Expended tab reinforcement sleeve

A sleeve can be adapted to reinforce a bone anchor, and can include a body, a lock, and an actuator. The body can include a first sleeve arm and a second sleeve arm, where each can extend longitudinally along opposing sides of a longitudinal bore open at a distal end of the sleeve. The lock can be coupled to the body and releasably securable to a channel of a head of the bone anchor to secure the sleeve to the anchor.

BACKGROUND

Orthopedic devices such as rods, plates, tethers, staples, and other devices can be used in various spinal procedures to correct abnormalities (e.g., scoliosis) or to address injuries (e.g., vertebral fracture). In some spinal procedures, anchors and rods can be secured along a spinal column between one or more vertebrae to stabilize a region of the spine. Some surgical procedures performed on the spinal column using such devices have become less invasive. However, some special parts used in minimally-invasive spinal procedures can increase the difficulty of the installation procedure.

DETAILED DESCRIPTION

Bone anchors can be used together with connecting members (such as rigid and semi-rigid rods) to straighten a region of a human spine to address an abnormality (e.g., scoliosis), to stabilize a spine following an injury (e.g., fractured vertebrae), or to address degeneration of the spine caused by disease. In minimally invasive spinal procedures to address these issues, multiple small incisions can be made to form multiple small cavities near individual vertebrae. A large amount of the procedure is performed through manipulation of instruments and components extending through the small surgical cavities using special instruments that are able to be manipulated from outside of the cavities. For example, anchors are commonly driven into vertebrae, where the anchors can include extended tabs rigidly coupled to the anchors and having a length sufficient to extend outside of the cavity so that the anchors (and components engaging the anchors) can be manipulated from outside of the cavities, Because the extended tabs comprise a length sufficient to extend through the cavities, they must be separable from the heads of the anchors when the heads remain secured to vertebrae.

Some designs include two extensions each coupled to the head of the anchor at a breakaway portion, where each extended tab can be individually bent to allow separation of the extension from the head at the breakaway portions. This design requires relative movement of the extended tabs for separation. However, in some procedures, forces must be transferred from a portion of the extended tabs external to the cavity to a portion of the extended tabs in the cavity and ultimately to the head and/or shank of the anchor. However, many extended tab pedicle screws suffer from instability at the proximal end of the tabs, which can cause unwanted separation at the distal end of the tabs from the housing and can limit a surgeon's ability to manipulate the extensions.

This disclosure addresses the problem of allowing individual separation of the extended tab while allowing transfer of forces and torques through the tabs without unintended separation of the extension tabs from the head by providing a sleeve couplable to the anchor where the sleeve can transfer forces directly to and from the head of the anchor instead of to and from the extended tabs. In one example, the sleeve can include a translating lock coupled to the body of the sleeve and an actuator. An actuator can be operated to translate the lock to engage and secure the anchor to the sleeve at a point below the break-off point of the extensions. This can help to transmit forces between the sleeve and the head of the anchor (and the shank in some examples) while helping to prevent unwanted separation of the extended tabs from the head of the anchor.

FIG.1Aillustrates an isometric view of an anchor102and sleeve assembly100, in accordance with at least one example of this disclosure.FIG.1Billustrates an isometric view of a sleeve assembly100, in accordance with at least one example of this disclosure.FIGS.1A and1Bare discussed concurrently below.

The sleeve assembly100can include a body104, a lock106, and an actuator (or knob)108. The anchor102(visible only inFIG.1A) can include a head110, extended tabs112A and112B (112A is opposite112B, but not visible), a breakaway portion113(shown inFIG.2C), a threaded portion114, a central bore116, and anchor slots118A and118B (only slot118B is visible inFIGS.1A and1B). The body104can include a first arm120A, a second arm120B (referred to collectively as arms120), a central bore122, and sleeve slots124A and124B. The sleeve assembly100can further include spring hooks126A and126B. Also shown inFIGS.1A and1Bis axis A, indicators8-8, and orientation indicators Proximal and Distal.

The components of the anchor102can be comprised of rigid and semi-rigid materials such as metals, plastics, composites, or the like. In some examples, the anchor102can be comprised of bio-compatible materials, such as stainless steel, titanium, or the like. In some examples, the anchor102can be comprised of only one material, and can be comprised of multiple materials in other examples.

The head110of the anchor102can be coupled to a shank, as shown inFIG.5, at a distal portion of the head110with the shank extending distally therefrom and where the axis A can be a central axis for the head110and the shank. In other examples, the shank can deviate from the axis A at various angles. The shank can be a threaded shank or screw including male threads configured to engage bone, such as a relatively coarse thread pattern. In some examples, the shank can be configured to threadably secure to a vertebra of a spine of a human, as shown and discussed inFIG.5below. The shank can be an integral component to the head110in some examples, coupled to a distal portion of the head110. In other examples, the shank can be a portion of a fastener that is a separate component from the head110and can be disposed within a bore of the head110and configured to be retained therein.

The anchor slots118A and118B of the anchor102can be generally U-shaped, in some examples, and can be configured to receive a connecting member (such as a connecting rod or wire) therethrough. In some examples, the head110can have flat sides and one or more tool interfaces, as discussed further below. The breakaway portions113A and113B can be a portion of the anchor102coupling the head110to the extended tabs112A and112B, respectively, where the breakaway portions113can have a thickness that is smaller than a thickness of the head110or the extended tabs112A and112B (only tab112B is visible inFIGS.1A and1B) that surrounds the breakaway portions113A and113B. The reduced thickness of the breakaway portions113A and113B can facilitate separation and removal of the extended tabs112A and112B from the head110.

The threaded portion114can be a female threaded portion within the anchor slots118A and118B of the head110and the extended tabs112A and112B. In some examples, the threaded portion114can be relatively fine threading (such as machine-type threading) configured to receive a component having male threading, such as a closure top or set screw configured to retain a connecting member or rod. The threaded portion114can include any known thread forms commonly utilized for pedicle screws.

The extended tabs112A and112B can extend substantially proximally from the head110and substantially parallel to axis A. Together, the extended tabs112A and112B can form an incomplete hollow cylinder separated by anchor slots118A and118B. The anchor slots118A and118B can be slots between the extended tabs112A and112B. The extended tabs112A and112B can be coupled to the head110by the break off portions113A and113B, as noted above.

Sleeve assembly100can be a generally hollow cylindrical member including the elongate body104. The components of the sleeve assembly100can be comprised of rigid and semi-rigid materials such as metals, plastics, composites, or the like. In some examples, the sleeve assembly100can be comprised of bio-compatible materials, such as stainless steel, titanium, cobalt chromium, or the like. In some examples, the sleeve assembly100can be comprised of only one material, and can be comprised of multiple materials in other examples.

The central bore122of the body104can be sized and shaped to receive the anchor102therein. The arms120can extend distally from the actuator108and can be separated by sleeve slots124A and124B, which can be sized to respectively align with the anchor slots118A and118B of the anchor102. Each of the first arm120A and the second arm120B can have a length sized to extend over the extended tabs112A and112B of the anchor102, while exposing part of the head110. In some examples, first arm120A and the second arm120B can have a length sized to extend over the entirety of the head110.

The lock106can be an elongate member secured to the body104and can be movable relative thereto. The lock106can be engaged with the actuator (or knob)108at a proximal portion of the lock106, where the actuator108can also be secured to the body104, but movable relative thereto. A distal portion of the lock106can be engageable with the spring hooks126A and126B, which can be biased or spring member comprised of resilient materials, such as spring steel, or the like. The spring hooks126can be secured to a distal portion of the body104and can be engaged by the lock106to be moved radially inward from the body104to engage the head110of the anchor102to secure the head110to the sleeve.

In operation of some examples, the extended tabs112A and112B can be inserted into the central bore122of the arms120with a proximal portion of the head110of the anchor102until the sleeve engages with the head110distally. The anchor102can be inserted into sleeve arms120either before or after the anchor102is inserted into a cavity and before or after the anchor102is secured to a bone.

Once the anchor102is fully inserted into the central bore122, the knob108can be operated (for example, by rotating the knob) to move the lock106to engage and move the spring hooks such that inwardly extending projections of the spring hooks126are moved radially inward. The knob108can be rotated until the spring hooks126extend radially inward to fully engage a rim or channel of the head110to secure the anchor110to the body104. By utilizing a lock with deflecting hooks, the sleeve assembly100provides a locking mechanism without small components (such as coil springs or pins) and with a relatively low number of parts.

In further operation of some examples, once a patient's spinal region (and specifically a vertebra) is prepared, the anchor102can be extended into an incision and aligned with a portion of the vertebra (for example a guide bore) configured to receive a shank. Once the shank is engaged with the guide bore in the vertebra, a torque can be applied to the head110about axis A using a tool to drive the shank into the vertebra. Once the shank is secured into the vertebra, a connecting member can be passed through the anchor slots118A and118B of the extended tabs112A and112B and can be reduced down through the sleeve slots124A and124B and into the head110. At a later time, or during reduction, a closure top (or other fastener) can be inserted into central bore122of the body104and can be threaded into the threaded portion114of the anchor102and down to the head110to retain the connecting member in the head110of the anchor102.

In some examples, the closure top or fastener (e.g., set screw) can be used to secure or reduce a connecting member into the head110, with the sleeve100helping to prevent premature breakage at113during this reduction. The sleeve100can also be used to reinforce the extended tabs112to prevent unwanted break off when other external forces and torques are applied to the extended tabs122. In one example, the sleeve100can reinforce the tabs112during hand positioning or manipulation of the anchor100, such as when rotating an anchor already secured to a vertebral body. This type of hand positioning and rotation of the sleeve100and the anchor102can be common during a spinal de-rotation procedure, for example.

FIG.2Aillustrates a front view of the sleeve assembly100, in accordance with at least one example of this disclosure.FIG.2Billustrates a front cross-sectional view across section2B-2B of the sleeve assembly100, in accordance with at least one example of this disclosure.FIG.2Cillustrates a focused portion2C front cross-sectional view of the anchor102and the sleeve assembly100, in accordance with at least one example of this disclosure.FIGS.2A-2Care discussed concurrently below.

The sleeve assembly100can include the body104, the lock106, and the actuator108. The anchor102(visible only inFIG.2C) can include the head110, the extended tabs112A and112B, the breakaway portion113, the threaded portion114, the central bore116, and the anchor slots118A and118B. The body104can include the first arm120A (including a first arm channel121A), the second arm120B (including a second arm channel121B), the central bore122, the sleeve slots124A and124B, and pockets128A and128B (collectively referred to as pockets128). The head110can include channels111A and111B (only111A shown inFIG.2C), which can each include a channel flat115. The sleeve assembly100can further include the spring hooks126A and126B, which can include barbs130A and130B, respectively, each of which can include a barb flat131. The lock106can include a first lock arm129A and a second lock arm129B, each of which can include a distal tapered portion133. Also shown inFIG.2Aare axis A, section indicators2B, and orientation indicators Proximal and Distal. Also shown inFIG.2Bare axis A, section indicator2C, and orientation indicators Proximal and Distal. Also shown inFIG.2Care orientation indicators Proximal and Distal.

The sleeve assembly100and the anchor102can be similar to the sleeve assembly100and the anchor assembly102ofFIGS.1A and1B; however,FIGS.2A-2Cshow additional details of the sleeve assembly100and the anchor102. For example,FIG.2Bshows pockets128A and128B of arms120A and120B, respectively, where each of the pockets128is located at a distal portion of each of the arms120and each pocket128is connected to one of the arm channels121. For example, the first pocket128A is connected to a distal portion of the first arm channel121A and the second pocket is connected to a distal portion of the second arm channel121B.

Each pocket128can be a cavity open to the central bore122of the body104and can extend radially outward therefrom. Each pocket128can be sized to receive one lock arm129and one spring hook126therein. In some examples, each pocket128can be sized such that when the lock arm129and spring hook126are disposed within the pocket and when the barb130is engaged with the channel111, there is relatively little space between a radially outer wall of the pocket, the lock arm129, the spring hook126, and the head110of the anchor. The tolerance stackup between the pocket128and the lock arm129, spring hook126, and barb130can range from a clearance fit to an interference fit, depending upon how tightly the sleeve assembly100needs to be connected to the anchor110. This can help to limit radially outward movement of the spring hook126when the lock arm129is in a locked position, helping to prevent the spring hook126, and therefore the sleeve assembly100, from disengaging the head110. The low gap between these components can also help to transfer forces and stress between the head110and the sleeve assembly100, which can further help limit bending of the anchor102and the sleeve assembly. Further, the arm129can act as a wedge within the pocket128to drive the spring hook into position by engaging the pocket128and a radially outer portion of the spring hook126.

FIG.2Calso shows the channel111A of the head110, which can be sized and shaped to receive the barb130A when the lock arm129A is in a locked position. When in the locked position, the barb flat131can engage the channel flat115to help limit proximal translation of the sleeve assembly100relative to the head110. The barb flat131can extend substantially around a perimeter of the head110, in some examples, and can be flat or planar from a proximal perspective. Similarly, the barb flat131can be flat or planar from a proximal perspective. In other examples, the barbs130can be of other shapes, such as a hook, to further help limit relative movement of the sleeve assembly100relative to the head110of the anchor102. A distal surface165connecting the barb to the distal tip164can be rounded to help improve disengagement of the barb131from the head110. In other examples, the distal surface165can be flat.

FIGS.2B and2Calso show the distal tapered portion133of each lock arm129. As shown inFIG.2B, the distal tapered portion133can rest at a proximal portion of the pocket128when the lock106is in an unlocked position (for example, when the lock arm129A is translated proximally).

In operation of some examples, the lock106can be in the unlocked position, as shown inFIG.2B, where the lock106is translated proximally sufficiently to allow the spring hooks126to be locked within the pockets128. That is, each spring hook126does not extend into the central bore122when the lock106is in the unlocked position. When it is desired to secure the sleeve assembly100to the anchor102, the head110of the anchor102can be inserted into the central bore122of the sleeve assembly, as described above with respect toFIGS.1A and1B. When the anchor102is completely inserted into the central bore122, the channels131of the anchor can align with the pockets128. At this point, the actuator108(or knob) can be rotated to cause distal translation of the lock106. Distal translation of the lock106causes distal translation of the lock arms129within their respective lock slots121A.

Because the distal portion133of each lock arm129is tapered and rests at a proximal opening of each pocket in the unlocked position of the lock106, the lock arms129thereby retain their position within the pocket128while allowing the spring hooks126to be disengaged from the head110and to be located within the pocket128when the lock arms129are in the unlocked (proximal) positions.

As the lock arms129extend into the pockets128(as shown inFIG.2C), an outer wall135of the pockets128guide the lock arms129to deflect radially inward to contact the spring hooks126, which causes the spring hooks126to move radially inward. Because each outer wall135is angled, the spring hooks126are deflected further radially inward as the lock arms129are translated further distally into the pockets128, causing the barbs130of the spring hooks to extend radially inward from the pockets128into the central bore122to engage the channels111of the head110of the anchor. The radially inward extension of the spring hooks126can be limited by contact between the barb130and the channel111and/or the spring hooks126and the head110, and/or by contact between a distal portion of the pockets128and a distal end of the tapered portion133of the lock arms129.

When the lock106is in the locked position, proximal translation of the head110relative to the sleeve assembly100is limited by contact between the extended tabs112and the body104, distal translation of the head110relative to the sleeve assembly100is limited by engagement of the barbs130with the channel111, and movement transverse to the axis A of the head110relative to the sleeve assembly100is limited by contact between the anchor102and the body104, thus securing the anchor102to the sleeve assembly100when the lock106is in the locked position. Because the channels111are positioned distally of the breakaway portions113of the extended tabs112, interaction between the sleeve assembly100and the head110(that is, interaction between the spring hooks126and the head110) is less likely to cause unwanted separation of the extended tabs112from the head110during manipulation of the sleeve assembly100during a procedure.

When it is desired to disengage the sleeve assembly100from the anchor102, the actuator108can be operated to translate the lock106proximally, causing the lock arms129to move proximally, such that the arms129will move out of the pockets128enough to allow the spring hooks126to retract into the pockets128while disengaging from the channel111of the head110. In some examples, the spring hooks126can be biased to a retracted position, as shown inFIG.2B, so that when the force applied by the lock arms129is removed, the spring hooks126retract into the pockets128without the application of a force external to the spring hooks126.

When the barbs disengage from the channel111of the head110, the anchor102can be translated distally relative to the sleeve assembly100, allowing the anchor102to be removed, if desired. Because the pockets128(together with the anchor102) substantially surround the spring hooks126, the pockets128help to protect the spring hooks126from interference from tissue of a patient, where such interference can prevent the sleeve assembly100disengaging from the anchor102. The pockets128therefore help to ensure the sleeve assembly100can be removed from the anchor102, as desired.

FIG.3Aillustrates a front view of the sleeve assembly100with a portion of the sleeve assembly in phantom, in accordance with at least one example of this disclosure.FIG.3Billustrates a front view of the sleeve assembly100with a portion of the sleeve assembly in phantom, in accordance with at least one example of this disclosure.FIGS.3A and3Bare discussed below concurrently.

The sleeve assembly100ofFIGS.3A and3Bcan be consistent with the sleeve assembly ofFIGS.1A-2C, butFIGS.3A and3Bcan show additional details of the sleeve assembly. For example,FIGS.3A and3Bshow how the actuator108, body104, and lock106are connected and how they interact.

FIGS.3A and3Bshow pin132, which can be a rigid or semi-rigid elongate fastener, such as a cylindrical pin, rivet, screw, or the like. The pin132can pass through a pin bore146of the lock106and can also pass through a pin channel148of the body104to couple the lock106to the body104. The pin channel148can have an axial length longer than a diameter of the pin132to allow the pin to move in a direction substantially parallel to axis A. This movement can permit the lock106to move axially relative to the body104. The pin channel148can also be sized to have a width similar to the diameter of the pin132to help limit non-axial movement of the lock106with respect to the body104.

FIGS.3A and3Balso show that lock106can include a proximal bore136and an undercut138, which can be sized and shaped to receive tabs140A-140N (collectively referred to as tabs140) and projections142A-142N (collectively referred to as projections142), respectively. The undercut138can be spaced away from a proximal end of the lock106such that once the projections142are disposed within the undercut138, axial movement of the actuator108is limited proximally and distally with respect to the lock106.

FIGS.3A and3Balso show that actuator108includes internal threading150, which can be complementary to external threading144of a proximal portion143of the body104. Interaction (screwing and unscrewing, for example) of internal threading150of the actuator can engage the external threading144of the proximal portion of the body143to cause movement of the actuator108relative to the body104.

For example, during operation of the sleeve assembly100, a torque T1about axis A can be applied to the actuator108to screw the internal threading150of the actuator108onto the internal threading144of the proximal portion143of the body104. Because the actuator108is coupled to the lock106via tabs140, as the actuator108screws further (distally) onto the body104, the lock106(and the lock arms129) are translated distally with respect to the body, allowing the lock arms129to engage the spring hooks126, as discussed above. When it is desired to unlock the spring hooks126from the anchor102, the actuator108can be rotated in a direction opposite the torque T1to translate the actuator108and the lock106proximally with respect to the body104. By providing a threaded interface to operate the actuator108to control translation of the lock106, the relatively small translation of the lock106with respect to the body is given a relatively high degree of controllability to the user while also providing user feedback during tightening and loosening.

FIGS.3A and3Balso show tool interfaces134A and134B, which can be bores in the lock106and/or the body104, where the tool interfaces can support another tool, such as a reducer, counter-torque, or de-rotator, for example.

FIG.4Aillustrates a side view of a portion of the body104of the sleeve assembly100, in accordance with at least one example of this disclosure.FIG.4Billustrates a front view of a portion of the body104of the sleeve assembly100, in accordance with at least one example of this disclosure.FIG.4Cillustrates an isometric view of the knob108of the sleeve assembly102, in accordance with at least one example of this disclosure.FIGS.4A-4Care discussed below concurrently.

The sleeve assembly100ofFIGS.4A-4Ccan be consistent with the sleeve assembly ofFIGS.1A-3B, butFIGS.4A-4Cshow additional details of the sleeve assembly. For example,FIGS.4A and4Bshow the proximal portion143of the body104extending proximally from the body arms120A and120B, where the male threaded portion144extends to a proximal end of the body104. The proximal portion143can include a pair of proximal arms extending from the body104, offset from the body arms120. In other examples, the proximal arms of the proximal portion143can be aligned with the body arms120.

FIG.4Balso shows the pin channel148extending proximally to distally along axis A where the pin channel148can terminate proximally before the threaded portion144.FIG.4Afurther shows tool interface134A which can be a slot or bore extending substantially perpendicular to the axis A.

Also shown inFIG.4Ais a spring hook channel152, which can include a proximal portion154and a distal portion156. The proximal portion154can have a width substantially wider than a width of the distal portion156for receiving a head or wings of the spring hook126, as discussed further below. Though the spring hook channel152is shown as being a substantially T-shaped channel, the spring hook channel152can be of other shapes, such as an I-shape, a J-shape, or the like. In some examples, the spring hooks126can be secured to the body104, such as by laser-welding, within the spring hook channels152, such as at the proximal portion154to provide a flex of the spring hook126relative to the body104.

FIG.4Cshows additional details of the actuator108such as a knob portion158and the fingers140(each including the tabs142). The knob portion148can be substantially cylindrical in some examples, and can have other shapes in other examples, such as hexagonal, octagonal, or the like. The fingers140can each extend distally from the knob portion158and can be in a cantilevered arrangement therewith.

Each of the fingers140can be circumferentially spaced. For example, finger140C can be spaced from finger140D by a gap G, which can allow the fingers140to deflect radially inward for attachment of the actuator108to the locking portion106. The number of fingers can be any number, such as 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 20, or the like. Similarly, the gap G can be varied for a desired number of fingers and for a desired radially inward deflection of the fingers140, The projections142of the fingers140can extend radially outward therefrom at a distal portion (and in some examples at a distal termination) of each of the fingers140.

FIG.5illustrates an isometric view of an anchor502with a sleeve assembly500, in accordance with at least one example of this disclosure. The anchor502can include a shank509, a head510, and extensions512A and512B. Also shown inFIG.5are a cutaneous portion50, an opening52, and vertebrae V1, V2, and V3.

The anchor502ofFIG.5can be consistent with the anchors discussed above. Similarly, the sleeve assembly500can be consistent with the sleeve assembly100discussed above with respect toFIGS.1-4C.FIG.5shows how the sleeve assembly500and the anchor502can be used in an example operation. In operation of some examples, an incision can be made on a posterior portion of a patient along the patient's vertebral column, for example, along the patient's thoracic spine. For example, an incision can be made on the cutaneous portion50where the incision extends through the dermis and subcutaneous tissue to create the opening52and exposes or partially exposes the vertebrae V1-V3. In some cases, multiple incisions can be made to minimize invasion. Next, a punch may be used to break the cortical bone to create a pilot or guide hole in a vertebra for the anchor502. Once the vertebra (for example, the vertebra V1) is prepared, the anchor502can be extended into the opening52such that the anchor502can be engaged with the vertebra V1, for example. The shank509of the anchor502can then be driven into, for example, a pedicle of the vertebra V1to secure the anchor502to the vertebra V1while of the anchor and the sleeve502can extend beyond the opening52.

While in this position, the extended tabs512can receive the sleeve assembly500thereon. In other examples, the sleeve assembly500can be secured to the anchor502prior to securing the anchor502to the vertebra V2. Once the sleeve assembly500is secured to the anchor502, the sleeve assembly500can be manipulated by hand (or tool) to position vertebra V1, such as during a de-rotation procedure. During this rotation, the sleeve assembly500can help prevent unwanted separation of the extended tabs512from the head510of the anchor502, where the lock of the sleeve assembly500can help to prevent such separation.

FIG.6Aillustrates an isometric view of the spring hook126, in accordance with at least one example of this disclosure.FIG.6Billustrates a side view of the spring hook126, in accordance with at least one example of this disclosure.FIG.6Cillustrates a front view of the spring hook126, in accordance with at least one example of this disclosure.FIGS.6A-6Care discussed below concurrently.

The spring hook126can include the barb130(including the flat131), a body160, tabs162A and162B (collectively referred to as tabs162), and a distal tip164, which can include the barb130, and a tapered portion166.

The spring hook126ofFIGS.6A-6Ccan be consistent with the spring hook126ofFIGS.1-4C, except thatFIGS.6A-6Cshow additional details of the spring hook126. As discussed above, the spring hook126can be comprised of resilient materials, such as steels, titanium alloys, or the like. Each of the components of the spring hook can be comprised of a single material in some examples, and can be an assembly comprised of multiple materials in other examples.

The body160can be substantially thin and elongate and can be connected to tabs162at a proximal portion of the body160and the distal tip164at a distal portion of the body160. The tabs162can respectively extend outward from the body (in substantially opposing directions). The tapered portion166of the distal tip164can be tapered toward the barb130as the distal tip164extends distally. In some examples, the tapered portion166of the distal tip164can have a taper that is sized and shaped to substantially match an angle of the outer wall135of the pockets128of the sleeve body120to help reduce engagement and friction between the spring hook and the outer wall135. Also, a width W of the distal tip164can be wider than the distal portion156of the opening of the hook channel152to limit radially outward movement of the distal tip164.

FIG.7Aillustrates an isometric view of the lock106of the sleeve assembly102, in accordance with at least one example of this disclosure.FIG.7Billustrates a front view of the lock106of the sleeve assembly102, in accordance with at least one example of this disclosure.FIG.7Cillustrates a side view of the lock106of the sleeve assembly102, in accordance with at least one example of this disclosure.FIG.7Dillustrates a front view of a portion of the lock106of the sleeve assembly102, in accordance with at least one example of this disclosure.FIGS.7A-7Dare discussed below concurrently.

The lock106can include a proximal portion170and the lock arms129A and129B. The proximal portion170can include the tool interfaces134A and134B, and the pin bore146. The lock arms129A and129B can include distal portions172A and172B, respectively. The distal portions172A can each include a distal tip174, partially formed by cut portion176. Also, the lock arm129A can include chamfers178and179and the lock arm129B can include chamfers180and181. The distal tip174can include a first portion182, a second portion184, a third portion186, and a fourth portion188. Also shown inFIGS.7A-7Dare width W, thicknesses t1, t2, t3, and t4, and orientation indicators Proximal and Distal.

The distal portions172of the lock arms129can be of a width W relatively smaller than that of a width of the proximal portion of the lock arms129to help allow the distal portions172to deflect radially inward for insertion into the pocket128of the body104during locking and unlocking operations. The distal tip174can also be sized and shaped for insertion into the pockets, as discussed further below. Also, the chamfers178-181can be sized and shaped to be retained by the body (for example, in a dovetail arrangement), as discussed below with respect toFIGS.8A-8B.

The distal tip174can include four portions of varying thicknesses, in some examples. The first portion182can have the first thickness t1; the second portion184can have the second thickness t2; the third portion186can have the third thickness t3; and, the fourth portion188can have the fourth thickness t4, In some examples, the thicknesses t1, t2, t3, and t4can all be different where the fourth thickness t4is smaller than the third thickness t3, which is smaller than the second thickness t2, which is smaller than the first thickness t1. In other examples, some or all of the thicknesses t1-t4can be the same thickness. In some examples, each of the first portion182, the second portion184, the third portion186, and the fourth portion188can be tapered from a larger to smaller thickness as the distal tip portion174extends proximally to distally. Such a tapered profile of the distal tip portion174can allow for the spring hook126to bias radially outward in an unlocked position within the pocket128of the body104. That is, the third portion186can also have the thickness t3to allow the third portion186to rest within a proximal portion (or proximal entrance) of the pocket128when the lock106is in an unlocked position to retain the lock106while allowing the swing hook126to extend radially outward to allow for clearance for the head110of the anchor102to enter the central bore122.

Though four portions of the distal tip174are shown, the distal tip174can have fewer portions (such as 1, 2, or 3 portion) or more portions. Also, the thicknesses and tapers of the portions of the distal tip174can vary in other examples.

FIG.8Aillustrates an isometric cross-sectional view of the anchor102and the sleeve assembly100across indicators8-8ofFIG.1A, in accordance with at least one example of this disclosure.FIG.8Billustrates a top view of a cross-section of the anchor102and the sleeve assembly100across indicators8-8ofFIG.1A, in accordance with at least one example of this disclosure.

The anchor102and the sleeve assembly100can be consistent with the anchor and sleeve assemblies discussed above; however,FIGS.8A and8Bshow additional details of the anchor102and the sleeve assembly100. For example,FIG.8Bshows show the extended tabs112A and112B of the anchor102can be secured to the body104using chamfered (or dovetailed) portions.

Each of the extended tabs112A and112B can include chamfered portions. The extended tab112A can include chamfers190and191and the extended tab112B can include chamfers192and193. The body104can include radially inward extending projections, where each projection has a chamfer complimentary to the chamfers of the extended tabs112A and112B. The arm120A can include inner projections194A and194B, which can respectively include faces195A and195B. The arm120B can include inner projections196A and196B, which can respectively include faces197A and197B.

The face195A can engage the chamfer190and the face195B can engage the chamfer191in a dovetail-type arrangement to retain the extended tab112A in the central bore122, by preventing movement of the extended tab112A in directions non-parallel to axis A, while still allowing translation of the extended tab112A with respect to the body104parallel to the axis A. Similarly, the face197A can engage the chamfer192and the face197B can engage the chamfer193in a dovetail-type arrangement to retain the extended tab112B in the central bore122, by preventing movement of the extended tab112B in directions non-parallel to axis A, while still allowing translations of the extended tab112B with respect to body104parallel to the axis A. Generally, this arrangement can allow for insertion of the anchor102into the body104and can prevent non-axial movement of the anchor102with respect to the body.

FIGS.8A and8Balso show how the lock106can be secured to the body104. The lock arm129A can include chamfers178and179and the lock arm129B can include chamfers178and179. The body104can include radially outward extending projections, where each projection has a chamfer complimentary to the chamfers of the lock arms129A and129B. The arm120A can include outer projections198A and198B, which can respectively include faces199A and199B. The arm120B can include outer projections200A and200B, which can respectively include faces201A and201B.

The face199A can engage the chamfer79and the face199B can engage the chamfer178in a dovetail-type arrangement to retain the lock arm129A in the first arm channel121A by preventing movement of the lock arm129A in directions non-parallel to axis A while still allowing translation of the lock arm129A with respect to the body104parallel to the axis A. Similarly, the face201A can engage the chamfer181and the face201B can engage the chamfer180in a dovetail-type arrangement to retain the lock arm129B in the second arm channel121B by preventing movement of the lock arm129B in directions non-parallel to axis A while still allowing translations of the lock arm129B with respect to the body104parallel to the axis A. Generally, this arrangement can allow for movement of the lock arms129A and129B with respect to the body104to allow the lock106to secure the anchor102to the body104.

Though the extended tabs112A and112B, the lock106, and the body104are discussed above as having chamfered portions to create a dovetail arrangement, other geometries and connection methods can be used to secure the extended tabs112A and112B and the lock106to the body104while enabling relative translation of the extended tabs112A and112B and the lock106to the body104.

FIG.9illustrates a front view of a sleeve assembly900with a portion of the sleeve assembly900in phantom, in accordance with at least one example of this disclosure. The sleeve assembly900can include a threaded engagement between an actuator and a two-piece lock. Any of the previously discussed sleeve assemblies can be modified to include such an actuator and lock assembly.

The sleeve assembly900can include a body904, a lock906, and an actuator908. The body904can include a pin slot910, the actuator908can include a pin channel912and a male threaded portion914, and the lock906can include a female threaded portion916. Also shown inFIG.9is axis A and orientation indicators Proximal and Distal.

The sleeve assembly900can be similar to the sleeve assemblies discussed above, except that the actuator908can be secured to the body via a pin passing through the pin slot910of the body904and the channel912of the actuator. The sleeve assembly900can also differ in that it can include the male threaded portion914on the actuator908, which can drive the female threaded portion916of the lock to translate the lock906relative to the body.

FIG.10illustrates a side view of a sleeve assembly1000, in accordance with at least one example of this disclosure. The sleeve assembly1000can include a spring boss, and a guide boss to translate a lock. Any of the previously discussed sleeve assemblies can be modified to include such a spring boss and guide boss.

The sleeve assembly1000can include a body1004, a lock1006, and an actuator1008. The body1004can include spring channel1010. The lock1006can include a guide channel1012, and the actuator1008can include a spring boss1014, and a guide boss1016. Also shown inFIG.10is axis A and orientation indicators Proximal and Distal.

The sleeve assembly1000can be similar to the sleeve assemblies discussed above, except that the actuator1008can be secured to the body via the spring boss1014, which can be disposed within the spring channel1010of the body1004. The spring boss1014can rotate within the spring channel1010and can limit axial translation of the actuator1008with respect to the body1004.

The sleeve assembly1000can also differ in that it can include the guide boss1016, which can be disposed within the guide channel1012of the lock1006. In some examples, the guide channel1012can be a diagonal channel configured to cause axial translation of the lock1006when the actuator1008is rotated.

In assembly of some examples, the lock1006(on both sides) can be aligned with channels of the body1004. The guide boss1016can be inserted into the guide channel1012. Then, the actuator1008and the lock1006can be translated distally together until the spring bosses extend radially into the spring channel1010.

FIG.11Aillustrates a side view of a sleeve assembly1100, in accordance with at least one example of this disclosure.FIG.11Billustrates a side view of a portion of the sleeve assembly1100with a portion of the sleeve assembly1100in phantom, in accordance with at least one example of this disclosure.FIG.11Cillustrates a side view of a portion of the sleeve assembly1100with a portion of the sleeve assembly1100in phantom, in accordance with at least one example of this disclosure. The sleeve assembly1100can include a ramp engagement between an actuator and a flexible lock. Any of the previously discussed sleeve assemblies can be modified to include such ramp interface and flexible lock.

The sleeve assembly1100can include an anchor1102, a body1104, a lock1106, and an actuator1108. The body1104can include a lock channel1109. The lock1106can include a proximal ramp1112and a distal flexible portion1114. The actuator1108can include a guide ramp1116. The anchor1102can include a head1110having a notch1111. Also shown inFIG.11is axis A and orientation indicators Proximal and Distal.

The sleeve assembly1100can be similar to the sleeve assemblies discussed above, except that the actuator1108can engage the proximal ramp1112of the lock1106such that when the actuator1008is rotated, the guide ramp1116of the actuator engages the proximal ramp1112to cause the lock1106to translate parallel to the axis A. The flexible portion1114of the lock1106can translate within the lock channel1109of the body. When the actuator1108is moved to the locked position, the flexible portion1114can move into the notch1111of the head of the anchor1102to retain the anchor1102within the sleeve assembly1100.

FIG.12illustrates a side view of a portion of a sleeve assembly1200with a portion of the sleeve assembly in phantom, in accordance with at least one example of this disclosure. The sleeve assembly1200can include a rotating lock securable to a channel of an anchor. Any of the previously discussed sleeve assemblies can be modified to include such translating lock assembly.

The sleeve assembly1200can include an anchor1202, a body1204, a lock1206, and an actuator. The body1204can include arms1220A and1220B. The lock1206can include a ring portion1207. The anchor1202can include a head1210having a channel1211. Also shown inFIG.12is axis A and orientation indicators Proximal and Distal.

The sleeve assembly1200can be similar to the sleeve assemblies discussed above, except that the lock1206can include the ring portion1207. The lock1206can be rotatable by the actuator to rotate the ring portion1207into the channel1211of the head1210to secure the anchor1202within the sleeve assembly1200.

FIG.13illustrates an isometric view of a portion of a sleeve assembly1300, in accordance with at least one example of this disclosure. The sleeve assembly1300can include translating locks to provide a low number of components. Any of the previously discussed sleeve assemblies can be modified to include such a lock assembly.

The sleeve assembly1300can include a body1304, a lock1306, and an actuator. The body1304can include arms1320A and1320B (including a boss1330). The lock1306can include lock arms1329A and1329B. Also shown inFIG.13is axis A and orientation indicators Proximal and Distal.

The sleeve assembly1300can be similar to the sleeve assemblies discussed above, except that the body1304can include the boss1330and can be flexible at a distal portion of the arm1320A such that when the lock arm1329A is moved to a locked position, the boss can engage a channel of an anchor head to retain the anchor within the sleeve assembly. When the lock arms are moved to the unlocked position (as shown with lock arm1329B), the arms1320can extend radially outward to release the anchor. Such an assembly can help reduce the number of total parts.

FIG.14illustrates a front view of a sleeve assembly, in accordance with at least one example of this disclosure. The sleeve assembly1400can include a sliding lock without an actuator. Any of the previously discussed sleeve assemblies can be modified to include such sliding lock.

The sleeve assembly1400can include a body1404and a lock1406. The lock1406can include lock arms1408and1410, which can respectively include position locks1412and1414. Also shown inFIG.14is axis A, directions D1and D2, and orientation indicators Proximal and Distal.

The sleeve assembly1400can be similar to the sleeve assemblies discussed above, except that the lock arms1408and1410can be prevented from translating with respect to the body1404by the position locks1412and1414. A pinching force (shown as directions D1and D2) can be applied to the position locks1412and1414to release the lock arms1408and1410, respectively, from the body1404to allow translation of the lock arms proximally1408and1410with respect to the body1404. Such an assembly can help reduce the number of total parts.

FIG.15Aillustrates a top view of a sleeve assembly1500, in accordance with at least one example of this disclosure.FIG.15Billustrates a side view of a portion of the sleeve assembly1500, in accordance with at least one example of this disclosure.FIGS.15A and15Bare discussed below concurrently. The sleeve assembly1500can include a hex drive to allow a tool to be used to operate the actuator. Any of the previously discussed sleeve assemblies can be modified to include such a hex drive.

The sleeve assembly1500can include a body1504, a lock1406, and an actuator1508, which can include a hex drive1510. The sleeve assembly1500can be similar to the sleeve assemblies discussed above, except that the actuator1508can include the hex drive1510to allow a tool to be used to operate the actuator1510, which can help save time. In some examples, other drive engagements, such as slot, cross-recess, hexalobular, double hex, or the like.

FIG.16illustrates a cross section view of a portion of an anchor1602and sleeve assembly1600, in accordance with at least one example of this disclosure. The sleeve assembly1600can include a living hinge lock configured to engage a channel of the anchor. Any of the previously discussed sleeve assemblies can be modified to include such a living hinge lock.

The sleeve assembly1600can include a body1604, a lock1606, and an actuator. The body1604can include a lock arm1620A and a stop1612. The lock1606can include a spring lock1626, which can include a living hinge1630. The anchor1602can include a head1610having a channel1611Also shown inFIG.16is axis A, directions D1and D2, and orientation indicators Proximal and Distal.

The sleeve assembly1600can be similar to the sleeve assemblies discussed above, except that the spring lock1626can include the living hinge1630which can fold or change shape in response to movement in direction D1and contact between a distal portion of the spring lock1626and the stop1612, resulting in a compressive force. This compressive force can cause the living hinge to compress and move radially inward into the channel1611of the head1610to retain the anchor1602within the sleeve assembly.

FIG.17illustrates a cross section view of a sleeve assembly1700, in accordance with at least one example of this disclosure. The sleeve assembly1700can include a lock internal to the body, which can help protect the lock from external forces. Any of the previously discussed sleeve assemblies can be modified to include such an actuator and lock assembly.

The sleeve assembly1700can include a body1704, a lock1706, an actuator1708, and spring hooks1726, The sleeve assembly1700can be similar to the sleeve assemblies discussed above, except that the lock1706(including the lock arms) can be located within the body1704and can be movable therein. Such an internal lock can help reduce external interference of translation of the lock1706.

FIG.18illustrates a front view of a portion of an anchor1802and sleeve assembly1800, in accordance with at least one example of this disclosure. The sleeve assembly1800can include a lock actuated by insertion of the anchor1802into the sleeve. Any of the previously discussed sleeve assemblies can be modified to include such a lock assembly.

The sleeve assembly1800can include a body1804, a lock1806, and an actuator. The anchor1802and include a head1810having a channel1811. The lock can include a projection1830.FIG.18also shows axis A, direction D1, and orientation indicators Proximal and Distal.

The sleeve assembly1800can be similar to the sleeve assemblies discussed above, except that the projection1830of the lock1806can be actuated to move radially inward by insertion of the anchor1802into the body1804, where the anchor1810can contact the lock1806to cause the projection1830to engage the channel1811to retain the head1810within the sleeve assembly1800. Such a lock can provide a sleeve without an actuator, which can help reduce the number of parts.

Notes and Examples

Example 1 is a sleeve adapted to reinforce a bone anchor, the sleeve comprising: a body including a first sleeve arm and a second sleeve arm extending longitudinally along opposing sides of a longitudinal bore open at a distal end of the sleeve, the first and second sleeve arms separated by first and second sleeve slots, the first and second sleeve slots aligned across the longitudinal bore to receive a connecting member therethrough; a lock coupled to the body and releasably securable to a channel of a head of the bone anchor to secure the sleeve to the anchor; and an actuator connected to the body and operable between a locked and an unlocked position, the actuator configured to move the lock to engage the channel when the actuator is moved from the unlocked position to the locked position.

In Example 2, the subject matter of Example 1 optionally includes wherein the longitudinal bore is configured to receive extended tab portions of the head of the anchor therein.

In Example 3, the subject matter of Example 2 optionally includes wherein the first sleeve arm includes a first dovetail slot configured to receive a first extended tab of the anchor therein and wherein the second sleeve arm includes a second dovetail slot configured to receive a second extended tab of the anchor therein.

In Example 4, the subject matter of any one or more of Examples 1-3 optionally include wherein the first sleeve arm includes a first pocket located at a distal portion of the first sleeve arm and the second sleeve arm includes a second pocket located at a distal portion of the second sleeve arm, the lock movable within the first pocket and the second pocket to releasably engage the channel of the head of the anchor.

In Example 5, the subject matter of any one or more of Examples 1-4 optionally include wherein the actuator is a knob coupled to a proximal portion of the body, the knob rotatable to translate the lock relative to the body.

In Example 6, the subject matter of any one or more of Examples 1-5 optionally include a first spring hook secured to a distal portion of the first sleeve arm and a second spring hook secured to a distal portion of the second sleeve arm, the lock engageable with the first spring hook and the second spring hook to force the first spring hook and the second spring hook into the channel when the actuator is in the locked position.

In Example 7, the subject matter of any one or more of Examples 1-6 optionally include wherein the lock includes a first lock arm and a second lock arm, and wherein the first sleeve arm includes a first external slot configured to receive the first lock arm therein and wherein the second sleeve arm includes a second external slot configured to receive the second lock arm therein, the first lock arm and the second lock arm translatable within the first external slot and the second external slot, respectively.

In Example 8, the subject matter of Example 7 optionally includes a first spring hook secured to a distal portion of the first sleeve arm and a second spring hook secured to a distal portion of the second sleeve arm; wherein the first sleeve arm includes a first pocket located at a distal portion of the first sleeve arm and the second sleeve arm includes a second pocket located at a distal portion of the second sleeve arm, the first lock arm movable within the first pocket and the second lock arm movable within the second pocket to respectively engage the first spring hook and the second spring hook to force the first spring hook and the second spring hook into the longitudinal bore to engage the channel of the anchor to retain the anchor within the longitudinal bore when the actuator is in the locked position; and wherein the actuator is a knob coupled to a proximal portion of the body, the knob rotatable to translate the lock arms relative to the body.

In Example 9, the subject matter of Example 8 optionally includes wherein the first spring hook and second spring hook each include a barb extending radially inward to engage the channel of the anchor when the actuator is in the locked position.

In Example 10, the subject matter of Example 9 optionally includes wherein the first spring hook and second spring hook are biased radially outward from the longitudinal bore to limit engagement with the anchor when the actuator is in the unlocked position.

In Example 11, the subject matter of any one or more of Examples optionally include wherein the first lock arm and the second lock arm are positioned radially outward of the first spring hook and the second spring hook, respectively, and wherein the first lock arm and second lock arm each include a tapered portion that is tapered radially at a distal portion of each of the first lock arm and the second lock arm.

In Example 12, the subject matter of Example 11 optionally includes wherein the tapered portion of the first lock arm and the tapered portion of the second lock arm are configured to translate into the pocket such that, as the first lock arm and the second lock arm translate distally, the pocket deflects each of the first lock arm and second lock arm, respectively, radially inward to contact the first spring hook and the second spring hook, respectively, to force the first spring hook and the second spring hook into the longitudinal bore to engage the channel of the anchor to retain the anchor within the longitudinal bore.

In Example 13, the subject matter of Example 12 optionally includes wherein the distal tip of each of the first spring hook and the second spring hook include a tip width that is wider than a width of a first hook channel and a second hook channel which respectively connect to the first pocket and the second pocket, to limit radially outward movement of the first spring hook and the second spring hook, respectively, from the first pocket and the second pocket.

In Example 14, the subject matter of any one or more of Examples 8-13 optionally include wherein each of the first spring hook and the second spring hook include a distal tip tapered radially inward to promote radially inward deflection of each of the first spring hook and the second spring hook through contact between each of the first spring hook and the second spring hook and the first pocket and the second pocket, respectively, as the first spring hook and the second spring hook are moved from an unlocked position to a locked position.

In Example 15, the subject matter of any one or more of Examples 8-14 optionally include wherein the cap is threadably couplable to the body and wherein the cap includes a plurality of fingers configured to engage a radially inner portion of the lock to couple the cap to a proximal portion of the lock.

In Example 16, the subject matter of any one or more of Examples 8-15 optionally include wherein the lock includes a proximal bore and the body includes a proximal slot alignable with the proximal bore, each configured to receive a pin therethrough to limit translation of the lock relative to the body.

Example 17 is an implant system for securing an anchor to a bone, the system comprising: an anchor comprising: a head open at a proximal end of the head and; a shank extending distally from the head and configured to engage the bone; a first extension extending from a first breakaway portion coupling the first extension to the proximal end of the head; a second extension extending from a second breakaway portion coupling the second extension to the proximal end of the head; and a channel extending around at least a portion of the head, the channel located distal of the first breakaway portion and the second breakaway portion; and a sleeve adapted to reinforce the anchor, the sleeve comprising: a body including a first sleeve arm and a second sleeve arm together extending longitudinally to form a longitudinal bore open at a distal end of the sleeve to receive the head therein, the first and second sleeve arms separated by a first sleeve slot and a second sleeve slot to receive a connecting member therethrough; a lock coupled to the body and releasably engageable with the channel of the head to secure the sleeve to the anchor; and an actuator connected to the body and operable between a locked and an unlocked position, the actuator configured to move the lock to engage the channel when the actuator is moved from the unlocked position to the locked position.

In Example 18, the subject matter of Example 17 optionally includes wherein the first sleeve arm includes a first pocket located at a distal portion of the first sleeve arm and the second sleeve arm includes a second pocket located at a distal portion of the second sleeve arm, the lock movable within the first pocket and the second pocket to releasably engage the channel of the head of the anchor.

In Example 19, the subject matter of Example 18 optionally includes a first spring hook secured to a distal portion of the first sleeve arm and a second spring hook secured to a distal portion of the second sleeve arm, the lock engageable with the first spring hook and the second spring hook to force the first spring hook and the second spring hook into the channel when the actuator is in the locked position.

In Example 20, the subject matter of Example 19 optionally includes wherein the first spring hook and second spring hook each include a barb extending radially inward to engage the channel of the anchor when the actuator is in the locked position, and wherein the first spring hook and second spring hook are biased radially outward from the longitudinal bore to limit engagement with the anchor when the actuator is in the unlocked position.

In Example 21, the apparatuses or methods of any one or any combination of Examples 1-20 can optionally be configured such that all elements or options recited are available to use or select from.