Combined distractor and retractor instrument and methods

[0001] 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 accessible space between two vertebral elements.

[0002] A wide variety of surgical techniques have been used to access the spinal column in spinal surgery procedures. For example, some techniques include making an incision in the patient's back and retracting or separating tissue and muscle to expose a wide area of the spine in order to perform the spinal surgery procedure. The invasiveness of such techniques often results in excessive damage to the normal anatomy, and significant and dangerous blood loss.

[0003] 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 a particular portion of the spinal column area. However, access to only a particular portion of the spinal column area does not provide sufficient access for all surgical procedures.

[0004] 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.

[0005] One aspect of the present disclosure relates to a surgical instrument for distracting a space between adjacent vertebral elements and retracting the nerve root to provide access to the distracted space. The instrument includes an elongated member having a first end and a second end, the first end defining a curved region. The instrument also includes a handle extending from the elongated member and a wing extending outward from the elongated member. The handle is positioned adjacent to the second end of the elongated member and the wing is positioned adjacent to the first end of the elongated member.

[0006] Another aspect of the present disclosure relates to a surgical instrument having an elongated member having a longitudinal axis that extends from a first end to a second end. The elongated member has first and second edges that extend generally parallel to the longitudinal axis. The instrument further includes a handle positioned adjacent to the second end of the elongated member. A wing extends outward from one of the first and second edges of the elongated member and a recess is formed in the other of the first and second edges of the elongated member.

[0007] Still another aspect of the present disclosure relates to a distracting first and second adjacent vertebral elements. The method includes providing a surgical instrument having an elongated blade member, the elongated blade member having a longitudinal axis extending between a first end and a second end, and a wing located adjacent to the first end. The method further includes inserting the surgical instrument in a first orientation between the first and second vertebral elements and rotating the instrument to distract the first and second vertebral elements a distance.

[0008] 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.

[0016] 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.

[0017] FIGS. 1–7 illustrate a surgical instrument embodiment having features that are examples of how inventive aspects in accordance with the principals of the present disclosure may be practiced. Referring to FIG. 1, the surgical instrument 10 includes an elongated member 12 and a handle 14. A surgeon, for example, grasps the handle 14 to manipulate the elongated member 12 during use. That is, the handle 14 is used to apply an insertion force and can be use to rotate the surgical instrument 10 to a desired orientation in relation to the vertebral elements during a surgical procedure. The handle 14 is also used to remove the elongated member 12 of the surgical instrument from between the vertebral elements.

[0018] Referring now to FIGS. 1 and 2, the elongated member 12 generally defines a blade 16. The blade 16 has a first end 18 and a second end 20 that defines a longitudinal axis A—A of the elongated member 12. The blade has first and second edges 22, 24 extending generally parallel to the longitudinal axis. In the illustrated embodiment, the blade 16 has a concave curvature 26 relative to a plane BB (represented by line BB) defined by the first and second edges 22, 24. The concave curvature 26 is generally perpendicular to the longitudinal axis A—A of the blade 16 and typically extends along a majority of the blade 16. In the illustrated, the concave curvature extends from the first end 18 of the blade to the second end 20.

[0019] Still referring to FIGS. 1 and 2, a wing 28 is located adjacent to the first end 18 of the blade 16 along one of the first and second edges 22, 24 of the blade 16. In the illustrated embodiment of FIGS. 1 and 2, the wing 28 is located along the first edge 22 for use in a left-handed application. That is, the surgical instrument 10 having the wing 28 located on the first edge 22 is for use in an application wherein the two vertebral elements are accessed from a posterior approach, and from a patient-left side of the two vertebral elements.

[0020] In the illustrated embodiment of FIGS. 3 and 4, the wing 28 is located along the second edge 24 for use in a right-handed application. That is, the surgical instrument 10 having the wing 28 located on the second edge 24 is for use in an application wherein the two vertebral elements are accessed from a posterior approach, and from a patient-right side of the two vertebral elements. During a surgical procedure, either the right-handed instrument or the left-handed instrument can be used when accessing the vertebral elements from the respective patient-right or patient-left side.

[0021] The wing 28 extends generally perpendicular to the plane BB defined by the first and second edges 22, 24 of the blade 16. Referring to FIG. 2, the wing 28 has a height H extending from a top edge 30 of the wing 28 to the plane BB (FIG. 1); although the disclosed principles can be applied in a variety of sizes and applications. The height H of the wing is preferably between 5 and 15 mm; more preferably between 8 and 12 mm.

[0022] In addition, the wing 28 is located a distance d from the first end 18 of the blade 16. The distance d extends from a rounded tip 36 (FIG. 1) at the first end 18 of the blade 16 to a front edge 60 of the wing 28. The distance d of the wing is preferably between 12 and 30 mm; more preferably between 18 and 26 mm.

[0023] Still referring to FIGS. 1 and 2, the blade 16 has a generally linear region 42 and a curved region 32. The curved region 32 is located at the first end 18 of the blade 16. The curved region 32 curves away from the plane BB defined by the first and second edges 22, 24 of the blade 16. That is, the curved region 32 has a convex curvature 34 that curves downward from the plane BB of the blade 16. The curved region 32 extends into the rounded tip 36 of the blade 16.

[0024] The handle 14 is located adjacent the second end 20 of the blade 16. The handle 14 includes a handle shaft 38 (FIG. 3) having an angled portion 40 and an extension portion 44. The angled portion 40 positions the extension portion 44 so that the surgical instrument 10 is easily and ergonomically maneuverable. A handle grip 46 is attached to the extension portion 44 of the handle shaft 38. The handle grip 46 can be attached by a fastener 48, such as a pin or threaded member, or may be attached by a bonding agent or weldment, for example.

[0025] Referring again to FIG. 1, a cutout section or recess 54 is located adjacent to the first end 18 of the blade 16 along one of the first and second edges 22, 24 of the blade 16. In particular, the recess 54 is located on the edge opposite the wing 28. In the left-handed embodiment of FIG. 1, the recess 54 is formed along the second edge 24 of the blade 16. In the right-handed embodiment of FIG. 4, the recess 54 is formed along the first edge 22 of the blade 16.

[0026] In the illustrated embodiment the recess 54 defines a curvature having a radius of approximately 1.5 inches. As will be described in greater detail hereinafter, the recess 54 provides clearance during use to permit the surgical tool 10 to be rotated or oriented from a first orientation relative to the vertebral elements to a second orientation.

[0027] Referring to FIGS. 2 and 3, the second end 20 of the blade 16 includes an extension 50 that extends outward from the blade 16 along the longitudinal axis A—A. The extension 50 defines an impact surface 52. The impact surface 52 can be defined only by the extension 50 of the blade 16, or may include a shaped surface or other structure designed to receive impact and positioned at the second end 20 of the surgical instrument.

[0028] Referring now to FIGS. 5–7, in use, the surgical instrument 10 may be used to distract two adjacent vertebral elements V1, V2. Prior to use of the instrument 10, portions of the lamina 86 (FIG. 7) of the first vertebral element V1 and the inferior facet 88 (FIG. 5) of the second vertebral element V2 are typically removed to provide access to the distraction site. (E.g., a lateral aspect of the lamina of the first vertebral element V1 and a superior aspect of the inferior facet of the second vertebral element V2 are typically removed.) In this particular application shown, the instrument is a left-handed instrument and the procedure is being performed on the patient-left side of the two vertebral bodies.

[0029] To insert the instrument 10, the instrument is oriented such that the handle 14 is directed toward the head of a patient when the patient is lying on his front, as shown in FIG. 5. The instrument 10 is then inserted between the inferior endplate 82 of the first vertebral element V1 and the superior endplate 84 of the second vertebral element V2. The rounded tip 36 (FIG. 1) of the instrument 10 aids in insertion. The surgeon may also use a tap hammer (not shown) on the impact surface 52 of the blade 16 to assist in insertion of the instrument 10.

[0030] The distance d of the wing 28 from the first end 18 (FIG. 2) is configured to limit the insertion depth of the instrument 10. That is, the front edge 60 of the wing 28 functions as a stop. During use, the front edge 60 contacts the posterior aspect 88 of the first vertebral element V1 (FIG. 7) to indicate to the surgeon that the proper insertion depth of the instrument 10 has been reached.

[0031] To distract the first and second vertebral elements, the instrument 10 is rotated typically about 90 degrees in a direction C (FIG. 5) about the longitudinal axis A—A of the blade 16. Referring back to FIG. 1, the direction C is in the direction toward the wing 28. Thus, the direction C of rotation of the right-handed embodiment will be opposite the direction C of rotation of the left-handed embodiment.

[0032] FIG. 6 illustrates the orientation of the instrument 10 of FIG. 5 in relation to the vertebral elements when rotated 90 degrees to a distracted position. As the instrument 10 is rotated, the wing 28 sweeps around in an arc to retract the nerve root 80 (FIG. 7). The wing 28 gently holds the nerve root 80 located at the inferior aspect of the first vertebral element V1 in a stationary position. As shown in FIG. 7, when positioned in the distracted orientation, the wing 28 retracts or holds the nerve root out 80 of the way so that the surgeon can easily access the distracted site.

[0033] The recess 54 formed on one of the first and second edges 22, 24 of the blade 16 provides for clearance for the inferior aspect of a superior pedical 90 (FIG. 5) of the first vertebral element V1. That is, while the surgeon is rotating the instrument 10 from the first position shown in FIG. 5 to the second position shown in FIGS. 6 and 7, the recess 54 permits the blade 16 to rotate without interference. This reduces the amount of bone removal necessary to access the distraction site as required by conventional distraction procedures.

[0034] The curved region 32 of the surgical instrument 10 assists in protecting the dura (not shown) medially during and after insertion of the instrument. In addition, the curved region 32 provides stability when rotated to the second position or the distraction position shown in FIGS. 6 and 7. That is, support edges or surfaces 56, 58 of the curved region 32 (FIG. 1) contact the superior and inferior endplates of the vertebral elements in a non-linear fashion. This arrangement distributes the contact points of the support surface 56, 58 in a non-linear arrangement to increase the support stability as compared to an instrument having a straight edge or end.

[0035] As can be understood, the distance of distraction or the space created between the first and second vertebral elements V1, V2 is determined by a width W (FIG. 4) of the first end 18 of the blade 16. Referring back to FIG. 4, the width W of the first end 18 extends between the support surfaces 56, 58 of the blade 16. The width W is preferably between 5 and 15 mm; more preferably between 6 and 12 mm. Typically, the surgeon chooses a blade 16 having a particular width that corresponds to the size of the implant that is to be inserted between the first and second vertebral elements.

[0036] With the two vertebral elements V1, V2 distracted, and the nerve root 80 retracted by the instrument 10, the surgeon can insert tools to prepare the distracted site for insertion of a spinal implant. For example, boring tools can inserted into the distracted site to drill and ream the site for implantation. The concave curvature 26 of the blade 16 guides the boring tool to the distracted site. That is, the radius of the concave curvature 26 cradles diametrically configured tools to guide the tools axially along the longitudinal axis A—A of the surgical instrument 10. The concave curvature 26 can also be used to guide the implant and implant insertion tools.

[0037] The curved region 32 of the first end 18 of the blade further assists the surgeon during a surgical procedure by providing visual access to the distracted site. The curve region 32 curves away from the location where, for example, an implant bore is formed. The surgeon can look down the longitudinal axis A—A of the instrument 10 and better view the formed implant bore, as the first end of the instrument 10 at the distracted site curves away from the formed implant bore and the longitudinal axis A—A of the instrument 10.

[0038] In an alternative method of use, the surgical tool 10 may simple be inserted between the first and second vertebral elements in the distracted position as shown in FIG. 6. That is, the surgical instrument may be oriented as shown in FIG. 6, and inserted between the elements as shown. The rounded tip 36 of the instrument 10 aids in insertion as the first and second support surface 56, 58 contact the superior and inferior endplates 82, 84. Similar to the previous method, the surgeon may also use a tap hammer on the impact surface 52 of the blade 16 to assist in insertion.

[0039] The above specification provides a complete description of the COMBINED DISTRACTOR AND RETRACTOR INSTRUMENT. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, certain aspects of the invention reside in the claims hereinafter appended.