of the bone screw is aligned with a longitudinal axis of the driver. In some embodiments, the driver is configured to unlock the bone screw when a longitudinal axis of the bone screw is angled away from a longitudinal axis of the driver. In some embodiments, the inner shaft further comprises a knob at a proximal end thereof, the knob is rotatable by the user thereby causing rotation of the inner shaft.
In yet another aspect, disclosed herein is a driver for removing a bone screw from a spinal implant, the driver comprising: a distal portion having a distal end; a drive feature proximal to the distal end, the drive feature configured to couple to a corresponding feature of a head of the bone screw to facilitate engagement to the bone screw; and a cam surface proximal to the drive feature. The cam surface is configured to deflect a deflectable latch of a spinal implant latching on the head of the bone screw outwardly thereby moving the deflectable latch out of a way of the bone screw.
In some embodiments, the distal end is narrower than the drive feature. In some embodiments, the drive feature comprises a trilobe. In some embodiments, the trilobe is configured to rotate and couple to an undercut of the corresponding feature of the head of the bone screw. In some embodiments, the driver further comprises an engagement feature configured to attach the distal portion to a handle. In some embodiments, the cam surf ace is located at least circumferentially on an outer surface of the distal portion.
In yet another aspect, disclosed herein is a driver for inserting a bone screw into a spinal implant, the driver comprising: an elongate body having a distal portion; a distal end; a drive feature located on an outer surface of the driver proximal to the distal end, the drive feature configured to couple to a corresponding feature of a head of the bone screw to facilitate engagement to the bone screw; and a flexible tab extending toward the distal end, the flexible tab configured to bias outwardly to retain the bone screw on the driver when the bone screw is loaded on the driver for insertion.
In some embodiments, the flexible tab comprises metal or alloy. In some embodiments, the flexible tab is positioned at least partly within a groove on the outer surface of the driver. In some embodiments, the drive feature comprises a corresponding trilobe feature distributed evenly around a circumference of the distal portion. In some embodiments, the drive feature comprises three grooves separating adjacent lobes of the trilobe feature. In some embodiments, the flexible tab is positioned at least partly within one of the three grooves. In some embodiments, the flexible tab is configured to move inwardly when loading the bone screw onto the driver. In some embodiments, the flexible tab, at its resting state, sits radially outward relative to an outer surface of the driver. In some embodiments, the flexible tab includes a proximal portion that is thicker than a distal portion thereof. In some embodiments, at least a part of the flexible tab is fixedly anchored to the elongate body of driver. In some embodiments, distal end is narrower than the drive feature. In some embodiments, the corresponding feature of the head of the bone screw includes a trilobe feature. In some embodiments, the trilobe feature is compatible with a driver with a hexalobe drive feature.
These and other aspects, advantages and salient features of the invention will become apparent from the following detailed description, which, when taken in conjunction with the annexed drawings, where like parts are designated by like reference characters throughout the drawings, disclose embodiments of the invention.
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
It is noted that the drawings of the disclosure are not necessarily to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.
As disclosed herein, the term “bone screw” is interchangeable with or equivalent to the terms, “bone anchor,” “bone fastener,” “fixation screw,” and simply “screw”. An “interbody” is interchangeable with or equivalent to a “spinal implant,” “fusion device,” “implant,” or “fusion implant” as used herein.
As disclosed herein, “proximal direction” indicates the direction away from attachment of an element to the subject, while “distal direction” indicates the direction opposite the proximal direction and toward attachment of an element to the subject.
In some embodiments, the bone screws, spinal implants or other devices are made of one or more biocompatible materials including, but not limited to, titanium, stainless steel, cobalt chrome, ceramics and/or thermoplastic materials.
Existing spinal implants, also referred to herein as interbodies, may be manufactured using additive manufacturing, or 3D printing processes, and may be made of titanium. Such interbodies may utilize a threaded connection to an inserter instrument. The threading can lead to inserters sticking to interbodies in situ and becoming difficult to remove. However, the lagging effect of a thread may be desirable as it eliminates toggle between the inserter and interbody or implant. Implants and instruments, including inserters, which address these and other challenges are described herein.
Disclosed herein are spinal implants, also referred to as fusion devices, interbodies, or fusion implants.
In some embodiments, the spinal implant is a 3D printed implant that requires no post machining. It can advantageously include a passive locking mechanism that deflects out of the way as the screw passes it during insertion. After traveling past the deflected latch, a small thread on the head of the screw can engage with a corresponding thread, e.g., a printed triple-lead thread, within the screw pocket to provide tactile feedback when the screw is past the latch and fully seated. The latch can spring back over the head of the screw to prevent screw back out should it loosen from the threads in the screw hole.
In some embodiments, the spinal implant advantageously includes a spring finger feature or latch that deflects out of the way during screw insertion and springs back capturing the head of the screw to keep it retained. The feature may be 3D printed or machined in.
The spinal implants disclosed herein advantageously provide a one step locking mechanism during screw insertion. Existing locking mechanisms have used springs but they are traditionally a separate piece from the implant. Other locking mechanisms may require a secondary step such as cam locks, additional cover plates, splaying of interfering component, etc. The locking deflectable latch disclosed herein requires no additional device or lock steps. The locking latch can be 3D printed into the implant with no post machining, which allows for small but complex geometries that were previously unattainable.
With reference to
Each fixation aperture 107 may include a solid wall 111 surrounding each aperture 107. One or more solid walls 111 can include a retaining feature configured to retain a bone screw 200 (
Solid walls 111 may further include a confirmation feature configured to provide tactile feedback to a user when the bone screw 200 has been fully inserted into the corresponding fixation aperture 107. In some embodiments, the confirmation feature is a thread 112 formed integrally as part of the solid wall 111 (
In some embodiments, the solid walls 111 defining each of the plurality of fixation apertures 107 are independent and have no contact with any of the other solid walls 111 defining other fixation apertures 107. In other embodiments, at least one of the solid walls 111 defining a fixation aperture 107 is in contact with at least one other solid wall 111 defining a different fixation aperture 107 (e.g.,
As depicted in
In some embodiments, one or more fixation apertures 107 comprise a solid wall 111 surrounding at least part of a corresponding fixation aperture 107. The deflectable latch 108 may be integral to or fixedly attached to the solid wall 111. The wall 111 may be made of a non-porous material. As discussed above, the wall 111 may include discontinuities near the deflectable latch 108 so that the latch 108 may move relative to the wall 111 and the rest of the implant 100. In some embodiments, one or more fixation apertures 107 may extend from the second end 105 to or through the upper end plate 101, and the lip 109 of the deflectable latch 108 associated with such fixation apertures 107 may extend at least toward the upper endplate 101. The fixation apertures 107 can extend from the second end 105 to and/or through the lower endplate 102. The lip 109 of the deflectable latch 108 may extend at least towards the lower endplate 102.
In some embodiments, one or more fixation apertures 107 extend in a first direction that is angled from the lower endplate 102 by a first acute angle, while other fixation aperture(s) extend in a second direction that is angled from the lower end plate 102 by a second acute angle.
The deflectable latch 108 may include an elongate flake 108a (
With reference to
In some embodiments, the bone screws 200 disclosed herein may, when fully inserted, extend beyond the upper end plate 101 and may anchor in a first vertebral bone or extend beyond the lower end plate 102 and anchor in a second vertebral bone. The lip 109 of the deflectable latch 108 contacts and holds a head 202 of the bone screw 200 in place, thereby retaining the bone screw 200 in the fully seated position, as can be seen in
In some embodiments, at least a portion of the spinal implant 100 may be formed using additive manufacturing, i.e., implant 100 may be 3D printed. In some embodiments, the entirety of the spinal implant may be 3D printed. In some embodiment, at least a part of spinal implant 100 or the entirety of spinal implant 100 may be made of titanium.
Central body 103 (
In some embodiments, implant 100 may further include a fusion aperture 114 extending from the upper end plate 101 to the lower end plate 102. Fusion implant 114 is shown in, e.g.,
With reference to
Engagement aperture 113a may be in contact with at least one of the solid walls 111 defining a fixation aperture 107. The engagement aperture 113a may be located between two solid walls 111 each defining a fixation aperture 107. In some embodiments, the engagement aperture 113a, e.g., the wall of the engagement aperture 113a, or at least part of the wall, may be located between and in contact with at least two solid walls 111, each defining a fixation aperture 107. In some embodiments, the engagement aperture 113a is located at or near a medial line of the implant 100, thus having an approximately equal distance to the two sides 106 of the implant 100.
As mentioned above, disclosed herein are inserters 300 configured for inserting the spinal fusion 100 implant into position in a patient.
With reference to
Outer shaft 301 may include a pair of opposing pins 303 disposed therein, near a distal end of elongate body 302. Opposing pins 303 may extend radially inwardly from an inner surface of elongate body 302, and are configured to mate with a barrel-cam style slot 313 (
Engagement feature 312 may be disposed at a distal end 311 of inner shaft 310. Engagement feature 312 is configured to be inserted into engagement aperture 113a on implant 100 in a keyed arrangement. After insertion of engagement feature 312 into engagement aperture 113a, thumbwheel 320 is turned to lag and retain implant 100. The inserters 300 disclosed herein can accomplish this motion with a slim profile which enables a medial attachment point to implant 100. This slim profile further facilitates the insertion or removal of screws 200 using drivers 500 and 400, respectively, while inserter 300 remains engaged with implant 100.
In some embodiments, the inserters 300 herein utilize a barrel-cam style mechanism to translate and rotate the inner shaft 310 with one input. The design achieves the lagging effect of a thread without utilizing a thread—in connection. The inserters 300 disclosed herein advantageously achieve the lagging effect without using the thread. The inserters 300 disclosed herein advantageously remove the problem of sticking (e.g., cold-welding) of inserter 300 and interbody 100 interface in-situ. In addition, existing 3D printed titanium interbodies 100 may require post-machining of a threaded inserter feature after the printing process. Eliminating the thread from the interbody 100 reduces steps in the process.
Thumbwheel 320 may be threadedly coupled to a proximal end of the inner shaft 310. As described herein, thumbwheel 320 may be configured to rotate and to cause rotation of the barrel cam element 313, thereby causing simultaneous rotating and translating of the inner shaft 310 relative to the outer shaft 302 and the spinal implant 100. In some embodiments, rotation of the thumb wheel 320 may cause simultaneous rotation and translation of the inner shaft 310 relative to the outer shaft 302 and may cause coupling or uncoupling of the distal tip 311 and engagement feature 312 of the inner shaft 310 with the engagement aperture 113a of the implant 100, thereby locking or unlocking the inserter 300 to or from the spinal implant 100.
In some embodiments, the outer shaft 301 may include two posts 304 at the distal end of elongate body 302. Posts 304 are best shown in
With reference generally to
In some embodiments, feature 203 may include a trilobe shape 205 (
In various embodiments, screw 200 may have a length of, e.g., 15 mm, 17.5 mm, 20 mm, 22.5 mm, 25 mm, 27.5 mm, or 30 mm Head 202 of screw 200 may have a diameter of, e.g., 5.0 mm or 6.0 mm in certain embodiments.
As described above, disclosed herein are removal drivers 400 configured for removing bone screws 200 seated in a spinal interbody or spinal implant 100.
In some embodiments, removal driver 400 includes an outer shaft 401 including a cavity, lumen, or cannulation 404 therewithin. The outer sleeve or shaft 401 may include a cannulated engagement feature 403 at its distal end. For example, in the embodiment shown in
Cannulation 404, which extends axially through engagement feature 403 and outer shaft 401, is configured to allow a distal end of an inner shaft 402 to pass through the cannulation 404. The inner shaft 402 may comprise an elongated body 407, and a threaded distal end 410. Threaded distal end 410 may be configured to engage with internal threading 204 at or near the head 202 of a bone screw 200, thereby allowing unthreading of bone screw 200 from spinal implant 100.
In some embodiments, a clutch 414 marries the outer shaft 401 with the drive feature 403, which may be, e.g., a hexalobe shaped driver. Turning clockwise or counter clockwise, clutch 414 may be disengaged, and the inner thread of the inner shaft 402 may be configured to pull the removal driver 400 onto the screw head 202. This action is configured to push the deflectable latch 108 of implant 100 (
In some embodiments, when inner shaft 402 is securely coupled to the threading 204 on the bone screw head 200, the outer shaft 401 may translate distally relative to the inner shaft 402. In some particular embodiments, the outer sleeve 401 can translate down onto the bone screw head 200 relative to the inner shaft 402, which is coupled to the bone screw head 202 to push the latch 108 (
In some embodiments, the cannulated drive feature 403 may be hexalobe-shaped. Cannulated drive feature 403 may be disposed at or near a distal end of the outer sleeve 401. In some embodiments, the threaded distal end 410 of the inner shaft 402 is positioned distally relative to a distal end of the outer sleeve 401. In other words, in such embodiments, threaded distal end 410 of inner shaft 402 extends distally through and out of outer sleeve 401 and cannulated drive feature 403. In some embodiments, drive feature 403 is configured to couple to feature 203 of the threaded head 202 of the bone screw 200 to facilitate engagement with the bone screw 200. In some embodiments, the removal driver 400 is configured to unlock the bone screw 200 when a longitudinal axis of the bone screw 200 is aligned with a longitudinal axis of the driver 400, as shown in
With reference to
The distal portion 409 of removal driver 400, in some embodiments, further includes a cam surface 408 disposed proximally relative to the drive feature 403, 405. The cam surface 408, when rotated, may be configured to outwardly deflect a deflectable latch 108 on an implant 100 from its position latching on the head 202 of the bone screw 200, thereby moving the deflectable latch out of a way of the bone screw.
In some embodiments, removal driver 400 advantageously allows for a single piece (e.g., solid) driver distal portion that can positively retain bone screw 200 during its removal. In some embodiments, the removal driver 400 can be used to unlock locking mechanisms that feature springs, tabs, or flexible features that cover the bone screws 200 in various spinal applications including but not limited to cervical plates, interfixated cages, and Anterior Lumbar Interbody Fusion (ALIF) plates. The removal driver 400 disclosed herein can also be used with a conventional u-joint in an angled application, as would be understood by a person of skill in the art.
With reference to
In some embodiments, screw driver 500 features a flexible tab component 501 that is permanently assembled to the elongate body 506 of driver 500. The flexible tab 501 can elastically deflect outwardly when a screw 200 is loaded on to the tip which creates an interference fit with the bone screw 200. This interference fit retains the screw 200 during use. In some embodiments, the flexible tab 501 advantageously removes minimal material from the driver distal portion which aids in strength of the screw driver 500.
In some embodiments, the screw driver 500 includes an elongate body 506 having a distal portion 507, a distal end 504, and a drive feature 505 located on an outer surface 508 of the driver 500 proximal to the distal end 504. The drive feature 505 may be configured to engage a corresponding feature 205 of a head 202 of the bone screw 200 to facilitate engagement with bone screw 200. As shown in
Screw driver 500 may further include a flexible tab 501 extending toward the distal end 504. Flexible tab 501 may include a proximal portion 509 that is fixedly anchored to elongate body 506. The proximal portion 509 of tab 501 may be thicker than a distal portion thereof, for example, in a radial direction. Flexible tab 501 also may include a distal portion 510 that is bendable or movable radially inward or outward. The movement of the distal portion 510 can be caused by a biasing energy or force. In some embodiments, flexible tab 501 is configured to bend or move inward from its resting position when the bone screw 200 is being loaded onto the screw driver 500. In some embodiments, flexible tab 501 sits radially outward relative to outer surface 508 of distal portion 504 of screw driver 500, at its resting state or balanced state, as can be seen in
In certain embodiments, the distal end 504 may be narrower, e.g., radially, than the drive feature 505, and/or the circumference of the distal end 504 may be smaller than the circumference of the rest of the distal portion 504 of the screw driver 500.
Instruments for Spinal Fusion Implant
As described above, an inserter 300 is provided for use in the insertion of implant 100, according to embodiments of the invention. With reference generally to
Turning first to
A barrel cam element 313 may be provided at a distal end of inner shaft 310, disposed proximally relative to distal tip 311 and engagement feature 312. Barrel cam element 313 is configured to provide a non-threaded connection to implant 100. A pair of opposing pins 303, configured to engage with barrel cam element 313, may extend radially inwardly from an inner surface of elongate body 302. The two opposing pins 303 may be disposed at or near a distal end of a barrel cam element 313 when inserter 300 is in an unlocked position (
A thumbwheel 320 (
The resulting positions of engagement feature 312 and posts 304, based on the position of posts 303 in barrel cam element 313, are illustrated in
In certain embodiments, as shown in
Turning next to
In the embodiment of
In another example, a cranial-caudal (C-C) inserter as shown in
In some embodiments, the head of inserter 300, i.e., the portion of inserter 300 that is distal of joint 316, is slim enough in profile to allow a driver such as, e.g., removal driver 400 or screw driver 500, to access and engage with a screw 200 that is being inserted into or removed from a fixation aperture 107 of implant 100 while inserter 300 is engaged with and coupled to implant 100 via engagement feature 312 and posts 304. This provides additional stability during the insertion and removal procedures.
Slap Mallet
Turning next to
In one embodiment, slap mallet 600 includes a first shaft 601 and a second shaft 602 that is disposed at least partially within first shaft 601. First shaft 601 may be configured for use as a handle, while second, inner shaft 602 may be configured to function as an extension rod. Slap mallet 600 may further include a button 603, a biasing element 604, a pin 605, and a clutch assembly 606. In one embodiment, slap mallet 600 includes a mallet head 607 may be coupled to first shaft 601, with second shaft 602 disposed at least partially within first shaft 601. First shaft 601 may be configured for use as a handle, while second shaft 602 may be configured for use as an extension rod.
Slap mallet 600 may be used like a standard slap hammer with second rod 602 disposed substantially or entirely within first shaft 601, as shown in, e.g.,
To use slap mallet 600 as a slaphammer, second shaft 602 may be extended proximally, and slap mallet 600 may be attached to an instrument in a manner readily understandable to one of skill in the art. A quick attachment can be implemented between second shaft 602 and an instrument for rapid engagement and disengagement with the instrument. Alternatively, the second shaft 602 can be threaded into the instrument. Keying the second shaft 602 to the first shaft 601 of the mallet allows for each rotation of the first shaft 601 to thread the second shaft 602 into the instrument. In certain embodiments, t-handle 330, shown in
Turning next to
Trial inserter 700 may include a shaft comprising multiple linked components, of which distal component 701 may be the terminal and distal-most. Distal component 701 may be considered a first link in the linked shaft, and may be coupled at a proximal end thereof to a second link 702. A rounded distal end of second link 702 is received within a proximal end of distal component 701, and is coupled in place by coupler 704, which passes through a distal aperture 703 in second link 702. Coupler 704 may be, e.g., a pin. Second link 702 may further include a rounded proximal end which is received within a distal end of barrel link 705, in a manner similar to a ball and socket joint, providing rotational flexibility between second link 702 and barrel link 705. When the proximal end of second link 702 is positioned within the distal end of barrel link 705, an aperture 706 is created that passes through the joint between the two components 702, 705. Aperture 703 may be rotated relative to aperture 706, for example by about 90°.
Returning to aperture 706, coupler 704 passes through aperture 706, thereby coupling the components together. Aperture 706 may have an hourglass shape, such that aperture 706 may have a smaller diameter in the center than at the open ends of the aperture, such that the axial center of coupler 704 is permitted less rotational movement than the ends thereof. This arrangement of coupler 704 within aperture 706 is configured to allow a range of motion of approximately 10° from the axis of coupler 704.
Barrel link 705 is configured to provide translation of the whole distal linkage, including distal component 701, second link 702, and barrel link 705, relative to shaft 707. Barrel link 705 connects to the main shaft 707 through a keyed drive feature 708 and coupler 704 allowing for translation and torque transmission. Keyed drive feature 708 may be, e.g., a square drive. Couplers 704 disposed at the proximal and distal ends of barrel link 705 may be substantially parallel to one another. A biasing element 709 such as, e.g., a coil spring, may be disposed between barrel link 705 and shaft 707. Biasing element 709 is configured to push the linkage 701, 702, 705 distally to aid in connection. Thus, the distal component link 701 is pinned to the second link 702, which is pinned to the barrel link 705, which is pinned to the main shaft 707, capturing the plunger spring 709 between the barrel link 705 and the shaft 707.
In another embodiment, shown in
The foregoing components, depicted in
In another embodiment for a trial inserter, a distal component is threaded to couple directly to an implant or trial. This distal component link (first link) is rotated to mate through the internal linkage to create the connection. The distal link connects to the main shaft through a square drive feature and slotted pin allowing for translation and torque transmission. The spring in between the distal link and main inner shaft pushes the linkage distally to aid in connection. All of this is housed within the outer shaft. The distal link is pinned to the main shaft capturing the plunger spring between the two components. The distal link can translate into and out of the outer shaft or housing.
Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Any reference to “or” herein is intended to encompass “and/or” unless otherwise stated. As used in this specification and the claims, unless otherwise stated, the term “about,” “approximately,” “generally,” and “substantially” refers to variations of less than or equal to +/−1%, +/−2%, +/−3%, +/−4%, +/−5%, +/−6%, +/−7%, +/−8%, +/−9%, +/−10%, +/−11%, +/−12%, +/−14%, +/−15%, +/−16%, +/−17%, +/−18%, +/−19%, or +/−20%, depending on the embodiment. As a further non-limiting example, about 100 millimeters represents a range of 95 millimeters to 105 millimeters, 90 millimeters to 110 millimeters, or 85 millimeters to 115 millimeters, depending on the embodiments.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
The present patent application claims the benefit of U.S. Provisional Patent Application No. 63/170,531, filed on Apr. 4, 2021; and U.S. Provisional Patent Application No. 63/188,277, filed on May 13, 2021. The foregoing applications are incorporated by reference as though fully set forth herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/023224 | 4/3/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63188277 | May 2021 | US | |
| 63170531 | Apr 2021 | US |
