The present invention relates to orthopedic implants, and more particularly, to tools for implanting spinal implants that facilitate fusion of bone segments and associated methods. Even more particularly, the invention relates to a combination distracter and inserter instrument for a spinal fusion device.
The integrity of the spine, including its subcomponents like the vertebral bodies and intervertebral discs that are well known structural body parts forming the spine, are key to a patient's health. These parts may become crushed or damaged as a result of trauma or injury, or damaged by disease (e.g., by tumor, autoimmune disease) or as a result of wear over time or degeneration caused by the normal aging process.
In many instances, one or more structural body parts can be repaired or replaced with a prosthesis or implant. For example, specific to the spine, one method of repair is to remove the vertebra (in whole or in part) and/or the disc (in whole or in part) and replace it with an implant or prosthesis. In some cases, it is necessary to stabilize a weakened or damaged spinal region by reducing or inhibiting mobility in the area to avoid further progression of the damage and/or to reduce or alleviate pain caused by the damage or injury. In other cases, it is desirable to join together the damaged vertebrae and/or induce healing of the vertebrae. Accordingly, an implant or prosthesis may be configured to facilitate fusion between two adjacent vertebrae. The implant or prosthesis may be placed without attachment means or fastened in position between adjacent structural body parts (e.g., adjacent vertebral bodies.)
Typically, an implant or prosthesis is secured directly to a bone structure by mechanical or biological means. One manner of spine repair involves attaching a fusion implant or prosthesis to adjacent vertebral bodies using a fixation element, such as a screw. Most implants and their attachment means are configured to provide an immediate, rigid fixation of the implant to the implantation site. In certain situations, the implantation process for the fusion implant can become cumbersome since multiple tools are required. It is therefore desirable to provide a delivery tool that facilitates ease of insertion of these types of spinal fusion implants, and consequently reduces the overall time in the operating room for the patient.
Although the following discussion focuses on spinal implants or prostheses, it will be appreciated that many of the principles may equally be applied to other structural body parts within a human or animal body.
The present disclosure provides a combination distracter and inserter instrument for a spinal fusion implant that allows a surgeon to distract the vertebral bodies between which the implant is to be placed, and also insert the implant into that site.
In accordance with one exemplary embodiment, a combination distracter and inserter instrument is provided. The instrument may comprise a pair of elongate paddles configured to be inserted in between a pair of adjacent vertebral bodies. Each paddle may be attached at one end to a control handle and terminate at an opposite end in a tapered tip. The instrument may also include a movable arm positioned in between the elongate paddles. The movable arm may be attached at one end to the control handle and configured at an opposite end to hold a spinal fusion implant for insertion into a disc space between the adjacent vertebral bodies. The movable arm may reside between the elongate paddles. In use, the instrument distracts the vertebral bodies with the elongate paddles as the spinal fusion implant is being delivered to the disc space with the movable arm. The instrument may also include a feature that prevents overinsertion of the paddles into the patient's spine, and a feature that prevents overinsertion of the implant into the disc space.
In accordance with another exemplary embodiment, a method for inserting a spinal fusion implant is provided. The method includes the steps of providing a spinal fusion implant, providing an insertion instrument for delivering the spinal fusion implant, and inserting the spinal fusion implant with the insertion instrument. The instrument may comprise a pair of elongate paddles configured to be inserted in between a pair of adjacent vertebral bodies. Each paddle may be attached at one end to a control handle and terminate at an opposite end in a tapered tip. The instrument may also include a movable arm positioned in between the elongate paddles. The movable arm may be attached at one end to the control handle and configured at an opposite end to hold a spinal fusion implant for insertion into a disc space between the adjacent vertebral bodies. The movable arm may reside between the elongate paddles.
In one step the control handle can be actuated to effect translational movement of the movable arm, and subsequent opening or closing of the elongate paddles. When the movable arm is translated towards the tapered tips of the elongate paddles, the elongate paddles open and distract the vertebral bodies. When the movable arm is translated away from the tapered tips of the elongate paddles, the elongate paddles close.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. Additional features of the disclosure will be set forth in part in the description which follows or may be learned by practice of the disclosure.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.
The present disclosure provides a combination distracter and inserter instrument for a spinal fusion implant that allows a surgeon to distract the vertebral bodies between which the implant is to be placed, and also insert the implant into that site. As shown in
In the embodiments shown, the instrument 10 is shown as a substantially linear device. However, in other embodiments, the instrument 10 may be curved or angled (not shown) if desired by the user or surgeon to facilitate access or visibility to the vertebral bodies. For example, in other embodiments, the instrument 10 may comprise a handle 12 having a gearing arrangement that permits handle 12 to extend to angled positions, such as about 30, 45, or 90 degrees, etc., while still translating rotation of T-shaped grip 16 into linear motion of the implant 100. The handle 12 may be provided with a preset angle or an adjustable angle. Such gearing arrangements are known to those skilled in the art.
As the motion arm 40 progresses (in response to rotation of the T-grip 16), paddles 20, 24 extend open along lines A-A and thereby distract vertebral bodies 2, 4. The notches 32 on the paddles 20, 24 can serve to provide tactile feedback or provide an interference to prevent overextension of the paddles 20, 24 into the intervertebral space.
The motion of T-grip 16 may also comprise features to ensure a user has selected a desired direction of motion. For example, T-grip 16 may provide a ratcheting feature and selector knob or lever (not shown) that the user or surgeon selects for a desired direction. Once a particular direction has been selected, the reverse motion of T-grip 16 may be prevented to confirm to the user that a particular direction has been selected. The ratcheting feature may also be used to allow the user to repeatedly use an arc of motion rather than a full circular motion to cause movement of the implant 100. In other embodiments, the T-grip 16 may comprise a quick release or other release feature that allows the user to quickly retract the implant 100.
In yet other embodiments, the instrument 10 may rely on linear motion rather than rotational motion to insert implant 100. For example, the instrument 10 may comprise a push rod type handle that the user pushes or pulls to control the insertion or retraction of the implant 100.
For example, the implant 100, once inserted, may be held in place by natural compression, thus allowing the user to release the attachment arm 42 from the implant 100. In other embodiments, the attachment arm 42 may engage implant 100 with a locking tab or threaded connector (not shown). Once implanted, the user may then manipulate T-grip 16 or other feature of instrument 10 to cause this engagement mechanism to release or unwind.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure provided herein. For example, the mechanism for actuating the motion arm 40 may comprise a lever, tensioned cable, a push-pull rod, etc. Further, in some embodiments, the paddles 20, 24 may be detachable and may be provided in a variety of sizes (i.e., lengths) and with different tensile strengths. The paddles 20, 24 may also include a variety of surface features or treatments to facilitate the distraction of the bone tissue of the vertebral bodies 2, 4. The shape of the tip regions 22, 26 may also be differently shaped, such as convex, V-shaped, etc. and may also be enlarged with respect to the rest of the paddles 20, 24. Additionally, the paddles 20, 24 may be curved so as to allow an angular or curved entry to reach the target site. The handle portion 14 may have any variety of grips and surfaces.
This application claims priority to U.S. Provisional No. 61/259,600, filed Nov. 9, 2009, and entitled “COMBINATION DISTRACTER AND INSERTER INSTRUMENT,” which is herein incorporated by reference in its entirety.
Number | Date | Country | |
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61259600 | Nov 2009 | US |