Embodiments described herein relate to medical instruments and, more particularly, to medical devices for use during anterior cervical discectomy, cervical arthroplasty, and other neurosurgical procedures of the spine.
Distraction devices are known for use during anterior cervical discectomy, cervical arthroplasty, and other neurosurgical procedures of the spine. However, it has been observed that the working corridor through the soft tissues of the neck may be crowded by the distraction devices that are available, thus limiting access to the cervical disc space and inhibiting maneuverability of other surgical instruments through the soft tissue corridor.
In some independent aspects, the invention may provide a low-profile distraction device with splayed distraction blades and a removable handle for adjusting the wedging action of the distraction blades. In some independent aspects, the invention may provide a method of using the distraction device in performing a surgery.
In some independent aspects, a medical device may be configured to engage a vertebrae body. The medical device may generally include a handle and a head configured to be removably coupled to the handle. The handle may include an elongate rod extending along a rod axis between a first end and a second end, and a grip coupled to the first end. The head is removably coupled to the second end. The head may include a frame defining an aperture, a pair of blades coupled to the frame for pivoting motion between a closed position and a splayed position, and a screw positioned in the aperture. The screw may be configured for movement along a central axis and includes a tip configured to engage the pair of blades. Movement of the screw moves the pair of blades between the closed position and the splayed position.
In some independent aspects, a medical device may include a handle extending along an axis; and a head configured to be removably coupled to the handle. The head may include a frame and a pair of blades pivotally coupled to the frame for movement between a closed position and a splayed position. The handle may be configured to couple to the head such that rotation of the handle about the axis drives the pair of blades between the closed position and the splayed position.
In some independent aspects, a method of operating a medical device configured to engage a vertebrae body may be provided. The medical device may include a handle extending along an axis and a head including a frame and a pair of blades pivotally coupled to the frame. The method may generally include removably coupling the handle and the head, and rotating the handle about the axis to move the pair of blades between a closed position and a splayed position.
Other independent aspects of the embodiments may become apparent by consideration of the detailed description, claims and accompanying drawings.
Before any embodiments are explained in detail, it is to be understood that the embodiments described herein are provided as examples and the details of construction and the arrangement of the components described herein or illustrated in the accompanying drawings should not be considered limiting. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limited.
The use of “including,” “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting, and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and may include electrical connections or couplings, whether direct or indirect.
Relative terminology, such as, for example, “about”, “approximately”, “substantially”, etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context (for example, the term includes at least the degree of error associated with the measurement of, tolerances (e.g., manufacturing, assembly, use, etc.) associated with the particular value, etc.). Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10% or more) of an indicated value.
Also, the functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not listed.
The embodiment(s) described below and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present disclosure. As such, it will be appreciated that variations and modifications to the elements and their configuration and/or arrangement exist within the spirit and scope of one or more independent aspects as described.
The caspar pin extension through the working corridor (the space allowing access through the anterior region to the vertebrae) is limiting to the surgeon while accessing the disc space. It is undesirable to increase the size of the working corridor, as increasing the size would result in additional damage to the patient and in longer recovery times. Additionally, when using caspar pin distracters, the distraction forces are limited to the anterior portion of the vertebral body where the caspar pins are placed. Deep soft tissue working corridors, particularly present in obese patients, those with kyphotic cervical spines, and those with inferiorly angled C6-7 and C7-T1 disc spaces, are difficult to access with the caspar distractor as the length of its distractor arms are limited.
Described here with reference to the
With reference to
The illustrated head 24 includes a frame 32, a pair of distraction blades 36, and a driver or an actuator 40 (e.g., a screw, as illustrated, or other threaded member) supported by the frame 32 for movement to a plurality of positions along a central axis A. The distraction blades 36 are mounted to the frame 32 on either side of the axis A for pivoting movement by respective pivot joints (e.g., pins 44) so that the distraction blades 36 may be pivoted or splayed to a variety of positions in accordance with the position of the actuator 40. The pins 44 are positioned perpendicular to the axis A so that movement of the blades 36 moves tips 48 of the blades 36 toward or away from the axis A.
The handle 28 has a quick-connect coupling with the head 24 to facilitate removable connection of the handle 28 and the head 24. When connected, the handle 28 is operable to position the head 24. When rotated, the connected handle 28 acts as a driver to separate the distraction blades 36.
With continued reference to
As mentioned above, in the illustrated embodiment, the handle 28 is removably coupled to the head 24. The handle 28 is selectively and alternatively connectable to the head 24 in two modes—in a first mode (see
Turning to
As shown in
The second end 60 of the handle 28 may be coupled to the frame 32 by a sequence of orientation and rotation, without tools or separate fasteners. For example, the handle 28 is positioned with the lugs 100 oriented toward open sides of the slot 88 while the handle 28 is moved axially along the axis A of the head 24 until the lugs 100 align with the groove 96. The handle 28 is subsequently pivoted about the axis A to move the lugs 100 into the groove 96 and lock the handle 28 to the head 24. In some embodiments, the handle 28 is pivoted about the axis A by about 90 degrees. In some embodiments, a different degree of pivoting movement may be used to engage the lug(s) 100 in the groove 96.
In some embodiments (not shown), the groove 96 may have a varying height (e.g., be tapered), and the lugs 100 are retained in the groove 96 by friction. In some embodiments (not shown), the groove 96 may include additional features to engage the lugs 100 and lock the handle 28 to the head 24. Other methods of retaining the lugs 100 within the groove 96 are also contemplated.
As shown best in
When the handle 28 is coupled to the head 24 in the first mode, the handle 28 may be positioned with the rod axis R in line with the axis A of the head 24 and with the lugs 100 overlying the rear surface 92. As the handle 28 is moved toward the frame 32, the screw head 72 is received by the socket 104, drivingly coupling the handle 28 and the screw 40. The handle 28 is then rotated about the axes A, R to rotate and linearly move the screw 40.
With reference to
As seen in
As illustrated, the distal end 112 extends generally parallel to the central axis A. Regardless of the orientation of the blades 36 with respect to the axis A, the distal end 112 forms a non-zero angle α with the proximal end 108. In other words, in an operational configuration in which the proximal end 108 (and its surface 116) is converging toward the central axis A (as taken from proximal to distal), the distal end 112 converges toward the central axis A to a lesser degree (including not converging at all). The reduced convergence may be a reduced angle or, in the case of a basic offset, simply a reduced proximity as compared to following the path of the proximal end 108.
As shown in
As shown in
In the splayed or open position, the tips 48 are spaced from each other to define a working space therebetween. In this position, the screw head 72 is at a second distance from the rear surface 92 of the frame 32. In some embodiments (as shown), the screw head 72 is partially received by the slot 88. At least a portion of the screw head 72 extends rearwardly of the rear surface 92 of the frame 32 so that the socket 104 of the handle 28 may engage the screw head 72 without entering the slot 88 or engaging the groove 96.
With reference to
The handle 28 may then be disconnected from the head 24. The handle 28 is removed by rotating the handle 28 about the axis A relative to the head 24 until the lugs 100 are disengaged from the groove 96 and removed from the slot 88. The handle 28 is then connected to the head 24 in the first mode to act as a driver to separate the distraction blades 36 via the screw 40. In some embodiments, the handle 28 may engage an alternate wedge mechanism to distract the blades 36.
In the illustrated embodiment, the handle 28 is connected to the head 24 to rotationally couple the screw 40 and the handle 28. The handle 28 is aligned with the head 24 and positioned so the socket 104 receives the screw head 72. The screw 40 receives rotational input from the handle 28 and acts to wedge apart the distraction blades 36. Thus, the handle 28 is rotated about the axis A in order to advance the screw 40, as shown in the change of position in
The linear displacement of the screw 40 moves the tip 84 into engagement with the co-facing surfaces 116 of the blades 36, drives distraction of the blades 36 and, as a result, widens the space between adjacent vertebrae, allowing access to the disc space. The distal ends 112 of the distraction blades 36 are angled with respect to the proximal ends 108, as described above, so that, when the blades 36 are in the splayed position, a working space is provided between the blades 36 for performing medical operations, such as a discectomy. Once the vertebrae are distracted, the handle 28 is detached from the head 24 by axially moving the handle 28 rearwardly. The handle 28 is removed from the surgical space, leaving the working corridor free during any subsequent operations.
Once the operation is completed for that region of interest, the handle 28 is re-attached onto the head 24 in the first mode, by engaging the screw 40 with the second end 60 of the handle 28. The screw head 72 is positioned within the socket 104 to couple the handle 28 and the screw 40 for corotation. The handle 28 is then used to retract the screw 40 to allow the distraction blades 36 to move inwardly toward the axis A. In some embodiments, as illustrated, the blades 36 are moved toward the axis A by the restorative force of the adjacent vertebrae returning to position. In some embodiments, the distraction blades 36 may be biased to retract toward the axis A (e.g., by a biasing member, such as a spring).
The handle 28 may be re-connected to the head 24 in the second mode, by positioning the lugs 100 within the slot 88 and rotating the handle 28 to lock the lugs 100 into place in the groove 96. The handle 28 is then manipulated to remove the device 20 from the patient.
The device 20 does not require pin placement or violation of the bone. The adjacent level of vertebrae is not at risk and the soft tissues of the neck are not retracted with the present anterior cervical disc space spreader device 20 as the device 20 provides distraction focally at the intended disc space. This device 20 may be inserted into the disc space and may be advanced to the posterior limit of the disc space to ensure equal distraction from the anterior to posterior disc margin avoiding a narrowed posterior corridor and providing access to posterior osteophytes and views of the spinal cord. Deep soft tissue corridors are not limiting to this device 20 as the device 20 sits entirely on the anterior cervical spine and does not extend out of the incision.
The illustrated device 20 provides a low-profile means of anterior cervical disc space distraction compared to current methods of caspar pin extension. With the conventional caspar pin distractor 1, the working corridor through the soft tissues of the neck is crowded by the distraction devices. This device 20 may improve access to the cervical disc space while maintaining maneuverability of other surgical instruments through the soft tissue corridor. This device 20 may be scaled for use to distract any vertebrae pair, including the cervical, thoracic, and lumbar vertebrae, for accessing the disc space therebetween.
One or more independent features and/or independent advantages of the embodiments may be set forth in the following claims:
The present application claims the benefit of co-pending U.S. Provisional Patent Application No. 63/291,089, filed Dec. 17, 2021, the entire contents of which is hereby incorporated by reference.
Number | Date | Country | |
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63291089 | Dec 2021 | US |