Multiple set screw insertion tool

Abstract

The present disclosure generally relates to a surgical instrument used to deliver a locking or set screw (110) to secure a rod or spinal fixation element to an implanted bone anchor or other spinal fixation construct during spinal surgery. In one embodiment, the inserter instrument (100) includes an inner drive shaft (102), a ratcheted outer sleeve (104), and a handle (106) configured to receive the shaft and sleeve therein. The inner drive shaft can receive multiple set screws on its distal end. A side latch, pawl, or button (178) engages the ratcheted outer sleeve to facilitate incremental advancement of the sleeve relative to the drive shaft for set screw delivery. The incremental advancement can be controlled using a separate button that causes movement of the side latch.

Description

[Technical Field]

[0001] The present disclosure relates generally to surgical instruments and methods of use, and more particularly to surgical instruments utilized to deliver locking or set screws to secure rods or spinal fixation elements to implanted bone anchors or other spinal fixation constructs during spinal surgery. [Background technology]

[0002] During spinal surgery, such as procedures to correct spinal deformities, fixation constructs are often assembled to hold the spine in a desired shape. Such constructs often include multiple implanted bone anchors along multiple vertebrae and connecting spinal fixation elements, such as rods, received within the heads of each of the bone anchors and secured using set screws. Often, the bone anchors are first implanted into the vertebrae, and then the rods are positioned relative to the bone anchor heads and set screws are applied to secure the rods relative to each bone anchor.

[0003] Current posterior fixation systems utilizing the implanted bone anchors and spinal fixation rods or elements coupled to the anchors described above require the delivery of a set screw to each implanted anchor to secure the rod relative to the anchor. For each set screw / implanted anchor, a user must connect the set screw to an insertion instrument and deliver this assembly to the implanted bone anchor, often through a narrow extension tube, guide, or other instrument extending from the implanted bone anchor, away from the patient's body and toward the user performing the procedure. Furthermore, often a first user, such as an assistant, loads the set screw into the insertion device and hands the assembly to a second user, such as a surgeon, who introduces the assembly into the patient's body and delivers the set screw. The second user then returns the insertion device to the first user for reloading and repeats the process for each implanted bone anchor, which can be multiple times, especially in spinal deformity correction procedures where particularly long spinal fixation constructs may be assembled. This process requires some surgical time, which can be significant. Each handover also adds complexity and risk to the process, such as mishandling or dropping a component. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, a need exists for improved instruments and methods for delivering set screws, including improved instruments and methods for delivering multiple set screws for securing components to bone anchors during spinal surgery while minimizing instrument loading time. [Means for solving the problem]

[0005] The present disclosure generally relates to a multiple set screw insertion instrument and method of use that addresses the problems of conventional techniques. The multiple set screw insertion instrument disclosed herein can reduce the number of times the instrument needs to be passed between a surgeon and an assistant while maintaining the ability to deliver set screws and secure spinal surgical instruments. Generally speaking, the multiple set screw insertion instrument disclosed herein can include an inner drive shaft having a plurality of set screws stacked thereon and an outer driver sleeve having a ratcheting portion for incremental advancement of the set screws along the inner drive shaft for insertion into bone anchors and other spinal instruments. The inner drive shaft and outer sleeve can be received within a handle having a button for actuating the instrument. Actuation of the instrument can result in relative movement between the inner drive shaft and the outer sleeve to sequentially eject the set screws from the instrument into bone anchor receiver heads or other spinal instruments.

[0006] In one aspect, a surgical instrument is provided that can include a shaft having a distal portion configured to drive set screws to seat a plurality of stacked set screws relative to one another on the shaft; a handle coupled to the shaft; a sleeve disposed on the shaft and configured to contact a proximal-most set screw stacked on the shaft; a first button disposed within the handle and configured to advance the sleeve distally a first increment relative to the shaft; and a second button disposed within the handle and configured to allow proximal retraction of the sleeve.

[0007] Any of a variety of alternative or additional features may be included and are considered within the scope of the present disclosure. For example, in some embodiments, the sleeve may include a plurality of ratchet teeth. In certain embodiments, the first increment may correspond to the distance between two adjacent teeth of the plurality of ratchet teeth. In some embodiments, the instrument may further include a detent disposed within the handle configured to interface with the plurality of ratchet teeth to resist movement of the sleeve. In certain embodiments, the detent may be a spring-loaded ball. In some embodiments, the second button may be biased to contact one ratchet tooth of the plurality of ratchet teeth. In certain embodiments, the second button may allow proximal retraction of the sleeve when the bias of the second button is overcome.

[0008] In some embodiments, the instrument can further include a spring clip disposed around the distal end of the shaft and configured to hold the set screw thereon with an interference fit.

[0009] In certain embodiments, movement of the first button can cause movement of the second button. In some embodiments, movement of the first button can translate the second button distally. Additionally, in some embodiments, the first button can be proximally biased such that proximal movement of the first button causes the second button to move proximally relative to the sleeve.

[0010] In some embodiments, the outer diameter of the plurality of set screws stacked on the shaft can be substantially equal to the outer diameter of the sleeve disposed over the shaft.

[0011] In certain embodiments, the sleeve may also include a retention mechanism thereon to prevent release of the sleeve from the handle. The retention mechanism may abut against a second button to hold the sleeve in a particular configuration within the handle.

[0012] In some embodiments, the first button can be disposed at the proximal end of the handle and the second button can be disposed on a side of the handle.

[0013] In certain embodiments, either the first button or the second button can be activated.

[0014] In another aspect, a surgical method is provided, the surgical method can include delivering a first set screw to a first implanted bone anchor using an inserter, actuating the inserter to advance a second set screw distally relative to a shaft of the inserter, and delivering the second set screw to a second implanted bone anchor using the inserter.

[0015] Similar to the instruments described above, the methods disclosed herein can include any of a variety of additional or alternative steps deemed within the scope of this disclosure. In some embodiments, for example, actuating the inserter can include depressing a first button disposed on a handle of the inserter. Further, in some embodiments, actuating the inserter can include distally advancing a sleeve disposed on the shaft to urge a second set screw toward the distal end of the shaft.

[0016] In another aspect, a surgical method is provided, the surgical method can include actuating a first button disposed in a handle of an inserter, proximally sliding a sleeve disposed on a shaft of the inserter, and advancing a plurality of set screws proximally on a distal portion of the shaft of the inserter.

[0017] In some embodiments, the first button can be disposed on a side of the handle. In certain embodiments, the sleeve can slide against a proximal wall of a recess formed in the handle.

[0018] Any of the features or variations described herein may be applied to any particular aspect or embodiment of the present disclosure in several different combinations, and the explicit description of any particular combination is omitted, but only to avoid unnecessary length or repetition. [Brief explanation of the drawings]

[0019] Aspects and embodiments of the present disclosure can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a perspective view of one embodiment of the presently disclosed multiple set screw insertion instrument having a plurality of set screws disposed thereon. [Figure 2A] FIG. 2 is an exploded perspective view of the multiple set screw insertion instrument of FIG. 1. [Figure 2B] FIG. 2B is a cross-sectional perspective view of the multiple set screw insertion instrument of FIG. 2A. [Figure 3] FIG. 2 is a perspective view of the inner drive shaft of the multiple setscrew insertion tool of FIG. 1 having multiple setscrews disposed thereon. [Figure 4] FIG. 2 is a cross-sectional perspective view of the handle of the multiple setscrew insertion instrument of FIG. 1. [Figure 5] FIG. 2 is a perspective view of a plurality of set screws for use with the multiple set screw insertion tool of FIG. 1; [Figure 6] 2 is a cross-sectional perspective view of the multiple setscrew insertion instrument of FIG. 1 in a first position. [Figure 7] FIG. 2 is a cross-sectional detail view of the distal end of the multiple setscrew insertion instrument of FIG. 1. [Figure 8] FIG. 2 is a cross-sectional detail view of the handle of the multiple setscrew insertion instrument of FIG. 1. [Figure 9] FIG. 2 is a perspective view of a button of the multiple setscrew insertion instrument of FIG. 1. [Figure 10] FIG. 2 is a perspective view of the proximal end of the handle of the multiple setscrew insertion instrument of FIG. 1. [Figure 11] 2 is a perspective view of the multiple setscrew insertion instrument of FIG. 1 in a first position. [Figure 12]2 is a perspective view of the multiple setscrew insertion instrument of FIG. 1 with the button in a depressed second position. [Figure 13] 2 is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 1 in a first position; [Figure 14] 2 is a side cross-sectional view of the multiple setscrew insertion tool of FIG. 1 after the setscrews have been inserted. [Figure 15] 2 is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 1 with the button in a depressed second position. [Figure 16] 2 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 1 in a reset third position for inserting set screws. [Figure 17] FIG. 2 is a cross-sectional perspective view of the multiple setscrew insertion tool of FIG. 1 with a final setscrew disposed thereon. [Figure 18] FIG. 18 is a cross-sectional detail view of the distal end of the multiple setscrew insertion instrument of FIG. 17. [Figure 19A] FIG. 10 is a detailed view of one embodiment of a drive shaft and retaining features. [Figure 19B] FIG. 19B is a cross-sectional detail of the drive shaft and retention feature of FIG. 19A. [Figure 20] FIG. 10 is a detailed view of another embodiment of a drive shaft and retaining feature. [Figure 21] FIG. 10 is a side cross-sectional view of another embodiment of a drive shaft and retaining feature. [Figure 22] FIG. 10 is a side cross-sectional view of another embodiment of a drive shaft and retaining feature. [Figure 23] 2 is a cross-sectional perspective view of the multiple setscrew insertion instrument of FIG. 1 in a used configuration. [Figure 24] 2 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 1 with outer shafts ejected therefrom. [Figure 25] 2 is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 1 with the outer shaft inserted into the handle. [Figure 26] 2 is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 1 reloaded into a first position. [Figure 27] FIG. 10 is a perspective view of another embodiment of a handle according to the present disclosure. [Figure 28] FIG. 10 is a detailed view of another embodiment of a multiple set screw insertion tool having pins inserted through the handle. [Figure 29] FIG. 29 is a cross-sectional detail view of the multiple set screw insertion instrument of FIG. 28. [Figure 30] FIG. 29 is a cross-sectional detail of a pin passing through the multiple setscrew insertion tool of FIG. 28. [Figure 31] FIG. 10 is a perspective view of another embodiment of a multiple set screw insertion tool. [Figure 32] FIG. 32 is a perspective view of the multiple set screw insertion instrument of FIG. 31. [Figure 33] FIG. 32 is a cross-sectional view of the multiple set screw insertion instrument of FIG. 31. [Figure 34] FIG. 32 is a perspective view of the drive shaft of the multiple setscrew insertion instrument of FIG. 31; [Figure 35A] FIG. 32 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 31 in a first position. [Figure 35B] FIG. 32 is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 31 after the setscrews have been inserted. [Figure 35C] 32 is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 31 in a second position with the button depressed and the outer sleeve advanced. [Figure 35D] FIG. 32 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 31 in a reset third position for inserting set screws. [Figure 36A] FIG. 32 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 31 in a fourth position with the outer shafts ejected therefrom. [Figure 36B] FIG. 32 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 31 in a fifth position with the outer shaft being reintroduced into the handle. [Figure 36C] FIG. 32 is a side cross-sectional view of the multiple set screw insertion instrument of FIG. 31 being reloaded into a first position. [Figure 37] FIG. 10 is a cross-sectional detail view of one embodiment of a multiple setscrew insertion instrument handle. [Figure 38] FIG. 38 is a cross-sectional detail view of the multiple set screw insertion instrument of FIG. 37 in a first position. [Figure 39]FIG. 38 is a cross-sectional detail view of the multiple set screw insertion instrument of FIG. 37 in a second position. [Figure 40A] FIG. 1 is a perspective view of one embodiment of a multiple set screw insertion tool. [Figure 40B] FIG. 40B is an exploded perspective view of the multiple setscrew insertion instrument of FIG. 40A. [Figure 40C] FIG. 40B is a side view of the multiple setscrew insertion instrument of FIG. 40A. [Figure 40D] FIG. 40B is a cross-sectional detail view of the distal end of the multiple setscrew insertion instrument of FIG. 40A. [Figure 40E] FIG. 40B is a top view of the multiple setscrew insertion instrument of FIG. 40A. [Figure 40F] FIG. 40B is a side cross-sectional view of the multiple setscrew insertion instrument of FIG. 40A. [Figure 41A] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 41B] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 41C] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 41D] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 41E] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 41F] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 41G] 40B illustrates a setscrew inserter shaft of the instrument of FIG. 40A. [Figure 42A] 40B illustrates a setscrew inserter handle of the instrument of FIG. 40A. [Figure 42B] 40B illustrates a setscrew inserter handle of the instrument of FIG. 40A. [Figure 42C] 40B illustrates a setscrew inserter handle of the instrument of FIG. 40A. [Figure 42D] 40B illustrates a setscrew inserter handle of the instrument of FIG. 40A. [Figure 43A] 40B illustrates the actuator button of the device of FIG. 40A. [Figure 43B]40B illustrates the actuator button of the device of FIG. 40A. [Figure 43C] 40B illustrates the actuator button of the device of FIG. 40A. [Figure 44A] 43B illustrates the distal end of the actuator button of FIG. 43A. [Figure 44B] 43B illustrates the distal end of the actuator button of FIG. 43A. [Figure 44C] 43B illustrates the distal end of the actuator button of FIG. 43A. [Figure 45A] 40B illustrates a side latch of the device of FIG. 40A. [Figure 45B] 40B illustrates a side latch of the device of FIG. 40A. [Figure 45C] 40B illustrates a side latch of the device of FIG. 40A. [Figure 45D] 40B illustrates a side latch of the device of FIG. 40A. [Figure 45E] 40B illustrates a side latch of the device of FIG. 40A. [Figure 46A] 40B illustrates the spring clip of the device of FIG. 40A. [Figure 46B] 40B illustrates the spring clip of the device of FIG. 40A. [Figure 46C] 40B illustrates the spring clip of the device of FIG. 40A. [Figure 47A] 40B illustrates the outer ratcheting sleeve of the device of FIG. 40A. [Figure 47B] 40B illustrates the outer ratcheting sleeve of the device of FIG. 40A. [Figure 47C] 40B illustrates the outer ratcheting sleeve of the device of FIG. 40A. [Figure 47D] 40B illustrates the outer ratcheting sleeve of the device of FIG. 40A. [Figure 48] 40B illustrates one embodiment of a set screw for use with the multiple set screw insertion tool of FIG. 40A. DETAILED DESCRIPTION OF THE INVENTION

[0020] Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices, systems, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. The devices, systems, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments. Features illustrated or described in connection with one embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be within the scope of the present disclosure. Additionally, to the extent that linear, circular, or other dimensions are used in describing the disclosed devices and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such devices and methods. Equivalent dimensions can be determined for different geometries, etc. Furthermore, like-numbered components of embodiments may generally have similar characteristics. Still further, the size and shape of a device and its components may depend at least on the anatomy of the subject with whom the device is used, the size and shape of the object with which the device is used, and the method and procedure for which the device is used.

[0021] The present disclosure generally relates to a multiple set screw insertion instrument and method of use that addresses the problems of conventional techniques. The multiple set screw insertion instrument disclosed herein can reduce the number of times the instrument needs to be passed between the surgeon and an assistant while maintaining the ability to deliver set screws and secure spinal surgical instruments. In one embodiment, the multiple set screw insertion instrument can include an inner drive shaft having a plurality of set screws stacked thereon and an outer driver sleeve having a ratcheting portion for incremental advancement of the set screws along the inner drive shaft for insertion into bone anchors and other spinal instruments. The inner drive shaft and outer sleeve can be received within a handle having a button for actuating the instrument. Actuation of the instrument can result in relative movement between the inner drive shaft and the outer sleeve to sequentially eject the set screws from the instrument into the bone anchor receiver heads or other spinal instruments.

[0022] 1-2B illustrate one embodiment of a multiple set screw insertion or inserter instrument 100. The multiple set screw insertion instrument 100 can be used to deliver set screws to spinal instruments during a procedure (e.g., spinal surgery). The instrument 100 can include an inner drive shaft 102, an outer sleeve 104, and a handle 106 configured to receive the inner drive shaft 102 and the outer sleeve 104 therein. The inner drive shaft 102 can include a drive feature 108 for receiving multiple set screws 110 thereon. In some embodiments, the instrument 100 can include a central longitudinal axis A1 extending therethrough such that the axis A1 passes through one or more of the inner drive shaft 102, the outer sleeve 104, and / or the handle 106. In use, the inner drive shaft 102 can be received within the outer sleeve 104, with the outer sleeve configured to translate relative to the inner drive shaft 102. Translation of the outer sleeve 104 can sequentially advance one of the multiple set screws 110 to a distal tip 112 positioned on the drive feature 108 of the inner drive shaft 108, for example, after ejecting the previous set screw from the instrument by performing insertion of the previous set screw into the spine.

[0023] 2A-2B specifically illustrate the assembly of the multiple set screw insertion instrument 100. The inner drive shaft 102 can include a generally tubular body 114 having a proximal end 102p and a distal end 102d, with a central longitudinal axis A1 extending between the proximal and distal ends. The tubular body 114 can be solid, although in some embodiments, the body can be hollow with an opening extending therethrough. The proximal end 102p of the inner drive shaft 102 can include a mating feature 116, e.g., a threaded male member, as shown in FIG. 2B, for mating with a corresponding threaded bore 120 in the handle 106, as described in more detail below with respect to FIG. 4. In some embodiments, the mating feature 116 can be keyed to be received within the bore in a specific orientation so that the inner drive shaft 102 mates with the handle 106 in a specific orientation.

[0024] The drive feature 108 on the distal end 102d of the inner drive shaft 102 can be shaped to accommodate the internal openings of the plurality of set screws 110. As shown, the drive feature 108 can be a male Torx®-shaped protrusion extending along the distal portion 102 of the shaft so that the plurality of set screws 110 can be stacked on the drive feature 108. The plurality of set screws 110 can include recesses shaped to accommodate the drive feature 108 to secure the set screws to the drive feature and allow them to rotate therewith, while also allowing the set screws to translate proximally on the drive feature 108. In some embodiments, the drive feature 108 can include a retention feature 118, as shown in FIG. 3, to prevent the set screws 110 from unintentionally separating from the drive feature 108. Details regarding retention features are discussed in more detail below.

[0025] The overall shape of the inserter instrument 100 may be similar to an elongated setscrew driver. The outer sleeve 104 may include a generally tubular body 122 having a proximal end 104p and a distal end 104d defining a channel 124 therebetween. The channel 124 may extend coaxially with the central longitudinal axis A1 of the inner drive shaft 102 such that the central longitudinal axis A1 extends from the proximal end 104p to the distal end 104d of the outer shaft 104. As shown, the channel 124 may be configured to receive at least a portion of the inner drive shaft 104 therethrough. For example, the body 122 of the outer sleeve 104 may define an inner diameter ID that is substantially the same as or larger than the outer diameter OD of the inner drive shaft 102 for receiving the inner drive shaft 102 therethrough.

[0026] In some embodiments, the outer sleeve 104 can include a non-uniform outer diameter OD1. For example, the outer diameter OD1 of the tubular body 122 of the outer sleeve 104 can be larger in some locations than in others. In some embodiments, the outer diameter OD1 can taper along its length. In some embodiments, the outer sleeve 104 can taper from the proximal end 104p to the distal end 104d such that the proximal end 104p engages one or more features in the handle 106 to selectively allow or prevent translation of the outer sleeve 104 relative to the handle and / or inner drive shaft 102. As shown, the outer sleeve 104 can include a proximal head 126 thereon having a larger outer diameter OD1 than a portion of the sleeve extending distally from the proximal head. The proximal head 126 can function as a retention feature to prevent inadvertent or undesired separation of the sleeve 104 from the handle 106. For example, the proximal head 126 may interface with a latch or button 178 to provide a stop against complete removal of the sleeve 104 from the handle 106. The stop may prevent axial translation of the outer shaft 104 relative to other components of the inserter instrument 100. While the proximal head 126 is shown, the stop may include a ribbed surface, a protrusion, a catch, or another component configured to retain the outer sleeve 104 within the handle 106.

[0027] The outer sleeve 104 may include a ratchet portion 128 formed along the tubular body 122. As shown, the ratchet portion 128 may extend along a mid-section of the outer sleeve 104, although in some embodiments, the ratchet portion 128 may extend along any length of the sleeve. The ratchet portion 128 may include a series of ratchet teeth, ribs, or protrusions 130 formed along the outer surface of the outer sleeve 104. The ratchet portion 128 may engage with one or more components of the instrument 100, such as a pawl 178, discussed in more detail below, for incremental advancement of the outer shaft 104 relative to other components. The ratchet portion 128 may extend around the circumference of the tubular body 122 to allow the outer sleeve 104 to be fitted into the handle 106 in any rotational orientation. In use, ratchet portion 128 can enable outer sleeve 104 to provide a hard stop against the backside of the set screw, which can assist a user in beginning to thread the set screw into the implant and can assist in preventing proximal movement of the set screw or outer sleeve if the user exerts axial pushing force on the device during insertion. Additionally, ratchet portion 128 can facilitate advancement of a subsequent set screw toward the distal end of drive shaft 102 in conjunction with the insertion of a previous set screw into a spinal fixation construct, such as a bone screw receiving member.

[0028] The handle 106 may include a tubular body 132 having a central lumen 134 formed therein. The central lumen 134 extends along the central longitudinal axis A1 of the instrument 100 from the distal end 106d to the proximal end 106p of the handle 106 and may receive one or more of the inner drive shaft 102 and / or the outer sleeve 104 therethrough. The central lumen may include an inner diameter ID2, which may be substantially the same as or larger than the outer diameter OD1 of the outer sleeve 104 to enable the outer sleeve to be disposed within the central lumen 134.

[0029] The central lumen 134 can include a receiving portion 136 at the proximal end 106p of the handle 106. The receiving portion 136 can extend into the central lumen 134 and receive the proximal end 102p of the inner drive shaft 102 therein. As shown in more detail in FIG. 4 , the receiving portion 136 can include a bore 138 having a reduced diameter portion that resides along the central longitudinal axis A1 with the central lumen 134. In some embodiments, the receiving portion 136, or a section thereof, can be threaded. For example, as discussed above, the receiving portion 136 can include threads 120 to allow the inner drive shaft 102 to be threaded therein. During assembly, the proximal end 102p of the inner drive shaft 102 can be inserted into the receiving portion 136, with the mating feature 116 threaded onto the threads 120 to couple the inner drive shaft 102 to the handle 106.

[0030] The receiving portion 136 can include a lumen 140 formed therein. For example, the threads 120 can extend through the receiving portion 136 and terminate at or near the lumen 140. As described in more detail below, the lumen 140 can receive one or more coupling features of the instrument 100 therein. The handle 106 can include a recess 142 formed in its proximal end 106p. For example, as shown, the distal receiving portion 136 can terminate at the proximal end 106p of the handle 106 to define the recess 142 therebetween. The recess 142 can receive one or more components configured to actuate the instrument. For example, as shown, a button 150 can be disposed within the handle 106 to control advancement of the outer sleeve 104 to urge the set screw 110 distally.

[0031] The handle 106 can be made from a variety of materials, including any of a variety of plastics, ceramics, or metals, among others. In some embodiments, the handle 106 can include a multi-material overmolding, such as a silicone overmolding, formed over another underlying material. The handle 106 can include a series of openings 148 at its distal end 106d to allow for easy movement of the components of the instrument 100. The series of openings 148 can extend laterally into the central lumen 134, which communicates with the outer sleeve 104 disposed therein. The series of openings 148 will be discussed in more detail below with respect to FIGS. 11 and 12.

[0032] 5 illustrates a plurality of set screws 110 that can be used with the multiple set screw insertion instrument 100 of the present disclosure. As shown, each set screw in the plurality of set screws 100 can include a female drive feature or through-hole 144 extending therethrough. The set screws 110 can be stacked on top of one another such that the axis A passing therethrough is aligned with the central longitudinal axis A1. The female drive feature 144 can be configured to receive the male drive feature 108 of the inner drive shaft 102 therethrough to arrange the stacked set screws 110 along the inner drive shaft. For example, the through-hole 144 can include a geometry complementary to the drive feature 108 to enable the set screws 110 to be stacked onto the inserter shaft 102 and rotationally driven by the inserter shaft 102 when the inserter instrument 100 is rotated. The through holes 144 can be sized to allow axial translation of each of the set screws 110 along the drive feature 108 when the outer sleeve 104 is advanced relative to the inner drive shaft 102. Additionally, each set screw can have an outer diameter OD2, and the profile of the outer sleeve 104 can be equal to or smaller than the outer diameter OD2 of the set screws 110 in some embodiments.

[0033] 6-8 illustrate the inserter instrument in more detail. As shown, when the inserter instrument 100 is positioned in an initial position, it includes an inner drive shaft 102 disposed within a channel 124 of an outer sleeve 104, with both components received within a central lumen 134 of a handle 106. Specifically, as described above, the mating feature 116 of the inner drive shaft 102 can thread onto threads 120 within a receiving portion 136, while the proximal end 104p of the outer sleeve 104 can abut against the receiving portion 136. A plurality of set screws 110 can be disposed in the drive feature 108 of the inner drive shaft 102 distal to the outer sleeve 104.

[0034] Figure 7 illustrates in more detail the relationship between the stacked set screw 110 and the inner drive shaft 102. As mentioned above, the inner drive shaft 102 can include a retention feature 118, such as a spring clip or circlip, that engages the distal tip 112 of the drive feature 108. As shown in Figure 7, the spring clip 118 disposed at the distal end of the drive feature 108 can provide an interference fit between the spring clip and the set screw 110, thereby limiting unwanted distal translation between the set screw and the drive feature.

[0035] 8 illustrates the interaction of the inner drive shaft 102, outer sleeve 104, and handle 106 of the inserter instrument 100 while in the initial position described above. The outer shaft 104 is received within the central lumen 134, while the proximal head 126 abuts the receiving portion 136. The bore 140 can receive a biasing element 152, such as a coil spring, configured to axially compress and expand upon engagement with one or more components of the instrument 100. For example, as shown, the biasing element 152 can be disposed between the receiving portion 136 and the button 150. The biasing element 152 can bias the button 150 proximally such that the button 150 at least partially extends from the recess 142.

[0036] 9 illustrates button 150 in more detail. As shown, button 150 includes a proximal head 154 and a distal body 156 extending therefrom. Proximal head 154 may include an outer diameter (not shown) that is substantially the same as or smaller than the diameter of recess 142 to enable disposition of the head within recess 142. Head 154 may include a distally facing surface 158 for engaging a portion of biasing element 152 and compressing the biasing element when button 150 is actuated. In some embodiments, proximal head 154 may include a bore 160 formed therein.

[0037] The distal body 156 may include a sidewall 162 that extends from the proximal head 154 and continues along an interior portion of the inserter instrument handle 106. For example, the handle 106 may include a lumen 164 formed therein to allow the distal body 156 to pass therethrough. In some embodiments, the lumen 164 may be separate from the central lumen 134. As shown in FIG. 8 , the lumen 164 may terminate within the handle 106, for example, distal to the receiving portion 136. However, in some embodiments, the second lumen 164 may extend through the distal end of the handle 106.

[0038] The distal body 156 may include one or more access points in its sidewall 162. The access points may align with one or more of the openings 148 in the handle 106 to facilitate advancement or indexing of the outer sleeve 104 relative to the handle. For example, the distal body 156 may include a notch 166 formed therein that forms a pair of flanges 168, 170. The notch 166 may align with one or more of the series of openings 148 in the handle 106, as described above, to allow another component to extend through the handle 106 and the distal body 156 simultaneously to engage the outer sleeve 104, as discussed further below. As shown, one or more lateral openings 172, 174 may be formed in each of the flanges 168, 170 to facilitate coupling between components disposed within the notches 166.

[0039] The access point can be formed on the outer surface of the sidewall 162. For example, the top surface of the sidewall 162 illustrated in FIG. 9 can include a recess 176 for receiving a biasing element 177, such as a coil spring or other biasing element. As described in more detail below, the biasing element 177 can bias another component disposed in the cutout 166, for example, such that a portion of the biasing element extends into the central lumen 134 and engages the outer shaft 104. One embodiment of such a component can be a pawl, latch, or button 178 (see FIG. 8) that extends into the central lumen 134 and engages the outer shaft 104. For example, the feature 178 can extend from a distal end 178d to a proximal end 178p, with the distal end 178d having an engagement surface 180 thereon. Engagement surface 180 may extend radially inward from notch 166 in button 150 and opening 148 in handle 106 to engage ratchet portion 128 of outer sleeve 104. Pawl 178 may be coupled to button 150 by a pin 182 received in openings 172, 174 in flanges 168, 170. Pin 182 may allow pawl 178 to pivot about its axis. Proximal end 178p of pawl 178 may include a recess for receiving one end of biasing element 177. Biasing element 177 may urge proximal end 178p radially outward and distal end 178d radially inward toward outer sleeve 104 and ratchet portion 128.

[0040] The sidewall 162 may include a slot 184 configured to receive a pin 186. The pin may be anchored in a bore formed in the sidewall of the handle 106 to prevent axial translation of the pin relative to the handle. The slot may extend axially along the distal body 156 to allow axial translation of the button 150 between proximal and distal positions defined by the length of the slot 184. Movement of the slot 184 relative to the pin 186 may define a translation limit for the distal body 156 and the button 150 during actuation of the inserter instrument 100. For example, actuation of the button 150 may advance the distal body 156 until the pin 186 reaches the proximal end of the slot 184. Retraction of the button 150 may similarly move the pin 186 to the distal end of the slot 184, and interference between the pin and the end of the slot may prevent further movement of the button 150.

[0041] The inserter instrument 100 may also include a detent 188, such as a spring plunger or ball detent, received through an opening 149 in the handle 106. The detent 188 is illustrated as a ball bearing biased radially inward by a coil spring and may engage the ratchet portion 128 to resist movement of the outer sleeve 104 relative to the handle 106. This may prevent undesired proximal or distal movement of the outer sleeve 104 relative to the handle 106, and may be particularly useful in preventing proximal movement of the outer sleeve 104 with the button 150 as the button retracts proximally after actuation. It will be appreciated that in some embodiments, a leaf spring, cantilevered deformable element, or other component may be used in place of the illustrated spring plunger of the instrument 100.

[0042] 11-16 illustrate in more detail the actuation of multiple set screw insertion tool 100. As shown in FIG. 11, in an initial position, button 150 of multiple set screw insertion tool 100 can protrude proximally from the proximal end of handle 106. Upon actuation, as shown in FIG. 12, the resistance of biasing element 152 can be overcome, causing button 150 to move distally into recess 142 of handle 106.

[0043] 13-16 illustrate a sequence of uses of the multiple set screw insertion tool 100 to insert set screws during a procedure. Similar to FIG. 11, FIG. 13 shows the multiple set screw insertion tool 100 in an initial position with multiple set screws 110 stacked on the distal portion of the inner drive shaft 102. In this configuration, the first button 150 is biased to its proximal-most position, and the pawl or second button 178 is biased to a position where its distal end engagement surface 180 is received within the distal-most recess 130 of the ratchet portion 128 of the outer sleeve 104. The outer sleeve 104 is prevented from proximal movement relative to the drive shaft 102 and handle 106 by interaction of the proximal end of the outer sleeve with the handle receiving portion 136 and by interaction of the ratchet portion 128 with the pawl 178, which in turn is limited by interaction of the pin 186 and slot 184. Thus, a user can urge the distal-most set screw to be positioned, for example, within the receiving member of a bone anchor, and couple the set screw thereto. Axial and rotational forces can be transferred to the distal-most set screw to facilitate its insertion. Once the set screw 110 is coupled to the bone anchor, the multiple set screw insertion instrument 100 can be retracted proximally such that the distal-most set screw overcomes any resistance from the retention feature 118 and moves away from the drive shaft 102. Alternatively or additionally, a user can depress a button 150 to advance the outer sleeve 104 relative to the drive shaft 102, as described below, to assist in ejecting the distal-most set screw from the device.

[0044] As shown in FIG. 14 , once the set screws are coupled to the bone anchors and the instrument is retracted proximally, the drive feature 108 and distal tip 112 of the inner drive shaft 102 are exposed, allowing the distal-most set screw to be uncoupled from the instrument. As shown in FIG. 15 , the button 150 can be actuated to advance the stacked set screws 110 distally toward the tip 112. Actuation of the button 150 can overcome the force of the biasing element 152, and distal advancement of the button 150 includes advancement of the distal body 156 within the lumen 164 relative to the handle 106. Advancement of the distal body 156 includes advancement of the pawl 178, which engages the distal-most recess 130 of the ratchet portion 128, urging the outer sleeve 104, along with the pawl and button 150, distally. Actuation of the button can also provide sufficient force to overcome the resistance of the detent 188 to movement of the outer sleeve 104.

[0045] Distal advancement of outer sleeve 104 terminates when pin 186 abuts the proximal end of slot 174 and distal-facing surface 158 of button 150 reaches the proximal end of recess 142. In such position, a new distal-most set screw can be positioned proximal to distal tip 112 of drive shaft 108. In this orientation, detent 188 can engage second recess 131 of ratchet portion 128, again providing resistance to movement of outer sleeve 104, as shown in FIG. 15 . Button 150 can then be released, and biasing element 152 can return button 150 to its proximal-most position. This, in turn, can urge pawl 178 proximally. The resistance provided by the detent 188 can overcome the frictional force between the pawl 178 and the ratchet portion 128 of the outer sleeve 104, so that the outer sleeve remains stationary relative to the handle 106 and the pawl 178 rides up into the second recess 131 in the ratchet portion 128 as it moves proximally relative to the handle 106 and outer sleeve 104. Without the detent 188, the outer sleeve 104 could retract proximally due to the frictional force between the pawl or button 178. Once the button 150 has returned to its initial proximal orientation, the set screw insertion process can be repeated until all of the stacked set screws 110 have been inserted into their desired locations along the inner drive shaft 102 and ejected from the insertion tool.

[0046] FIG. 17 illustrates the inserter instrument 100 after inserting several set screws 110, leaving a single set screw disposed thereon. As shown, a pawl or second button 178 and a detent 188 engage with the proximal-most recess of the ratchet portion 128 of the outer sleeve 104. FIG. 18 illustrates a detailed view of the distal tip of the instrument 100, where the set screw engages a retention feature 118 to prevent the set screw from backing out of the retention feature 118. The retention feature 118 may include a spring clip or circlip that surrounds the distal tip 112 and provides a radially outward interference fit with a female drive recess or bore formed in the set screw 110. The spring clip 118 may deform to reduce its outer diameter, thereby allowing sufficient force to be applied from the outer sleeve 104 to urge the set screw 110 over the clip and eject it from the instrument 100.

[0047] 19-21 show alternative embodiments of drive features formed on the distal portion of the drive shaft 108 and retaining feature 118. While a spring clip or circlip is discussed above, other embodiments are possible. As shown in these figures, the retaining feature 218 can include opposing ball detents extending laterally from the distal tip of the drive shaft 202. The opposing ball detents can be biased by a spring 220 or another biasing element. As shown in FIGS. 19A and 19B, the drive shaft 202 can include a protruding distal tip 212 at the distal end of the drive feature 208. The protruding distal tip 212 can have a cylindrical profile with a diameter substantially the same as or smaller than the inner diameter of the drive feature 208 and can include a chamfered or tapered edge to help facilitate insertion of the drive shaft and a set screw disposed thereabout, for example, into a bone screw receiver head. In other embodiments, as shown in FIG. 20, the drive shaft 302 can include a drive feature 308 that extends to the distal tip of the drive shaft, and a retaining feature 318 can be incorporated into the drive feature without a protruding distal tip, having a different profile than the drive feature.

[0048] 21 and 22 illustrate another embodiment of a retention feature 408 that can be incorporated into the drive shaft 402. The retention feature 408 can include a leaf spring or other resilient element disposed within a recess formed in the drive shaft 402. In the embodiment of FIG. 21, the spring 408 resembles a wishbone or U-shape, with a proximal end anchored within the shaft 402 and a distal end protruding through opposing openings formed in the outer surface of the shaft. The protruding distal end of the leaf spring 408 can be configured to retain the set screw on the drive shaft via an interference fit, similar to the other retention feature embodiments described above. FIG. 22 illustrates an embodiment in which a more linear spring element 508 presents a single protrusion from a single opening formed in the outer surface of the shaft 502. In embodiments in which the resilient element is anchored within the drive shaft, the shaft may be provided in two pieces, such as distal piece 402d and proximal piece 402p shown in FIG. 21, such that the resilient element 408 can be positioned within a recess formed in each piece and the pieces can then be joined to joint 403 by, for example, adhesive, welding, mechanical fasteners, etc. Any of the embodiments of the drive features and retention features described above may be utilized with any of the embodiments of the multiple set screw insertion instrument disclosed herein.

[0049] Additionally, various other components of the multiple set screw inserter instrument can be configured to provide different interactions with the retention feature utilized to secure the set screws against inadvertent ejection from the instrument. For example, in some embodiments, the device can be configured to position the set screws immediately proximal to the retention feature so that the distal-facing surface of the distal set screw abuts a portion of the retention feature. However, in other embodiments, the instrument can be configured so that the distal-most set screw is disposed on the retention feature, such that the radially inner-facing surface of the set screw abuts the radially outer-facing portion of the retention feature. Different configurations can be achieved by adjusting one or more of the lengths of the outer sleeve, inner shaft, ratchet portion, and first button to achieve the desired spacing and advancement. Choosing to use one configuration or another can generate different tactile feedback to the user. For example, in one embodiment where the distal-most set screw is stacked proximally of the retention feature, the user may feel or overcome one resistance during actuation of the first button, i.e., as the distal-most set screw advances over the retention feature (first resistance), and the next set screw advances just to abut the retention feature. In another embodiment where the distal-most set screw is positioned over the retention feature, the user may feel or overcome two resistances during actuation of the first button, i.e., as the distal-most set screw is released from the retention feature (first resistance), and the next set screw advances over the top of the retention feature (second resistance). Any of the various embodiments disclosed herein can be configured to operate in either manner.

[0050] As noted above, the outer sleeve 104 can include a proximal head 126 that can function as a retention mechanism against inadvertent separation of the outer sleeve 104 from the device after all set screws have been ejected. FIG. 23 illustrates the proximal head 126 used to prevent the outer shaft 104 from popping distally out of the central lumen 134 and falling off the inner shaft 102. To further explain, once the pawl or second button 178 no longer engages the ratchet portion 128 of the outer sleeve 104, distal advancement of the outer sleeve can continue substantially uninterrupted until the pawl 178 engages the proximal head 126, which, in some embodiments, can have an outer diameter that is substantially the same as the outer or major diameter of the ratchet portion 128. Friction between the engagement surface 180 of the distal end 178d of the pawl and the proximal head 126 can prevent separation of the outer sleeve 104 from the central lumen 134. To separate the outer sleeve 104 from the rest of the instrument, a user can depress the proximal end 178p of the pawl or second button 178 and retract the distal end 178d radially outward to provide clearance for the proximal head 126 to pass distally from the lumen 134 of the handle 106. In some embodiments, the proximal head 126 can include a distally facing surface having a tapered diameter to provide a lead-in, allowing a user to remove the outer sleeve 104 by applying sufficient force without separately depressing the second button 178.

[0051] 24-26 illustrate the process of at least partially assembling the instrument and loading the set screw. In FIG. 24, the outer sleeve 104 is shown assembled to the remainder of the instrument 100. The outer sleeve 104 can be inserted proximally onto the drive shaft 102, and once it enters the lumen 134 of the handle 106, its distal end can abut the distal end 178d of the pawl or second button 178. In some embodiments, as shown in FIG. 25, the proximal end 178p of the pawl or second button 178 can be pressed to compress the spring 177, pivoting the distal end 178d radially outward and allowing the outer sleeve 104 to be inserted further into the central lumen 134. In some embodiments, the proximal end of the outer sleeve 104 and the head 126 formed thereon can include a proximally facing surface with a tapered diameter to provide a lead-in, allowing a user to insert the outer sleeve 104 by applying sufficient force without separately depressing the second button 178. Once the outer sleeve 104 is inserted sufficiently into the handle 106 that the proximal head 126 passes the pawl or second button 178, insertion can continue until the ratchet portion 128 reaches the pawl. The proximal end 178p of the pawl or second button 178 can then be depressed to allow the outer sleeve to continue moving proximally until the pawl reaches the distal end of the ratchet portion. At this point, the distal end of the drive shaft 102 will be exposed beyond the distal end of the outer sleeve 104, and multiple set screws can be inserted onto the distal end of the drive shaft and stacked along the drive feature 108, as shown in FIG. 26 .

[0052] Additional details and alternative embodiments of the device are shown in Figures 27-48. Figure 27 illustrates a handle 206 that may include, for example, a silicone overmolded grip 207. The handle may be formed utilizing any of a variety of materials, including metals, polymers, etc. Grip-enhancing features such as ribs, knurling, other texturing, etc. may be provided on the exterior surface of the handle.

[0053] 28-30 illustrate one embodiment in which the handle 606 includes a bore formed therein for receiving a pin 608, which can assist in securing the drive shaft 602 to the handle. As shown, the pin 608 can extend laterally through the handle 606 and through the inner drive shaft 602 of the inserter instrument 600 to prevent unwanted rotation of the drive shaft relative to the handle during use. In embodiments in which the drive shaft 602 is threadedly coupled to the handle 606, undesired relative rotation between these components during use can cause separation or adjustment of the relative positioning. The use of the pin 608 disposed through coaxial transverse bores formed in the handle 606 and the shaft 602 can prevent any such relative rotation between these components.

[0054] FIG. 31 illustrates another embodiment of a multiple set screw insertion instrument 500. The overall shape of the instrument 500 can be similar to an intermediate set screw driver. The inserter 500 can include an inner drive shaft 502 with a relatively long male drive feature at its distal end and a spring clip retention mechanism at its distal tip 512. Several set screws 510 can be stacked on the driver along their axis, with the female drive feature passing completely through the set screws. Stacking the set screws 510 in this manner allows the diameter of the instrument 500 at its distal end to remain equal to or smaller than the set screw outer diameter OD4, facilitating instrument interchangeability without increasing the instrument profile. A ratcheting outer sleeve 504 can be advanced on the inner drive shaft 502 to insert the next set screw after inserting the previous one and then move it into the retention feature at the driver's distal tip 512. The ratcheting feature can provide a hard stop on the back of the set screw, which can assist the user in beginning to thread it into the implant. The proximal handle 506 can have a diameter small enough to limit the amount of torque applied by the user and can accommodate two buttons. The first button on the proximal end can be pressed to advance the outer sleeve 504 and set screw 510. The second button on the side of the handle 506 can be pressed to move the outer sleeve 504 back proximally to reload the instrument. A retention mechanism on the handle can temporarily hold the outer sleeve in place when the proximal button is released, allowing the ratchet mechanism to advance.

[0055] 32 illustrates an alternative view of the multiple set screw insertion instrument 500. As noted above, the instrument 500 can reduce the time and hands-on effort required to install several set screws when assembling a spinal fusion construct, and the savings in lengthy deformity correction can be significant when the construct spans several vertebral levels and includes several termination or fixation points between the rods or other spinal fixation elements and the implanted bone anchors. The relatively low-profile cylindrical handle 506 can inhibit the application of large torques to the set screws, and the reduced-diameter distal portion can enable delivery of the set screws through instruments such as extension tubes coupled to the implanted bone anchors, etc.

[0056] 32 also shows the above-described features of the inserter including a button 550 at its proximal end that controls the advancement of the ratcheting outer sleeve 504 over the inner sleeve after delivering the first set screw, pushing the loaded set screw 510 distally to prepare the second set screw. Also shown is a second button 578 on the side of the handle 506 that allows proximal movement of the outer sleeve 504 to reload the device with additional set screws. Finally, this figure shows multiple set screws 510 stacked on the inner shaft at the distal end of the inserter 500.

[0057] FIG. 33 shows a partial perspective view of the inserter 500 of FIG. 32 to illustrate its operation and internal mechanisms in more detail. Starting at the distal end of the device, the inner shaft 502 includes an enlarged distal section with a driver tip 512 geometry to allow for stacking multiple set screws on the tip. As shown in FIG. 34, there is a spring clip 518 disposed at the distal end of the driver to provide flexible retention of the set screw 510 through interference between the spring clip 518 and the set screw 510. At the proximal end, a spring or other biasing element 552 urges the button 550 proximally, returning it to its original position after the user depresses the button to advance the outer sleeve 504. The proximal button 550 interfaces with a side button 578 to transfer load from the proximal button 550 to the outer sleeve 504. The spring plunger 588 prevents the ratcheting outer sleeve 504 from following the side button 578 during its return stroke by the proximal button 550 .

[0058] 35A-35D illustrate cross-sectional views of the set screw insertion process. First, the user inserts the distal-most set screw into the receiver head or tulip of the implanted bone anchor. Then, the user rotates the inserter 500 to thread the set screw into the threaded portion of the bone anchor receiver head. The user then pulls the inserter proximally to separate it from the implanted set screw. As shown in FIG. 35B, the user's pulling force and the fixed threaded position of the set screw in the receiver head cause the set screw to overcome the distal spring clip and separate from the inserter. Then, as shown in FIG. 35C, the user can depress the proximal button 550 to advance the side button 578 and outer ratcheting sleeve 504 relative to the inner shaft 502 to urge the stacked set screws distally until the distal-most set screw approaches the distal end of the inserter 500 and fastener due to interference with the spring clip. As the ratcheting outer sleeve 504 advances distally, the spring plunger 588 indexes from a first detent to an adjacent detent on the outer sleeve 504. As shown in FIG. 35D, the spring plunger 588 provides enough holding force to temporarily maintain the position of the outer sleeve 504 when the proximal button 440 is released, and advances back along with the side button 578 to their initial positions where they can be advanced again after delivery of another set screw.

[0059] 36A-36C illustrate cross-sectional views of the set screw reloading process. As shown in FIG. 36A, the ratcheting outer sleeve 504 can be in its distal-most position after all set screws have been delivered. To reload, as shown in FIG. 36B, the user can press and hold the recessed side button 578, which releases and moves the ratcheting outer sleeve 504 proximally when sufficient force is applied to overcome the spring plunger retention force, as shown in FIG. 36C. An additional set screw 510 can then be loaded onto the distal drive tip and stacked together, as shown in FIG. 36C. Once the recessed side button 578 is released, it re-engages with one of the ratchet teeth on the outer sleeve 504 when the proximal button is depressed, maintaining its position and controlling the advancement of the outer sleeve 504.

[0060] Figures 37-39 illustrate cross-sectional views of another embodiment 700 having a side button or latch 778 that extends outside the handle. Specifically, Figures 38 and 39 illustrate the relative positions of the spring plunger / ball detent 788 when the outer sleeve 704 is in a first position and after the outer sleeve 704 has been advanced to deliver a new set screw.

[0061] 40A-48 illustrate additional views of an embodiment of a multiple set screw insertion tool. More specifically, FIGS. 40A-40F illustrate various views of one embodiment of a multiple set screw insertion tool 800, including an exploded view showing an outer sleeve 804, an inserter shaft 802, a handle 806, a dowel 808 for securing the inserter shaft 802 to the handle 806, a side latch 878, a biasing spring 877 and pivot pin 882 for the side latch 878, a proximal actuator button 850, and a biasing spring 852 for the actuator button.

[0062] 41A-41G illustrate various views of the set screw inserter shaft 802, including its distal portion having a drive tip geometry 854 and groove 856 for receiving a spring clip.

[0063] 42A-42D illustrate various views of the set screw inserter handle 806, including the inserter shaft, ratcheting outer sleeve, proximal button, and lumen 858 for receiving the side latch component.

[0064] 43A-43C illustrate various views of actuator button 850, including proximal button face 860 that a user contacts and distal extension portion 862 that mates with side latch or second button 878. FIGS. 44A-44C illustrate various detailed views of the distal end of actuator button 850 that mates with the side latch, including notch 864 with a protruding flange 866 having bore 868 formed therein that can receive pin 882 to couple side latch or second button 878 to distal extension portion 862. Also shown is recess 870 that can receive a portion of biasing spring 877 and slot 872 that can receive dowel 808 to limit the range of motion of button 850 relative to handle 806.

[0065] 45A-45E illustrate various views of side latch 878, including biasing spring 877, its distal end 878d, and its proximal end 878p having a recess 874 for receiving bore 876 that receives pin 882.

[0066] 46A-46C illustrate various views of a spring clip 818 that holds the set screw to the inserter shaft with an interference fit.

[0067] 47A-47D illustrate various views of the outer ratcheting sleeve 804, including a proximal portion having ratchet teeth 828 that interface with a side latch 878. Note that in this embodiment, the ratchet teeth 828 are formed on only a portion of the circumference of the sleeve 804. In other embodiments, as disclosed above, the ratchet teeth 828 can be formed around the entire circumference of the outer sleeve 804. Additionally, in some embodiments, a first set of ratchet teeth or other surface features can be formed on one side of the outer sleeve and a second set of ratchet teeth or other surface features can be formed on the other side of the outer sleeve, for example, to provide different surface features for interacting with each of the second button and detent / spring plunger.

[0068] 48 illustrates one embodiment of a set screw 810 for use with multiple set screw insertion instrument 800. The set screw 810 can include a through hole 811 formed therein having a complementary geometry to the inserter shaft distal portion 854 to allow the set screw to be stacked on the inserter shaft 802 and driven by the inserter shaft 802 when the inserter 800 is rotated. The set screw 810 can also include threads 813 formed on an outer surface thereof that can mate with threads formed on the inner surface of, for example, a bone screw receiver head during insertion of the set screw using instrument 800.

[0069] The instruments disclosed herein can be constructed from any of a variety of known materials, including materials suitable for use in surgical applications, including metals such as stainless steel, titanium, nickel, cobalt chromium, or alloys and combinations thereof, polymers such as PEEK, ceramics, carbon fiber, and the like.

[0070] The devices and methods disclosed herein can be used in minimally invasive and / or open surgery. Although the devices and methods disclosed herein are generally described in the context of surgery on a human patient, it will be understood that the methods and devices disclosed herein can be used in any of a variety of surgical procedures or in non-surgical procedures with any human or animal subject.

[0071] The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular parts, and subsequent reassembly. Specifically, the device can be disassembled, and any number of particular parts or portions of the device can be selectively replaced or removed in any combination. Following cleaning and / or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility or by a surgical team immediately prior to a surgical procedure. Reconditioning of a device can utilize a variety of techniques for disassembly, cleaning / replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

[0072] The devices described herein can be processed before being used in a surgical procedure. First, new or used instruments can be obtained and cleaned as needed. The instruments can then be sterilized. In one sterilization technique, the instruments can be placed in a closed and sealed container, such as a plastic bag or a TYVEK bag. The container and its contents can then be placed in a field of radiation that can penetrate the container, such as gamma rays, X-rays, or high-energy electrons. The radiation can kill bacteria on the instruments and within the container. The sterilized instruments can then be stored in the sterile container. The sealed container can keep the instruments sterile until opened in the medical facility. Other forms of sterilization are also possible, including beta or other radiation, ethylene oxide, steam, or a liquid bath (e.g., cold immersion). Depending on the materials used, the presence of electrical components, etc., certain forms of sterilization techniques may be more suitable for use with different parts of the device.

[0073] Further features and advantages based on the above-described embodiments are possible and are within the scope of the present disclosure. Therefore, the present disclosure is not limited by what has been specifically shown and described. All publications and references cited herein are incorporated herein by reference in their entirety, except for any definitions, disclaimers or denials of subject matter, and except where the incorporated material contradicts the explicit disclosure of this specification (in which case the language of the present disclosure shall prevail).

[0074] Examples of the above-described embodiments may include the following.

[0075] Example 1. A surgical instrument comprising: a shaft having a distal portion configured to drive a set screw to seat a plurality of set screws stacked relative to one another on the shaft; a handle coupled to the shaft; a sleeve disposed on the shaft and configured to contact a proximal-most set screw stacked on the shaft; a first button disposed within the handle and configured to distally advance the sleeve relative to the shaft a first increment; a second button disposed within the handle and configured to allow proximal retraction of the sleeve. Example 2. The device of claim 1, wherein the sleeve includes a plurality of ratchet teeth. Example 3. The instrument of claim 2, wherein the first increment corresponds to the distance between two adjacent teeth of the plurality of ratchet teeth. Example 4. The instrument of claim 2, further comprising a detent disposed within the handle configured to mate with the plurality of ratchet teeth to resist movement of the sleeve. Example 5. The device of claim 4, wherein the detent is a spring-loaded ball. Example 6. The instrument of claim 2, wherein the second button is biased into contact with one ratchet tooth of the plurality of ratchet teeth. Example 7. The device of claim 6, wherein the second button allows proximal retraction of the sleeve when the bias of the second button is overcome. Example 8. The instrument of any one of claims 1-7, further comprising a spring clip disposed around the distal end of the shaft and configured to retain the set screw thereon by an interference fit. Example 9. The device of any one of claims 1 to 8, wherein movement of a first button causes movement of a second button. Example 10. The device of claim 9, wherein movement of the first button causes the second button to translate distally. Example 11. The device of claim 10, wherein the first button is proximally biased such that proximal movement of the first button causes the second button to move proximally relative to the sleeve. Example 12. The device of any one of claims 1 to 11, wherein the outer diameter of the plurality of set screws stacked on the shaft is substantially equal to the outer diameter of the sleeve disposed on the shaft. Example 13. The device of any one of claims 1 to 12, wherein the sleeve further comprises a retention mechanism thereon to prevent ejection of the sleeve from the handle. Example 14. The device of claim 13, wherein the retention mechanism abuts the second button to retain the sleeve within the handle. Example 15. The device of any one of claims 1 to 14, wherein the first button is disposed at the proximal end of the handle and the second button is disposed on a side of the handle. Example 16. The device of any one of claims 1 to 15, wherein the first button is biased. Example 17. The device of any one of claims 1 to 16, wherein the second button is biased. Example 18. A surgical method comprising: delivering a first set screw to the first implanted bone anchor using an inserter; actuating the inserter to advance the second set screw distally relative to the shaft of the inserter; and delivering a second set screw to the second implanted bone anchor using the inserter. Example 19. The method of claim 18, wherein actuating the inserter comprises depressing a first button disposed in a handle of the inserter. Example 20. The method of claim 18 or 19, wherein actuating the inserter includes distally advancing a sleeve disposed on the shaft to urge the second set screw toward the distal end of the shaft. Example 21. A surgical method comprising: activating a first button disposed in a handle of the inserter; proximally sliding a sleeve disposed on the shaft of the inserter; advancing a plurality of set screws proximally on a distal portion of the shaft of the inserter. Example 22. The method of claim 21, wherein the first button is disposed on a side of the handle. Example 23. The method of claim 21 or 22, wherein the sleeve slides against the proximal wall of a recess formed in the handle.

[0076] [Embodiment] (1) A surgical instrument, a shaft having a distal portion configured to drive a set screw and seat a plurality of set screws stacked relative to one another on the shaft; a handle coupled to the shaft; a sleeve disposed on the shaft and configured to contact a proximal-most set screw stacked on the shaft; a first button disposed within the handle and configured to distally advance the sleeve relative to the shaft a first increment; and a second button disposed within the handle and configured to allow proximal retraction of the sleeve. (2) The device of embodiment 1, wherein the sleeve includes a plurality of ratchet teeth. (3) The tool of embodiment 2, wherein the first increment corresponds to the distance between two adjacent teeth of the plurality of ratchet teeth. (4) The instrument of embodiment 2, further comprising a detent disposed within the handle configured to engage with the plurality of ratchet teeth to resist movement of the sleeve. (5) The device of claim 4, wherein the detent is a spring-loaded ball.

[0077] (6) The device of embodiment 2, wherein the second button is biased to contact one ratchet tooth of the plurality of ratchet teeth. (7) The device of embodiment 6, wherein the second button allows proximal retraction of the sleeve when the bias of the second button is overcome. (8) The device of embodiment 1, further comprising a spring clip disposed around the distal end of the shaft and configured to hold a set screw thereon by an interference fit. (9) The device of embodiment 1, wherein movement of the first button causes the second button to translate distally. (10) The device of embodiment 9, wherein the first button is proximally biased such that proximal movement of the first button moves the second button proximally relative to the sleeve.

[0078] (11) The device of embodiment 1, wherein the outer diameter of the plurality of set screws stacked on the shaft is substantially equal to the outer diameter of the sleeve disposed on the shaft. (12) The device of claim 1, wherein the sleeve further comprises a retention mechanism thereon to prevent release of the sleeve from the handle. (13) The device of embodiment 12, wherein the retention mechanism abuts against the second button to retain the sleeve within the handle. (14) The device of embodiment 1, wherein the first button is disposed at the proximal end of the handle and the second button is disposed on a side of the handle. (15) A surgical method comprising: delivering a first set screw to the first implanted bone anchor using an inserter; actuating the inserter to advance a second set screw distally relative to the inserter shaft; and using the inserter to deliver a second set screw to a second implanted bone anchor.

[0079] (16) The method of embodiment 15, wherein actuating the inserter includes depressing a first button disposed in a handle of the inserter. (17) The method of embodiment 15, wherein actuating the inserter includes distally advancing a sleeve disposed on the shaft to urge the second set screw toward the distal end of the shaft. (18) A surgical method comprising: activating a first button disposed in a handle of the inserter; proximally sliding a sleeve disposed on a shaft of the inserter; and advancing a plurality of set screws proximally on a distal portion of the shaft of the inserter. (19) The method of embodiment 18, wherein the first button is disposed on a side of the handle. (20) The method of embodiment 18, wherein the sleeve slides against a proximal wall of a recess formed in the handle.

Claims

1. A surgical instrument comprising: a shaft having a distal portion configured to drive a set screw and seat a plurality of set screws stacked relative to one another on the shaft; a handle coupled to the shaft; a sleeve disposed on the shaft and configured to contact a proximal-most set screw stacked on the shaft; a first button disposed within the handle and configured to distally advance the sleeve relative to the shaft a first increment; and a second button disposed within the handle and configured to allow proximal retraction of the sleeve; the sleeve includes a plurality of ratchet teeth; the second button is biased into contact with one ratchet tooth of the plurality of ratchet teeth; The surgical instrument wherein the second button allows proximal retraction of the sleeve when the bias of the second button is overcome.

2. The instrument of claim 1 , wherein the first increment corresponds to the distance between two adjacent ones of the plurality of ratchet teeth.

3. The instrument of claim 1 , further comprising a detent disposed within the handle configured to mate with the plurality of ratchet teeth to resist movement of the sleeve.

4. The instrument of claim 3 , wherein the detent is a spring-loaded ball.

5. The instrument of claim 1 , further comprising a spring clip disposed around the distal end of the shaft and configured to retain a set screw thereon with an interference fit.

6. The instrument of claim 1 , wherein movement of the first button causes the second button to translate distally.

7. The device of claim 6 , wherein the first button is proximally biased such that proximal movement of the first button causes the second button to move proximally relative to the sleeve.

8. The instrument of claim 1 , wherein an outer diameter of the plurality of set screws stacked on the shaft is substantially equal to an outer diameter of the sleeve disposed on the shaft.

9. The instrument of claim 1 , wherein the sleeve further comprises a retention mechanism thereon to prevent ejection of the sleeve from the handle.

10. The device of claim 9 , wherein the retention mechanism abuts the second button to retain the sleeve within the handle.

11. The device of claim 1 , wherein the first button is disposed at a proximal end of the handle and the second button is disposed on a side of the handle.

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