Patent Description:
In some minimally invasive spinal surgeries, bone plates may be secured onto an outer surface of a vertebra or vertebrae of the spine as part of a complete repair. Bone plates may be used to provide supplemental fixation and to ensure that an interbody implant remains in its intended position between vertebrae by blocking a pathway out of the disc space thereby preventing backout of the interbody. This manner of usage is common in lateral lumbar interbody fusion procedures.

To secure bone plates to the spine, existing procedures tend to be cumbersome and involve multiple instruments. For example, in one known approach, a bone plate, also known as a buttress plate, is secured to a buttress plate inserter which is then used to position the bone plate on a vertebral body. Then, in a separate step, a shaft of an awl instrument is inserted through the buttress plate inserter to create a pilot hole for a bone screw to be placed through the bone plate. In other known approaches, the buttress plate inserter may be removed after placement of the bone plate, and again in a separate step, an awl instrument is inserted through the bone plate to create a pilot hole. In either of these approaches, the buttress plate inserter is removed from the bone plate prior to screw insertion into the vertebra.

Because existing approaches involve separate instruments and steps for bone plate placement and pilot hole creation for receipt of a bone plate screw, the time required to switch instruments for each step tends to lengthen the duration of the surgical procedure, which may lead to increased blood loss in a patient. Additionally, surgery of a longer duration may reduce retraction time on the nerves of the patient, which may cause leg numbness.

Thus, a need exists for improved surgical instrumentation and methods of using surgical instrumentation for the placement of bone plates on the spine.

Document <CIT> discloses methods for forming or enlarging holes in bone tissue and methods for fixing medical plates to bodies. Document <CIT> discloses an instrument for use in the implantation of a rod connector. An awl is provided with the instrument to make a keyway for a bone anchor in the bone of the patient.

The present disclosure relates to a system that includes a plate holder that is engageable with an awl. According to the invention, the system is for placing a bone plate onto a bone and includes a plate holder and an awl that is releasably engaged to the plate holder. The plate holder extends from a first end to a second end and includes an engagement feature at the second end. The engagement feature is engageable with the bone plate. The awl includes a locking mechanism adjustable from a first setting to a second setting and a tip. When the locking mechanism is in the first setting, the awl is fixed relative to the plate holder and the tip is disposed within the plate holder. When the locking mechanism is in the second setting, the awl is axially translatable relative to the plate holder such that the tip of the awl is extendable out of the second end of the plate holder.

In some examples, the releasable engagement between the awl and the plate holder may be provided by a first engagement feature on the awl and a second engagement feature on the plate holder. The first and second engagement features may be engageable with one another and disengageable from one another. In some examples, the awl may include a shaft and a housing surrounding the shaft.

Still according to the invention, the locking mechanism may be on the housing and include a pin. The pin may be biased in a first position when the locking mechanism is in the first setting and may be displaced from the first position into a second position such that the locking mechanism is in the second setting. Displacement into the second position may be through application of load onto the locking mechanism. In some examples, the locking mechanism may include a spring at one end of the pin to keep the locking mechanism in the first setting unless load is applied to displace the locking mechanism. In some examples, the shaft may include a slot oriented along a length of the shaft and the pin may be disposed in the slot such that when the locking mechanism is in the first setting, a ridge protruding from the pin prevents axial movement of the awl. In some examples, the ridge may be dimensioned such that when the locking mechanism is in the second setting, the ridge does not prevent axial movement of the awl. In some examples, the locking mechanism may be a button and the shaft of the awl passes through an opening through the button. In some embodiments, the button may rest on a locking spring disposed internally within the housing of the awl. In some examples, the button may be translatable along an axis that is orthogonal to a longitudinal axis of the shaft of the awl. In some examples, the system may also include a compression spring disposed in between the housing of the awl and the shaft of the awl. The compression spring may be centered along a longitudinal axis of the shaft such that the compression spring changes in length when the shaft moves axially relative to the plate holder.

The awl may include a cap attached to an end of the shaft opposite the tip, the cap sized for impaction by an impaction instrument. In some examples, the plate holder may include a plate gripper and a handle that surrounds the plate gripper. In some examples, the handle of the plate holder may include an interior surface that defines a lumen of the handle, the second engagement feature disposed on the interior surface.

In another embodiment, a system includes a plate holder with a first engagement feature and an awl with a second engagement feature engaged with the first engagement feature. The plate holder includes a body that extends from a proximal end to a distal end and two arms that extend distally from the distal end. The awl includes a housing and a shaft disposed in the housing. The housing includes the second engagement feature and the shaft includes a sharp tip. When the second engagement feature is engaged to the first engagement feature, the awl device is partially disposed within the plate holder body, the shaft is axially translatable relative to the plate holder body, and the two arms of the plate holder are engageable with a bone plate. Additionally, the awl device is disengageable from and reengagable with the plate holder.

In some examples, the first engagement feature may be a protrusion on a surface of a cannulated handle that surrounds the body of the plate holder and the second engagement feature may be knurling on the housing of the awl. In some examples, when the first engagement feature is engaged with the second engagement feature, at least a portion of the housing may be external to the handle of the plate holder. In some examples, each of the two arms of the plate holder may include protrusions at respective free ends of the two arms, the protrusions facing each other. In some examples, the body of the plate holder may include slits that separate the body into two parts at the distal end, each part including one of the two arms. In some examples, the plate holder may include a sleeve surrounding a portion of the body, the sleeve being translatable along a length of the body to control a distance between the two arms.

In another aspect, the present disclosure relates to a kit that includes instrumentation and bone plates for bone plate placement onto a bone. In one example, a kit includes a plate holder, an awl and a bone plate. The plate holder includes a first engagement feature and a second engagement feature. The awl includes a third engagement feature engaged with the first engagement feature. The bone plate includes a fourth engagement feature engageable with the second engagement feature. The awl includes a locked setting and an unlocked setting. The locked setting fixes the awl relative to the plate holder along a longitudinal axis of the awl. The unlocked setting allows movement of the awl relative to the plate holder along the longitudinal axis of the awl when the awl is subject to an impaction force.

In some examples, the third engagement feature of the awl may be on a housing of the awl, the housing being cannulated such that a shaft of the awl passes entirely therethrough. In some examples, the plate holder may have a length extending between two ends and the first engagement feature is located at one of the two ends. In some examples, the awl may have a length extending between two ends and the third engagement feature is located between the two ends.

In some examples, the plate holder may have a length that extends from a first end to a second end such that the first engagement feature is at the first end and the second engagement feature is at the second end. In some examples, the third engagement feature may be formed on a housing of the awl. The housing may be cannulated with a shaft of the awl disposed entirely therethrough such that the shaft extends out of the housing from two sides of the housing. In some examples, the awl may include a button adjustable to toggle the awl between the locked and unlocked settings, the shaft of the awl passing through an opening in the button. In some examples, the shaft may include a slot having a length along a longitudinal axis of the shaft, a portion of the button passing through the slot such that the length of the slot defines a range of axial translation of the shaft of the awl relative to the housing of the awl. In some examples, the kit may include a screw insertion tool with a driver sized to pass through a cannulation of the plate holder. In some examples, the kit may include a bone screw sized for engagement by the screw insertion tool.

The present disclosure relates to a method (not claimed) of placing a bone plate onto a bone surface of a patient using an instrument. In one example, the method involves using an instrument that includes a plate holder and an awl engaged to the plate holder. The steps of the method include: engaging a first engagement feature of the instrument with a second engagement feature of the bone plate; positioning the bone plate on the bone surface by manipulating the instrument; applying a first impaction force onto a second end of the instrument opposite a first end of the instrument to achieve purchase of the bone plate with the bone surface, the second end remaining fixed relative to the first end during application of the first impaction force; toggling a locking mechanism on the instrument from a first setting in which a shaft of the awl is fixed relative to the plate holder to a second setting; and applying a second impaction force onto the second end of the instrument while the locking mechanism is in the second setting, the second end of the instrument temporarily moving closer to the first end of the instrument during application of the second impaction force. The shaft of the awl used in the method includes a cutting tip such that application of the second impaction force causes the cutting tip of the awl to remove bone from the bone surface.

In some examples, the method (not claimed) may include assembling the instrument prior to the engaging step. Assembly may involve engagement of a third engagement feature of the awl with a fourth engagement feature of the plate holder. In some examples, engaging the third engagement feature with the fourth engagement feature may involve inserting a housing of the awl into a cannulation of a handle of the plate holder. In some examples, toggling the locking mechanism from the first setting to the second setting may involve pressing and holding a button of the locking mechanism, the locking mechanism remaining in the second setting until the button is released. In some examples, applying the second impaction force may cause the shaft of the awl to move relative to the locking mechanism of the awl by an amount defined by a length of a longitudinal slot in the shaft of the awl, a pin of the locking mechanism abutting a first end of the slot prior to application of the second impaction force and abutting a second end of the slot at least momentarily during or after application of the second impaction force.

In some examples, applying the first impaction force may include applying an initial impaction force and a subsequent impaction force that is the same or different from the initial impaction force, both the initial impaction force and the subsequent impaction force being applied while the locking mechanism is in the first setting. In some examples, applying the second impaction force may include applying an initial impaction force and a subsequent impaction force that is the same or different from the initial impaction force, both the initial impaction force and the subsequent impaction force being applied while the locking mechanism is in the second setting. In some examples, the method (not claimed) may include disengaging the awl from the plate holder by rotating the awl relative to the plate holder.

The present disclosure relates to a method (not claimed) of assembling a dual-function instrument. In one example, the method of assembly of a dual-function instrument involves: advancing a first portion of an awl into a cannulation of a plate holder; and engaging the awl with the plate holder to form the dual-function instrument, a second portion of the awl remaining external to the plate holder subsequent to engagement. When the awl is engaged with the plate holder, the plate holder is simultaneously engageable with a bone plate and a sharp tip of the awl is axially translatable out of the plate holder to chip bone material. Additionally, when a locking mechanism on the dual-function instrument is in a first setting, the awl is fixed relative to the plate holder, and when the locking mechanism is in a second setting, the awl is axially translatable relative to the plate holder.

In some examples, engaging the awl with the plate holder may involve rotation of a knurled surface on the awl into an inner surface of the cannulated plate holder, the inner surface having protrusions thereon. In some examples, advancing the awl into the cannulation of the plate holder may involve advancing a housing of the awl surrounding a shaft of the awl into the cannulation of the plate holder such that upon engagement of the awl with the plate holder, a first portion of the housing is within the cannulation of the plate holder and a second portion of the housing is external to the cannulation of the plate holder. In some examples, following advancement of the awl into the cannulation of the plate holder to form the dual-function instrument, a portion of the shaft of the awl may remain external to the cannulation of the plate holder.

The present disclosure will be better understood on reading the following detailed description of non-limiting aspects thereof, and on examining the accompanying drawings, in which:.

As used herein, the term "clinician" refers to a doctor (e.g., a surgeon), a nurse, or any other care provider, and may include support personnel or indeed other users of the contemplated medical instruments, implants and/or other technology described herein.

As used herein in reference to a bone plate or an intervertebral implant, i.e., cage, the term "superior" refers to a portion of the plate or implant nearer the patient's head, while the term "inferior" refers to a portion of the plate or implant nearer the patient's feet, when the implant is implanted in an intended position and orientation. As with the terms "superior" and "inferior," the term "anterior" refers to a portion of the plate or implant nearer the front of the patient, the term "posterior" refers to a portion of the plate or implant nearer the rear of the patient, the term "medial" refers to a portion of the plate or implant nearer the mid-line of the patient, and the term "lateral" refers to a portion of the plate or implant farther away from the mid-line of the patient. Additionally, the term "leading" refers to a portion of the plate or implant that is inserted into the patient ahead of the remainder of the plate or implant while conversely, the term "trailing" refers to a portion of the plate or implant closest to an inserter instrument and is the last part of the plate or implant inserted into the patient.

The present disclosure relates to a combined plate holder and awl system. In one embodiment shown in <FIG>, system <NUM> includes a plate holder <NUM> with an awl <NUM> disposed therein and engaged thereto. We initially turn to the plate holder <NUM> part of system <NUM>.

Plate holder <NUM> is shown in its entirety in <FIG> and in parts in <FIG>. Plate holder <NUM> includes a plate gripper <NUM>, a retention sleeve <NUM>, a bushing <NUM> and a handle <NUM>. As shown in <FIG>, the retention sleeve surrounds a first portion of the plate gripper while both the bushing and the handle surround the plate gripper along a second portion of the plate gripper.

Plate gripper <NUM>, as shown in <FIG>, has a length that extends from a first end <NUM> to a second end <NUM>. When in use, the first end is proximal to the clinician and the second end is distal to the clinician. Plate gripper <NUM> includes a body that is cannulated <NUM> throughout its length. As depicted, plate gripper is cylindrical though in alternative variations it may have other cross-sectional shapes. Adjacent to second end <NUM> is a threaded surface portion <NUM> with external threads extending around an external surface of the plate gripper. Between threaded surface portion <NUM> and second end <NUM> are a pair of slits opposite one another through a wall of plate gripper <NUM>. Each slit includes a slit base 28A, 28B with an oblong shape, each slit base 28A, 28B extending into a slit extension 29A, 29B. Each slit base is separated from second end <NUM> by its respective slit extension 29A, 29B, as best shown in <FIG>. The slits are sized and positioned so that parts of the plate gripper on opposing sides of the slits are movable with respect to each other. At second end <NUM>, opposing parts of plate gripper <NUM> form arms <NUM>, <NUM>, as shown in <FIG>. Each arm <NUM>, <NUM> includes an inward protrusion <NUM>, <NUM> at its free end. As shown in <FIG>, inward protrusions <NUM>, <NUM> face each other.

Surrounding plate gripper <NUM> on the first portion of the plate gripper length is retention sleeve <NUM>, shown surrounding plate gripper in <FIG> and independently in <FIG>. Retention sleeve <NUM> is cannulated and includes a threaded portion <NUM> on its inner surface. Threaded portion <NUM> is dimensioned so that it is engageable with threaded surface portion <NUM> of plate gripper <NUM> to lock retention sleeve <NUM> to plate gripper <NUM>. Further, through the inclusion of a thread-type connection, an axial position of retention sleeve <NUM> relative to plate gripper <NUM> is adjustable through rotation of retention sleeve <NUM> relative to plate gripper <NUM>. The relationship between the retention sleeve and the plate gripper is such that advancement of retention sleeve towards arms <NUM>, <NUM> causes arms to move toward one another and withdrawal of retention sleeve away from arms <NUM>, <NUM> causes arms to move apart until the arms reach a neutral, unloaded position.

Between a position of retention sleeve <NUM> secured to plate gripper <NUM> and first end <NUM> of plate gripper <NUM> are handle <NUM> and bushing <NUM>. Both the plate gripper and the handle are cannulated and each surrounds plate gripper <NUM>. Bushing <NUM>, shown in isolation in <FIG>, is fixedly secured to plate gripper <NUM>, as shown in <FIG>. Fixation of bushing <NUM> to plate gripper <NUM> may be through a weld at an end of the bushing facing second end <NUM> of plate gripper <NUM>. In turn, handle <NUM> is fixed to bushing <NUM> via internal threads <NUM> of handle <NUM> that are engaged with external threads <NUM> of bushing <NUM>. As additional securement, first end <NUM> of plate gripper <NUM> may be fixed to handle <NUM> directly. Such fixation may be in the form of a weld at the first end of the plate gripper.

As shown in <FIG>, an interior surface of handle <NUM> includes various engagement features. In particular, disposed on a groove 46B on the inner surface of handle <NUM> at its trailing end adjacent to first end <NUM> of the plate gripper is a circumferential retaining ring <NUM>. Retaining ring <NUM> fits loosely within groove 46B when no structures are disposed within handle <NUM>. Additionally, further from the trailing end of the handle than the groove are a plurality of pins extending radially inward from the interior surface and spaced apart from one another. The depicted embodiment includes three pins, two of these, pins 49A, 49B, being shown in <FIG>. The pins are fixed relative to handle <NUM> with fixation by weld, for example. As described in greater detail below, the retaining ring and pin features provide one exemplary means of releasable fixation of the awl to the plate holder. It should be appreciated, however, that alternative engagement features for the complementary awl and handle, such as protrusions and/or recesses of various arrangements, are also contemplated.

Turning now to the awl of system <NUM>, awl <NUM> is best shown in <FIG>. Awl <NUM> includes shaft <NUM> and housing <NUM> that surrounds and encloses a portion of shaft <NUM>. Shaft <NUM> of awl <NUM> extends from a cap <NUM> attached to the shaft at a first end and a tip <NUM> at a second end. Although cap <NUM> is shown having a particular shape and size, it is contemplated that in variations the cap may be any shape that allows for receipt of impaction forces. Tip <NUM> includes a cutting feature. The cutting feature is shaped for cutting bone, but in alternative variations, may be adapted for other functions. Awl shaft <NUM> has a generally uniform shape over most of its length, although adjacent to cap <NUM>, includes several structural features for interaction with housing <NUM>. In particular, and as shown in <FIG>, closest to the first end of the awl is a longitudinally extending slot <NUM> through shaft <NUM>. Slot <NUM> forms a path entirely through shaft <NUM> such that an element may be disposed through a full depth of the shaft in a direction orthogonal to a length of shaft, as described in detail elsewhere in the disclosure with respect to pin <NUM>. Shaft <NUM> also includes a recessed portion <NUM> located over an end portion of slot <NUM>. An overall sectional size of shaft <NUM> in recessed portion <NUM> is smaller than on adjacent surfaces of the shaft, as shown in <FIG>. Recessed portion <NUM> extends from a first end 55A to a second end 55B. Slot <NUM> is positioned so that one end of slot <NUM> is within recess <NUM> while an opposite end extends past first end 55A. Shaft <NUM> includes a circumferential protrusion <NUM> at second end 55B of recess <NUM>.

Housing <NUM> of awl <NUM> is best shown in <FIG>. Housing <NUM> includes a longitudinal passageway <NUM> for the disposal of awl shaft <NUM>, a cavity <NUM> that is transverse to longitudinal passageway <NUM>, and an engagement feature <NUM> on its external surface distal to cap <NUM>. In one example, and as shown, engagement feature <NUM> is in the form of a knurled surface with features sized and shaped for engagement with inner surface 46A of housing <NUM>. In some examples, the housing includes an engagement feature with a triple lead groove and is used with a handle that has pins positioned in a complementary manner. In other examples, the engagement feature may be helical threads. Longitudinal passageway <NUM> includes shoulder <NUM> adjacent to a leading end of housing <NUM> such that a portion of longitudinal passageway between shoulder <NUM> and a leading end of housing <NUM> is narrower than a remainder of the passageway, as shown in <FIG>. With awl shaft <NUM> and longitudinal spring <NUM> disposed in longitudinal passageway <NUM>, longitudinal spring <NUM> surrounds awl shaft <NUM> and is held in place by circumferential protrusion <NUM> at one end and shoulder <NUM> at an opposite end. In the depicted embodiment, no additional elements are required to hold spring <NUM> in place within housing <NUM>.

Turning to the elements within cavity <NUM> of housing, a locking spring <NUM> is positioned at a base of cavity <NUM> as shown in <FIG>. In some examples, including for awl <NUM> shown in <FIG>, awl housing <NUM> may include a cleaning slot that provides access to locking spring <NUM> from knurled surface <NUM>. Immediately adjacent to locking spring <NUM> within cavity <NUM> and resting on spring <NUM> is button <NUM>, shown in isolation in <FIG>. Button <NUM> includes a pin <NUM> disposed therein, as shown in <FIG>. Pin <NUM> is fixed relative to button <NUM>. In some examples, fixation may be in the form of a weld. Additionally, button <NUM> includes a transverse passageway <NUM> that defines an enclosed path parallel to a longitudinal axis of the awl shaft when button <NUM> is disposed within cavity <NUM>. At a base of through passageway <NUM> is locking ridge <NUM> which encloses a void that defines a seat <NUM> therein. Aligned with the seat and orthogonal to through passageway <NUM> is pin opening <NUM>, extending from an outer surface of button <NUM> to through passageway <NUM>. Pin opening <NUM> and seat <NUM> are sized and positioned so that pin <NUM>, a generally linear structure, is disposed within both when installed in button <NUM>, as shown in <FIG>. Moreover, when pin <NUM> is disposed in button <NUM>, a base of pin <NUM> is surrounded by locking ridge <NUM>. Slot <NUM> of shaft <NUM> has a width marginally wider than a diameter of pin <NUM>. In this manner, when locking ridge <NUM> is within recess <NUM> and aligned with circumferential protrusion <NUM>, as shown in <FIG>, shaft <NUM> is prevented from moving axially by such alignment. However, when button <NUM> is depressed and locking ridge <NUM> is entirely out of a path of translation of awl shaft <NUM>, i.e., below the shaft in the awl orientation shown in <FIG>, slot <NUM> is axially translatable relative to pin <NUM>. This is described in greater detail in the method of use (not claimed).

Combining plate holder <NUM> with awl <NUM>, components described in detail above, produces system <NUM>, as shown in <FIG>. Through connection of the plate holder and the awl, the system becomes a single all-in-one structure. <FIG> illustrates the location of interconnection between the elements. In particular, engagement feature <NUM> of housing <NUM> is engaged to the inner surface of handle <NUM>, thereby creating a releasably fixed connection between the elements. In the embodiment shown, engagement is based on rotational engagement between engagement feature <NUM> and inner surface 46A of housing. A fixed relationship between the awl and the bone plate holder is established when retaining ring <NUM> is compressed on an outer surface of housing <NUM> and pins 49A-C (not all shown) project from inner surface 46A into recessed surfaces of the knurled surface of engagement feature <NUM>. The above described fixation is not irreversible and the awl may be disengaged by rotation of the awl relative to the plate holder in a direction opposite to that used for engagement.

With the plate holder <NUM> and awl <NUM> fixed to one another as described above, system <NUM> is usable as a single unit during surgery and does not require separate placement of each instrument into the surgical site or any other two step process. When awl <NUM> is fixed to plate holder <NUM>, button <NUM> remains actuatable to control whether the awl is locked or unlocked relative to plate holder <NUM>, i.e., to control whether the awl may translate axially upon application of force to cap <NUM>. Further, in addition to the functions of the awl, the arms of the plate holder remain usable in the combined system. In particular, the arms may be used to engage with an implant, such as a bone plate, for example. In these respects, the system <NUM> when assembled is a dual-function instrument and is advantageous in that it combines two instruments into a single instrument, thereby eliminating the need to switch instruments to perform the bone plate placement and cutting function of the awl. Greater detail regarding the functional features of the system is provided elsewhere in the disclosure in the description of the methods of use (not claimed).

Although described together as part of system <NUM>, it should be appreciated that the present disclosure is also directed to singular structures of the system such as the plate holder, for example.

The plate holder may be varied in many ways. In some examples, the retention sleeve may be non-rotatably engaged to the plate gripper. For example, the retention sleeve may engaged with the plate gripper so that the retention sleeve may be shifted longitudinally without rotation to axially translate the retention sleeve along the plate gripper from a first position to a second position thereby changing the spacing between the arms of the plate gripper. In these examples, the engagement feature may be on an internal surface of the retention sleeve and may be sized to engage with a complementary feature on an external surface of the plate gripper. In some examples, the connection between the retention sleeve and the plate gripper may be snap fit. In another example, the plate holder may have no retention sleeve at all. Instead, the arms at the distal end of the plate gripper may be biased in a closed position and include tapered tips so that upon contact with a plate, the arms may spread apart and then snap into place once disposed within recesses of a bone plate. In other examples, the arms may include outward facing protrusions at their respective free ends. In some examples, the arms may include engagement features facing distally from respective free ends of the arms. In either of these variations, a bone plate to be engaged may have recesses on its surface to complement the engagement features of the arms. In still further examples, the shape of the protrusions, in an applicable direction from the arms, may be any shape suitable to engage with a complementary feature on a bone plate to be engaged. In other examples, the arms may be shaped to engage with implants other than bone plates.

The awl may be varied in many ways. In some examples, the longitudinal spring and/or the locking spring within the awl housing may be a biasing element that is not a spring. In some examples, the axially translatable button, i.e., push-button, may be substituted with a rotatable knob to control whether the awl is in the locked or unlocked position. The knob may include a pin that passes through a slot in the shaft of the awl, as with the depicted embodiment, and may include a threaded engagement with a base outside of the shaft. The pin may include a wider section that is aligned with the awl shaft in the locked position while being out of alignment with the awl shaft in the unlocked position, the change in position being obtained through rotation of the knob. In this manner, the wider section performs a function similar to that of locking ridge in button <NUM>. In still other examples, a setting of the button, i.e., locked or unlocked, in the awl housing may be controlled electronically via a touch screen or other similar means.

Finally, the overall system may be varied in many ways. In some examples, the engagement between the plate holder and the awl may be snap fit so that the awl may be inserted into the opening in the handle of the plate holder in a linear manner. For instance, the plate holder and the awl may include complementary ball and detent components. In some examples, the engagement between the plate holder and the awl may be through an interference fit. For instance, an outer surface of the awl housing may be formed from an elastic material that may be compressed upon advancement into the cannulation of the plate holder housing, and upon release once disposed in the housing, may expand to form a fixed engagement between the awl and the plate holder. In still other examples, the housing of the awl may include an outer wall (outer portion) spaced apart from and enclosing an inner portion of the housing holding the longitudinal spring such that the outer wall is sized to fit around an outer surface of the plate holder handle. In these examples, engagement features on an inner surface of the outer wall are engageable with complementary engagement features on an outer surface of the plate holder handle. When engaged with one another, the circumferential handle structure is disposed in between the outer portion and the inner portion of the awl housing. In some examples, the awl housing may be uniform in size along its length from a leading end to a trailing end. In other examples, the awl housing may have a reverse taper. In these variations, the inner surface of the handle is shaped to complement the shape of the awl housing.

In yet another example, the housing of the awl may be built into the plate holder structure. In particular, each feature of the awl housing, including the longitudinal spring and the button, may be built into the handle of the plate holder. Thus, the only structure engaged to and removed from the plate holder is the awl shaft. With this configuration, the pin of the button is removed in order to place the awl shaft into the plate holder. Then, with the awl disposed in the plate holder, the pin is placed back into engagement with the button to engage the awl to the plate holder. Similarly, to remove the awl from the plate holder, the pin is removed from the button. Thus, the pin may be removably engaged to the button to allow for removal of the awl shaft from the remainder of the system and for engagement of the awl shaft to the remainder of the system.

The dual-function instrument and/or its parts as contemplated herein may be included as part of a kit. In some examples, a kit includes an awl and a plate holder. In some examples a kit includes an awl, a plate holder and a bone plate. In other examples, a kit includes two or more of at least one of an awl, a plate holder and a bone plate. Thus, a kit may include five awls, five plate holders and five bone plates. Another kit may include two awls and two plate holders. In yet another example, a kit may include one awl, one plate holder, and ten bone plates. In another example, a kit may include at least two sizes and/or types of bone plates. In some examples, the kit is limited to including bone plates, while in other examples, the variety of bone plates may be accompanied by one or more awls and plate holders. It should be appreciated that the above examples are illustrative and that any combination of the above components may be used to form a kit.

In some examples, a kit includes an awl, a plate holder and one or more additional surgical instruments, such as instruments used for spinal access in spinal surgery. For example, a kit may include an awl, a plate holder and one or more of a retractor, a driver, a tool to actuate a locking cover on a bone plate, modular instrument handles, screws, implants, and other related components.

The kit may be varied in many ways. For example, the various combinations of elements of any kit contemplated herein may be included in a single package or distributed among multiple packages. In other examples, the kit contemplated herein may be accompanied by an instruction manual on how to perform one or more of the methods of using the contents of the kit.

The present disclosure relates to a method (not claimed) of assembling an awl <NUM> with a plate holder <NUM>. It should be appreciated that the assembly of the awl with the plate holder may also be an initial step in a method of using system <NUM> to fix a bone plate onto a bone, as described separately below. Turning to the details of the assembly process, in one example, shaft <NUM> of awl <NUM> is advanced through cannulation <NUM> of plate gripper <NUM> until housing <NUM> of awl <NUM> contacts inner surface 46A of handle <NUM>. This step commences from a position such as that shown in <FIG>, where advancement of the awl is denoted by reference numeral <NUM>. Once housing <NUM> is in contact with the inner surface of handle <NUM>, awl <NUM> is rotated about its longitudinal axis and relative to plate holder <NUM> to rotate housing <NUM> into an interior of handle <NUM> and thereby engage the awl with the plate holder to form a fixed connection. In particular, the groove of knurling <NUM> on the outer surface of housing <NUM> engages with pins 49A-C protruding from inner surface 46A of housing <NUM> so that each pin sits within the groove as the awl is rotated relative to the housing. Additionally, once the housing approaches its fully inserted position within the handle through the threading of the housing into the handle, retaining ring <NUM>, also on inner surface 46A of housing <NUM>, presses against an outer surface of awl housing <NUM> to form an interference fit between the retaining ring and the awl housing. In some examples, the outer surface of the awl housing at its trailing end may have a groove for receipt of the retaining ring. When the awl housing includes a groove or other engagement feature for the retaining ring, an audible snap is heard along with tactile feedback to the clinician when the retaining ring moves into place in the groove. One advantage of the retaining ring is that it prevents loosening of the awl from the plate holder. Assembly is complete when awl <NUM> is fixed to plate holder <NUM>, as shown in <FIG>. The engagement between the awl and the plate holder is sometimes referred to herein as releasable or detachable because although the awl and plate holder are integrated with one another once assembled, they may also be separated again at a later time. In the above described example, for example, such disassembly involves rotating the awl relative to the plate holder in a direction opposite to that used for assembly.

In some examples, a method of assembly involves assembly of the awl. For example, with awl housing <NUM>, assembly commences with insertion of locking spring <NUM> into a base of cavity <NUM>, as shown in <FIG>. Button <NUM> is then inserted through cavity <NUM> so that button <NUM> rests directly over locking spring <NUM>. With button <NUM> in position within housing <NUM>, longitudinal spring <NUM> is advanced through longitudinal passageway <NUM> and through passageway <NUM> of button <NUM> until it abuts shoulder <NUM>. Next, awl shaft <NUM> is advanced through longitudinal passageway <NUM> until slot <NUM> of shaft <NUM> is aligned with button <NUM>. Then, pin <NUM> is inserted through pin opening <NUM> of button, through slot <NUM> of shaft <NUM>, and finally into seat <NUM>. Pin <NUM> may then be welded into place onto button <NUM>, a final secured position being shown again in <FIG>. Substitutes for welding are also contemplated. Cap <NUM> may be secured to shaft <NUM> at any time during assembly. To secure cap <NUM> to shaft <NUM>, a pin <NUM> may be welded in place to make the connection between the elements, though any other form of fixation may also be used.

In some examples, a method of assembly involves assembly of the plate holder. For example, and as shown in <FIG>, retaining ring <NUM> is snapped into groove 46B on inner surface 46A of handle <NUM>. Pins 49A-C (not all shown) are then placed onto openings in handle <NUM> and secured into place. Securement may be in the form of a weld. Bushing <NUM> is then rotated into engagement with handle <NUM> via complementary threads: Threads <NUM> on the outer surface of bushing <NUM> engaging with threads <NUM> on inner surface 46A of handle <NUM>. In some variations, a medical grade thread lock may be applied to the threads of the bushing to promote locking when the elements are rotatably engaged. Retention sleeve <NUM> is then advanced relative to plate gripper <NUM> through rotation of retention sleeve <NUM> about its axis over plate gripper <NUM> until inner threads <NUM> of retention sleeve <NUM> are axially aligned with threaded surface portion <NUM> on plate gripper <NUM> and part of retention sleeve <NUM> is distal to threaded surface portion <NUM>. Combined handle <NUM> and bushing <NUM> are then slid over plate gripper <NUM> on a proximal side of plate gripper <NUM>. Retention sleeve <NUM> and handle <NUM> are shown positioned on plate gripper <NUM> in <FIG>. Handle <NUM>, when properly positioned on plate gripper <NUM>, is then fixed to the plate gripper. In some examples, fixation may be via welds between bushing <NUM> and plate gripper <NUM> and between plate gripper <NUM> and handle <NUM> at a proximal end of plate gripper <NUM>.

The present disclosure relates to a method (not claimed) of using the awl and plate holder system to secure a bone plate to a bone and to create a pilot hole in the bone for a screw to be placed through the bone plate. In the described examples, the method is described with respect to a bone plate placed minimally invasively onto the spine of a patient. However, it is envisioned that the instruments of the examples of the present disclosure may be used in other areas of the body.

In one example, a method involves the use of system <NUM> and begins with awl <NUM> already fixed to plate holder <NUM>, as shown in <FIG>. In a variation of this method, the method may commence with an additional initial step involving assembly of awl <NUM> and plate holder <NUM> as described above and shown in <FIG>. With system <NUM> in an assembled state, retention sleeve <NUM> is checked to verify that it is rotated counterclockwise (or clockwise with a reverse thread) so that it is withdrawn sufficiently from arms <NUM>, <NUM> so that arms <NUM>, <NUM> are in an open, or spread apart position. System <NUM> is then advanced onto bone plate <NUM> as denoted by reference numeral <NUM> and shown in <FIG>. Bone plate <NUM> includes a trailing surface <NUM> that faces away from bone when secured onto a bone surface. Within trailing surface are recesses 83A, 83B on lateral sides of the bone plate, an aperture <NUM> through the bone plate in between the recesses, and a locking element <NUM> adjacent to the aperture. As shown in <FIG>, arms <NUM>, <NUM> of plate gripper <NUM> of system <NUM> are advanced toward and into recesses 83A, 83B. Although arms <NUM>, <NUM> are shown at a particular spacing in <FIG>, it should be appreciated that the arms may be further apart and retention sleeve <NUM> further withdrawn toward the clinician during performance of this step than is shown in <FIG>. Once the arms are in a position within the recesses, retention sleeve <NUM> is rotated clockwise to axially advance retention sleeve <NUM> over the arms to bring the arms together into a closed position, as shown in <FIG>. This grips the arms of the plate gripper onto bone plate <NUM>.

It should be appreciated that in alternative arrangements, the retention sleeve of the plate holder may operate differently than described above to control whether the arms of the plate gripper are in an open or closed position. For example, the retention sleeve may slide along the plate gripper in an axial movement, rather than through a rotational movement about its axis.

Once plate holder <NUM> is engaged with bone plate <NUM>, the combined elements are ready for passage through a surgical portal to a target site on the spine of the patient. At this time, or at any time prior to reaching this step, a surgical access portal into the spine of the patient is prepared (not shown). Preparation of a surgical access portal may be accomplished through the use of a retractor, such as the retractors described in any one of <CIT>, <CIT>, and <CIT> and in <CIT>. Of course, other established methods (not claimed) of retraction to create a surgical portal for access may also be employed Then, in some examples, material of disc <NUM> may be removed so that an intervertebral implant <NUM> may be implanted into the intervertebral space.

With a surgical access portal created and a target site for bone plate placement accessible, and in some cases, an implant <NUM> being implanted into the intervertebral space, system <NUM> with bone plate <NUM> attached is advanced through the access portal and onto vertebral body <NUM> of the spine as denoted by reference numeral <NUM>. As shown in <FIG>, fangs 87A, 87B of bone plate <NUM> are pushed through vertebral body <NUM> to prevent any rotation of bone plate <NUM> during subsequent steps of the method (not claimed). To push the fangs into the bone, or to aid in pushing the fangs into the bone, a mallet may be applied to cap <NUM> of the awl component of the system. Because the awl will be in the locked position at this time by virtue of button <NUM> being in its biased position, i.e., the awl is locked relative to the plate holder, the force applied to the system by the mallet will go directly into bone plate <NUM>. In this manner, the clinician is able to control the force applied to the plate based on the force applied to the awl cap by the mallet. Of course, in a variation of this step, another impaction tool may also be used in place of a mallet.

When it is established that the bone plate is satisfactorily held in place on the bone, the next step involves preparation of a pilot hole in the bone for insertion of a screw. During the previous step, awl <NUM> was in its locked position, and tip <NUM> of awl <NUM> was disposed entirely within an interior channel (cannulation <NUM>) of the plate gripper. In this manner, while the system <NUM> is used as an impaction device, the awl does not project out of the plate holder and impact any external surfaces. However, once bone plate <NUM> is satisfactorily held on the surface of vertebral body <NUM> via fangs 87A, 87B, button <NUM> may be toggled, i.e., actuated, to commence use of the awl component of system <NUM> for the creation of a hole in the bone for screw placement through the bone plate. Thus, from a first setting where the button is not loaded, the button is moved to a second setting by applying load to hold it in a displaced position.

When the clinician depresses button <NUM> as indicated by reference numeral <NUM> in <FIG>, awl shaft <NUM> becomes unlocked relative to plate holder <NUM> so that shaft <NUM> is axially translatable within plate holder <NUM> as long as button <NUM> is depressed. In terms of mechanics, <FIG> illustrate the details of the awl locking mechanism including the features that provide for the locked and unlocked settings. As button <NUM> is depressed within housing <NUM>, locking ridge <NUM> of button <NUM> moves out of recess <NUM> on shaft <NUM>, and thus out of the path of shaft <NUM>. When locking ridge <NUM> is out of the path of shaft <NUM>, the only structure restraining axial movement of shaft <NUM> is pin <NUM>, as opposed to pin <NUM> and locking ridge <NUM>. In this setting while button <NUM> remains depressed, shaft <NUM> is free to slide relative to pin <NUM> over a length of slot <NUM>. Thus, impaction forces applied to cap <NUM> advance tip <NUM> of shaft <NUM> out of plate holder <NUM>, as shown in <FIG>. Reference numeral <NUM> indicates the direction of impaction force applied to system <NUM>.

Thus, to create a hole for screw placement through bone plate <NUM>, button <NUM> is held in a depressed position and cap <NUM> is impacted as indicated by reference numeral <NUM>. The application of an impaction force on cap <NUM> causes shaft <NUM> to advance through housing <NUM> and relative to plate holder <NUM>. In doing so, longitudinal spring <NUM> compresses to control the displacement of shaft <NUM>. After each impact, longitudinal spring <NUM> expands and awl <NUM> returns to its biased position where tip <NUM> rests within the cannulated portion of plate gripper <NUM>, and the process is repeated. A clinician may perform any number of impactions to create a desired pilot hole in the bone for screw placement. During this step, arms <NUM>, <NUM> of plate holder <NUM> remain engaged to bone plate <NUM> and thus plate holder <NUM> and awl <NUM> are not only engaged to one another as part of system <NUM>, but are serving simultaneous functions: The plate holder maintaining alignment of the system with the bone plate, and the awl creating the hole aligned with aperture <NUM> for screw placement. Through the described procedure, one advantage, particularly when the procedure is employed in minimally invasive procedures such as lateral lumbar interbody fusion, is the significantly reduced duration required to position and prepare the bone plate relative to existing procedures where separate steps are required for bone plate placement and pilot hole creation. Thus, potential blood loss is reduced and the duration the nerves are subject to retraction time is also reduced. Returning to the method, once the pilot hole is deemed satisfactory, the bone plate is ready to receive a screw that will be inserted into the pilot hole.

The screw placement step may be performed in a variety of ways, as will now be described in greater detail. In some examples, the awl is detached from the plate holder by rotating the awl housing out of the handle. Then, with plate holder <NUM> still engaged to bone plate <NUM>, a handle <NUM>, a driver <NUM> attached to the handle, and a holding screw <NUM> attached to the driver, are advanced into plate holder <NUM>, as shown in <FIG>. The pathway through cannulation <NUM> of plate gripper <NUM> is sufficiently sized so that driver <NUM> is advanceable therethrough. Screw <NUM> is inserted through aperture <NUM> in plate <NUM> and then rotated into place within the pilot hole formed in vertebra <NUM>. This technique is particularly suitable when screw <NUM> is intended to be inserted perpendicular to the bone plate, as shown in <FIG>.

In other examples, the entire system <NUM> is removed from bone plate <NUM> after the hole is formed in vertebrae <NUM>, and screw is inserted into the pilot hole. When the surgery calls for insertion of the screw at an acute angle relative to the bone plate, an anti-torque handle may be placed on the bone plate prior to driving in the screw (not shown). The anti-torque handle is attached to the bone plate in a manner that prevents rotation of the bone plate during insertion of the screw. In these examples, it is contemplated that the screw may be placed at any desired angle relative to the vertebral end plate from <NUM> degrees to <NUM> degrees. In still further examples, the screw may be inserted with a screw insertion tool without any additional supporting instruments affixed to the bone plate.

Once screw <NUM> is securely in place in the vertebra, a driver is retrieved with a drive element that complements the drive element of locking element <NUM> of bone plate <NUM>. Locking element <NUM> is shown as part of bone plate <NUM> in <FIG>. By engaging and rotating locking element <NUM>, locking element <NUM> rotates to block screw <NUM> from back out and thereby prevent it from dislodging from vertebra <NUM> (not shown). In examples where the bone plate does not include a locking element for blocking a screw, this step is not performed. The bone plate placement is final at this point in the procedure and any remaining tools are removed from the surgical site. Procedures are then chosen by the clinician to close the surgical access portal and the wound.

The method (not claimed) of using system <NUM> and its components may be varied in many ways For instance, in one example, plate holder <NUM> may be engaged to bone plate <NUM> prior to engagement of awl <NUM> to plate holder <NUM>. In this manner, awl <NUM> may subsequently be engaged to plate holder <NUM> either before or after plate holder <NUM> is advanced to the surgical site. Engagement between the plate holder and the bone plate, along with engagement between the awl and the plate holder, may be as described for the example depicted in <FIG>.

In other examples, plate holder <NUM> may be used independently in a method (not claimed) of placing a bone plate on a bone. The method may involve engagement of the plate holder to the bone plate, followed by advancement of the bone plate to a desired engagement surface on the spine. The plate holder may be engaged to the bone plate in the manner described for the example depicted in <FIG>. For application of impaction forces, an impaction tool may be applied to a proximal end of the handle of the plate holder in the absence of the awl.

In still further examples, the methods (not claimed) of using system <NUM> may be employed to place implants other than bone plate <NUM>. In some examples, implants may be other bone plates. In still further examples, other types of implants may be held by the plate holder and positioned for the creation of a pilot hole through an aperture of the implant. Provided that the implant has recesses that may be engaged by the arms of the plate holder, and provided that an aperture of the implant is positioned on the implant so that the awl may advance therethrough, the plate holder and awl system may be used with such implants.

It should be noted that any of the instruments and methods disclosed herein may be used in conjunction with robotic technology (not claimed). For example, any of the instruments described herein may be used with robotic surgical systems to place a bone plate or screw in a patient. The bone plate or screw may be manipulated with a robotic system or a robotic arm to rotate or position the bone plate or screw, and/or to anchor the screw through the bone plate during a procedure. Further, any or all of the steps described in the methods for performing a bone plate placement procedure of the present disclosure may be performed using a robotic system.

Claim 1:
A system (<NUM>) for placing a bone plate (<NUM>) onto a bone comprising:
a plate holder (<NUM>) extending from a first end to a second end, the plate holder (<NUM>) including an engagement feature (<NUM>, <NUM>) at the second end, the engagement feature engageable with the bone plate (<NUM>); and
an awl (<NUM>) disposed in the plate holder (<NUM>), the awl (<NUM>) including a tip (<NUM>),
characterized in that the awl (<NUM>) is releasably engaged to the plate holder (<NUM>) and the awl (<NUM>) includes a locking mechanism adjustable from a first setting to a second setting,
wherein when the locking mechanism is in the first setting, the awl (<NUM>) is fixed relative to the plate holder (<NUM>) and the tip (<NUM>) is disposed within the plate holder (<NUM>), and
wherein when the locking mechanism is in the second setting, the awl (<NUM>) is axially translatable relative to the plate holder (<NUM>) such that the tip (<NUM>) of the awl (<NUM>) is extendable out of the second end of the plate holder (<NUM>).