Patent Description:
Surgical procedures are used to treat and cure a wide range of diseases, conditions, and injuries. Surgery often requires access to internal tissue through open or minimally invasive surgical procedures. The term "minimally invasive" refers to all types of minimally invasive surgical procedures, including endoscopic, laparoscopic, arthroscopic, natural orifice intraluminal, and natural orifice transluminal procedures. Minimally invasive surgery can have numerous advantages compared to traditional open surgical procedures, including reduced trauma, faster recovery, reduced risk of infection, and reduced scarring.

Whether minimally invasive or not, there are a number of surgical procedures in which it can be desirable to form a working channel in a patient to provide access to a surgical site within the patient. One such example is orthopedic or neurologic surgical procedures, including, e.g., spinal fusion procedures where it can be desirable to form a working channel through a patient's tissue to access their vertebrae and/or the intervertebral discs disposed between adjacent vertebrae.

A variety of methods for providing such a working channel are known, including various devices that are anchored to a surgical table upon which a patient is disposed, devices that penetrate tissue without being anchored to any other structure, or devices that couple to a plurality of anchors implanted in a patient's bone. In such arrangements, the devices may be inadequately supported, may undesirably move relative to a patient if the patient moves relative to the operating table or some other external structure, or may impede a surgeon or other user in performing some aspect of a procedure.

By way of example, in spinal procedures involving operation on a patient's intervertebral disc disposed between adjacent vertebrae, access to the disc space can be difficult. Prior approaches can involve performing work on intervertebral discs before implanting pedicle screws in the adjacent vertebrae. Surgery on the intervertebral disc, however, can involve removal of portions of bone from the adjacent vertebrae, which can make subsequent implanting of pedicle screws more difficult. Implanting screws before removing vertebral bone can therefore be desirable, but surgeons cannot implant the pedicle screws with receiver heads before performing intervertebral disc work because the receiver heads (and extension posts typically coupled thereto) can block access to the intervertebral disc space. As a result, surgeons often resort to inserting guidewires for the pedicle screws, bending the guidewires away from the intervertebral space to perform disc operations around the guidewires, then implanting the pedicle screws.

The advent of modular pedicle screws can allow pedicle anchors to be implanted before performing intervertebral disc operations. This is because modular pedicle screws can include a lower-profile implantable anchor that can be implanted without impeding access to, e.g., an intervertebral disc. A spinal fixation element receiver can be coupled to the anchor after implantation and completion of any intervertebral disc operation. Such anchors can also provide a rigid access point indexed to the patient's anatomy.

Accordingly, there is a need for improved access devices, systems, and methods that can streamline the instrumentation and methodology of various surgical procedures. For example, there is a need for improved access devices, systems, and methods that can utilize anchors implanted in a patient's anatomy to support surgical instruments. <CIT> discloses a retractor-distractor system comprising a frame with slidably coupled superior and inferior arms extending therefrom. The superior arm comprises a superior clamp arm pivotally coupled to a lateral end of the superior arm, a superior ball joint received between the superior clamp arm and the superior arm, and a superior ball joint lock operable to pivot the superior clamp arm proximate to the superior arm, thereby locking the orientation of the superior ball joint. The inferior arm comprises an inferior clamp arm pivotally coupled to a lateral end of the inferior arm, an inferior ball joint received between the inferior clamp arm and the inferior arm, and an inferior ball joint lock operable to pivot the inferior clamp arm proximate to the inferior arm, thereby locking the orientation of the inferior ball joint. The superior and inferior arms are operable to receive a modular blade to retract and distract tissue. <CIT> discloses derotation instrument assemblies and systems that are provided to facilitate positioning one or more vertebrae of a spinal column into a desired alignment. The instrument assemblies and systems include implant holders engageable to respective implants engaged to vertebrae of the spinal column, transverse bridges to connect implant holders associated with a particular vertebra, and inter-level linking assemblies to connect instrument assemblies associated with different vertebrae. Derotation handles can be provided to facilitate application of the alignment forces, while the assemblies distribute the corrective forces to the connected implants and vertebrae. In one embodiment of <CIT>, implant holder includes a first arm in the form of a tubular body and a second arm providing a clamp portion pivotally coupled to first arm. Each of the first and second arms includes a respective distal end portion of a distal holding end of implant holder. Each of the portions forms a space in which to receive a portion of the bone implant, and further includes a projection extending into the space toward the other portion. The projections are received in detents formed in the receiver of the implant to which holder is engaged by clamping arms to the receiver of the implant when implant holder is closed. To release the implant, implant holder is opened by pivoting second arm about pivotal connection with first arm. <CIT> describes a surgical retractor and related methods for providing access to a surgical target site for the purpose performing minimally invasive spinal fusion across one or more segments of the spinal column. <CIT> discloses instruments, tools, and methods that assist in assembling components of a surgical construct, for example, a press-on rod to a pedicle screw. An instrument includes an elongate driving rod having a distal tip adapted to engage and transfer a rotational force to a surgical screw and a driver connection at a proximate end thereof, a first elongate shaft having a distal end, a proximal end, and a generally U-shaped channel adapted to receive the elongate driving rod therein, and a retention mechanism to retain the elongate driving rod in the generally U-shaped channel. A tool includes an elongate hollow rod having a collapsible distal tip, an elongate shaft slidingly disposed within the elongate hollow rod, the elongate shaft having a distal end comprising a driving feature, and a locking mechanism to prevent the distal end of the elongate shaft from being inadvertently removed from the distal tip of the elongate hollow rod. <CIT> discloses devices, systems and methods for minimally open orthopedic spine surgery. A first flexible screw-based retractor is designed to be coupled to each pedicle screw inserted into adjacent vertebral bodies. A retractor system is provided in which a first retractor blade is mounted to one of the screws and a second movable retractor blade is moved away from the first blade, in a medial direction, to create a working channel through which the disc space may be accessed for passing instruments and implants. Light may be incorporated into the device to illuminate the surgical field. One or all of the retractor blades may be made of a sterilizable plastic or metal and be disposable or reusable.

The invention provides a surgical instrument according to claim <NUM>; optional features are set out in the dependent claims. No methods are explicitly claimed, although it is intended that the surgical instrument of the invention may be used to perform the methods disclosed below. In some embodiments, a patient-mounted surgical support is provided that can couple to an implanted anchor and provide an adjustable and selectively lockable platform for securing other surgical instruments and/or assemblies. For example, a surgical support can be provided that can couple to a single implanted pedicle screw or other anchor and provide selective or lockable polyaxial adjustment relative thereto. Further, the surgical support is configured to couple to a tissue retractor, that can manipulate tissue to provide a working channel to a surgical site, such as a patient's intervertebral disc space. Such a support instrument can advantageously be indexed to a patient via coupling with the implanted anchor and can minimize space required to support a retractor or other instrumentation. While the instruments, devices, systems, and methods described herein can be utilized in a variety of surgical procedures, they can have particular utility in various orthopedic or neurologic surgical procedures, such as spinal operations.

A surgical instrument is provided that can include an elongate body and opposed projections extending laterally from a distal portion of the elongate body that can be configured to at least partially surround a shank of an implantable anchor at a position distal of a proximal head of the anchor such that a longitudinal axis of the elongate body is laterally offset from a longitudinal axis of the anchor. The instrument includes a lock configured to exert a drag force on the head of the anchor to control polyaxial movement of the instrument relative to the anchor. Further, a proximal portion of the elongate body is configured to receive a retractor assembly including a plurality of tissue manipulating blades and selectively lock the retractor assembly at any of a plurality of positions along a length of the proximal portion of the elongate body.

The instruments and methods described herein can have a number of additional features and/or variations, all of which are within the scope of the present disclosure. No methods are explicitly claimed, although it is intended that the surgical instrument of the invention may be used to perform the described methods. The lock is configured to translate relative to the elongate body and contact an upper portion of the proximal head of the anchor. In some embodiments, the instrument can further include a biasing element disposed within a lumen of the elongate body that can be configured to urge the lock into contact with the anchor head to exert the drag force on the anchor. The instrument includes a locking screw disposed within a lumen of the elongate body and configured to adjust the drag force exerted on the head of the anchor. Still further, the lock can include a laterally-extending ring-shaped projection at a distal end thereof that can contact the anchor head while maintaining access to a drive feature formed on a proximal end of the anchor head. In some embodiments, the lock can further include a ring-shaped driver guide pivotally coupled thereto.

In certain embodiments, the proximal portion of the elongate body can include a plurality of holes formed therein that can be configured to receive a locking pin of the retractor assembly to selectively lock the retractor assembly at any of a plurality of positions along the length of the proximal portion of the elongate body. In other embodiments, the proximal portion of the elongate body can include a ratchet configured to interface with a pawl coupled to the retractor assembly to selectively lock the retractor assembly at a plurality of positions along the proximal portion of the elongate body.

In some embodiments, the plurality of tissue manipulating blades can be translated laterally relative to the longitudinal axis of the elongate body. For example, in some embodiments the blades can be translated in a medial-lateral direction toward or away from one another. Moreover, in some embodiments the plurality of tissue manipulating blades can be pivoted about an axis that is transverse to the longitudinal axis of the elongate body. Such movement can include toeing, wherein a distal end of the plurality of tissue manipulating implements moves any of toward or away from one another while a distance between proximal ends of the plurality of tissue manipulating implements remains unchanged.

In another aspect, a surgical method is provided that includes positioning opposed projections of a shank extension instrument to at least partially surround a shank of an implantable anchor at a position distal of a proximal head of the anchor such that a longitudinal axis of the elongate body is laterally offset from a longitudinal axis of the anchor, as well as exerting a drag force on the head of the anchor to control polyaxial movement of the shank extension instrument relative to the anchor. The method can also include coupling a retractor assembly including a plurality of tissue manipulating implements to a proximal portion of the shank extension instrument, and retracting soft tissue by moving the plurality of tissue manipulating implements of the retractor assembly.

As with the system described above, a number of variations and additional features are possible. For example, in some embodiments exerting a drag force on the head of the anchor can include translating a lock relative to the elongate body to contact an upper portion of the proximal head of the anchor. By way of further example, in some embodiments the method can further include adjusting a position of the retractor assembly relative to the elongate body to position the plurality of tissue manipulating implements relative to tissue, as well as locking a position of the retractor assembly relative to the elongate body.

In some embodiments, retracting soft tissue by moving the plurality of tissue manipulating implements of the retractor assembly can include translating opposed implements in a medial-lateral direction. In certain embodiments, retracting soft tissue by moving the plurality of tissue manipulating implements of the retractor assembly can also and/or alternatively include toeing the opposed implements to bring distal ends thereof any of closer or father away from one another.

In some embodiments, the method can further include coupling a light to the retractor assembly to illuminate a workspace between the plurality of tissue manipulating blades. Moreover, in some embodiments the method can further include coupling the retractor assembly to an external rigid structure, such as a surgical table, etc. In certain other embodiments, however, the retractor assembly can be anchored solely to the anchor.

In some embodiments, the method can further include implanting the anchor in bone prior to positioning the opposed projections of the shank extension instrument to at least partially surround the shank of the anchor. In other embodiments, the method can include implanting the anchor in bone after positioning the opposed projections of the shank extension instrument to at least partially surround the shank of the anchor. Moreover, in some embodiments the method can include coupling a polyaxial receiver head to the proximal head of the anchor.

In another aspect, a surgical instrument assembly is provided that includes an implantable anchor having a proximal head and a distally-extending shank with a diameter smaller than a diameter of the proximal head, as well as an anchor extension. The anchor extension can include an elongate body and opposed projections extending laterally from a distal portion of the elongate body that at least partially surround the shank of the anchor at a position distal of a proximal head of the anchor such that a longitudinal axis of the elongate body is laterally offset from a longitudinal axis of the anchor. The anchor extension can also include a lock that exerts a drag force on the head of the anchor to control polyaxial movement of the extension relative to the anchor. The assembly can further include a tissue retractor coupled to a proximal portion of the anchor extension, the tissue retractor including a plurality of implements that move laterally relative to the longitudinal axis of the elongate body of the anchor extension to retract tissue.

Any of the features or variations described above can be applied to any particular aspect or embodiment of the present disclosure in a number of different combinations. The absence of explicit recitation of any particular combination is due solely to the avoidance of repetition in this summary.

Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices, systems, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices, systems, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.

Additionally, to the extent that linear or circular dimensions are used in the description of the disclosed devices and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such devices and methods. Further, in the present disclosure, like-numbered components of the embodiments generally have similar features. Still further, sizes and shapes of the devices, and the components thereof, can depend at least on the anatomy of the subject in which the devices will be used, the size and shape of components with which the devices will be used, and the methods and procedures in which the devices will be used.

<FIG> illustrate an exemplary surgical instrument <NUM> according to the teachings provided herein. The instrument <NUM> can be used in various surgical procedures, including spinal surgeries such as microsurgical bone resection, spinal decompression, spinal fusion, and the like. In general, the instrument <NUM> can include an elongate body <NUM>, a lock body <NUM>, and a lock actuator <NUM>. The instrument <NUM> can be configured to couple to an implantable anchor <NUM>, such as a pedicle screw or other bone screw. Other components not illustrated here can be included or coupled to the instrument <NUM>. Such components can include, for example, any of a variety of retractor assemblies, as described herein, as well as other components, such as a camera or visualization system, and any of a variety of other surgical instruments.

An exemplary method of using the instrument <NUM> of <FIG> can include any one or more of the following steps, performed in any of a variety of sequences: a) making an incision in a skin of a patient; b) percutaneously inserting through the incision an implantable anchor, such as a pedicle or other bone screw; c) coupling the instrument <NUM> to the implanted anchor (e.g., a pedicle anchor); d) coupling a tissue retractor to the instrument; e) providing medial-lateral retraction of tissue surrounding an incision; f) coupling an optical visualization instrument to the tissue retractor and/or instrument; g) resecting a portion of the superior articular process, and/or performing a microsurgical decompression procedure; h) extracting intervertebral disc material including removing cartilaginous material from the vertebral endplates; i) inserting an interbody device; and j) deploying a mechanism of stabilization to stabilize the intervertebral segment.

Returning to <FIG>, the elongate body <NUM> of the instrument <NUM> can include a fork <NUM> formed at a distal end thereof that can interface with a narrowed neck <NUM> of the anchor <NUM>. The fork <NUM> can include opposed projections 302a, 302b that extend laterally from a distal portion of the elongate body <NUM> in a manner that is transverse or oblique to a longitudinal axis L<NUM> of the elongate body. The projections 302a, 302b can define a U-shaped or otherwise openended recess <NUM> that can be sized to receive a portion of the implantable anchor <NUM>. For example, the projections 302a, 302b can be configured to fit around a proximal portion of a bone anchor that can be part of a modular mono- or poly-axial pedicle screw. Such anchors can include a generally cylindrical distal shank portion <NUM> with threads for tapping into bone, as well as a narrowed neck <NUM> proximal of the shank portion <NUM> and a wider proximal head <NUM>. The proximal head <NUM> can be generally spherical or semi-spherical in shape and can be configured to couple with a receiver head before or after implantation in a patient's bone. Such bone anchor assemblies are known in the art and described, for example, in <CIT> and entitled "BONE ANCHOR ASSEMBLIES AND RELATED INSTRUMENTATION,". The size and spacing of the projections 302a, 302b can be configured such that the narrowed neck <NUM> fits within the recess <NUM> but proximal or upward movement of the elongate body <NUM> is prevented by interference between the projections and the wider proximal head <NUM>.

Once the projections 302a, 302b of the fork <NUM> are disposed around the neck <NUM> of the anchor <NUM>, friction between the elongate body and the anchor can cause a drag force to any of resist and prevent movement of the elongate body relative to the anchor. In certain embodiments, the drag force can be sufficient to prevent movement of the elongate body <NUM> relative to the anchor <NUM> in the absence of deliberate manipulating force applied, for example, by a user grasping the elongate body and adjusting its position polyaxially relative to the anchor. Such a drag force can be applied in a variety of manners. For example, in some embodiments tissue forming incision walls surrounding the anchor <NUM> can exert sufficient force against the fork <NUM> to prevent relative movement between the fork and the anchor. Such force might be an inward or compression force exerted by tissue surrounding the anchor <NUM>, or the fork <NUM> can be pulled upward such that a skin surface of the patient is disposed below the fork and exerts an upward force on the fork. As another example, the anchor <NUM> can be tightened to compress the fork <NUM> between the head portion <NUM> of the anchor and a bone surface.

In addition or alternatively, the instrument can include a lock configured to exert a drag force on the head of the anchor to control polyaxial movement of the instrument <NUM> relative to the anchor <NUM>. As shown in <FIG>, such a lock can include a lock body <NUM> that is coupled to the elongate body <NUM> and translatable relative thereto along the longitudinal axis L<NUM> of the elongate body. The lock body <NUM> can have a generally elongate shape to facilitate coupling with and translating or sliding along or relative to the elongate body <NUM>. The lock body <NUM> can further include a laterally-extending ring-shaped projection <NUM> at a distal end thereof that can be configured to contact the proximal head <NUM> of the anchor <NUM> and exert a drag force thereon. A lumen <NUM> defined by the ring-shaped projection <NUM> can maintain access to a drive feature <NUM> formed on a proximal end of the head <NUM> of the anchor <NUM>. This lumen, in combination with the lateral extension of the projection <NUM> and fork <NUM> can orient the instrument <NUM> such that a longitudinal axis L<NUM> of the instrument is laterally offset or non-coaxial with a longitudinal axis L<NUM> of the anchor <NUM>. Such a configuration can allow a driver or other instrument to access the drive feature <NUM> of the anchor <NUM> even when the instrument <NUM> is coupled thereto. This can enable flexibility to implant the anchor <NUM> any of before and after coupling the instrument <NUM> thereto.

The lock body <NUM> can also include any of a variety of features to facilitate slidable coupling with the elongate body <NUM>. For example, the lock body <NUM> can include indexing projections <NUM>, <NUM> that can be configured to be received within longitudinally-extending slot <NUM> formed in the elongate body. The projections <NUM>, <NUM> and slot <NUM> can have any of a variety of complementary shapes and, in some embodiments, can include one or more angled surfaces, e.g., dovetails, etc., that can permit longitudinal or axial translation while preventing lateral or radial separation of the components. The slot <NUM> can also include one or more widened portions <NUM>, <NUM> such that the lock body <NUM> can be translated to a position where lateral or radial separation of the lock body and the elongate body <NUM> is permitted.

The lock body <NUM> can also include a slot <NUM> formed therein that can receive a second lock <NUM>. The second lock <NUM> can be configured to prevent the lock body <NUM> from being translated to the above-described position relative to the elongate body <NUM> wherein lateral or radial separation of the lock body from the elongate body is permitted. For example, the second lock <NUM> can include a projection <NUM> that when assembled, can extend through a passage <NUM> formed in the lock body <NUM> and into a bore <NUM> formed in the elongate body <NUM>. Proximal translation of the lock body <NUM> can therefore be limited by interaction of the projection <NUM> with a proximal sidewall of the bore <NUM> at a position wherein the projections <NUM>, <NUM> of the lock body <NUM> are not aligned with the widened portions <NUM>, <NUM> of the slot <NUM> in the elongate body. Removal of the second lock <NUM>, however, can allow unrestricted proximal translation of the lock body <NUM> relative to the elongate body <NUM> to a position where the projections <NUM>, <NUM> align with the widened portions <NUM>, <NUM> of the slot <NUM> and separation of the two components is possible.

As noted above, the lock body <NUM> can impart a drag force on the proximal head <NUM> of the anchor <NUM> to control (e.g., selectively permit or prevent, with varying levels of manipulating force required to achieve) polyaxial movement of the instrument <NUM> relative to the anchor <NUM>. The level of force imparted by the lock body <NUM> can be controlled by a locking screw. The locking screw <NUM> is disposed within a lumen <NUM> of the elongate body <NUM>, for example, threads <NUM> formed on the locking screw <NUM> can engage complementary threads <NUM> formed on an inner surface of the lumen <NUM>. Distal advancement of the screw <NUM> can exert a distal force on the lock body <NUM> via a protrusion <NUM> extending into a bore <NUM> formed in the elongate body <NUM>. In some embodiments, a distal portion of the locking screw or other actuator <NUM> can directly contact the protrusion <NUM>. In other embodiments, and as illustrated in <FIG> for example, a biasing element <NUM> can be disposed between the screw <NUM> and the protrusion <NUM>. The biasing element <NUM>, which can be, e.g., a coil or other compression spring, can impart a desired drag force that can semi-rigidly maintain a position of the instrument <NUM> relative to the anchor <NUM> while continuing to permit polyaxial movement of the instrument if, for example, a user overcomes the drag force. When desired, a complete lockout of all relative movement between the instrument and the anchor can be achieved by distal advancement of the locking screw or other actuator <NUM>.

In some embodiments, the instrument <NUM> can be configured to permit attachment of a modular receiver head to the proximal head <NUM> of the anchor <NUM> without decoupling of the anchor and the instrument <NUM>. For example, in the illustrated embodiment the locking actuator <NUM> can be proximally retracted at least partially and can be removed entirely to remove the drag force imparted on the anchor <NUM> by the lock body <NUM>. Further, the second lock <NUM> can be removed to allow the lock body <NUM> to be translated proximally and subsequently decoupled from the elongate body <NUM>. An instrument for assisting in removal of the lock body <NUM> is illustrated in <FIG>, described in more detail below. A modular receiver head (not shown) can then be coupled to the proximal head <NUM> of the anchor <NUM>. The elongate body <NUM> can be left in place, as it is offset from the anchor <NUM> by the laterally-extending projections 302a, 302b of the fork <NUM> and because the projections 302a, 302b disposed below the proximal head <NUM> will not interfere with coupling a receiver head to the proximal head of the anchor <NUM>. Further, and as noted above, in some embodiments a position of the elongate body <NUM> relative to the anchor <NUM> can continue to be maintained even after the lock body <NUM> is removed by, for example, force applied by tissue surrounding the anchor and elongate body. Still further, in some embodiments the elongate body <NUM> or other component coupled thereto can be coupled to an external rigid structure, such as a surgical table, etc. Such an external rigid structure can aid in maintaining a position of the elongate body <NUM> even after removal of the lock body <NUM>.

The instrument <NUM> can be configured to couple with a retractor assembly, as described in more detail below. The retractor assembly can include a plurality of tissue manipulating implements that can be used to, for example, widen an incision formed in a patient's skin and tissue to enable better access to a surgical site. In some embodiments, the retractor assembly can couple to a proximal portion of the elongate body <NUM> and can selectively lock at any of a plurality of positions along a length of the proximal portion of the elongate body. For example, and as shown in <FIG> and <FIG>, the elongate body <NUM> can include a plurality of notches <NUM> formed along a length of a proximal portion thereof. The series of notches <NUM> can serve as a ratchet that can interface with a pawl-like feature of the retractor assembly, such as a protrusion or other portion of the assembly, to secure the assembly against movement along the longitudinal axis L<NUM> of the elongate body <NUM>.

Accordingly, the above described support instrument <NUM> can provide a platform for mounting a retractor assembly that is anchored to a single implanted bone screw or other anchor. This can provide a number of advantages. For example, it can be advantageous to utilize a support that is anchored to a patient's body, as opposed to an external structure, such as a surgical table, etc. For example, anchoring relative to a patient's body can provide an advantage by maintaining a relative position between an access device and a patient even if a patient moves during a procedure. Moreover, it can be advantageous to anchor to a single bone screw or other anchor (e.g., as opposed to constructs that span across multiple implanted anchors), as this can reduce the footprint of instrumentation and can allow greater working space for other implements employed in a procedure. In some embodiments, however, it can be possible to also anchor the instruments and assemblies described herein to an external structure, such as a surgical table, etc. In some embodiments where external fixation is employed, locking against movement relative to an implanted anchor can be avoided such that some adjustment relative to an implanted anchor is possible in case of patient movement, etc..

A variety of alternative embodiments of support instruments are within the scope of the present disclosure. For example, <FIG> illustrate various exemplary alternative embodiments of a surgical support instrument similar to the instrument <NUM>. The instrument <NUM> of <FIG>, for example, is coupled to the anchor <NUM> and includes an alternative configuration of an elongate body <NUM> and lock body <NUM>. For example, the lock body <NUM> can include a hook-shaped projection <NUM> that can be disposed within a slot <NUM> formed in the elongate body <NUM>. The projection <NUM> and slot <NUM> are an alternative geometry that can serve a similar purpose as the projections <NUM>, <NUM> and slot <NUM> described above. Also visible in <FIG> is an alternative geometry for the locking screw <NUM>, which threads through a proximal portion <NUM> of the elongate body <NUM> and directly contacts a proximal end <NUM> of the lock body <NUM>. Further, the elongate body <NUM> includes a proximally extending post <NUM> that can be utilized to couple the instrument <NUM> to, for example, a retractor assembly or external fixation structure, as described herein.

<FIG> illustrates another embodiment of an instrument <NUM> coupled to the anchor <NUM>. The instrument <NUM> includes an elongate body <NUM>, lock body <NUM>, and lock actuator <NUM> for selectively controlling polyaxial movement of the instrument relative to the anchor. The elongate body <NUM> includes an extended proximal portion <NUM> that increases a height of the elongate body to provide additional mounting options for a retractor assembly to be coupled thereto. Any desired length of the elongate body <NUM> and proximal portion <NUM> thereof is possible, and a length of the lock actuator <NUM> can be adjusted accordingly to maintain operability of the instrument. Moreover, the proximal portion <NUM> can include a plurality of holes <NUM> formed therein that can be used to lock a position of a retractor assembly relative thereto. For example, one or more of the holes <NUM> can receive one or more locking pins coupled to the retractor assembly to achieve a lock between the components, similar to the ratchet-and-pawl configuration described above. Alternatively, a retractor assembly or other implement can couple to the elongate body proximal portion <NUM> in another manner, for example by clamping around the cylindrical proximal portion of the elongate body with sufficient force to prevent relative movement between the two components.

<FIG> illustrate another embodiment of an instrument <NUM> that can couple to the anchor <NUM> and includes an alternative configuration of an elongate body <NUM> and a lock body <NUM>. For example, the lock body <NUM> can include a hook-shaped projection <NUM> disposed within a slot formed in the elongate body <NUM>, similar to the instrument <NUM> described above. Moreover, a proximal surface of the hook-shaped projection <NUM> can be used to control the drag force imparted on the anchor <NUM> by the lock body <NUM> via the lock actuator <NUM>. The lock actuator includes a screw <NUM> threaded into a proximal portion of the elongate body <NUM> and, in the illustrated embodiment, a biasing element <NUM> and an intermediate member <NUM> that extends between the projection <NUM> and the biasing element <NUM>.

A proximal portion of the elongate body <NUM> can include one or more holes <NUM> formed therein that can receive, for example, a locking pin from a retractor assembly or other implement to be coupled to the instrument <NUM>, similar to the holes <NUM> described above. The proximal portion of the elongate body can also include one or more tool-interfacing surfaces <NUM>, such as one or more pairs of opposed planar surfaces, that can be utilized to prevent rotation of the elongate body <NUM> as a torque is applied to the locking screw <NUM>. For example, a wrench or other tool can be utilized to immobilize the elongate body <NUM> or apply a counter torque thereto as the locking screw <NUM> is rotated to engage or disengage locking of the instrument <NUM> relative to the anchor <NUM>.

Still further, the lock body <NUM> of the instrument <NUM> can include a driver guide <NUM> coupled thereto. In the illustrated embodiment, the driver guide <NUM> is a ring-shaped member pivotably coupled to a proximal end of the lock body <NUM>. The driver guide <NUM> can be pivoted or rotated between a first configuration, as shown in <FIG>, and a second configuration, as shown in <FIG>. In the first configuration, the driver guide extends laterally from the elongate body <NUM> and lock body <NUM> such that an inner lumen <NUM> defined by the guide is aligned with an inner lumen of the ring-shaped projection <NUM> of the lock body <NUM>. In the second configuration, the driver guide <NUM> is aligned with the lock body <NUM> and lays flush against the elongate body <NUM>, thereby clearing the space above the anchor <NUM> and ring-shaped projection <NUM>. In some embodiments, the driver guide <NUM> can include one or more retention features, such as protrusions 822a, 822b that can interface with complementary features, such as recesses 824a, 824b formed on the elongate body <NUM>, to maintain the driver guide <NUM> in the second configuration of <FIG> and prevent it from inadvertently falling into the first configuration of <FIG>.

<FIG> illustrate a similar instrument <NUM> that includes an elongated proximal portion <NUM> have a plurality of holes 915a, 915b formed therein both around a circumference thereof and along a length thereof. The holes <NUM> can be configured to receive one or more locking pins of a retractor assembly or other surgical implement that can couple to the instrument <NUM> in order to lock any of a rotational and longitudinal position of the implement relative to the instrument. The instrument <NUM> also includes an alternative locking actuator that includes a screw <NUM> with a distal post <NUM> that can extend into an inner lumen of a compression spring biasing element <NUM> and, when advanced distally to a sufficient extent, can directly contact the intermediate member <NUM>, as shown in <FIG>. When not in contact with the intermediate member <NUM> to directly impart force thereto, the post can aid in preventing buckling of the compression spring <NUM>.

<FIG> illustrate still another embodiment of an instrument <NUM> that includes an elongate body <NUM>, a two-part lock body <NUM>, <NUM>, and a locking actuator <NUM>. The elongate body <NUM> is similar in configuration to the embodiments described above, including a proximal portion <NUM> with a plurality of sets of holes 1015a, 1015b distributed along a length thereof that can be utilized to lock a retractor assembly or other implement at a particular position along a length of the elongate body <NUM>. The elongate body <NUM> also includes a slot <NUM> formed in a distal portion thereof. Portions of the distal lock body <NUM> and proximal lock body <NUM> are disposed within the slot <NUM> and a biasing element <NUM>, such as a compression spring, can be disposed therebetween to urge the proximal lock body proximally and the distal lock body distally. Movement of the lock bodies <NUM>, <NUM> can be limited by proximal and distal ends of the slot <NUM> and the biasing element can function to exert at least a minimal drag force on an anchor <NUM> via the distal lock body <NUM>. Additional drag force, up to and including complete lockout against relative movement between the instrument <NUM> and an anchor <NUM>, can be achieved by rotating the screw <NUM> to distally advance it relative to the elongate body <NUM> and urge the proximal lock body <NUM> distally toward the distal lock body <NUM>.

The proximal and distal lock bodies <NUM>, <NUM> can include one or more complementary slots <NUM> and projections (not visible) to join the lock bodies together and prevent undesirable separation or movement other than translation relative to one another along a longitudinal axis L<NUM> of the instrument. Moreover, the proximal lock body <NUM> can include a pivoting driver guide <NUM>, similar to the above-described driver guide <NUM>. In the illustrated embodiment, however, a further retention feature in the form of a slot <NUM> is formed on a distal end of the driver guide and can be configured to interface with a projection <NUM> formed on the elongate body <NUM> when the driver guide is retracted toward the elongate body to prevent its inadvertent movement away from the elongate body. The retention features <NUM>, <NUM> can be additional to, or in place or, projection features <NUM> formed at an opposite end of the driver guide and configured to interface with ridge <NUM> formed on the elongate body. Moreover, in the illustrated embodiment the ridge <NUM> extends for a distance along the elongate body to allow the projection feature <NUM> to translate relative to the elongate body along with the proximal lock body <NUM>.

<FIG> illustrates an example of a support instrument <NUM> configured to couple to an anchor <NUM>. This example is helpful for understanding the disclosure; the invention is defined by appended claim <NUM>. The instrument <NUM> includes first and second opposed elongate bodies <NUM>, <NUM> that are pivotably coupled to one another at hinge <NUM> and therefore rotate relative to one another about an axis P<NUM>. The instrument <NUM> also includes a lock <NUM> that includes first and second lumens 1108a, 1108b configured to receive proximal portions of each elongate bodies <NUM>, <NUM>. The lumens 1108a, 1108b can have a fixed size and position relative to one another, such that when assembled over the proximal ends of the elongate bodies <NUM>, <NUM> the lock <NUM> can maintain a position of the elongate bodies relative to one another.

A distal portion of each elongate body <NUM>, <NUM> can include a laterally-extending projection 1110a, 1110b that can form a semi-circular shape such that the two elongate bodies <NUM>, <NUM>, when positioned adjacent to one another, define a circular recess <NUM> between the projections. Accordingly, the instrument <NUM> can be used by separating the lock <NUM> from the elongate bodies <NUM>, <NUM> and bringing proximal ends 1114a, 1114b toward one another. Such motion can cause rotating of the elongate bodies <NUM>, <NUM> about the pivot <NUM>, thereby moving the distal projections 1110a, 1110b away from one another. The instrument <NUM> can then be passed down over a proximal head <NUM> of an anchor <NUM> or laterally over a shank <NUM> or neck <NUM> underneath the proximal head <NUM>. The proximal ends 1114a, 1114b of the elongate bodies <NUM>, <NUM> can be moved away from one another to cause the distal projections 1110a, 1110b to move toward one another and abut against the anchor <NUM>. Imparting sufficient force to the proximal ends (urging them away from one another) can clamp the anchor <NUM> with sufficient force to prevent relative movement between the instrument <NUM> and the anchor <NUM>.

A position of the instrument <NUM> relative to the anchor <NUM> can be locked by passing the lock <NUM> distally over the proximal ends 1114a, 1114b of the elongate bodies <NUM>, <NUM> such that the elongate body <NUM> is received within the lumen 1108a and the elongate body <NUM> is received within the lumen 1108b. Because the sizes of the elongate bodies and the lumens of the lock are complementary, and because the lumens are fixed relative to one another on the lock <NUM>, the lock can maintain the relative positioning of the elongate bodies <NUM>, <NUM> and prevent separation of the distal projections 1110a, 1110b.

Moreover, the lock <NUM> can include one or more pawls, protrusions, or other features (not visible) that can interact with a series of notches, teeth, shelves, or other recesses 1116a, 1116b formed on each elongate body <NUM>, <NUM> to set and maintain a desired height of the lock <NUM> relative to the elongate bodies. A retractor assembly or other implement can then be coupled to the lock <NUM> or the lock can be eliminated and the assembly can include the correctly spaced and sized lumens to directly interface with the elongate bodies <NUM>, <NUM>.

Adjusting a position of the lock <NUM> along a length of the elongate bodies <NUM>, <NUM> can, in some examples, not influence the clamping force maintained by the lock. For example, if sufficient clamping is achieved when the proximal portions 1114a, 1114b of the elongate bodies <NUM>, <NUM> are parallel, the lock <NUM> can exert and maintain a same clamping force at any position along the series of recesses 1116a, 1116b. Adjusting the positioning of the lock <NUM> (or retractor assembly include lumens like the lock <NUM>) along the elongate bodies <NUM>, <NUM> can serve to set a height of any retractor assembly or other implement that couples to the lock <NUM>.

In one example, a user can place the distal projections 1110a, 1110b of the instrument <NUM> around a cylindrical shank or neck of an anchor <NUM> and urge the proximal ends of the elongate bodies <NUM>, <NUM> away from one another to secure the instrument to the anchor. The user can then couple a retractor assembly to the elongate bodies <NUM>, <NUM> by passing the elongate bodies through lumens formed in the retractor assembly (or coupling the retractor assembly to the lock <NUM> and coupling the lock to the elongate bodies). The user can then push the retractor down toward the patient's tissue causing it to slide distally along the elongate bodies <NUM>, <NUM> until the retractor abuts against the patient's tissue. At such a point, the rigid positioning of the lumens receiving the elongate bodies <NUM>, <NUM> can maintain their relative positioning and upward or proximal force imparted to the elongate bodies by the retractor assembly being in contact with the patient's tissue can secure the distal projections against, for example, the underside of a proximal head <NUM> of an anchor <NUM>, thereby stabilizing the instrument's position.

As noted above, the various support instrument embodiments described above can be configured to couple with or receive a retractor assembly that can include a plurality of tissue manipulating implements. <FIG> illustrate various embodiments of retractor assemblies that can be utilized in combination with the support instruments described herein. Further details on retractor assemblies can be found in <CIT>.

<FIG> illustrate a first embodiment of a retractor assembly <NUM> that can couple to, for example, the surgical support instrument <NUM> described above. The retractor <NUM> can include a plurality of tissue manipulating implements, such as tissue manipulating blades <NUM>, <NUM>. The tissue manipulating implements or blades <NUM>, <NUM> can have any of a variety of shapes and sizes. For example, the tissue manipulating blades <NUM>, <NUM> can have a variety of heights to extend to various depths below a patient's skin surface and to various heights above the skin surface. Further, in some embodiments a height of any of the blades <NUM>, <NUM> can be adjustable, e.g., in an embodiment where a blade includes an inner component and an outer component configured to translate relative to one another to vary the amount by which they overlap and an overall length of the two components together. The blades <NUM>, <NUM> can also have any of a variety of widths, shapes, and curves. For example, in some embodiments the blades can be planar, while in other embodiments, such as the illustrated embodiment, the blades can have a semi-circular curve extending along a length thereof.

The tissue manipulating implements or blades <NUM>, <NUM> can each be coupled to a housing <NUM>, <NUM> that can be coupled to a rack <NUM>. The implements <NUM>, <NUM> can be arranged opposite one another such that they can be translated any of toward and away from one another to perform tissue retraction. In addition, other forms of movement of the implements <NUM>, <NUM> are also possible. For example, in some embodiments the implements <NUM>, <NUM> can be toed toward or away from one another. Toeing can involve pivoting the implements such that distal ends thereof move any of toward and away from one another while a distance between proximal ends of the implements remains unchanged.

The various movements of the implements or blades <NUM>, <NUM> can be controlled by any of a variety of actuators. For example, thumbwheel actuators <NUM>, <NUM> can be rotated to control translation of the implements <NUM>, <NUM> toward or away from one another by moving the housings <NUM>, <NUM> along the rack <NUM> via, e.g., a cog or gear coupled to each actuator <NUM>, <NUM> within each respective housing. Moreover, in embodiments capable of toeing opposed implements <NUM>, <NUM> relative to one another, screw actuators <NUM>, <NUM> can be included in the housings to control pivoting of the implements or blades <NUM>, <NUM> about axes P<NUM>, P<NUM>, respectively. The retractor assembly <NUM> can also include features to facilitate resetting a position of the implements <NUM>, <NUM>, such as releases <NUM>, <NUM> that can disengage the actuators <NUM>, <NUM> from the rack <NUM> and allow the housings <NUM>, <NUM> to be rapidly slid along the rack, e.g., from a position at an end of the rack to a central or home position, as shown in <FIG>.

A central portion of the rack <NUM> can include a complete or partial through-hole or recess <NUM> formed therein that can be configured to be disposed around a proximal portion of a support instrument, e.g., the proximal portion <NUM> of the instrument <NUM> described above and shown in <FIG>. Using any of a variety of locking mechanisms, such as those described herein (e.g., movable pawls or locking pins), the retractor <NUM> can be selectively locked to a support instrument at any of a particular position along a length of the support instrument and a rotational orientation relative thereto.

<FIG> illustrate the retractor assembly <NUM> coupled to the support instrument <NUM> and the anchor <NUM>. Moreover, a driver <NUM> is inserted through the driver guide <NUM> and the lumen defined by the ring-shaped projection <NUM> of the lock body <NUM> to interface with the drive feature <NUM> of the anchor <NUM>. The driver <NUM> can include a proximal end <NUM> configured to be rotated by hand or using a tool to aid in implanting or adjusting a position of the anchor <NUM>.

<FIG> also illustrates a lock release <NUM> that can, for example, retract one or more locking pins inserted into the one or more holes <NUM> formed in the proximal portion <NUM> of the support instrument <NUM>. Similarly, when a user first couples the instrument <NUM> and retractor <NUM>, the lock release <NUM> can be depressed to allow the retractor to slide along a length of the elongate body proximal portion <NUM> without interference. At a desired position along the elongate body, the lock release <NUM> can be released, thereby advancing the one or more locking pins into one or more holes formed in the elongate body to lock the relative position and/or orientation of the retractor and the elongate body. Any of a variety of positions along a length of the elongate body can be selected. For example, in the embodiment shown in <FIG>, only the distal end <NUM> of the instrument <NUM> can be seen above an upper surface of the retractor assembly <NUM>. In <FIG>, in contrast, the retractor <NUM> is shown at a more distal position along a length of the instrument <NUM> or elongate body <NUM> thereof. In addition to the distal end <NUM>, several levels of holes <NUM> are visible above an upper surface of the retractor <NUM>.

<FIG> and <FIG> illustrate the retractor assembly <NUM> coupled to the support instrument <NUM> and the anchor <NUM> implanted in a patient's vertebra <NUM>. As mentioned above, a surgical procedure according to the teachings provided herein can include forming an incision <NUM> in a patient's skin and tissue above the implantation site. The anchor <NUM> can then be implanted in the patient's vertebra <NUM>. The anchor can be implanted alone and the support instrument <NUM> and retractor assembly <NUM> can be coupled thereto after implantation either together or sequentially. Alternatively, the entire assembly of the anchor <NUM>, instrument <NUM>, and retractor <NUM> can be implanted together using a driver, as shown in <FIG>.

Once coupled to the anchor, the instrument <NUM> and retractor <NUM> can be positioned relative to the anchor <NUM> as shown. This can be done, for example, by manually manipulating the instrument <NUM> and retractor <NUM> to move them polyaxially relative to the anchor <NUM>. When a desired position is reached, for example, as shown in <FIG> and <FIG> wherein the opposed tissue manipulating implements <NUM>, <NUM> are configured to retract tissue in the medial and lateral directions relative to the patient, the position of the instrument <NUM> can be locked using the actuator <NUM>.

A position of the retractor <NUM> along the instrument <NUM> can be adjusted if necessary to achieve a desired height of the tissue manipulating implements <NUM>, <NUM>. Alternatively, if so equipped a length of each tissue manipulating implement can be adjusted to a desired height. For example, the tissue manipulating implements can be adjusted such that they extend into the incision <NUM> and abut against the tissue on the medial and lateral sides of the incision.

To enable better access to, for example, an intervertebral disc <NUM> adjacent to the vertebra <NUM>, the tissue manipulating implements <NUM>, <NUM> can be any of translated away from one another and toed away from one another in the medial and lateral directions relative to the patient. <FIG> illustrates one possible combination of such movements, wherein the tissue manipulating implements <NUM>, <NUM> have both been translated medially and laterally away from one another along the rack <NUM> (e.g., see separation of the housings <NUM>, <NUM> from the central portion <NUM> of the rack). Moreover, the tissue manipulating implement <NUM> is shown toed away from the implement <NUM>, as its distal end <NUM> is angled away from the distal end <NUM> of the implement <NUM>. A distance between the proximal ends <NUM>, <NUM> of the implements <NUM>, <NUM> remains unchanged.

<FIG> illustrates the tissue retraction that can be provided by moving the tissue manipulating implements in the above-described manner. Namely, the incision <NUM> formed in the patient's skin and underlying tissue can be retracted medially and laterally to provide a wider opening and working channel between the tissue manipulating implements to access the patient's spine or intervertebral space. In some embodiments, the working channel can extend to an adjacent implantable anchor <NUM> implanted in an adjacent vertebra <NUM>. The adjacent implanted anchor <NUM> can be any of a number of anchor and/or extension assemblies known in the art. Examples of such assemblies are described in <CIT> entitled "PERCUTANEOUS ACCESS DEVICES AND BONE ANCHOR ASSEMBLIES,".

<FIG> also illustrates that other surgical instruments can be introduced into the working channel defined by the tissue manipulating implements <NUM>, <NUM> and, in some embodiments, one or more instruments can be coupled to one or more of the tissue manipulating implements. For example, a light or illumination source <NUM> can be coupled to one of the tissue manipulating implements to illuminate the working channel. Alternatively or in addition, a visualization system <NUM>, such as a camera, can be coupled to one of the implements <NUM>, <NUM> to provide magnified viewing of the working channel on an external monitor, etc..

Once the tissue of the incision walls is retracted to form the working channel, any of a variety of surgical procedures can be performed by introducing one or more instruments through the working channel defined by the tissue manipulating implements of the retractor assembly. For example, procedures on the intervertebral disc space, such as disc replacement, discectomy, endplate preparation, fusion cage insertion, bone graft delivery, and the like can be performed by passing instruments or implants through the working channel.

A number of variations and alternative embodiments to the instruments and assemblies described above are also possible. In <FIG>, for example, a retractor <NUM> is shown that only provides for translation of its tissue manipulating implements <NUM>, <NUM> toward or away from one another along its rack <NUM>. The implements <NUM>, <NUM>, as shown in <FIG>, do not include any mechanism for toeing relative to one another. In some embodiments, however, this can allow the implements to be smaller and lower profile than those described above.

<FIG> illustrate still other embodiments in which tissue manipulating implements are more directly incorporated into a support instrument that couples to an anchor and provides selective polyaxial movement relative thereto. Such embodiments can eliminate the need for a separate retractor assembly. In the embodiment shown in <FIG> for example, opposed tissue manipulating implements or blades <NUM>, <NUM> can be pivotably coupled to the elongate body <NUM> of the instrument <NUM>. Accordingly, the instrument <NUM> can be introduced into an incision in the configuration of <FIG> wherein the tissue manipulating implements are in contact with one another and can easily pass into the incision. The implements can then be pivoted away from one another in the direction of arrows <NUM>, <NUM> to retract the tissue forming the incision walls and provide a larger working channel for a surgeon, as shown in <FIG>.

Moreover, each tissue manipulating implement <NUM>, <NUM> can include a distal portion <NUM> that can be pivotably coupled to the remainder of the implement. As shown in <FIG>, the distal portion <NUM> can be configured such that a distal end of the implement <NUM> or <NUM> can pivot away from the remainder of the implement to approximate toeing movement of the implement that can aid in tissue retraction. In some embodiments, the pivot axis <NUM> of the distal portion <NUM> can be transverse to the pivot axis <NUM> of the implement <NUM>.

<FIG> illustrate still another embodiment of an instrument <NUM> wherein individual tissue manipulating implements <NUM>, <NUM> can be selectively coupled to opposed sides of the elongate body <NUM> of the instrument. As shown in <FIG>, for example, the instrument <NUM> can include an elongate body <NUM> configured to couple to the anchor <NUM> and provide selective polyaxial movement relative thereto. The elongate body <NUM> can include mating features <NUM> formed on opposed sides thereof. The mating features can be, for example, a slot or protrusion formed along a length of the elongate body.

A tissue manipulating implement <NUM> can be coupled to the elongate body <NUM> by sliding a complementary mating feature of the implement over the mating feature <NUM> on the elongate body, as shown in <FIG>. Any of a variety of mechanisms, such as the pawl or locking pins described above, can be utilized to set a height of the implement along the elongate body <NUM>. Moreover, and as shown in <FIG>, a blade <NUM> can be modular with respect to a base <NUM> of the tissue manipulating implement <NUM>, so in some embodiments the height of the implement <NUM> relative to the elongate body <NUM> need not be adjustable, as a blade <NUM> of a desired height can be selected. In some embodiments, however, both adjustment mechanisms can be included.

<FIG> illustrate the various degrees of freedom of the tissue manipulating implements <NUM>, <NUM> once coupled to the elongate body <NUM>. For example, rotation of a first actuator <NUM>, <NUM> on each base <NUM>, <NUM> can cause the tissue manipulating implements <NUM>, <NUM> to pivot away from one another, as shown by arrows <NUM>, <NUM>. The pivot axis of each implement <NUM>, <NUM> can be parallel to a longitudinal axis of the elongate body <NUM>.

Moreover, rotation of a second actuator <NUM>, <NUM> on each base <NUM>, <NUM> can pivot the implements <NUM>, <NUM> about an axis transverse to the longitudinal axis of the elongate body <NUM> to create a toeing movement, as shown by arrows <NUM>, <NUM> of <FIG>. This toeing movement can involve distal ends of the tissue manipulating implements <NUM>, <NUM> moving away from one another while a distance between proximal ends thereof remains unchanged.

<FIG> illustrate various embodiments of instruments for distracting adjacent vertebrae and their use with the support instruments and retractor assemblies described herein. For example, <FIG> illustrates one embodiment of a distractor <NUM> that includes a rack <NUM> and two interfaces <NUM>, <NUM> for coupling with any of an anchor or an instrument coupled to an anchor. The interface <NUM> can be anchored to one end of the rack <NUM> and the interface <NUM> can be coupled to the rack <NUM> via a pawl, cog, gear, or other feature that can interface with a series of teeth, recesses, or other features formed along a length of the rack. A thumbwheel <NUM> can be coupled to the cog or gear to control movement of the interface <NUM> along the rack <NUM>.

As shown in <FIG>, the interfaces <NUM>, <NUM> can be coupled to anchors implanted in adjacent vertebrae and the thumbwheel <NUM> can be rotated to distract the vertebrae by moving the interfaces away from one another along the rack <NUM>. In the illustrated embodiment, the interfaces can couple to the anchors implanted in the adjacent vertebrae via an extension tower and/or support instrument as described herein that can be coupled to the implanted anchors and locked against movement relative thereto. Accordingly, as shown in <FIG> and <FIG>, the interface <NUM> can couple to a proximal end of an extension tower <NUM> that is coupled to an anchor <NUM> implanted in a first vertebra and the interface <NUM> can couple to a proximal end of a support instrument <NUM> that is coupled to a second anchor <NUM> implanted in a second vertebra. As shown in <FIG>, the interfaces <NUM>, <NUM> can include distal ends configured to couple with features formed on proximal ends of the extension tower <NUM> and support instrument <NUM>, e.g., the opposed planar surfaces <NUM> of the instrument <NUM> described above. Also note that a retractor assembly <NUM> is coupled to the support instrument <NUM> to provide, e.g., medial-lateral tissue retraction during the procedure.

Once the distraction instrument <NUM> is coupled to the anchors <NUM>, <NUM> implanted in adjacent vertebrae via the extension tower <NUM> and support instrument <NUM>, and the tower and support instrument are locked against movement relative to the anchors, the thumbwheel <NUM> or other distraction actuator can be rotated as shown by arrow <NUM> in <FIG>. This can cause the interface <NUM> to move away from interface <NUM> along the rack <NUM>, thereby causing corresponding distraction of the anchors <NUM>, <NUM> and the adjacent vertebrae they are implanted into, as shown by arrows <NUM>, <NUM>.

In an alternative embodiment illustrated in <FIG>, a forceps-like distractor <NUM> can be utilized instead of the distractor <NUM> described above. Furthermore, the distractor <NUM> can include interfaces <NUM>, <NUM> that can be configured to abut against the extension tower <NUM> and support instrument <NUM> laterally at a position along a length thereof, rather than interfacing with a proximal end thereof, as described above. The method of operation can be similar to that described above, wherein the extension tower <NUM> and support instrument <NUM> can be locked to prevent movement relative to the implanted anchors <NUM>, <NUM>. The interfaces <NUM>, <NUM> can then be inserted into the working channel provided between the opposed tissue manipulating implements of the retractor assembly <NUM> and opposed handles <NUM>, <NUM> of the distractor <NUM> can be urged toward one another, as shown by the arrows <NUM>, <NUM> of <FIG>. This can cause the interfaces <NUM>, <NUM> to move apart from one another, contact the tower <NUM> and support instrument <NUM>, and urge the two components away from one another, as shown by arrows <NUM>, <NUM> of <FIG>. Given the rigid implantation of the anchors <NUM>, <NUM> in adjacent vertebrae (not shown), the vertebrae can be drawn away from one another in the same manner.

<FIG> and <FIG> illustrate one embodiment of a surgical retractor system <NUM> according to the teachings provided herein. The system can be used to facilitate retraction of skin, muscle, and other soft tissue to access, for example, various portions of a patient's spine. Further, the system can include a retractor and other components docked via surgical instruments as described herein to a patient's body via, e.g., vertebrae, and as a result can be utilized to perform various procedures, including vertebral distraction, etc..

As shown by the assembled system of <FIG> and the disassembled view of <FIG>, the system <NUM> can include one or more surgical support instruments <NUM> coupled to screws implanted in a patient's vertebrae, a retractor <NUM> coupled to a support instrument, one or more tissue manipulating implements <NUM> coupled to the retractor, a stability handle <NUM> with light source <NUM> coupled to the retractor <NUM>, a distraction module <NUM> coupled to another support instrument <NUM> from the retractor <NUM>, and a distraction rack <NUM> coupled to the retractor <NUM> and the distraction module <NUM> to perform distraction, e.g., between adjacent vertebrae. Also shown in <FIG> is an actuating instrument <NUM> that can be used to couple the tissue manipulating implements <NUM> to the retractor <NUM> and control positioning/locking thereof, as well as a tissue manipulating implement adjuster <NUM> that can be utilized to adjust a position, depth, etc. of an expandable tissue manipulating implement coupled to the retractor <NUM>. <FIG> also illustrates several different sizes of surgical support instruments <NUM>, e.g., a larger instrument 3202a, a middle-size instrument 3202b, and a smaller instrument 3202c. Finally, <FIG> also illustrates a reference stick <NUM> that can be utilized to determine the appropriate size of support instrument <NUM> and a surgical instrument component removal tool <NUM> that can be utilized to separate two part surgical support instruments, as described herein.

<FIG> illustrates the various sizes of surgical support instruments <NUM> in greater detail. While any variety of sizes are possible, the illustrated embodiments include a larger instrument 3202a, a mid-size instrument 3202b, and a smaller instrument 3202c. In some embodiments, a difference between the difference sizes can be embodied solely in their length extending above the screw to which they couple, such that different size instruments can be chosen based on a depth of a surgical site below a patient's skin surface and a desired amount of extension of the instrument above the skin surface. The reference stick <NUM> shown in <FIG> can be utilized to determine the proper size of surgical support instrument <NUM> to utilize for any particular patient. For example, the reference stick <NUM> can be inserted into an incision formed in a patient's skin and soft tissue and advanced until it docks against a desired anatomical feature, e.g., a patient's pedicle. Looking at the "S, M, L" markings <NUM> on one side of the reference stick (as shown in <FIG>) and noting the first marking showing above the patient's skin shows the appropriate size support instrument to use for that tissue depth. The "S, M, L" markings can be mirrored on the smaller, mid-size, and larger instruments 3202c, 3202b, 3202a, respectively. The reference stick <NUM> can also include depth markings <NUM> on an opposite side thereof from the surgical instrument size markings (as shown in <FIG>) that can advise a user of the correct length of retractor blades or tissue manipulating implements <NUM> to utilize in connection with the surgical retractor <NUM> coupled to the support instrument <NUM>.

<FIG> illustrate one embodiment of a surgical instrument component removal tool <NUM> that can be utilized to remove a component of, e.g., a two-part surgical support instrument, such as the instrument <NUM> described above. As noted above, the tool <NUM> can be utilized to remove, e.g., a lock body or cap <NUM> of a surgical support instrument <NUM>, which may be desirable to provide access to a proximal portion of a bone anchor to attach a modular receiver head (not shown) thereto. As described above in connection with the lock body <NUM> of the instrument <NUM>, removal of the lock body can allow a modular receiver head to be coupled to the proximal head <NUM> of the anchor <NUM>. The elongate body <NUM> can be left in place, as it is offset from the anchor <NUM> by the laterally-extending projections 302a, 302b of the fork <NUM> and because the projections 302a, 302b disposed below the proximal head <NUM> will not interfere with coupling a receiver head to the proximal head of the anchor <NUM>. Returning to <FIG>, utilizing the removal tool <NUM> can include sliding the tool down onto a cap <NUM> of a surgical support instrument <NUM> in the direction of arrow <NUM> until a spring button <NUM> engages with the cap, as shown in <FIG>. The removal tool <NUM> can then be utilized to detach the cap <NUM> from the shank extension <NUM> by withdrawing the tool and coupled cap in the direction of arrow <NUM> in <FIG>. To detach the cap <NUM> from the tool <NUM> after detachment from the shank extension <NUM>, a user can press the button <NUM> in the direction of arrow <NUM> in <FIG>.

In combination with the above-described distraction, any of a variety of surgical procedures can be performed utilizing the working channel provided by, e.g., the support instrument <NUM> and retractor assembly <NUM>. For example, a user can perform a spinal fusion cage insertion procedure via the working channel between the opposed tissue manipulating implements of the retractor assembly <NUM>. Other exemplary procedures can include disc replacement, discectomy, endplate preparation, bone graft delivery, and the like.

It should be noted that any ordering of method steps expressed or implied in the description above or in the accompanying drawings is not to be construed as limiting the disclosed methods to performing the steps in that order. Rather, the various steps of each of the methods disclosed herein can be performed in any of a variety of sequences. In addition, as the described methods are merely exemplary embodiments, various other methods that include additional steps or include fewer steps are also within the scope of the present disclosure.

The instruments disclosed herein can be constructed from any of a variety of known materials. Exemplary materials include those which are suitable for use in surgical applications, including metals such as stainless steel, titanium, nickel, cobalt-chromium, or alloys and combinations thereof, polymers such as PEEK, ceramics, carbon fiber, and so forth. The various components of the instruments disclosed herein can have varying degrees of rigidity or flexibility, as appropriate for their use. Device sizes can also vary greatly, depending on the intended use and surgical site anatomy. Furthermore, particular components can be formed from a different material than other components. One or more components or portions of the instrument can be formed from a radiopaque material to facilitate visualization under fluoroscopy and other imaging techniques, or from a radiolucent material so as not to interfere with visualization of other structures. Exemplary radiolucent materials include carbon fiber and high-strength polymers.

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

The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly.

The devices described herein can be processed before use in a surgical procedure. First, a new or used instrument can be obtained and, if necessary, cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument can be placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and its contents can then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation can kill bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container can keep the instrument sterile until it is opened in the medical facility. Other forms of sterilization known in the art are also possible. This can include beta or other forms of radiation, ethylene oxide, steam, or a liquid bath (e.g., cold soak). Certain forms of sterilization may be better suited to use with different portions of the device due to the materials utilized, the presence of electrical components, etc..

Claim 1:
A surgical instrument, comprising:
an elongate body (<NUM>);
opposed projections (302a, 302b) extending laterally from a distal portion of the elongate body that are configured to at least partially surround a shank of an implantable anchor (<NUM>) at a position distal of a proximal head (<NUM>) of the anchor such that a longitudinal axis of the elongate body is laterally offset from a longitudinal axis of the anchor;
a lock configured to exert a drag force on the head of the anchor to control polyaxial movement of the instrument relative to the anchor, wherein the lock is configured to translate relative to the elongate body and contact an upper portion of the proximal head of the anchor; and
a locking screw (<NUM>) disposed within a lumen (<NUM>) of the elongate body and configured to adjust the drag force exerted on the head of the anchor,
wherein a proximal portion of the elongate body is configured to receive a retractor assembly including a plurality of tissue manipulating implements and selectively lock the retractor assembly at any of a plurality of positions along a length of the proximal portion of the elongate body.