Sequential Reducer

Abstract

A surgical instrument is provided that is configured to couple to the bone anchor assembly to provide a modular platform for performing various steps of a surgical procedure, such as spinal rod reduction and derotation. For example, in one embodiment, the surgical instrument can include an outer sleeve terminating in a pair of extensions, an inner sleeve having a proximal threaded portion and a distal translating portion configured to pass through the outer sleeve, and a pair of pivot arms received within the extensions of the outer sleeve. The pivot arms can be configured to extend into a channel in the outer sleeve to couple the bone anchor to the outer sleeve, and a proximal end portion of the outer sleeve can include one or more flats configured to engage another instrument.

Description

Technical Field

[0001] The present disclosure generally relates to surgical instruments and methods of use, and more specifically to surgical instruments for performing rod reduction, rotation release, and / or screw insertion during spinal surgery.

Background Art

[0002] Fixation systems can be used in orthopedic or neurosurgery to maintain a desired spatial relationship between multiple bones or bone fragments. For example, in spinal surgery, a spinal fixation system can be implanted in a patient to align and / or fix one or more vertebrae in a desired orientation. A typical spinal fixation system can include bone anchors implanted within the vertebrae and longitudinal rods fixed to the bone anchors by screws or other closure mechanisms. Implanting a fixation system can involve multiple steps, such as, in particular, rod reduction, rotation release, and screw insertion.

[0003] Rod reduction, rotation release, and screw management can be difficult parts of a posterior spinal fixation procedure. Conventionally, multiple separate instruments have been required to perform these steps. Thus, a number of instruments must be prepared and made available during surgery, and the surgeon must repeatedly switch between several different instruments, which can require frequent insertion, removal, and reinsertion of instruments into and from the surgical site. All of this can lead to surgeon fatigue, long surgical times, and the associated patient risks.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Thus, there is a need for improved instruments, systems, and methods that can reduce the number of steps and amount of instruments required to perform a spinal fixation procedure.

Means for Solving the Problems

[0005] This disclosure relates to various embodiments of rod reducers and rotation release sleeves that can generally address challenges relating to the workflow, usability, and manufacture of such devices. Exemplary devices may include an outer sleeve configured to connect to a bone anchor assembly to provide a modular platform for performing various steps of a surgical procedure. For example, the outer sleeve may receive an inner sleeve passing through it for retracting a vertebral rod into the bone anchor assembly. The inner sleeve may include a threaded member and a translational member that contacts the rod to drive the rod distally into the bone anchor assembly. A rotation release device may be attached to a retraction device to perform a rotation release procedure or to apply other manipulative forces. A modular screwdriver or handle adapter may be attached to the retraction device and / or rotation release device to facilitate rod retraction. The device body, retraction device, and rotation release device may each include a working channel passing through its interior. Set screws or closing mechanisms, and screwdriver devices for applying the set screws or closing mechanisms to the bone anchor assembly, may be inserted through the working channel.

[0006] In one embodiment, a surgical instrument is disclosed comprising an outer sleeve having an internal channel defined therein, the outer sleeve terminating at a pair of extending portions at its distal end. The instrument further comprises an internal sleeve having a proximal threaded portion and a distal translational portion configured to pass through the outer sleeve, and a pair of pivot arms received within the extending portion of the outer sleeve. The pivot arms are configured to extend within the channel to connect a bone anchor to the outer sleeve. Furthermore, the proximal end portion of the outer sleeve includes one or more flat portions configured to engage with another instrument.

[0007] Any of the various alternative or additional features may be included and will be considered within the scope of this disclosure. For example, in some embodiments, the pivot arm may be fitted with a spring to bias it to the closed position.

[0008] In certain embodiments, the threaded portion may include a first threaded portion and a second threaded portion, separated by a non-threaded portion.

[0009] In some embodiments, the threaded portion can be configured to be pulled and rotated in order to be removed from the outer sleeve.

[0010] In certain embodiments, the proximal end portion of the outer sleeve may include a circumferential groove.

[0011] In some embodiments, the pair of pivot arms may include a nub extending into one or more longitudinal grooves of the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion relative to the outer sleeve. In other embodiments, the device may include a pin extending into one or more longitudinal grooves of the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion.

[0012] In certain embodiments, the device may further include a counter torque device having a fitting feature corresponding to one or more flat portions on an outer sleeve.

[0013] In some embodiments, the device may further include a release sleeve that defines a lumen passing through its interior and is configured to connect to an outer sleeve. The release sleeve may have one or more engaging surfaces that overlap one or more flat portions to facilitate connection. In certain embodiments, the release sleeve may further include a pair of hinged arms configured to extend into the lumen for further connection of the release sleeve to the outer sleeve. In some embodiments, the release sleeve may further include a locking ring configured to selectively restrict the movement of the hinged arms. Furthermore, in some embodiments, the hinged arms may be received in a circumferential groove along the outer sleeve.

[0014] In another embodiment, a surgical instrument is disclosed, comprising a housing having a central opening, a proximal end, a distal end, and a longitudinal central axis (Al) extending between the proximal and distal ends. The instrument further comprises first and second fixed arms extending distally from the housing, and first and second pivot arms movably connected to the housing. Each pivot arm may have a proximal and distal end, and the pivot arms are configured to selectively hold a bone anchor between them. The instrument further comprises a reducer shaft screwed into the central opening of the housing. Furthermore, each of the first and second arms extends distally from the housing and defines an inner surface, and each of the first and second arms includes a side wall extending outward from the inner surface at the lateral end of each arm.

[0015] As with the devices described above, any of the various additional or alternative features are considered to be within the scope of this disclosure. For example, in some embodiments, the inner surfaces of each of the first and second arms may have a conical tapered profile.

[0016] In certain embodiments, the opposing inward-facing surfaces of each side wall of the arm may have a planar tapered profile.

[0017] In some embodiments, the pivot arm can be mounted in a recess formed within the fixed arm.

[0018] In certain embodiments, the pivot arm can be pivotably connected to the housing at a position midway between the proximal and distal ends of the pivot arm.

[0019] In some embodiments, the reducer shaft may include a first portion having a male thread and configured to rotate relative to the housing to advance the reducer shaft distally relative to the housing. The reducer shaft may further include a second portion rotatably fixed relative to the housing, the second portion comprising a rod engagement surface facing distally. The first portion may include one or more inwardly facing projections that are received in circumferential grooves formed on the outer surface of the second portion.

[0020] In certain embodiments, the reducer shaft can define a working channel that extends through its interior.

[0021] In some embodiments, the distal end portion of the reducer shaft may include a visualization window formed therein.

[0022] In certain embodiments, the reducer shaft may include a drive interface at its proximal end.

[0023] In some embodiments, the reducer shaft may include a handle at its proximal end that is configured to be grasped by a user.

[0024] In certain embodiments, the instrument can further include a rotation release shaft that is selectively attachable to the reducer shaft. In some embodiments, the rotation release shaft can include an elongated body that defines a working channel extending therethrough, and the working channel of the rotation release shaft is in communication with the working channel of the reducer shaft and the central opening of the housing. In other embodiments, the rotation release shaft can include opposing hinged arms and a locking ring. The locking ring is movable between a locking position in which the locking ring maintains the hinged arms in a radially inward position where the hinged arms engage a groove formed in the housing, and a release position in which the hinged arms can move radially outward to disengage from the groove in the housing.

[0025] In some embodiments, the rotation release shaft can include a drive interface at the proximal end of the rotation release shaft.

[0026] In certain embodiments, the side wall can include an extension that forms a notch between each extension and the inner surface. The notch can be configured to receive a portion of the bone anchor.

[0027] In some embodiments, the reducer shaft can include a substantially flat distal surface configured to engage a spinal rod. In other embodiments, the reducer shaft can include a concave distal surface configured to engage a spinal rod.

[0028] Any of the features or variations described herein can be applied to any particular aspect or embodiment of the present disclosure in several different combinations. Although there is no explicit description of any particular combination, this is simply to avoid being unnecessarily long or repetitive.

Brief Description of the Drawings

[0029] The aspects and embodiments of this disclosure can be better understood by the following "Modes for Carrying Out the Invention," provided in conjunction with the accompanying drawings. [Figure 1] This is a side view of one embodiment of a reducer device according to the present disclosure. [Figure 2] Figure 1 is an exploded perspective view of the reducer device. [Figure 3] Figure 1 is a detailed side cross-sectional view of the reducer device. [Figure 4] Figure 1 is a side view of the inner sleeve of the reducer device. [Figure 5] This is a perspective view of another embodiment of the reducer device according to the present disclosure. [Figure 6] This is a perspective view of one embodiment of the reducer device of the present disclosure, connected to a bone anchor and a spinal fixation rod. [Figure 7] This is a perspective view of another embodiment of the reducer device of the present disclosure having an expanded inner sleeve. [Figure 8] This is a perspective view of another embodiment of the reducer device of the present disclosure, having an inner sleeve of intermediate length. [Figure 9A] Figure 7 is a side cross-sectional view of the reducer device, showing a bone anchor engaged with an internal sleeve positioned proximally. [Figure 9B] Figure 8 is a side cross-sectional view of the reducer device, showing a bone anchor engaged with an internal sleeve positioned proximally. [Figure 9C] Figure 6 is a side cross-sectional view of the reducer device, showing a bone anchor engaged with an internal sleeve positioned proximally. [Figure 9D] Figure 7 is a side cross-sectional view of the reducer device, showing a bone anchor engaged with an internal sleeve positioned proximally. [Figure 9E] Figure 8 is a side cross-sectional view of the reducer device, showing a bone anchor engaged with an internal sleeve positioned proximally. [Figure 9F] Figure 6 is a side cross-sectional view of the reducer device, showing a bone anchor engaged with an internal sleeve positioned proximally. [Figure 10]This is an exploded perspective view of one embodiment of a reducer device of the present disclosure. [Figure 11] Figure 10 is a perspective view of the device. [Figure 12] Figure 10 is a side view of the reducer device positioned on the spinal rod and adjacent to the bone anchor. [Figure 13] This is a side view of the reducer device shown in Figure 12, which is connected to a bone anchor. [Figure 14] This is a side view of the reducer device shown in Figure 12, docked to a bone anchor. [Figure 15] Figure 12 is a side view of the initial rod reduction using the reducer device. [Figure 16] Figure 12 is a side view of the intermediate rod reduction using the reducer device. [Figure 17] Figure 12 is a side view of distal rod reduction using a reducer device. [Figure 18] Figure 17 is a perspective view of the set screw advancing toward the distally reduced spinal rod. [Figure 19] Figure 12 is a side cross-sectional view of a set screw connected to a bone anchor through a reducer device. [Figure 20] Figure 12 is a side cross-sectional view of the rotation release procedure performed on a reducer device. [Figure 21] Figure 12 is a side cross-sectional view of the stretching procedure performed on a reducer device. [Figure 22] Figure 12 is a side view of the counter torque device connected to the reducer. [Figure 23] Figure 22 is a side view of the driver introduced into the inner sleeve of the reducer device. [Figure 24] Figure 1 is a side view of the modular rotation release sleeve connected to the outer sleeve of the reducer device. [Figure 25] Figure 24 is a perspective view of the modular rotation release sleeve. [Figure 26] Figure 24 is an exploded perspective view of the modular rotation release sleeve. [Figure 27]Figure 24 is a detailed perspective view of the distal end of the modular rotation release sleeve. [Figure 28] Figure 24 is a perspective view of the modular rotation release sleeve connected to the outer sleeve of the reducer device in Figure 1. [Figure 29] This is a side cross-sectional view of the connection between the modular rotation release sleeve in Figure 24 and the outer sleeve in Figure 1. [Figure 30] This is a side view of the counter torque device shown in Figure 22, connected to the reducer shown in Figure 1. [Figure 31] This is a side view of the counter torque device shown in Figure 22, connected to the assembly shown in Figure 24. [Figure 32] This is a perspective view of one embodiment of a reducer device of the present disclosure. [Figure 33] Figure 32 is an exploded perspective view of the reducer device. [Figure 34] Figure 32 is a perspective view of the reducer device docked to a bone anchor and reducing the spinal rod. [Figure 35] Figure 32 is a detailed perspective view of the distal end of the outer sleeve of the reducer device. [Figure 36] Figure 34 shows a detailed perspective view of the reducer device connected to a bone anchor. [Figure 37] Figure 32 is a detailed side view of the reducer device, which is docked to a bone anchor and reduces the spinal rod. [Figure 38] This is a side cross-sectional view of the reducer device shown in Figure 37, cut along line AA. [Figure 39] This is a lateral cross-sectional view of the reducer device shown in Figure 37, taken along line BB, facing distally. [Figure 40] Figure 32 is a perspective view of the inner sleeve of the reducer device. [Figure 41] This is a side view of one embodiment of an inner sleeve having a concave distal surface. [Figure 42] Figure 34 is a side cross-sectional view of the reducer device and bone anchor. [Figure 43]This is an exploded perspective view of one embodiment of a reducer device having a pin coupling mechanism. [Figure 44] This is a partial perspective view of the reducer device of Figure 43, which has an outer sleeve hidden from view. [Figure 45] Figure 43 is a side cross-sectional view of the reducer device. [Figure 46] This is an exploded perspective view of another embodiment of an inner sleeve having an integrated proximal handle. [Figure 47] This is a perspective view of one embodiment of a driver instrument extending through the outer sleeve of a reducer instrument connected to a bone anchor to drive the implantable shank of the bone anchor. [Modes for carrying out the invention]

[0030] To provide a comprehensive understanding of the structure, function, manufacture, and use principles of the devices, systems, and methods disclosed herein, certain exemplary embodiments are described below. One or more examples of these embodiments are illustrated in the accompanying drawings. The devices, systems, and methods described herein and illustrated in the accompanying drawings are non-limiting embodiments. Features illustrated or described in relation to one embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be included within the scope of this disclosure. In addition, to the extent that linear, circular, or other dimensions are used in the description of the devices and methods disclosed, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such devices and methods. Dimensions equivalent to such dimensions may be determined for different geometric shapes, etc. Furthermore, components of the same numbering in an embodiment may generally have similar characteristics. Moreover, the size and shape of a device, and its components, may depend at least on the anatomical form of the subject in which the device is used, the size and shape of the object in which the device is used together, and the method and procedure in which the device is used.

[0031] This specification discloses various embodiments of rod reducers and rotation release sleeves that can address challenges related to the workflow, usability, and manufacturing of the devices. Exemplary devices may include an outer sleeve configured to connect to a bone anchor assembly to provide a modular platform for performing various steps of a surgical procedure. For example, the outer sleeve may receive an inner sleeve passing through the outer sleeve for retracting a vertebral rod into the bone anchor assembly. The inner sleeve may include a threaded member and a translational member that contacts the rod to drive the rod distally into the bone anchor assembly. A rotation release device may be attached to a retraction device to perform a rotation release procedure or to apply other manipulative forces. A modular screwdriver or handle adapter may be attached to the retraction device and / or rotation release device to facilitate rod retraction. The device body, retraction device, and rotation release device may each include a working channel passing through its interior. Set screws or closing mechanisms, and screwdriver devices for applying the set screws or closing mechanisms to the bone anchor assembly, may be inserted through the working channel.

[0032] The instruments and devices disclosed herein can be used in the same procedures as those described in U.S. Patent No. 10,610,269, entitled “Modular surgical instruments and related methods,” the disclosure thereof is incorporated herein by reference in its entirety. The instruments and devices disclosed herein may be advantageous for certain clinical applications, providing the ability to connect to an implant separately from the rod reduction process. For example, as discussed below, the disclosed instruments and devices can facilitate connection to an implant structure either before or after implantation of the structure in a patient. Once positioned relative to a spinal fixation rod or other element, the disclosed instruments and devices can achieve rod reduction through the operation of a threaded mechanism. In some surgical procedures, the disclosed instruments and devices can be operated to connect to an implant structure, reduce the rod into the implant, and allow the user to lock the rod into the implant structure, disengage it from the implant structure, and reduce the rod into another implant structure by repeating the same or similar actions, for example, using a set screw.

[0033] As shown above, the disclosed instruments and devices can be connected to the implant before initiating the rod reduction process. This feature can provide options such as locking multiple reducer instruments onto their respective implant structures before achieving the rod reduction process. The reducer instruments can remain self-supporting without user input to maintain their position and / or degree of rod reduction, and the reducer instruments can be operated individually to reduce or partially reduce each of the implants into the rod, thereby enabling the surgeon to sequentially achieve the entire reduction process along the patient's spine without disengaging and reengaging the reducer instruments to different implants. In some embodiments, the reducer instruments can serve to temporarily hold the rod in the desired position until the surgeon is satisfied with the entire reduction process. As described below, once the rod is fully reduced into the implant structure, the rod can be locked to the respective implant structure by applying a set screw or other fixing device through a lumen formed within each reducer instrument.

[0034] Figures 1 and 2 illustrate one embodiment of a reducer instrument 100 of the present disclosure, which can be used to provide a platform for various surgical procedures such as rod reduction, rotation release, and / or set screw insertion. The reducer instrument 100 may include an outer sleeve 102, an inner sleeve 104, and a pair of pivot arms 106 attached to the outer sleeve. The outer sleeve 102 may define a working channel 108 configured to receive another tool or instrument, for example, at least a portion of the inner sleeve 104. The channel 108 may provide access to the surgical site to allow an instrument or implant to pass through. The channel 108 may extend from the proximal end 100p of the reducer instrument 100 to the distal end 100d of the reducer instrument. A pin 110 may connect the arms 106 to the outer sleeve 102.

[0035] When in use, the reducer device 100 can be positioned to dock with the bone anchor 10 by engaging pivot arms 106a, 106b positioned between them, as shown, for example, in Figures 6-8. The pivot arms may be spring-loaded lever arms that are biased to a closed position to allow the retention of the screw (or hook) head during rod retraction (Figure 3 illustrates one exemplary use of coil springs 119 for biasing the arms 106a, 106b). The bone anchor may include a shank 12 and a receiving head or member 14 into which the rod 16 can be retracted. In some embodiments, the reducer device may allow insertion of a bone anchor or screw pre-mounted in the reducer so that a screw inserter advances through a channel 108 in the outer sleeve 102 to deliver the bone screw into the bone, such as a pedicle. An example of such a configuration is shown in Figure 47, which will be described in more detail below.

[0036] The outer sleeve 102 may include a substantially tubular central portion terminating at a first extension 112a and a second extension 112b. The extensions 112a and 112b have one or more recesses formed therein to receive the extensions 112a and 112b. The outer sleeve 102 may be defined by a side wall 114 surrounding the channel 108. The inner surface of the channel 108 may be threaded or may include other fitting features, such as an inner sleeve 104 inserted through the outer sleeve to cooperate with the instrument in advancing the instrument longitudinally relative to the outer sleeve 102.

[0037] The inner sleeve 104 may include a proximal threaded member 120 and a distal translational member 122. The relationship between the two members is shown in detail in Figure 3. As shown, the threaded member 120 and the translational member 122 can be connected via a series of radially oriented pins or projections 117 that can protrude from the inner surface of the threaded member 120 and be received in circumferential grooves formed on the outer surface of the distal translational member 122. As shown, a washer 124 made of polymer or wear-resistant metal material, such as a thrust washer, can separate the translational member and the threaded member and act as a bearing surface between them.

[0038] In some embodiments, the translational member 122 may include one or more longitudinal grooves 123 formed therein. In some embodiments, the nub 127 may be integrally formed with the pivot arms 106a, 106b so that no pin is required to fix it in place. That is, the longitudinal groove 123 can engage with the cam-shaped semicircular surface or the nub 127 below the lever pivot point to prevent rotation of the translational member during retraction. This can be used in place of conventional pins to minimize the complexity of manufacturing, welding, and assembly. However, in some embodiments, as shown in Figures 43-45 and described in more detail below, one or more pins can be used instead of the nub 127. Returning to the nub 127, this nub extends from the surface of the arm 106 and rides on the longitudinal groove 123 to facilitate translation but prevent rotation of the translational member 122.

[0039] Figure 4 illustrates the threaded member 120 in more detail. As shown, the threaded member 120 may include multiple threaded portions formed thereon. For example, the threaded member 120 may include a first threaded portion 126 and an additional second distal threaded portion 128, which can prevent the threaded member 120 from unintentionally detaching proximal to the outer sleeve 102, but still allow for complete disassembly from the outer sleeve 102 for cleaning. In use, the first and second threads of the inner sleeve 104 are screwed into the outer sleeve 102 to fully retract the vertebral rod within the bone anchor, but both the first and second threads are loosened from the outer sleeve 102 to remove the inner sleeve 104 from the outer sleeve. More specifically, the first and second threaded portions may be separated by an unthreaded portion 130. The unthreaded portion 130 may include alternative surface features such as ribs, nub, or other features. When the threaded portion 126 is disengaged, the inner sleeve 104 is free to translate relative to the outer sleeve 102, so the presence of the unthreaded portion 130 allows for user feedback that the inner sleeve 104 subassembly or retractable shaft has been retracted to its maximum extent. However, in order to completely detach the inner sleeve 104 subassembly from the outer sleeve 102, the user must pull both sleeves proximal to translate and rotate the inner sleeve 104, engaging the second threaded portion 128 at the distal end of the threaded member 120. Only when the engagement is completely disengaged by screwing the second threaded portion 128 proximal to the outer sleeve 102 can the inner sleeve 104 subassembly be completely removed from the outer sleeve. That is, the removal of the inner sleeve 104 from the outer sleeve 102 is performed by pulling / pushing forces and rotation, which can prevent unwanted retraction of the inner sleeve 104.

[0040] In some embodiments, the threaded member 120 includes a triple-stub Acme thread to minimize the profile, increase the shrinkage rate, reduce mechanical advantages, and enhance tactile response. However, other thread configurations are also possible. This can be done to balance performance under various load conditions (e.g., axial load versus lateral load, etc.), device size (e.g., required thread outer diameter), etc. For example, in some embodiments, a concentrated Acme thread can be used to provide enhanced performance under lateral load conditions (e.g., higher resistance to screw coupling). Further possible thread configurations include trapezoidal threads, square threads, and buttress threads. In some embodiments, one or more configurations of thread configurations can be combined to create improved thread configurations. Furthermore, in some embodiments, the threaded member 120 may include an internal channel defined within the threaded member to receive one or more devices (e.g., set screws) passing through the internal channel.

[0041] The threaded member 120 may also include a proximal drive interface 402 to facilitate the transmission of torque thereto during use. In some embodiments, the proximal drive interface 402 may be a modular drive interface comprising one or more flat sections or other torque transmission features formed thereon. In an illustrated embodiment, the proximal drive interface 402 is a hexagonal drive interface comprising a plurality of flat sections spaced apart around the outer circumference of the member 120. Such a modular drive interface can maintain a low profile / small diameter threaded member 120, while facilitating attachment to various drivers or other tools as needed. In certain embodiments, the proximal drive interface 402 can be used to modularly connect either a handle or other structure that can be gripped by various users to the threaded member 120. In other embodiments, either a handle or other structure that can be gripped by various users may be formed integrally with the threaded member 120 or otherwise permanently connected to the threaded member 120, instead of the modular proximal drive feature 402 shown in Figure 4. Figure 46 illustrates one embodiment of an inner sleeve 304 having a threaded member 320 integrally formed with a handle 326 at its proximal end.

[0042] As shown in Figure 5, the distal translation member 122 includes a first stationary or fixed arm 134a and a second stationary or fixed arm 134b, which extend distally therefrom to perform rod reduction. The stationary arms 134a and 134b can be configured to advance distally without rotation to advance the spinal rod into the receiving member. As shown in Figure 1, the translation member 122 may include a window 125 therein to allow observation of the set screw when screwing it into the bone anchor during tightening or loosening, as will be discussed further below. The window 125 can have various shapes and sizes, including a teardrop shape as shown in Figure 1 or a slit shape as shown in Figure 40. Furthermore, the window 125 can be positioned at various locations along the length of the translation member 122. In some embodiments, the window can be positioned close enough to the distal end of the translation member 122 to allow visualization of the set screw after it has been fully screwed into the receiving member of the bone anchor. In some embodiments, longer slit-shaped windows can provide greater visibility of the set screws during insertion and tightening procedures, while also maximizing the strength and rigidity of the translational member 122, which can be reduced when too much material is removed, especially when closer to the distal end of the translational member. Returning to the inner sleeve 104, more generally, it can be translated relative to the outer sleeve 102.

[0043] Figure 5 illustrates one embodiment of an inner sleeve 104a in which no window is located within the outer sleeve 102. The outer sleeve 102 has a distal pocket 131 formed between opposing arms 112a and 112b that can receive and connect to the receiving member of a bone anchor. The distal pocket 131 may vary in size, but in some embodiments, the window 131 may be about 9 mm wide. The size and shape of the distal end of the outer sleeve 102 can allow connection to the bone anchor with some degree of lateral displacement. Furthermore, the inner surfaces of the arms 112a, 112b may have a shape or profile complementary to the outer surface of the bone anchor to facilitate connection even when some displacement exists, regardless of, for example, lateral or rotational displacement along the axis of the rod, or rotational displacement along the longitudinal axis of the device 100. In some embodiments, for example, the inner surfaces 132 of each arm 112a, 112b may include a tapered profile complementary to the outer surfaces of the opposing arms of the multiaxial bone anchor receiving head. In some cases, the inner surfaces 132 of each arm 112a, 112b may include a conical tapered profile complementary to the conical tapered profile of the receiving member. Such arrangements can accommodate some pivotal misalignment between the receiving head and the instrument 100, which can be corrected when the instrument advances distally relative to the receiving head and the receiving head advances into the distal pocket 131.

[0044] Furthermore, the arms 112a and 112b may include side walls 133 extending outward from the inner surface 132 at the lateral ends of each arm. The side walls 133 may also include a tapered profile to assist in alignment with the bone anchor receiving member by self-correcting rotational misalignment around the longitudinal axis of the instrument, for example, when the instrument advances distally to the bone anchor and receives the anchor in the distal pocket 131. In some embodiments, the opposing, inwardly facing surfaces of each side wall 133 may have a planar tapered profile that is complementary to the planar tapered profile of the contact surface on the bone anchor receiving member. Various tapered surfaces can accommodate misalignment when the instrument 100 is connected to the bone anchor, such that the advance of the outer sleeve 102 on the bone anchor 10 aligns the two components appropriately just before secure engagement of the pivot arms 106a and 106b with the anchor 10, simplifying the attachment of the instrument 100 to the anchor 10. As stated herein, the receiving member 14 may include one or more tapered profiles complementary to the tapered surface provided on the outer sleeve. Further details regarding the features of the anchor 10 that can be used with the fixtures disclosed herein can be found in U.S. Patents No. 10,039,578 and No. 10,299,839, as well as in U.S. Provisional Application No. 63 / 157,362, filed on March 5, 2021, entitled “Multi-Feature Polyaxial Screw,” and in U.S. Application No. ____, also entitled “Multi-Feature Polyaxial Screw,” filed on the same date as this specification and claiming priority to the aforementioned Provisional Application. The entire contents of each of these applications are incorporated herein by reference.

[0045] The proximal end of the outer sleeve 102 may include one or more mating features. For example, the outer sleeve 102 may include one or more proximal flat portions 144 having a square or rectangular shape oriented around its outer circumference. The flat portions 144 may be spaced apart around the outer circumference of the outer sleeve and connected to corresponding mating features of a device that engages with the outer sleeve. Furthermore, the outer sleeve 102 may include a circumferential groove 145 extending around the outer circumference of the outer sleeve 102 to facilitate engagement of the outer sleeve with a device, as will be discussed further below. As shown, the circumferential groove 145 may be oriented distal to the flat portions 144, but it will be understood that their relative orientations may be reversed.

[0046] Figure 5 also illustrates that in some embodiments, the actuator facing the surgeon can be distinguished from the rest of the device by using different colors, textures, materials, etc. For example, in the embodiment of Figure 5, the surgeon-operated actuator 135 on arms 106a and 106b may be colored black, for example, using an aluminum-titanium-nitride (AlTiN) coating.

[0047] The length of the inner sleeve can vary. Figure 6 illustrates a reducer device 100' with a shorter inner sleeve 104'. In some embodiments, the inner sleeve 104' can provide an axial rod reduction of approximately 20 mm. The use of a shorter inner sleeve 104' can prevent proximal insertion in lordotic / concave segments or may be particularly useful in pediatric applications where space is limited.

[0048] Figure 7 illustrates a reducer instrument 100'' having a longer inner sleeve 104''. In some embodiments, the inner sleeve 104'' can provide an axial rod reduction of approximately 60 mm. In some embodiments, the extension length can be achieved by welding or otherwise connecting two or more components to create the inner sleeve. When using an extended sleeve 104'' with an increased range of reduction, an alternative surgical technique may be possible in which the rod is inserted after the reducer is connected to the anchor.

[0049] Figure 8 illustrates a reducer device 100''' having an inner sleeve 104''' of an intermediate length between the lengths shown in Figures 6 and 7. In some embodiments, this intermediate length inner sleeve 104''' can provide an axial rod reduction of about 40 mm and may be suitable for a wide range of applications.

[0050] Figures 9A to 9F illustrate cross-sectional views of reducer devices 100 having internal sleeves 104 of varying lengths positioned within them. More specifically, each figure illustrates a reducer device 100 having internal sleeves of varying lengths that engage bone anchors and their respective pivot arms 106a, 106b. Figures 9A and 9D illustrate, for example, the range of possible axial reductions with respect to the device 100'' shown in Figure 7, with Figure 9A showing the device 100'' with the internal sleeve 104'' in a proximal position, and Figure 9B showing the device 100'' with the internal sleeve 104'' in a distal position. This pattern is repeated in Figures 9B and 9E with respect to the intermediate-length device 100'''' in Figure 8, and in Figures 9C and 9F with respect to the shorter device 100''' in Figure 6.

[0051] Figure 10 illustrates one embodiment of the assembly of the reducer device 100 of the present disclosure, and Figures 10 to 23 illustrate one embodiment of a method for utilizing such device. Referring to the device 100 shown in Figure 10, the inner sleeve 104 can be translated distally through the opening of the outer sleeve 102 to accommodate the translation member 122 therein. When assembled, as shown in Figure 11, the threaded member 120 can extend proximal to the outer sleeve 104 as it rotates relative to the outer sleeve 102, while the translation member 122 remains positioned therein to advance distally toward the extended portions 112a, 112b of the outer sleeve.

[0052] Figure 12 illustrates a reducer device 100 that engages on a rod 16 and adjacent to a bone anchor or pedicle screw 14. As shown, the spinal rod 16 can be positioned between the pivot arms 106a, 106b and the extensions 112a, 112b of the outer sleeve 102, while the receiving member 14 is positioned distal to the outer sleeve 102. The outer sleeve 102 can advance toward the bone anchor 10 and engage with its notch. Figure 12 illustrates one embodiment in which the reducer device 100 advances distally, first passing over the extensions 112a, 112b and capturing the rod 16 between them, and then reaching the bone anchor 14. However, in other embodiments, the reducer device can be connected to the bone anchor before positioning the rod. In such embodiments, the rod can be introduced laterally into the space between the extensions 112a, 112b. Such embodiments are discussed further below.

[0053] Figure 13 illustrates a reducer device 100 engaging with a receiving member 14. As shown, during engagement, the pivot arms 106a and 106b move radially outward at their distal ends to cross a notch in the receiving member, while the outer sleeve 102 is positioned on top of the receiving member. Once the outer sleeve 102 has advanced sufficiently over the receiving member 14, the distal ends of the pivot arms 106a and 106b move radially inward toward the receiving member (for example, as a result of a biasing force such as a radially outward spring force applied to the proximal ends of the pivot arms) and click into place. As described above, the tapered sidewall 132 allows for some initial rotational displacement between the outer sleeve 102 and the implant head 14 during engagement, along the axis of the device 100.

[0054] Figure 14 illustrates a reducer device 100 docked to a pedicle screw 10, with a rod 16 positioned between the pivot arms 106a, 106b and extensions 112a, 112b of the outer sleeve 102. The above processes for assembling the reducer device 100 and / or connecting the outer sleeve 102 of the reducer device to a bone anchor can be performed in various sequences, which can increase efficiency and allow for flexibility to different surgical workflows that can accommodate different user preferences. For example, the assembly of the inner and outer sleeve components of the device 100 can be performed in the "back table" or surgical preparation area before handing the assembled device to the surgeon for use. In addition, the bone anchor can be connected to the outer sleeve 102 before or after implantation in the patient and / or before or after assembling the outer sleeve 102 and inner sleeve 104.

[0055] In certain embodiments, for example, the outer sleeve 102 can be connected to the bone anchor before implanting the bone anchor in the patient, and the bone anchor can be implanted using an instrument that passes through the outer sleeve 102 and connects to the implantable shank of the bone anchor. This can be done whether or not the inner sleeve 104 is connected to the outer sleeve 102. In embodiments where the bone anchor is connected thereto and the outer sleeve 102 is implanted without the inner sleeve 104, the inner sleeve can be connected to the outer sleeve 102 after the bone anchor has been implanted and the driver instrument has been removed from the outer sleeve 102.

[0056] Figure 47 illustrates one embodiment of a screwdriver instrument 4702 extending through the outer sleeve 102 of a reducer instrument connected to a receiving member 14 of a bone anchor 10. The screwdriver instrument 4702 is shown connected to the implantable shank 12 of the bone anchor 10 so that rotation of the screwdriver instrument can cause rotation of the implantable shank, driving it into the bone. As described above, once the implantable shank 12 is positioned in the bone, the screwdriver instrument 4702 can be removed proximal to separate it from the shank 12 and withdrawn from the lumen of the outer sleeve 102. The inner sleeve 104 can then be connected to the outer sleeve 102 to continue the rod capture and retraction process disclosed herein (for example, the rod can be introduced laterally through the rod slot of the outer sleeve, and the inner sleeve can be rotated relative to the outer sleeve to achieve axial retraction of the rod toward the bone anchor 10).

[0057] This assembly flexibility allows for a workflow in which the reducer instrument 100 is connected to the bone anchor and driver instrument in, for example, a “back table” or surgical preparation area. The assembly can then be handed to a ready surgeon or other user to implant the bone anchor in the patient. After implantation, as described below, the driver instrument can be removed and the reducer instrument 100 can remain connected to the implanted bone anchor, ready for use when reducing the rod. In embodiments in which the outer sleeve 102 is connected to the bone anchor before implantation, or otherwise before the rod is positioned approximately proximal to the bone anchor, the rod can later be positioned by passing it laterally through the rod slot opening of the outer sleeve 102 between the extended portions 112a and 112b.

[0058] Figure 15 illustrates the rotational force 1502 applied to the threaded member 120 to advance the translational member 122 toward the spinal rod. As shown, the threaded member 120 can be rotated while the translational member 122 is advanced distally, allowing the stationary arm 134 to engage with the spinal rod 16.

[0059] Figure 16 shows the further rotation of the threaded member 120, which causes the stationary arms 134a and 134b to advance the vertebral rod 16 toward the bone anchor 10.

[0060] Figure 17 shows the threaded member 120 in its most distal position, in contact with the outer sleeve 104, so as not to be able to advance distally. In this orientation, the vertebral rod 16 is reduced within the bone anchor 10.

[0061] Figures 18 and 19 illustrate a set screw 140 that is inserted through a channel 142 in an inner sleeve 104 and screwed into a bone anchor receiving member using an inserter 1802. In some embodiments, the set screw can be temporarily tightened to the bone anchor using the inserter, as shown in Figure 19, by applying a rotational force 1902. The set screw 140 can be advanced distally through the inner sleeve 104, for example, through a threaded member 120 and a translational member 122, to engage with the vertebral rod and lock the vertebral rod to the bone anchor. Furthermore, when positioning and introducing and driving the set screw 140 through the inner sleeve 104, the inserter can be used to perform a rotation release procedure, as shown by arrow 2002 in Figure 20, or an extension procedure, as shown by arrow 2102 in Figure 21. In other embodiments, such rotation release and / or extension procedures can be performed using an instrument 100 in which no inserter is present.

[0062] The final tightening of the set screw 140 may require the application of a counter torque to which the force involved is applied. Figure 22 illustrates a counter torque device 146 positioned on the outer sleeve 102. The counter torque device 146 can be coupled to the proximal flat portion 144 and groove 145 on the outer sleeve 102 to form a secure connection that, together with it, prevents relative rotation between the components. The proximal flat portion 144 can be spaced apart in a manner that allows the corresponding mating feature 148 of the counter torque device 146 to be coupled in multiple orientations (for example, the flat portion can be formed around the outer circumference of the fixture in a hexagonal or other pattern to allow coupling in various rotational orientations relative to the fixture). As shown in Figure 23, a driver 150 can be introduced through the inner sleeve 104 and engaged with the set screw to tighten using the counter torque device 146 that locks the rod within the receiving member of the anchor.

[0063] In addition, the modular release sleeve or tube 152 can also be used to bypass the threaded inner sleeve by connecting to the outer sleeve 102 of the fixture 100. By directly engaging with the flat portion of the outer sleeve 102, it is possible to directly apply counter torque through the release sleeve 152 via a connection to the same type of modular counter torque device 146 shown in Figures 22 and 23. This is in contrast to other devices that provide connection through an inner threaded sleeve component. Figure 24 illustrates a modular release sleeve 152 connected to the fixture 100.

[0064] Figures 25-27 illustrate in more detail a derotation sleeve 152 that can be connected to the outer sleeve 102. The derotation sleeve 152 can be used to provide additional force when manipulating the vertebra or other bone to which the sleeve is connected. For example, the derotation sleeve 152 can facilitate the application of derotation, extension, compression, or other forces to the vertebra or fixation structure, for example, to correct a patient's spinal angle, malformation, or other condition. The derotation sleeve can also provide a mounting point for a derotation rack, navigation system, or other surgical instrument.

[0065] The rotation release sleeve 152 may include a tubular shaft 154 having one or more hinged arms or leaf springs 156 for engaging with the reducer device 100 or other device to secure the rotation release sleeve 152. The rotation release sleeve 152 may include a locking ring 158 for selectively retaining the arms 156 by engaging with the reducer device 100 or other device. The sleeve 152 may include internal side walls defining a lumen or working channel 160 extending through the shaft. The locking ring 158 may be positioned around the outer sleeve surface 152 and movable axially relative to it. The locking ring 158 may be connected to the sleeve 152 via one or more pins 162 inserted through its interior.

[0066] The hinged arm 156 can be configured to grip the drive interface of an instrument inserted through its interior. The hinged arm 156 may be movable between an open configuration in which the instrument can be inserted into and removed from the release sleeve 152, and a closed position in which the instrument is trapped or held within the release sleeve. The locking ring 158 can be positioned in an unlocked position in which the hinged arm 156 can move or pivot freely relative to the release sleeve 154, and in a locked position in which the movement of the hinged arm 156 relative to the sleeve 154 is restricted. The hinged arm 156 can pivot radially inward and / or radially outward with respect to the longitudinal axis Al.

[0067] The hinged arm 156 may include a body 161 having a projection 164 at its distal end. The body 161 can pivot radially inward so that the projection 164 enters the lumen 160, allowing it to grip an instrument or other object inserted through it. A locking ring 158 slides axially over the hinged arm 156 to move the arm from an open configuration to a closed configuration and / or prevent the arm 156 from moving relative to the sleeve 152, thereby locking the arm in the closed configuration.

[0068] The rotation release sleeve 152 may include a distal drive interface 166 configured to engage with a proximal flat portion on the outer sleeve 102. The drive interface 166 can communicate with the lumen 503 so that a tool inserted through the drive interface 166 can pass through at least a portion of the lumen 160, and a tool inserted through the lumen 160 can pass through at least a portion of the drive interface 166. The drive interface 166 and the lumen 160 are separated by a contact surface or shoulder portion 168 defined by the internal side wall of the rotation release sleeve 152 to prevent an instrument inserted into the drive interface 166 from advancing too far proximally into the lumen 160.

[0069] The proximal end of the rotation release sleeve 152 may include a flat portion 172 similar to the flat portion formed on the outer sleeve 102, thereby enabling the same modular handle to be connected to both subassemblies and thus allowing counter-torque to be applied to both subassemblies via the same handle. In some embodiments, the length of the proximal end portion of the rotation release sleeve 152 including the flat portion 172 may be extended to provide a larger surface area for engagement by various devices connected thereto.

[0070] Figure 28 illustrates a derotation sleeve 152 that connects to the outer sleeve 102 while bypassing the threaded member of the inner sleeve. For example, the derotation sleeve 502 may include one or more engaging surfaces 170 positioned on the drive interface 166 or lumen 160. As shown, the engaging surfaces 170 can protrude from the inner surface of the derotation sleeve 152 at various angles to engage with a proximal flat portion 144 formed on the outer sleeve 102. In this way, the derotation sleeve 152 makes a secure connection with the outer sleeve 102, while the threaded member 120 of the inner sleeve 104 remains positioned within the channel of the derotation sleeve 152 without engaging with the derotation sleeve 152. As a result, the derotation sleeve 152 may remain fixed to the outer sleeve 102 so that a derotation force can be applied to the vertebra without rotation of the vertebra. As shown in Figure 27, the contact surfaces 170 can be positioned at an angle of approximately 90 degrees relative to each other so as to abut the flat portions in order to facilitate connection and to restrict the rotation of the release sleeve 152 relative to the outer sleeve 102. However, in other embodiments, fewer or additional contact surfaces 170 can be spaced apart around the outer circumference of the sleeve 152, with the corresponding flat portions 144 positioned around the outer circumference of the outer sleeve.

[0071] Figure 29 illustrates a cross-sectional view of the connection between the outer sleeve 102 and the rotation release sleeve 152. As discussed above, the retention of the rotation release sleeve 152 can be achieved via a locking ring 158 that restrains a hinged arm 156 that engages with a circumferential groove 145 on the outer sleeve. As described above, the proximal end of the rotation release sleeve 152 may include a flat portion 172 similar to the flat portion formed on the outer sleeve, thereby enabling the same modular handle to be connected to both subassemblies and, therefore, to apply counter torque to both subassemblies via the same handle. This can be seen, for example, in Figure 30, where the modular counter torque device 146 shown in Figures 22 and 23 is directly connected to the device 100, and in Figure 31, where the counter torque device 146 is connected to the modular rotation release sleeve 152, which is then connected to the device 100.

[0072] Figures 32 and 33 illustrate another embodiment of the reducer device 200 of the present disclosure. Since the reducer device 200 may be similar in many respects to the device described above, a detailed description of all features will be omitted for brevity.

[0073] As shown, the reducer instrument 200 may include an outer sleeve 202, an inner sleeve 204, and a pair of pivot arms 206 attached to the outer sleeve 202. Similar to the embodiment discussed in Figure 1, the outer sleeve 202 may define a working channel 208 configured to receive at least a portion of another tool or instrument (e.g., the inner sleeve 204). The channel 208 may provide access to the surgical site to allow the instrument or implant to pass through. The channel 208 may extend from the proximal end 200p of the reducer instrument 200 to the distal end 200d of the reducer instrument. The pivot arms 206 may be positioned within opposing recesses 209 formed in the outer sleeve 202. As will be further described below, the distal ends 206ad, 206bd of the pivot arms 206a, 206b, and the nub 227 of the pivot arms 206a, 206b may enter the channel 208. The inclusion of the recess 209 allows the pivot arms 206a and 206b to be positioned closer to the body of the reducer instrument 200, reducing the overall profile of the instrument and preventing the arms from interfering with body tissue, other surgical instruments, etc. The pin 210 allows the arm 206 to be connected to the outer sleeve 202. When in use, the reducer instrument 200 can be positioned so that the pivot arms 206a and 206b engage with the bone anchor 10 positioned between them, as shown, for example in Figure 34 and discussed in more detail below, thereby docking the reducer instrument 200 with the bone anchor 10.

[0074] Each pair of stationary or fixed arms 234a, 234b for rod reduction may include a window 225 formed in the arm to allow observation of the set screw as it is screwed into the bone anchor during tightening and loosening. As shown, the window 225 may be formed as a narrow slit extending along the length of the stationary arms 234a, 234b to allow visibility of the set screw or another instrument as it progresses through the reducer instrument 200 to engage with the bone anchor. The window 225 may extend more distally than the window 125 in Figure 1 to allow better visibility of the set screw when it is tightened into the bone anchor. In some embodiments, the size of the window 225 may vary based on the size of the inner sleeve 204, e.g., its diameter, length, thickness, etc. For example, as discussed above with respect to Figures 6-8, the size of the inner sleeve 204 may vary with respect to the size of the corresponding window, but in some embodiments, windows of different sizes may be formed in different sizes of inner sleeves in various combinations to provide the best visibility of the set screw.

[0075] The outer sleeve 202 may include a substantially tubular central portion terminating at the first and second extensions or arms 212a, 212b. The extensions 212a, 212b may include side walls 233 extending from the inner surface 232 at the lateral ends of each arm 212a, 212b. The side walls 233 may include a tapered profile to assist in alignment with the receiving member of the bone anchor. The outer sleeve 202 has a distal pocket 231 formed between the opposing arms 212a, 212b that corresponds to and can be connected to the receiving member of the bone anchor 10.

[0076] Figure 34 illustrates a reducer device 200 that docks to a bone anchor 10 and reduces a spinal fixation rod 16. Arms 212a and 212b can engage with the bone anchor 10, and the spinal rod 16 can be positioned laterally through the outer sleeve 202 between arms 212a and 212b, and distal to the stationary arms 234a and 234b of the inner sleeve 204, such that distal advance of the inner sleeve 204 causes the stationary arms 234a and 234b to translate distally and bring into contact with the spinal rod 16. Further distal advancement translates the inner sleeve 204 through the outer sleeve 202, pushing the spinal rod distally toward the bone anchor until the spinal rod is reduced into the rod seat of the receiving member of the bone anchor 10.

[0077] In some cases, the reducer device may unintentionally disengage from the bone anchor as a result of the arms 212a, 212b spreading outward when the reducer device is subjected to certain loading conditions during use. In some embodiments, the distal portions of the arms 212a, 212b may have increased thickness, resulting in an increased outer diameter further toward the distal ends of the arms 212a, 212b. This can increase the rigidity and strength of the arms, which can help resist unintended arm spreading and possible disengagement from the bone anchor during use. Alternatively or additionally, the side walls 233 extending from the inner surface 232 of each arm 212 may include one or more extending portions 235 projecting inward into the channel 208 and distal pocket 231. Each extending portion 235 may form a notch 237 between the extending portion and the inner surface 232, the notch may be configured to receive a portion of the bone anchor therein. Figure 35 shows that the extensions 235 can be formed on both sides of each arm 212. The creation of the notches 237 provides multiple contact points between the arm 212 and the bone anchor to which it is engaged.

[0078] Figures 36–40 illustrate the interaction between the notch 237 and the bone anchor receiving member when connecting the reducer device 200 to the bone anchor. As shown in the detailed perspective view of Figure 36, the proximal portion of the bone anchor receiving member 240 can be received within the notch 237 created between the inner surface 232 and the extended portion 235 of the arm 212. The spreading force biases the arm 212 radially outward relative to the bone anchor receiving member 240, so that the radially inwardly positioned extended portion 235 of one of the opposing arms 242 of the bone anchor receiving member can effectively resist any relative movement between the outer sleeve arm 212 and the receiving member 240. The bone anchor receiving member 240 may include one or more notches 239 formed at the lateral ends of its opposing arms 242, which can be configured to receive the extended portion 235 without reducing the width of the rod slot opening between the opposing arms 242 of the receiving member 240. When positioned as shown in Figure 36, the reducer device 200 prevents the arm 212 from spreading by having its extended portion 235 abut against the side wall of the corresponding bone anchor notch 239, so that it can withstand high loads in different directions, such as the loads that occur during spinal rod reduction, without being disconnected from the bone anchor 10.

[0079] Figure 37 illustrates a side view of a reducer device 200 connected to a bone anchor 10 to reduce a spinal fixation rod 16. As shown in this figure, the outer sleeve 202 includes a rod capture opening 224 between the arms 212a, 212b, which is wider along its proximal portion and tapers to a narrower width distally. This configuration allows for greater tolerance to rotation and / or lateral displacement of the rod and the reducer device, which can be corrected incrementally as the rod is reduced axially toward the bone anchor. In some embodiments, the transition between the wider and narrower widths of the rod capture opening can be made incrementally or smoothly to prevent the rod from being constrained to a more abrupt transition (e.g., a stepwise transition or a small-diameter curve transition).

[0080] Figure 38 illustrates a cross-sectional view of the reducer device 200 and bone anchor 10 cut along line AA in Figure 37. Similar to Figure 36, it can be seen that the extension portion 235 is located within a notch 239 formed on the lateral edge of the bone anchor receiving member 240, which means that the opposing arm of the receiving member 240 is located within a notch 237 formed between the extension portion 235 of the arm 212 and the inner surface 232 (obscured in this figure). This creates a backstop, thereby allowing the extension portion 235 to resist forces that pull the arm 212 radially (into the plane of the page in this figure) away from the receiving member 240.

[0081] Figure 39 illustrates a cross-sectional view of the reducer device 200 and bone anchor 10 cut along line BB in Figure 37. Similar to Figures 36 and 38, the configuration of the extension 235 for creating a notch 237 between the inner surface 232 of the arm 212 and the extension itself is shown. Also shown is a portion of the bone anchor receiving member arm 242 positioned within the notch 237 so that the extension 235 can resist any radially outward (left and right in this figure, in the plane of the page) force that could cause the arm 212 to disengage from the receiving member of the opposing arm 242. Finally, the figure also shows that the extension 235 is housed within a notch 239 formed within the opposing arm 242 of the receiving member 240 so as not to reduce the width W of the rod slot. This configuration is repeated at each lateral edge of each arm 212.

[0082] As discussed above with respect to Figure 5, the distal translation member 222 may include a first stationary or fixed arm 234a and a second stationary or fixed arm 234b extending distally therefrom to perform rod reduction. For example, the arms 234a, 234b may contact and support the spinal rod to bias it distally as the inner sleeve 204 translates distally within the reducer device 200. The arms 234 may include distal contact surfaces 234s1, 234s2 that can be configured to abut and / or otherwise engage with the spinal rod during reduction of the reducer device 200 to advance the spinal rod distally into the bone anchor 10. As shown, the translation member 222 may taper distally toward substantially flat distal contact surfaces 234s1, 234s2 as shown in Figure 40. However, in some embodiments, other distal contact surface shapes may be utilized. For example, in some embodiments, the distal contact surfaces 234s1 and 234s2 of the arms 234a and 234b can be molded to match the shape of the rod in which the inner sleeve 204 is used. As shown in Figure 41, for example, the arms 234a and 234b may include contact surfaces 234s1' and 234s2' (not shown in the side view of the figure) which are concave in shape and have a diameter approximately equal to the diameter of the rod.

[0083] As described above with respect to Figure 34, the translational member 222 can be configured to advance distally without rotation in order to advance the spinal rod into the receiving member 240. As shown in Figure 42, in order to prevent unwanted rotation of the inner sleeve 204 relative to the outer sleeve 202, a longitudinal groove 223 formed in the translational member 222 (see Figure 40) can be fitted with a cam-shaped semicircular surface or nub 227 below the lever pivot point to prevent rotation of the translational member during retraction. The nub 227 can extend from the surface of the arm 206 through an opening recess and ride on the longitudinal groove 223, allowing it to translate while preventing rotation of the translational member 222 relative to the outer sleeve 202.

[0084] Figures 43–45 illustrate alternative embodiments of the reducer device 200'. The reducer device 200' may include alternative designs of pivot arms 206a', 206b' without the nub 227. As shown in Figure 44 illustrating the reducer device 200' without the outer sleeve 202', the pivot 227' of the pivot arms 206a', 206b' is flattened compared to the nub 227 of the reducer device 100. Furthermore, as shown in Figure 45, the pivot arm 206' of the reducer device 200' does not extend into the channel 223' of the inner sleeve 204'. To prevent rotation of the inner sleeve 204', the reducer device 200' includes one or more pins 242' positioned in one or more bores formed in the outer sleeve 202', such that the pins extend into the channel 223' of the inner sleeve 204'. One or more pins can be positioned proximal or distal to the pivot 227' at a distal position of the threads formed in the outer sleeve 202', so as to be able to receive them in the groove 223' without interfering with the threaded connection between the outer sleeve and the inner sleeve 204. More specifically, one or more pins 242' can ride in a key or groove 223' formed in the translation member 222' of the inner sleeve 204', as shown in Figure 44, to prevent rotation of the translation member 222' relative to the outer sleeve 202'. When in use, such as when docking the reducer device 200' to the bone anchor 10, the pivot arms 206a', 206b' can bend outward as they pass over the receiving member 240, and can also bend inward to engage with a notch or other feature formed on the outer surface of the receiving member 240.

[0085] Figure 46 illustrates an alternative embodiment of the inner sleeve 304. The inner sleeve 304 may include a threaded member 320, a translational member 322, and a washer 324, for example, a thrust washer that can be separated and act as a bearing surface between the translational member 322 and the threaded member 320. As shown, the inner sleeve 304 may include an integrated handle 326 at the proximal end of the threaded member 320. The handle 326 can be formed integrally with the threaded member 320 to provide a single unit. The handle 326 can be configured for a user to grip and rotate the threaded member 320. In this way, the integrated handle 326 can replace the modular drive features (e.g., flat features, hexagonal features, etc.) of the reducer devices 100, 200 to allow direct operation of the inner sleeve without the need for any additional tools. As described above, any of the various handle configurations or other structures can be connected to threaded members in any of the various modular or permanent forms. Such connections may include the use of modular connecting features such as the hexagonal drive feature 402, integrally formed structures such as the integrated handle 326 and threaded member 320, and joining components with set screws, or other connecting methods such as other mechanical fasteners, adhesive components, or welded components.

[0086] In addition, the handle 326 may include a lumen 328 extending through its interior to allow the introduction of a set screw or other device into the bone anchor connected to the reducer device. The lumen 328 may extend through the integrated handle 326 and the threaded member 320. In embodiments where a modular handle is used, a lumen may also be included that, when connected to the threaded member, can be aligned with the lumen of the threaded member to allow the introduction of a set screw or other device through its interior. Thus, the methods described above (for example, in relation to Figures 18 to 21) can be used with embodiments that include both modularly connected handles and integrally formed and / or permanently connected handles.

[0087] The instruments disclosed herein may be composed of any of a variety of known materials. Exemplary materials include metals such as stainless steel, titanium, nickel, cobalt-chromium, or alloys and combinations thereof; polymers such as PEEK; ceramics; carbon fiber; and other materials suitable for use in surgical applications. Furthermore, a variety of manufacturing methods may be utilized, including 3D printing or other additive manufacturing techniques, as well as more conventional manufacturing techniques such as molding, stamping, casting, and machining.

[0088] The devices and methods disclosed herein can be used in minimally invasive surgery and / or incisional surgery. Although the devices and methods disclosed herein are generally described in the context of surgery in human patients, it will be understood that the methods and devices disclosed herein can be used in any human or animal subject in any variety of surgical or non-surgical procedures.

[0089] The devices disclosed herein may be designed to be discarded after a single use or to be designed for multiple uses. However, in either case, the devices may be reconditioned for reuse after at least one use. Reconditioning may include any combination of disassembly, subsequent cleaning or replacement of specific parts, and subsequent reassembly. Specifically, the device or components may be disassembled, and any number of specific parts or components of the device may be selectively replaced or removed in any combination. After the specific parts have been cleaned and / or replaced, the device may be reassembled for subsequent use either in a reconditioning facility or by a surgical team immediately before surgical intervention. Reconditioning of the device or components may utilize a variety of techniques for disassembly, cleaning / replacement, and reassembly. The use of such techniques and the resulting reconditioned devices are all within the scope of this application.

[0090] The devices described herein can be treated before use in surgical procedures. For example, new or used instruments or components can be obtained and cleaned as necessary. Instruments or components can be sterilized. In one sterilization technique, instruments or components can be placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and its contents can then be placed in a radiation field that can penetrate the container, such as gamma rays, X-rays, or high-energy electrons. The radiation can kill bacteria on the instruments or components and within the container. The sterilized instruments or components can then be stored in the sterilized container. The sealed container can keep the instruments or components sterile until opened in a medical facility. Other forms of sterilization are also possible, including beta rays or other forms of radiation, ethylene oxide, steam, or liquid baths (e.g., cryo-immersion). Depending on the materials used, the presence of electrical components, etc., certain forms of sterilization techniques may be more suitable for use on different parts of the device.

[0091] In this disclosure, phrases such as “at least one of ~” or “one or more of ~” may appear following a contiguous list of elements or features. The term “and / or” may also appear in lists of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it is used, such phrases are intended to mean any of the enumerated elements or features individually, or any of the enumerated elements or features in combination with any of the other enumerated elements or features. For example, “at least one of A and B,” “one or more of A and B,” and “A and / or B” are intended to mean “A alone, B alone, or A and B together,” respectively. The same interpretation is intended for lists containing three or more items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, and / or C" are intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together," respectively. In addition, the use of the term "based on" is intended to mean "at least partially based on," so that features or elements not listed are also acceptable.

[0092] Further features and advantages based on the embodiments described above are possible and are within the scope of this disclosure. Therefore, this disclosure is not limited to what is specifically shown and described. All publications and references cited herein are incorporated herein in their entirety by reference, except for any definitions, waivers of subject matter, or denials, and unless the incorporated references conflict with the express disclosures herein, in which case the language in this disclosure shall prevail.

[0093] Examples of the embodiments described above may include the following: 1. Surgical instruments, An outer sleeve having an internal channel defined therein, terminating at a pair of extensions at its distal end, An inner sleeve having a proximal threaded portion and a distal translational portion, configured to pass through an outer sleeve, A pair of pivot arms, which are received within the extended portion of the outer sleeve, and which extend within the channel and are configured to connect the bone anchor to the outer sleeve, are included. A surgical instrument comprising one or more flat portions configured to engage with another instrument, with the proximal end portion of the outer sleeve being a flat portion. 2. The apparatus according to claim 1, wherein the pivot arm is fitted with a spring so as to bias it to the closed position. 3. The apparatus according to any one of claims 1 to 2, wherein the threaded portion includes a first threaded portion and a second threaded portion, separated by a non-threaded portion. 4. The apparatus according to any one of claims 1 to 3, wherein the threaded portion is configured to be pulled and rotated in order to be removed from the outer sleeve. 5. The apparatus according to any one of claims 1 to 4, wherein the proximal end portion of the outer sleeve includes a circumferential groove. 6. The apparatus according to any one of claims 1 to 5, wherein the pair of pivot arms further comprises nubs extending into one or more longitudinal grooves of the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion of the outer sleeve. 7. The apparatus according to any one of claims 1 to 5, further comprising pins extending into one or more longitudinal grooves in the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion. 8. The apparatus according to any one of claims 1 to 7, further comprising a counter torque device having a fitting feature corresponding to one or more flat portions on an outer sleeve. 9. The apparatus according to any one of claims 1 to 8, further comprising a rotation release sleeve defining a lumen passing through the interior, wherein the rotation release sleeve is configured to connect to an outer sleeve, and the rotation release sleeve has one or more engaging surfaces that overlap one or more flat portions to facilitate connection. 10. The apparatus according to claim 9, wherein the rotation release sleeve further comprises a pair of hinged arms configured to extend into the lumen for further connecting the rotation release sleeve to an outer sleeve. 11. The apparatus according to claim 10, wherein the rotation release sleeve further comprises a locking ring configured to selectively restrict the movement of a hinged arm. 12. The apparatus according to claim 10, wherein a hinged arm is received in a circumferential groove along an outer sleeve. 13. Surgical instruments, A housing having a central opening, a proximal end, a distal end, and a longitudinal central axis (Al) extending between the proximal and distal ends, First and second fixing arms extending distally from the housing, First and second pivot arms movably connected to a housing, each pivot arm having a proximal end and a distal end, and configured to selectively hold a bone anchor between them, The housing comprises a reducer shaft that is screwed into the central opening, A surgical instrument comprising first and second arms, each extending distally from a housing, defining an inner surface, and each of the first and second arms including a side wall extending outward from the inner surface at the lateral end of each arm. 14. The apparatus according to claim 13, wherein the inner surfaces of each of the first and second arms have a conical tapered profile. 15. The apparatus according to any one of claims 13 to 14, wherein the opposing inner surfaces of each side wall of the arm have a planar tapered profile. 16. The apparatus according to any one of claims 13 to 15, wherein the pivot arm is mounted in a recess formed within the fixed arm. 17. The apparatus according to any one of claims 13 to 16, wherein the pivot arm is pivotably connected to the housing at a position midway between the proximal and distal ends of the pivot arm. 18. The apparatus according to any one of claims 13 to 17, wherein the reducer shaft comprises a first portion, the first portion having a male thread, and is configured to rotate relative to the housing to advance the reducer shaft distally relative to the housing. 19. The apparatus according to claim 18, wherein the reducer shaft comprises a second portion rotatably fixed to the housing, the second portion comprising a rod engaging surface facing distally. 20. The apparatus according to claim 19, wherein the first portion includes one or more inwardly facing projections that are received in a circumferential groove formed on the outer surface of the second portion. 21. The apparatus according to any one of claims 13 to 20, wherein the reducer shaft defines a working channel extending through the interior. 22. The apparatus according to any one of claims 13 to 21, wherein the distal end portion of the reducer shaft includes a visualization window formed therein. 23. The apparatus according to any one of claims 13 to 21, wherein the reducer shaft is provided with a drive interface at the proximal end of the reducer shaft. 24. The apparatus according to any one of claims 13 to 21, wherein the reducer shaft comprises a handle configured to be grasped by a user at its proximal end. 25. The apparatus according to any one of claims 13 to 23, further comprising a rotation release shaft that can be selectively attached to the reducer shaft. 26. The apparatus according to claim 25, wherein the rotation release shaft comprises an elongated body defining a working channel extending through its interior, the working channel of the rotation release shaft communicating with the working channel of the reducer shaft and the central opening of the housing. 27. The device according to claim 25, wherein the rotation release shaft includes opposing hinged arms and a locking ring, the locking ring being movable between a locking position in which the locking ring maintains the hinged arms in a radially inward position in which the hinged arms engage with a groove formed in the housing, and a release position in which the hinged arms can move radially outward to disengage from the groove in the housing. 28. The apparatus according to claim 25, wherein the rotation release shaft is provided with a drive interface at the proximal end of the rotation release shaft. 29. The apparatus according to any one of claims 13 to 28, wherein the side wall includes an extended portion, and the extended portion forms a notch between each extended portion and the inner surface. 30. The device according to claim 29, wherein the notch is configured to receive a portion of the bone anchor. 31. The apparatus according to any one of claims 13 to 30, wherein the reducer shaft includes a substantially flat distal surface configured to engage with a spinal rod. 32. The apparatus according to any one of claims 13 to 30, wherein the reducer shaft includes a concave distal surface configured to engage with a spinal rod.

[0094] [Implementation Method] (1) Surgical instruments, An outer sleeve having an internal channel defined therein, terminating at a pair of extensions at its distal end, An inner sleeve having a proximal threaded portion and a distal translational portion, configured to pass through the outer sleeve, A pair of pivot arms, which are received within the extended portion of the outer sleeve, and which extend into the channel and are configured to connect a bone anchor to the outer sleeve, are provided. A surgical instrument wherein the proximal end portion of the outer sleeve includes one or more flat portions configured to engage with another instrument. (2) The apparatus according to Embodiment 1, wherein the pivot arm is fitted with a spring so as to bias it to the closed position. (3) The apparatus according to Embodiment 1, wherein the threaded portion includes a first threaded portion and a second threaded portion, separated by a non-threaded portion. (4) The device according to Embodiment 1, wherein the threaded portion is configured to be pulled and rotated in order to be removed from the outer sleeve. (5) The apparatus according to Embodiment 1, wherein the proximal end portion of the outer sleeve includes a circumferential groove.

[0095] (6) The apparatus according to Embodiment 1, wherein the pair of pivot arms further comprises nubs extending into one or more longitudinal grooves of the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion of the outer sleeve. (7) The apparatus according to Embodiment 1, further comprising pins extending into one or more longitudinal grooves of the distal translation portion of the inner sleeve in order to prevent rotation of the distal translation portion. (8) The apparatus according to Embodiment 1, further comprising a counter torque device having a fitting feature corresponding to one or more flat portions on the outer sleeve. (9) The apparatus according to Embodiment 1, further comprising a derotation sleeve that defines a lumen passing through the interior, wherein the derotation sleeve is configured to connect to the outer sleeve, and the derotation sleeve has one or more engaging surfaces that overlap with one or more flat portions to facilitate connection. (10) The apparatus according to embodiment 9, wherein the rotation release sleeve further comprises a pair of hinged arms configured to extend into the lumen for further connecting the rotation release sleeve to the outer sleeve.

[0096] (11) The apparatus according to embodiment 10, wherein the rotation release sleeve further comprises a locking ring configured to selectively restrict the movement of the hinged arm. (12) The apparatus according to embodiment 10, wherein the hinged arm is received in a circumferential groove along the outer sleeve. (13) Surgical instruments, A housing having a central opening, a proximal end, a distal end, and a longitudinal central axis (Al) extending between the proximal end and the distal end, First and second fixing arms extending distally from the housing, First and second pivot arms movably connected to the housing, each pivot arm having a proximal end and a distal end, and configured to selectively hold a bone anchor between them, The housing comprises a reducer shaft that is screwed into the central opening of the housing, A surgical instrument in which each of the first and second arms, which extend distally from the housing, defines an inner surface, and each of the first and second arms includes a side wall that extends outward from the inner surface at the lateral end of each arm. (14) The apparatus according to embodiment 13, wherein the inner surfaces of each of the first and second arms have a conical tapered profile. (15) The apparatus according to embodiment 13, wherein the opposing inner surfaces of each side wall of the arm have a planar tapered profile.

[0097] (16) The apparatus according to embodiment 13, wherein the pivot arm is mounted in a recess formed within the fixed arm. (17) The apparatus according to embodiment 13, wherein the pivot arm is pivotably connected to the housing at a position midway between the proximal end and the distal end of the pivot arm. (18) The apparatus according to embodiment 13, wherein the reducer shaft comprises a first portion, the first portion having a male thread, and is configured to rotate relative to the housing to advance the reducer shaft distally relative to the housing. (19) The apparatus according to embodiment 18, wherein the reducer shaft comprises a second portion rotatably fixed to the housing, the second portion comprising a rod engagement surface facing distally. (20) The apparatus according to embodiment 19, wherein the first portion includes one or more inwardly facing projections that are received in a circumferential groove formed on the outer surface of the second portion.

[0098] (21) The apparatus according to embodiment 13, wherein the reducer shaft defines a working channel extending through the interior. (22) The apparatus according to embodiment 13, wherein the distal end portion of the reducer shaft includes a visualization window formed therein. (23) The apparatus according to embodiment 13, wherein the reducer shaft is provided with a drive interface at the proximal end of the reducer shaft. (24) The apparatus according to embodiment 13, wherein the reducer shaft has a handle configured to be grasped by a user at its proximal end. (25) The apparatus according to embodiment 13, further comprising a rotation release shaft that can be selectively attached to the reducer shaft.

[0099] (26) The apparatus according to embodiment 25, wherein the rotation release shaft comprises an elongated body defining a working channel extending through its interior, and the working channel of the rotation release shaft communicates with the working channel of the reducer shaft and the central opening of the housing. (27) The device according to embodiment 25, wherein the rotation release shaft includes opposing hinged arms and a locking ring, the locking ring being movable between a locking position in which the locking ring maintains the hinged arms in a radially inward position in which the hinged arms engage with a groove formed in the housing, and a release position in which the hinged arms can move radially outward to disengage from the groove in the housing. (28) The apparatus according to embodiment 25, wherein the rotation release shaft is provided with a drive interface at the proximal end of the rotation release shaft. (29) The apparatus according to embodiment 13, wherein the side wall includes an extended portion, and the extended portion forms a notch between each extended portion and the inner surface. (30) The device according to embodiment 29, wherein the notch is configured to receive a portion of the bone anchor.

[0100] (31) The apparatus according to embodiment 13, wherein the reducer shaft includes a substantially flat distal surface configured to engage with a spinal rod. (32) The apparatus according to embodiment 13, wherein the reducer shaft includes a concave distal surface configured to engage with a spinal rod.

Claims

1. Surgical instruments, An outer sleeve having an internal channel defined therein, terminating at a pair of extensions at its distal end, An inner sleeve having a proximal threaded portion and a distal translational portion, configured to pass through the outer sleeve, A pair of pivot arms, which are received within the extended portion of the outer sleeve, and which extend into the channel and are configured to connect a bone anchor to the outer sleeve, are provided. The proximal end portion of the outer sleeve includes one or more flat portions configured to engage with another device, A surgical instrument wherein the first pivot arm of the pair of pivot arms is provided with a first nub extending into a first longitudinal groove of the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion of the outer sleeve, and the first portion of the first nub extending into the first longitudinal groove is located longitudinally at the same position as the first fulcrum on which the first pivot arm rotates.

2. The apparatus according to claim 1, wherein the first fulcrum is located near the first nub.

3. The apparatus according to claim 1 or 2, wherein the second pivot arm of the pair of pivot arms includes a second nub extending into a second longitudinal groove of the distal translation portion of the inner sleeve to prevent rotation of the distal translation portion of the outer sleeve, and the second portion of the second nub extending into the second longitudinal groove is located in the same position in the longitudinal direction as the second fulcrum on which the second pivot arm rotates.

4. The device according to claim 3, wherein the second fulcrum is located near the second nub.

5. The device according to claim 1, wherein the pivot arm is fitted with a spring so as to bias it to the closed position.

6. The apparatus according to claim 1, wherein the proximal threaded portion includes a first threaded portion and a second threaded portion, separated by a non-threaded portion.

7. The device according to claim 1, wherein the proximal threaded portion is configured to rotate while being pulled in order to be removed from the outer sleeve.

8. The apparatus according to claim 1, wherein the proximal end portion of the outer sleeve includes a circumferential groove.

9. The apparatus according to claim 1, further comprising a counter torque device having fitting features corresponding to one or more flat portions on the outer sleeve.

10. The apparatus according to claim 1, further comprising a rotation release sleeve that defines a lumen passing through the interior, wherein the rotation release sleeve is configured to connect to the outer sleeve, and the rotation release sleeve has one or more engaging surfaces that overlap with one or more flat portions to facilitate connection.

11. The apparatus according to claim 10, wherein the rotation release sleeve comprises a pair of hinged arms, each of which includes a body having a projection, the projection pivoting radially inward so as to enter the lumen.

12. The apparatus according to claim 11, wherein the rotation release sleeve further comprises a locking ring configured to restrain the movement of the hinged arm.

13. The device according to claim 11, wherein the hinged arm is received in a circumferential groove formed on the outer surface of the outer sleeve and which is circular in a plane perpendicular to the longitudinal direction.

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