Spinal access instrument

A method of, and surgical instrument for accessing first and second pedicle locations of a spinal column area. The surgical instrument including a blade member slidably positionable along first and second wires. The instrument having a nested arrangement of members, including a portal member having an elongated aperture to access the first and second pedicle locations. The nested arrangement further including a plurality of members configured and sized to incrementally expand the access opening to the spinal column area.

TECHNICAL FIELD

This disclosure relates generally to methods and devices for accessing an area of a patient's spinal column during a surgical procedure. More particularly, this disclosure relates to an instrument that provides an access opening to the spinal column.

BACKGROUND

A wide variety of surgical techniques have been used to access the spinal column in spinal surgery procedures. For example, some techniques included making an incision in the patient's back and distracting or separating tissue and muscle to expose a wide area of the spine in order to perform the spinal surgery procedure. Such techniques often result in excessive invasions into the patient's spine and back region causing major damage to the normal anatomy, and significant and dangerous blood loss.

In an attempt to minimize risks associated with spinal surgery procedures, some surgical techniques have been developed wherein only portions of the spinal column area are accessed during various stages of the surgical procedure. In these procedures, a smaller incision can be used to access the portion of the spinal column area. However, access to only a portion of the spinal column area does not provide sufficient access for all surgical procedures.

In general, improvement has been sought with respect to such surgical techniques, generally to better provide sufficient accessibility to a spinal column area while minimizing anatomical trauma and blood loss.

SUMMARY

One aspect of the present disclosure relates to a surgical instrument for accessing first and second pedicle locations of a spinal column. The surgical instrument includes a portal member having an elongated aperture. The elongated aperture of the portal member is sized to provide simultaneous access to each of the first and second pedicle locations. The instrument also includes a placement wire and a blade member. The blade member is positionable over the placement wire and is positionable within the elongated aperture of the portal member.

Another aspect of the present disclosure relates to a surgical instrument including a first wire, a second wire, and an incremental opening arrangement. The incremental opening arrangement includes a plurality of nested members, including at least a dissector member slidably positionable along the first and second wires and a sleeve member slidably positionable of the dissector member.

Still another aspect of the present disclosure relates to a surgical instrument for accessing first and second pedicle locations including a first wire and a nested arrangement. The nested arrangement includes a blade member slidably positionable over the first wire and configured to provide an incisional opening, and an outer portal member configured to slide over the blade member for introduction into the incisional opening. The outer portal member has an elongated access aperture having a longitudinal dimension that corresponds to the distance between the first and second pedicle locations.

Yet another aspect of the present disclosure relates to a method of accessing the firs and second pedicle sites at a spinal column area incorporated the use of the presently described surgical instrument.

A variety of examples of desirable product features or methods are set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing various aspects of the disclosure. The aspects of the disclosure may relate to individual features as well as combinations of features. It is to be understood that both the foregoing general description and the following detailed description are explanatory only, and are not restrictive of the claimed invention.

DETAILED DESCRIPTION

Reference will now be made in detail to various features of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIGS. 1-18illustrate surgical instrument embodiments having features that are examples of how inventive aspects in accordance with the principals of the present disclosure may be practiced. Preferred features of the embodiments are adapted for providing a sufficient access opening to a spinal column area while minimizing risks associated with spinal surgery, such as incisional invasiveness, trauma, and blood loss.

Referring toFIG. 1, one embodiment of the spinal access instrument10is illustrated in complete assembly. The spinal access instrument is used to dissect skin tissue and muscle and provide a sufficiently sized opening for accessing a patient's spinal column. A sufficiently sized opening is an opening that is large enough to perform the desired surgical procedure. Preferably the opening provides access to a spinal column area or region such that the surgical procedure can be performed without having to provide more than one incision or opening.

For example, when performing a spinal procedure involving placement of pedicle screws (schematically represented inFIG. 20by dashed lines), preferably the accessed spinal column area or region includes first and second pedicle sites. As shown inFIGS. 19 and 20, the first and second pedicle sites or locations are the two sites (A1, A2(hidden) or B1, B2) that are vertically aligned on upper and lower vertebral bodies V1, V2. That is, the access opening is preferably sized to provide access to the spinal column area including both the first pedicle site (e.g. B1) and the second pedicle site (e.g. B2) of two adjacent vertebrae.

Referring back toFIG. 1, the surgical instrument10generally includes a nested arrangement12, a first guide or placement wire14, and a second guide or placement wire16. As shown inFIGS. 2 and 3, the nested arrangement12of the spinal access instrument10includes a plurality of components or members sized so that each member fits with the other members in a nested configuration (as shown inFIG. 1). In the nested configuration, each of the members at least partially contains or is at least partially contained within the other members. The plurality of nested members includes at least one portal member (18,24or26) and a dissector or blade member20. As will be discussed in greater detail, the blade member20is used to provide an initial incision and the portal member provides access to the spinal column area through the incision.

Preferably the nested arrangement12is configured to incrementally provide an access opening to the spinal column area. What is meant by “incrementally provide an access opening” is that the arrangement provides an initial opening, and thereafter can be used to expand the opening (i.e. increase the cross-sectional area of the opening) as needed. By incrementally expanding the opening, surgical trauma and blood loss is minimized. In contrast, some existing procedures involve making an incision much wider than the incision needed by the present disclosure. The wider incision is needed in some existing procedures so that the skin tissue and muscle can be separated or pulled apart to adequately expose the spinal column area. This excessive invasion often results in anatomical trauma to the tissue or muscle and high blood loss.

In the illustrated embodiment ofFIGS. 2 and 3, the nested arrangement12includes the blade member20, and second, third, and fourth sleeve members24,26, and18; although any number of sleeve members can be used in accord with the present disclosure. The second sleeve member or inner portal member24is slidably positionable over the blade member20. The second sleeve member24is sized to expand the area of initial incision created by the blade member20to a second opening area. The second opening area is generally defined by the outer perimeter of the second sleeve member24. The third sleeve member or intermediate portal member26is slidably positionable over the second sleeve member24. The third sleeve member26is sized and configured to expand the access opening from the second opening area defined by the second sleeve member24to a third opening area. The third opening area is generally defined by the outer perimeter of the third sleeve member26. Finally, the fourth sleeve member or outer portal member18is slidably positionable over the third sleeve member26. The outer portal member26is sized and configured to expand the access opening from the third opening area defined by the third sleeve member26to a final opening area. The final opening area is generally defined by the outer perimeter of the outer portal member18.

Referring now toFIGS. 4-6, the blade member20of the surgical instrument10includes a first end28and a second end30. The first end28of the blade member20is typically a solid construction defining a blade edge22. The blade edge22is configured to provide an initial incision of length IL (FIG. 4) in the skin tissue and muscle of a patient. A handle32is located at the second end30opposite the first end28of the blade member20. As shown inFIGS. 4 and 6, the handle includes recessed areas56and an aperture58for gripping. The handle32can include a variety of shapes and geometries configured for gripping and moving the blade member20during use.

In general, the blade member20has an overall width W1, an overall height H1, and an overall length L1, although the disclosed principles can be applied in a variety of sizes and applications. The width W1of the blade member20is shown inFIG. 5, and is preferably between 19 mm and 58 mm (0.75 inches and 2.25 inches); more preferably between 38 mm and 45 mm (1.5 inches and 1.75 inches). The height H1of the blade member20is shown inFIG. 6, and is preferably between 4 mm and 10 mm (0.175 inches and 0.375 inches); more preferably between 5 mm and 7 mm (0.200 inches and 0.250 inches). The length L1of the blade member20is generally defined between the first end28and the second end30of the blade member20, excluding the handle32. The length L1of the blade member20is preferably between 88 mm and 140 mm (3.5 inches and 5.5 inches); more preferably between 101 mm and 127 mm (4.0 inches and 5.0 inches).

As shown inFIGS. 4 and 5, the blade member20includes first and second apertures34,36extending along the length L1of the blade member20. The first and second aperture34,36are offset from edges38,40of the blade member20and extend from the first end28to the second end30of the blade member20. Each of the first and second apertures34,36is sized and configured for receipt of the corresponding first and second placement wires14,16(FIG. 2). In the illustrated embodiment, the first and second placement wires14,16are approximately 2 mm (0.08 inches) in diameter; correspondingly the first and second apertures34,36are approximately 2.3 mm (0.09 inches) in diameter.

Referring now toFIGS. 7-9, the second sleeve member or inner portal member24of the nested arrangement12is illustrated. The second sleeve member24is generally a tubular construction having a first end50and a second end52. The tubular construction of the second sleeve member defines an elongated aperture42sized and configured for receipt of the blade member20. In particular, the second sleeve member24fits over the handle and slides along the blade member to nest with or cover the blade member20. The first end50of the second sleeve member24is tapered. In use, the tapered first end50assists in gradually expanding the access opening from the initial area of the incision created by the blade member20to the second opening area defined by the outer perimeter P2(FIG. 8) of the second sleeve member24.

The second sleeve member24is configured to slide over the blade member20until shoulders44(FIG. 4) of the blade member20contact stop structures46of the second sleeve member24. In the illustrated embodiment, the stop structures46include pins48positioned within the elongated aperture42. The pins48are positioned adjacent to the second end52of the second sleeve member24. Each of the pins48is offset from sidewalls54of the second sleeve member24so that when assembled as shown inFIGS. 1 and 2, the first and second placement wires14,16extend between the pins48and the sidewalls54of the second sleeve member24.

In general, the second sleeve member24has an overall width W2, an overall height H2, and an overall length L2, although the disclosed principles can be applied in a variety of sizes and applications. The width W2of the second sleeve member24is shown inFIG. 8, and is preferably between 24 mm and 63 mm (0.95 inches and 2.45 inches); more preferably between 43 mm and 50 mm (1.70 inches and 1.95 inches). The height H2of the second sleeve member24is shown inFIG. 9, and is preferably between 9 mm and 15 mm (0.375 inches and 0.575 inches); more preferably between 10 mm and 12 mm (0.400 inches and 0.450 inches). The length L2of the second sleeve member24is generally defined between the first end50and the second end52of the second sleeve member24. The length L2of the second sleeve member is preferably between 95 mm and 146 mm (3.75 inches and 5.75 inches); more preferably between 107 mm and 134 mm (4.25 inches and 5.25 inches). The outer perimeter P2of the second sleeve member24defines the second access opening area; the second access opening area is generally between 180 and 716 square mm (0.28 and 1.11 square inches).

Referring now toFIGS. 10-12, the third sleeve member or intermediate portal member26of the nested arrangement12is illustrated. The third sleeve member26is also generally a tubular construction having a first end60and a second end62. The tubular construction of the third sleeve member26defines an elongated aperture76sized and configured for receipt of the second sleeve member24. In particular, the third sleeve member26fits over the second sleeve member24to nest with or cover the second sleeve member24. Similar to the second sleeve member, the first end60of the third sleeve member is tapered to assist in gradually expanding the access opening from the second opening area to the third opening area defined by the outer perimeter P3of the third sleeve member26.

The third sleeve member26slides over the second sleeve member24until notches56(FIG. 7) of the second sleeve member24contact stop structures66of the third sleeve member26. In the illustrated embodiment, the stop structures66include pins68positioned within the elongated aperture76. The pins68are positioned adjacent to the second end62of the third sleeve member26. Each of the pins68is offset from sidewalls78of the third sleeve member26so that when assembled as shown inFIG. 2, the first and second placement wires14,16extend between the pins68and the sidewalls78of the third sleeve member26.

In general, the third sleeve member24has an overall width W3, an overall height H3, and an overall length L3, although the disclosed principles can be applied in a variety of sizes and applications. The width W3of the third sleeve member26is shown inFIG. 11, and is preferably between 27 mm and 66 mm (1.08 inches and 2.58 inches); more preferably between 46 mm and 53 mm (1.83 inches and 2.08 inches). The height H3of the third sleeve member26is shown inFIG. 12, and is preferably between 17 mm and 23 mm (0.675 inches and 0.875 inches); more preferably between 17 mm and 19 mm (0.700 inches and 0.750 inches). The length L3of the third sleeve member26is generally defined between the first end60and the second end62of the third sleeve member26. The length L3of the third sleeve member is preferably between 95 mm and 146 mm (3.75 inches and 5.75 inches); more preferably between 107 mm and 134 mm (4.25 inches and 5.25 inches). The outer perimeter P3of the third sleeve member26defines the third access opening area; the third access opening area is generally between 368 and 1148 square mm (0.57 and 1.78 square inches).

Referring now toFIGS. 13-15, the fourth sleeve member or outer portal member18of the nested arrangement12is illustrated. The outer portal member18generally includes a sleeve portion70having a first end82and a second end84. The sleeve portion70defines an elongated aperture74that extends from the first end82to the second end84.

A handle portion72of the outer portal member18is located at the second end84of the sleeve portion70. The handle portion72can include a plurality of holes80. The holes80provide locations at which other surgical tools (not shown) can be attached for use during the surgical procedure.

In general, the outer portal member18has an overall width W4, an overall height H4, and an overall length L4, although the disclosed principles can be applied in a variety of sizes and applications. The width W4of the outer portal member18is shown inFIG. 15, and is preferably between 30 mm and 68 mm (1.19 inches and 2.69 inches); more preferably between 49 mm and 56 mm (1.94 inches and 2.19 inches). The height H4of the outer portal member18is also shown inFIG. 15, and is preferably between 20 mm and 25 mm (0.787 inches and 0.987 inches); more preferably between 20 mm and 22 mm (0.812 inches and 0.862 inches). The length L4of the outer portal member18is generally defined between the first end82and the second end84of the outer portal member18. The length L4of the outer portal member is preferably between 97 mm and 149 mm (3.85 inches and 5.85 inches); more preferably between 110 mm and 136 mm (4.35 inches and 5.35 inches). The outer perimeter P4of the outer portal member18defines the fourth or final access opening area; the fourth or final access opening area is generally between 477 and 1348 square mm (0.74 and 2.09 square inches).

In use, the surgical access instrument10provides access to first and second pedicle sites at a spinal column area or region. To begin a procedure, the first placement wire14is advanced through a patient's skin tissue and muscle until the wire14is positioned at a selected first pedicle site (e.g. B1inFIG. 19) of a first vertebral body V1. The second placement wire16is positioned at a corresponding upper or lower second pedicle site (e.g. B2inFIG. 19) of an adjacent vertebral body V2. The first and second pedicle sites are located a general distance D apart from one another. The site of the access opening is located at the region defined generally between and adjacent to the first and second placement wires14,16.

While first ends of the first and second placement wires14,16are positioned at the first and second pedicle locations, opposite ends of the placement wires14,16are inserted within the first and second apertures34,36at the first end28of the blade member20. The blade member20slides along the first and second placement wires14,16in a first direction (represented by arrow A inFIG. 2) until the blade member20is adjacent to the skin tissue located between the first and second placement wires14,16. As the blade member20is further advanced toward the first and second pedicle sites, the blade edge22provides an initial incision through the skin tissue and muscle to the spinal column area. The surgeon can use hand force or a tapping hammer, for example, to advance the blade member along the placement wires14,16to a desired depth.

When the blade member20is position at the desired depth adjacent to the spinal column area, the first end50of the second sleeve member24is positioned over the second end30of the blade member20(FIG. 2). The second sleeve member24slides along the blade member20in the first direction A until the second sleeve member24is adjacent to the initial incision in the skin tissue. As the second sleeve member24is further advanced toward the spinal column area, the tapered first end50of the second sleeve member24is introduced into the initial incision and begins to enlarge the incisional area. The incisional area is incrementally enlarged to the second opening area defined by the outer perimeter of the second sleeve member24.

The second sleeve member24is inserted to a desired depth adjacent to the spinal column area, however cannot be inserted a depth exceeding the depth of the blade member20. That is, the stop structures46of the second sleeve member24contact the shoulders44of the blade member20to limit the insertion depth of the second sleeve member.

When the second sleeve member24is position at the desired depth adjacent to the spinal column area, the first end60of the third sleeve member26is positioned over the second end52of the second sleeve member24(FIG. 2). The third sleeve member26slides along the second sleeve member24in the first direction A until the third sleeve member26is adjacent to the access opening in the skin tissue. As the third sleeve member26is further advanced toward the spinal column area, the tapered first end60of the third sleeve member26is introduced into the access opening and begins to enlarge the access opening. The access opening is incrementally enlarged from the second opening area to the third opening area defined by the outer perimeter of the third sleeve member26.

The third sleeve member26is inserted to a desired depth adjacent to the spinal column area, however cannot be inserted a depth exceeding the depth of the second sleeve member24. That is, the stop structures66of the third sleeve member26engage the notches56of the second sleeve member24to limit the insertion depth of the third sleeve member26.

Similar to the preceding steps, when the third sleeve member26is position at the desired depth adjacent to the spinal column area, the first end82of the outer portal member18is positioned over the second end62of the third sleeve member26(FIG. 2). The outer portal member18slides along the third sleeve member26in the first direction A until the outer portal member18is adjacent to the access opening in the skin tissue. As the outer portal member18is further advanced toward the spinal column area, the first end82of the outer portal member18is introduced into access opening and begins to enlarge the access opening. The access opening is incrementally enlarged from the third opening area to the final opening area defined by the outer perimeter of the outer portal member18.

When the portal member18has been positioned at the desired depth adjacent to the spinal column area, each of the members18,20,24, and26are in the nested configuration, generally shown inFIG. 1. The access opening to the first and second pedicle sites at the spinal column area has been incrementally expanded to minimized incisional trauma and blood loss.

To continue the surgical procedure, each of the blade member20, the second sleeve member24, and the third sleeve member26, is removed from the elongated aperture74of the portal member18. Removing all three members20,24, and26can be accomplished by simply grasping the handle32of the blade member20and pulling the blade member20out from the aperture74of the outer portal member18.

In particular, each of the blade, second sleeve and third sleeve members20,24,26are interconnected when moved in a second direction B (FIG. 1) relative to the outer portal member18. That is, the shoulders44of the blade member20contact the pins48of the second sleeve member24, and the notches56of the second sleeve member24engage the pins68of the third sleeve member26to form an interconnection that permits all three nested members20,24,26to be simultaneously removed from the aperture74of the outer portal member18. Thus, as a surgeon pulls the blade member20from the aperture74, the blade member20interconnects with the second sleeve member24and the second sleeve member interconnects with the third sleeve member26so that the three nested and interconnected members20,24,26can be removed at the same time.

When the three nested members20,24, and26, are removed from the elongated aperture74of the outer portal member18, the surgeon now has access to first and second pedicle sites at the spinal column area. The access is provided through the elongated aperture74; thereby the elongated aperture74of the outer portal member18is sized and configured to correspond to the distance (D) between the first and second pedicle sites. More preferably, the elongated aperture74provides access to each of the first and second pedicle sites and the immediate surrounding area of each pedicle site at the spinal column area. In the illustrated embodiment, the elongated aperture74is sized and configured to receive and guide pedicle screws into the first and second vertebral bodies at the first and second pedicle sites.

It is to be understood that the placement wires14,16may or may not be removed from the elongated aperture74with the three nested members20,24,26. In some procedures, pedicle screws having a bore extending through the screw shaft are positioned on the placement wires. The placement wires therein act as guide wires to direct the pedicle screws to the first and second pedicle sites. In other procedures, the first and second placement wires14,16are removed with the three nested members20,24,26and the screws are engaged by an appropriate driving tool and positioned down into the aperture to the first and second pedicle sites. In yet another alternative, the placement wires14,16can be removed from the blade member20after the blade member20has been properly positioned adjacent to the spinal column area.

The pedicle screws can include a variety of pedicle screw configurations known in the art. Typically the diameter of pedicle screws range between about 5 mm and 8 mm. These specific dimensions are merely illustrative of normal configurations and can be varied as needed. Accordingly, the elongated aperture74of the outer portal member18can be varied to accommodate the variety of pedicle screw configurations.

Referring now toFIGS. 16-18, a second embodiment of an outer portal member or fourth sleeve member118is illustrated. In this embodiment, the outer portal member118generally includes a sleeve portion170having a first end182and a second end184. The sleeve portion170defines an elongated aperture174that extends from the first end182to the second end184. The second outer portal member embodiment118generally has similar overall width, height, and length dimensions as the first outer portal member18shown inFIGS. 13-15.

The sleeve portion170illustrated in the second embodiment, however, includes a first sleeve section186and a second sleeve section188that define the elongated aperture174. The first and second sleeve sections186,188are coupled to a flange or collar190at pivot locations192. Each of the first and second sleeve sections186,188is configured to rotate or pivot, relative to the collar190, from a retracted position (shown inFIG. 16) to a distended position (shown inFIGS. 17 and 18).

The second end184of each of the sleeve sections186,188is angled such that an inner region194of each section is longer than an outer region196. In other words, the second end184of each section has an oblique edge construction198(partially shown inFIG. 16) relative to the inner and outer regions194,196of the first and second sleeve sections186,188.

The outer portal member118further includes a clamp plate210positioned adjacent to the collar190. Typically, the clamp plate210is positioned in relation to the collar190so that a gap G is provided between the collar190and the clamp plate210. Alignment spacers202in cooperation with holes206formed in the clamp plate210properly orient the clamp plate210relative to the collar190so that an opening212in the clamp plate210is aligned with the elongated aperture174of the sleeve portion170. The alignment spacers202can also be configured to maintain the gap G between the collar190and the clamp plate210. For example, the alignment spacers202can be configured to provide a sufficient interference fit with the holes206formed in the clamp plate210such that the clamp plate210seats in an offset position from the collar190when no force is applied. In the illustrated embodiment, the spacers202are pegs204extending from a first surface200of the collar190.

As shown inFIG. 16, when the gap G is provided between the collar190and the clamp plate210, the first and second sleeve sections186,188remain in the retracted position. In the retracted position, the outer portal member118can be introduced into an access opening area as previously described with respect to the first outer portal member embodiment.

When the outer portal member118is positioned adjacent to the spinal column area at the desired depth, and the three nested members20,24,26are removed from the elongated aperture174, the first and second sleeve sections186,188can be outwardly distended to further expose the first and second pedicle sites. In particular, the clamp plate210can be forcibly positioned to contact the first surface200of the collar190(FIGS. 17 and 18). As the clamp plate210is forced towards the collar190, the clamp plate210contacts the oblique edge construction198of the second end184of the first and second sleeve sections186,188. The force from the clamp plate210pivots the first end182of the first and second sleeve members186,188outward away from one another. That is, the second end184of the first and second sleeve members186,188pivot about pivot locations192, and the first end182of the first and second sleeve members186,188rotate in opposite directions from one another.

The clamp plate210, spacers198, and collar190can be configured such that a surgeon can forcibly position the outer portal member118in the distended position by hand, or such that a clamp (not shown) is required to press the clamp plate210toward the collar190. The pivoting design of this second outer portal member embodiment provides a greater access opening adjacent to the spinal column area without having to expand the access opening in the tissue and muscle region of the patient's back. This is advantageous in further reducing trauma in situations where access to a larger spinal column area is needed.

The above specification provides a complete description of SPINAL ACCESS INSTRUMENT. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.