Patent Application
20090299378
All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
The invention relates to devices, systems and methods for treating and supporting bone, including bone within vertebral bodies suffering from a vertebral compression fracture (VCF). More particularly, the devices, methods and systems described herein relate to rotary handles and applicator systems and controls for inserting self-expanding bone support implants.
Deterioration of bone tissue, and particularly micro-architecture deterioration, can result from a variety of factors including disease, aging, stress and use. For example, osteoporosis is a disease characterized by low bone mass and micro-architecture deterioration of bone tissue. Osteoporosis leads to bone fragility and an increase fracture risk. While osteoporosis affects the entire skeleton, it commonly causes fractures in the spine and hip. Spinal or vertebral fractures have serious consequences, with patients suffering from loss of height, deformity, and persistent pain that can significantly impair mobility and quality of life. Vertebral compression fractures (VCFs) and hip fractures are particularly debilitating and difficult to effectively treat.
Devices for supporting and repairing bone, including implants for repairing spinal compressions including VCFs have been described. One particularly useful type of implant for support and/or treatment of bone are self-expanding implants that may be deployed within bone to cut through the bone with little or any compression, and may be filled with one or more bone fillers (e.g., cement) in the regions within and around the implant for added support. Such implants may also act as supports or anchors for additional implants.
These bone implants (which are described in greater detail below) may be inserted using a controller (e.g., applicator system) that must provide support for the implant during and before implantation. For example, the implant may be released to self-expand within the bone, and must be manipulated into position and released while maintaining force on the implant to maintain it in a compressed (delivery) configuration. The inserter must allow precise control of the release of the implant into the bone. It may also be beneficial to allow the implant to be removed using the inserter.
It may be beneficial to have the inserter be modular, so that one or more portions could be reused, saving cost and time. For example, a handle portion may be re-used by connecting to various elongate (e.g., cannula) portions of the applicator.
It may also be helpful to provide a device having a minimum of components, and devices that are configured to include one or more failsafe mechanisms that permit the implant to be removed even in case the implant or applicator becomes jammed or otherwise disrupted.
Related U.S. application Ser. No. 12/024,938 (filed on Feb. 1, 2008), titled “SYSTEMS, DEVICES AND METHODS FOR STABILIZING BONE”) describes bone stabilization devices and methods for inserting them using a delivery device. The delivery device may be configured to include a cannula (or multiple cannula) and one or more trocars. As mentioned above, it would be extremely beneficial to have a delivery device including a handle that can be used to control the delivery and/or expansion of an implant device.
Examples of controllers, inserters, handles and devices forming such an improved handle are provided herein.
Described herein are handles and applicator systems including handles for engaging delivery (and/or retrieval) of a bone stabilization device, as well as systems or kits including handles, and methods for using them.
An applicator (or applicator system) may include a handle region and an elongate linkage member that couples with the handle. In particular, described herein are rotary applicator handles that are configured to couple with the proximal end of the elongate linkage member and drive the axial motion (e.g., in the direction of the long axis of the elongate linkage member) of a portion of the elongate linkage member. An implant such as a bone stabilizing implant may be coupled to the distal end of the elongate linkage member, and axial movement of a portion of the elongate linkage member may result in expansion or contraction of the implant. As used herein, “axial” motion of a component of the elongate linkage member refers to motion in the direction of the long axis of the elongate linkage member. For example, an elongate linkage member may include a first elongate member that may move relative to a second elongate member. In some variations the first elongate member is an outer (e.g., cannula) member and the second elongate member is an inner (e.g., rod) member. The outer cannula and the inner rod may coaxially slide relative to each other, which is one type of “axial” movement. Axial movement of the elongate linkage member is translated into force across an implant that is coupled to the distal end of the elongate linkage member, causing the implant to collapse (e.g., into a narrow-diameter delivery configuration) or expand (e.g., into an expanded-diameter deployed configuration in which a plurality of struts bow out from the body of the implant).
In general, the handles described herein are rotary applicator handles that are activated by rotating a control on the handle (e.g., a knob, a rotating grip, etc.). Rotating the control drives rotation of a rotary gear within the handle, and the rotary gear drives axial movement of a portion of an elongate linkage member when an elongate linkage member is coupled to the handle. In variations in which the elongate linkage member includes a first elongate member and a second elongate member that are movable relative to each other, the proximal ends of the first and second elongate members are held in separate seats in the handle. By holding the proximal ends of the first and second elongate members, these members may be moved relative to each other, thereby controlling the motion of the implant coupled to the distal end of the elongate linkage member. Typically the implant is coupled to the distal end of the elongate linkage member so that the proximal end is connected to one of the elongate members forming the elongate linkage member (e.g., the first elongate linkage member) and the distal end of the implant is coupled to the distal end of the other elongate linkage member (e.g., the second elongate linkage member).
In some variations, the rotary applicator handles described herein are ratcheting handles in which the rotary gear is a ratcheting gear including a pawl that helps control the direction of axial movement driven by the gear. A control on the handle (e.g., a direction switch or a ratchet switch) may be used to select the direction of movement enabled by the handle. This control may be connected to the pawl. Other controls, including safety controls for releasing the force applied by the handle to the elongate linkage member (and therefore the implant), or for releasing the elongate linkage member from the handle, may also be included. For example, the handles described herein may include a control for regulating/controlling the release of the stabilization device. Stabilization devices are typically self-expanding devices, and the control may regulate the self-expansion so that the rate and degree of self-expansion allowed is regulated. The handles may be lockable, and may include a latch or other locking structure. These handles may also include ratcheting mechanism or other controlled expansion/release mechanism. In some variations the devices include a failsafe release configured to release either the applicator and/or the device. These devices may also include a one or more finger controls for controlling the handle, and the handle may be configured for gripping in one or more of the subject's hands.
In some variations, the handle includes indicators or sensors. For example, the handle may include an indicator of the orientation of the implant attached to the distal end of a coupled elongate linkage member. In particular, the handle may be configured so that the elongate linkage member is not rotated when axial motion is applied and therefore the implant is not rotated during delivery of the device. For example, the seats for the proximal end of the elongate linkage member may be keyed to prevent rotation of the implant.
The implants described herein may also be referred to as bones stabilization devices. These implants may include a self-expanding body that can be deployed in a linear configuration. The deploying configuration is typically an elongate tubular shape that is open at both ends. In some variations the device may have an elongate, substantially tubular shape that includes a plurality of struts extending along the length of the implant in the deployed configuration. For example, the struts maybe extended laterally in an expanded configuration. Expansion of the struts may foreshorten the implant. A self-reshaping (e.g., self-expanding) device may include a preset configuration that is expanded, and may reset from another configuration into the preset configuration (or vice versa). For example, the devices may include a linear configuration (a deployed configuration) and an expanded configuration. The linear configuration can be stabilized by constraints that prevent self-reshaping of the device into an anchoring (expended) configuration. Self-reshaping to an anchoring configuration may be performed by two or more linear portions of the device, which (upon release from constraint) radially-expand into bowed struts of various configurations, while at the same time shortening the overall length of the device. Embodiments of the struts may include a cutting surface on the outwardly leading edge or surface of the strut, which cuts through cancellous bone as it radially expands. After implantation within a vertebral body, the bowed struts may expand though the cancellous bone to contact the cortical bone of the inner surfaces of superior and inferior endplates of the compressed vertebral body, and push the endplates outward to restore the vertebral body to a desired height.
In general, the implants described herein may be inserted into tissue (e.g., bone such as a vertebra) so that they do not foreshorten when allowed to self-expand. As described in greater detail below, this may be accomplished by controlling both the proximal and distal ends (or end regions) of the implant with the applicator. Thus, the applicator (including the handle) may be configured to control the relative motions of the ends of the implant. For example, if the distal end is held while the proximal end is allowed to foreshorten, the device may be inserted without distally foreshortening or otherwise moving. Movement of the distal end of the device may result in the implant moving undesirably from the implantation site, and may cause damage or inaccuracy.
The implant maybe prepared for insertion by collapsing it. An applicator or inserter (described below) may be used to collapse it from a pre-biased expanded configuration, in which the struts are bowed or otherwise expended, and a more linear collapsed or delivery configuration, in which the struts are collapsed towards the body. For example, the step of delivering the first self-expanding implant may include the step of applying a restraining force across the implant to hold the first implant in a collapsed configuration. In some variations, the method also includes the step of applying a restraining force across the first implant by applying force across the implant to collapse a plurality of expandable struts along the implant.
The step of releasing restraining forces to radially expand the self-expanding implant within the cancellous bone may comprise allowing the proximal end of the implant to foreshorten. The step of releasing restraining forces to radially expand the first and second self-expanding implants within the cancellous bone may also (or alternatively) comprise removing the distal end portion of the implant for a first inserter region and removing the proximal end portion of the implant from a second inserter region.
Any of the handle devices described herein may be used with any appropriate elongate linkage member. In some variations, a handle and an elongate linkage member may be used together to form an applicator or applicator system. The handles described herein may be reusable or disposable. In some variations a handle is intended for use in with multiple implants in a single procedure; each implant may be connected to a separate elongate linkage member. Thus, in some variations the rotary applicator handles described herein are configured for use with a single size of implant; in other variations, the handle may be used or adapted for use with implants of different sizes. Handles may distinguish different sizes of implants based on the shape (e.g., the keyed shape) of the proximal end of the elongate linkage member to which the implant is attached distally. In some variations the handle distinguishes different sizes of implants based on the separation between the proximal ends of first and second elongate members forming the elongate linkage member.
Rotary applicator handles may be formed of any appropriate materials, including metals, plastics (e.g., polymeric materials), ceramics, or the like, including any combination thereof.
For example, described herein are rotary applicator handle for delivery or removal of a bone stabilizing implant that is distally coupled to an elongate linkage member. These handles may include: a handle grip configured to be held in the palm of a hand; a housing at least partially surrounding a first seat configured to hold the proximal end of a first elongate member of the elongate linkage member and a second seat configured to hold the proximal end of a second elongate member of the elongate linkage member; a rotary gear within the housing, the rotary gear configured to drive the axial motion of the first member of the elongate linkage member relative to the second member of the elongate linkage member; and a rotatable control coupled to rotary gear and configured to rotate the rotary gear.
The rotary gear may be a ratcheting gear comprising a pawl. In some variations, the rotary applicator handle includes a directional switch coupled to the rotary gear and configured to control direction of axial motion driven by the rotary gear.
In some variations, the rotary gear comprises a drive shaft. The rotary or rotatable control may be a knob that rotates the drive shaft.
The rotary applicator may also include an indicator to indicate the orientation of the bone stabilizing implant relative to the handle. The handle may be marked (e.g., alphanumerically, etc.) to indicate the size of the implant that it is to be used with. The rotary applicator handle may also include a release control configured to release the elongate linkage member from the handle. For example, the handle may include a force release control configured to release the axial force applied to the elongate linkage member by the handle.
The rotary applicator handle may include a mating region configured to mate with a shaft stabilizer on the first member of the elongate linkage member. The mating region may be at the distal end of the handle, and may be a keyed fitting, maintaining the orientation of the elongate linkage member (and therefore the implant) when engaged with the handle.
In some variations the rotatable control is a rotatable control grip. This rotatable grip may be configured for use by a second hand (e.g., separate from the hand holding the handle grip), or it may be a finger grip, so that it may be rotated by the thumb and index finger, for example.
In general, the expansion and contraction of the implant (and particularly a self-expanding implant) may be controlled. For example, when the implant is converted a (constrained) elongate, tubular delivery configuration having a small cross-section to an expanded configuration in which the struts extend from the body of the device, the implant may be foreshortened. The applicator system controls the deployment of the implant (from the compressed configuration to the expanded configuration) by applying axial force to pull apart (collapse) or draw together (expand) the proximal and distal ends of the implant. One end of the implant (e.g., the distal end) may be held relatively motionless while the applicator system moves the other end to collapse or expand the implant. Preventing the distal end from moving during expansion or collapse may prevent damage to the patient, and may help maintain the position of the implant during insertion. For example, the rotary gear may be configured to axially move the second seat relative to the first seat so that the proximal end of an implant coupled to the first member of the elongate linkage member moves while the distal end of the implant remains relatively stationary.
In some variations, the handle is a ratcheting applicator handle for delivery or removal of a bone stabilizing implant that is distally coupled to an elongate linkage member. In this example, the handle includes: a first handle grip region; a housing at least partially surrounding a first seat configured to hold the proximal end of an inner member of the elongate linkage member and a second seat configured to hold the proximal end of an outer member of the elongate linkage member; a ratcheting gear within the housing, the ratcheting gear configured to drive the axial motion of the outer member of the elongate linkage member relative to the inner member of the elongate linkage member; a rotatable grip coupled to ratcheting gear and configured to rotate the ratcheting gear; and a directional switch coupled to a pawl and configured to select the axial direction that the outer member is driven relative to the inner member.
As mentioned, any of these handles may be used as part of an inserter or applicator system. Thus, described herein are inserter systems for delivery or removal of a bone stabilizing implant that include: an elongate linkage member configured to distally couple with the bone stabilizing implant and a rotary handle. The elongate linkage member may include: a first elongate member configured to releasably couple at its distal end with the proximal end region of the bone stabilizing implant; and a second elongate member configured to releasably couple at its distal end with the distal end region of the bone stabilizing implant. The rotary handle may include: a handle grip region; a housing at least partially surrounding a first seat configured to hold the proximal end of the first elongate member and a second seat configured to hold the proximal end of the second elongate member; a rotary gear within the housing, the rotary gear configured to drive the axial motion of the first member relative to the second elongate member; and a rotatable control configured so that rotation of the rotatable control moves the rotary gear.
As mentioned, the first member may comprise an outer cannula and the second elongate member may comprise an internal rod. These outer and inner members may be coaxially arranged.
The elongate linkage member may also include an end grip at the proximal end of the first elongate member that is keyed to fit within the first seat of the rotary handle. The rotary gear may be a ratcheting gear comprising a pawl. The system may also include a directional switch coupled to the rotary gear and configured to control the direction of axial motion driven by the rotary gear.
In some variations, the system also includes a self-expanding implant. Any of the implants described herein may be used, including implants having a plurality of self-expanding struts and a proximal attachment region configured to releasably attach to the first elongate member and a distal attachment region configured to releasably attach to the second elongate member.
Also described herein are methods of using the rotary handles described. For example, a method of collapsing and expanding a self-expanding implant is described. This method may include the steps of: seating the proximal end of an elongate linkage member within a rotary applicator handle so that the proximal end of a first elongate member of the elongate linkage member is held within a first seat and the proximal end of a second elongate member of the elongate linkage member is held within a second seat; and rotating a control on the rotary applicator handle to drive a rotary gear that axially moves the first elongate member relative to the second elongate member so that the proximal end of a self-expanding implant that is coupled to the distal end of the first elongate member is moved relative to the distal end of the self-expanding implant that is coupled to the distal end of the second elongate member.
The step of rotating the control on the rotary applicator handle may include limiting the axial motion of the first elongate member relative to the second elongate member to prevent damage to the self-expanding implant. A limiter may be included as a stop of other structure within the handle, limiting axial motion to within a specified range. This range may be adjustable in variations of the handle that are used for different sized implants.
The step of rotating the control on the rotary applicator may comprise moving the first elongate member relative to the second elongate member without substantially moving the second elongate member. As mentioned above, this may prevent movement of the distal end of the implant.
The methods may be performed with any of the ratcheting handles described. For example, the step of rotating the control on the rotary applicator handle may include driving a ratcheting rotary gear comprising a pawl. In some variations, the method may therefore include the step of selecting the direction of axial motion by switching a ratchet switch that is coupled to a pawl.
The method may also include the steps of releasing the device from the applicator system. For example the method may include the steps of disengaging (e.g., rotating) the first and second members to release the proximal and distal ends of the implant from the elongate linkage member. This step may be performed in some variations while the elongate linkage member is attached to the handle, or after the two are decoupled. For example, the method may include the steps of activating a control on the rotary applicator handle to release the axial force applied to the elongate linkage member by the rotary applicator handle. In some variations, the method may also include the steps of releasing the elongate linkage member from the handle.
The devices, systems and methods described herein may aid in the treatment of fractures and microarchitetcture deterioration of bone tissue, including vertebral compression fractures (“VCFs”). The implantable stabilization devices described herein (which may be referred to as “implants,” “stabilization devices,” or simply “devices”) may help restore and/or augment bone. Thus, the stabilization devices described herein may be used to treat pathologies or injuries. For purposes of illustration, many of the devices, systems and methods described herein are shown with reference to the spine. However, these devices, systems and methods may be used in any appropriate body region, particularly bony regions. For example, the methods, devices and systems described herein may be used to treat hip bones.
In general, the devices and systems described are rotary handles and systems including rotary handles for the insertion and/or removal of one or more bone stabilization devices. The systems may also be referred to as applicators or applicator systems. An applicator may include a handle and an elongate cannula region. An example of one variation of a system including an applicator and a bone stabilization device is shown in
Any of the applicators or inserters described herein may be used with any appropriate bone stabilization device (typically referred to as a “stabilization device”), examples of which are provided herein. These stabilization devices may be a self-expanding device that expands from a compressed profile having a relatively narrow diameter (e.g., a delivery configuration) into an expanded profile (e.g., a deployed configuration). Stabilization devices generally include a shaft region having a plurality of struts that may extend from the shaft body. The distal and proximal regions of a stabilization device may include one or more attachment regions configured to attach to an inserter for inserting (and/or removing) the stabilization device from the body.
Side profile views of five variations of stabilization devices are shown in
The struts 201, 201′ of the elongate shaft is the section of the shaft that projects from the axial (center) of the shaft. Three struts are visible in each of
The stabilization device is typically biased so that it is relaxed in the expanded or deployed configuration, as shown in
The struts in all of these examples are continuous curvature of bending struts. Continuous curvature of bending struts are struts that do not bend from the extended to an unextended configuration (closer to the central axis of the device shaft) at a localized point along the length of the shaft. Instead, the continuous curvature of bending struts are configured so that they translate between a delivery and a deployed configuration by bending over the length of the strut rather than by bending at a discrete portion (e.g., at a notch, hinge, channel, or the like). Bending typically occurs continuously over the length of the strut (e.g., continuously over the entire length of the strut, continuously over the majority of the length of the strut (e.g., between 100-90%, 100-80%, 100-70%, etc.), continuously over approximately half the length of the strut (e.g., between about 60-40%, approximately 50%, etc.).
The “curvature of bending” referred to by the continuous curvature of bending strut is the curvature of the change in configuration between the delivery and the deployed configuration. The actual curvature along the length of a continuous curvature of bending strut may vary (and may even have “sharp” changes in curvature). However, the change in the curvature of the strut between the delivery and the deployed configuration is continuous over a length of the strut, as described above, rather than transitioning at a hinge point. Struts that transition between delivery and deployed configurations in such a continuous manner may be stronger than hinged or notched struts, which may present a pivot point or localized region where more prone to structural failure.
Thus, the continuous curvature of bending struts do not include one or more notches or hinges along the length of the strut. Two variations of continuous curvature of bending struts are notchless struts and/or hingeless struts. In
An attachment region may be configured in any appropriate way. For example, the attachment region may be a cut-out region (or notched region), including an L-shaped cut out, an S-shaped cut out, a J-shaped cut out, or the like, into which a pin, bar, or other structure on the inserter may mate. In some variations, the attachment region is a threaded region which may mate with a pin, thread, screw or the like on the inserter. In some variations, the attachment region is a hook or latch. The attachment region may be a hole or pit, with which a pin, knob, or other structure on the inserter mates. In some variations, the attachment region includes a magnetic or electromagnetic attachment (or a magnetically permeable material), which may mate with a complementary magnetic or electromagnet region on the inserter. In each of these variations the attachment region on the device mates with an attachment region on the inserter so that the device may be removably attached to the inserter.
The attachment region on the implant may be formed of a material forming the majority of the implant (e.g., a shape memory material such as a shape memory alloy), or it may be formed of a different material and secured to the rest of the implant. In particular, when the implant attachment regions comprises threads, it may be particularly advantageous to form the threads in anther material (e.g., PMMA or other polymers, ceramics, or metals) that is then secured to the shape memory alloy forming the body of the implant. In some variations the attachment regions comprise an internal threaded region at the distal end of the implant and an external threaded region at the proximal end of the implant (counter-threaded as described below). It is known that shape memory materials such as Nitinol are particularly difficult to cut threads in and to weld to, particularly in an internal diameter such as the distal end of the device. Thus, in some variations the distal end of the device includes a plug formed of PMMA or other biocompatible material that forms threads and can be inserted into the implants distal end.
The stabilization devices described herein generally have two or more releasable attachment regions for attaching to an inserter. For example, a stabilization device may include at least one attachment region at the proximal end of the device and another attachment region at the distal end of the device. This may allow the inserter to apply force across the device (e.g., to pull the device from the expanded deployed configuration into the narrower delivery configuration), as well as to hold the device at the distal end of the inserter. However, the stabilization devices may also have a single attachment region (e.g., at the proximal end of the device). In this variation, the more distal end of the device may include a seating region against which a portion of the inserter can press to apply force to change the configuration of the device. In some variations of the self-expanding stabilization devices, the force to alter the configuration of the device from the delivery to the deployed configuration comes from the material of the device itself (e.g., from a shape-memory material), and thus only a single attachment region (or one or more attachment region at a single end of the device) is necessary.
In variations of the stabilization device that include a proximal releasable attachment site and a distal releasable attachment site (which may be located at either at the proximal and distal ends, or spaced from the ends), the releasable attachment sites may be configured to operate in opposite directions. For example, when the attachment sites are threaded regions (e.g.,
Similar to
The continuous curvature of bending struts described herein may be any appropriate dimension (e.g., thickness, length, width), and may have a uniform cross-sectional thickness along their length, or they may have a variable cross-sectional thickness along their length. For example, the region of the strut that is furthest from the tubular body of the device when deployed (e.g., the curved region 301 in
The dimensions of the struts may also be adjusted to calibrate or enhance the strength of the device, and/or the force that the device exerts to self-expand. For example, thicker struts (e.g., thicker cross-sectional area) may exert more force when self-expanding than thinner struts. This force may also be related to the material properties of the struts.
As mentioned, in some variations, different struts on the device may have different widths or thicknesses. In some variations, the same strut may have different widths of thicknesses along its length. Controlling the width and/or thickness of the strut may help control the forces applied when expanding. For example, controlling the thickness may help control cutting by the strut as it expands.
Similarly, the width of the strut (including the width of the outward-facing face of the strut) may be controlled. The outward-facing face may include a cutting element (e.g., a sharp surface) along all or part of its width, as mentioned.
Varying the width, thickness and cutting edge of the struts of a device may modulate the structural and/or cutting strength of the strut. This may help vary or control the direction of cutting. Another way to control the direction of cutting is to modify the pre-biased shape. For example, the expanded (pre-set) shape of the struts may include one or more struts having a different shape than the other struts. For example, one strut may be configured to expand less than the other struts, or more than other struts. Thus, in some variations, the shape of the expanded implant may have an asymmetric shape, in which different struts have different expanded configurations.
The struts may be made of any appropriate material. In some variations, the struts and other body regions are made of substantially the same material. Different portions of the stabilization device (including the struts) may be made of different materials. In some variations, the struts may be made of different materials (e.g., they may be formed of layers, and/or of adjacent regions of different materials, have different material properties). The struts may be formed of a biocompatible material or materials. It may be beneficial to form struts of a material having a sufficient spring constant so that the device may be elastically deformed from the deployed configuration into the delivery configuration, allowing the device to self-expand back to approximately the same deployed configuration. In some variation, the strut is formed of a shape memory material that may be reversibly and predictably converted between the deployed and delivery configurations. Thus, a list of exemplary materials may include (but is not limited to): biocompatible metals, biocompatible polymers, polymers, and other materials known in the orthopedic arts. Biocompatible metals may include cobalt chromium steel, surgical steel, titanium, titanium alloys (such as the nickel titanium alloy Nitinol), tantalum, tantalum alloys, aluminum, etc. Any appropriate shape memory material, including shape memory alloys such as Nitinol may also be used.
Other regions of the stabilization device may be made of the same material(s) as the struts, or they may be made of a different material. Any appropriate material (preferably a biocompatible material) may be used (including any of those materials previously mentioned), such as metals, plastics, ceramics, or combinations thereof. In variations where the devices have bearing surfaces (i.e. surfaces that contact another surface), the surfaces may be reinforced. For example, the surfaces may include a biocompatible metal. Ceramics may include pyrolytic carbon, and other suitable biocompatible materials known in the art. Portions of the device can also be formed from suitable polymers include polyesters, aromatic esters such as polyalkylene terephthalates, polyamides, polyalkenes, poly(vinyl) fluoride, PTFE, polyarylethyl ketone, and other materials. Various alternative embodiments of the devices and/or components could comprise a flexible polymer section (such as a biocompatible polymer) that is rigidly or semi rigidly fixed.
The devices (including the struts), may also include one or more coating or other surface treatment (embedding, etc.). Coatings may be protective coatings (e.g., of a biocompatible material such as a metal, plastic, ceramic, or the like), or they may be a bioactive coating (e.g., a drug, hormone, enzyme, or the like), or a combination thereof. For example, the stabilization devices may elute a bioactive substance to promote or inhibit bone growth, vascularization, etc. In one variation, the device includes an elutible reservoir of bone morphogenic protein (BMP).
As previously mentioned, the stabilization devices may be formed about a central elongate hollow body. In some variations, the struts are formed by cutting a plurality of slits long the length (distal to proximal) of the elongate body. This construction may provide one method of fabricating these devices, however the stabilization devices are not limited to this construction. If formed in this fashion, the slits may be cut (e.g., by drilling, laser cutting, etc.) and the struts formed by setting the device into the deployed shape so that this configuration is the default, or relaxed, configuration in the body. For example, the struts may be formed by plastically deforming the material of the struts into the deployed configuration. In general, any of the stabilization devices may be thermally treated (e.g., annealed) so that they retain this deployed configuration when relaxed. Thermal treatment may be particularly helpful when forming a strut from a shape memory material such as Nitinol into the deployed configuration.
As mentioned, the expansion limiter may be coupled to the applicator, or may for a portion of the applicator. Thus, the applicator may move the expansion limiter relative to the stabilization device to allow it to controllably expand (preferably while leaving the distal end fixed relative to the insertion site in the body). In some variation the expansion limiter may be an outer sleeve that fits over all or a portion of the stabilization device and may be withdrawn to deliver it.
As mentioned, an inserter may include an elongate body having a distal end to which the stabilization device may be attached and a proximal end which may include a handle or other manipulator that coordinates converting an attached stabilization device from a delivery and a deployed configuration, and also allows a user to selectively release the stabilization device from the distal end of the inserter.
The elongate linkage member (inserter) 611 shown in
The inserter shown in
An inserter may also limit or guide the movement of the first and second elongate members, so as to further control the configuration and activation of the stabilization device. For example, the inserter may include a guide for limiting the motion of the first and second elongate members. A guide may be a track in either (or both) elongate member in which a region of the other elongate member may move. The inserter may also include one or more stops for limiting the motion of the first and second elongate members.
As mentioned above, the attachment regions on the inserter mate with the stabilization device attachments. Thus, the attachment regions of the inserter may be complementary attachments that are configured to mate with the stabilization device attachments. For example, a complimentary attachment on an inserter may be a pin, knob, or protrusion that mates with a slot, hole, indentation, or the like on the stabilization device. The complementary attachment (the attachment region) of the inserter may be retractable. For example, the inserter may include a button, slider, etc. to retract the complementary attachment so that it disconnects from the stabilization device attachment. A single control may be used to engage/disengage all of the complementary attachments on an inserter, or they may be controlled individually or in groups.
In some variation the inserter includes a lock or locks that hold the stabilization device in a desired configuration. For example, the inserter may be locked so that the stabilization device is held in the delivery configuration (e.g., by applying force between the distal and proximal ends of the stabilization device). In an inserter such as the one shown in
The proximal ends of the coaxial first and second elongated members 721, 723 also include grips 731, 733. These grips are shown in greater detail in
Any of the inserters described herein may include, or may be used with, a handle. A handle may allow a user to control and manipulate an inserter. For example, a handle may conform to a subject's hand, and may include other controls, such as triggers or the like. Thus, a handle may be used to control the relative motion of the first and second elongate members of the inserter, or to release the connection between the stabilization device and the inserter, or any of the other features of the inserter described herein.
An inserter may be packaged or otherwise provided with a stabilization device attached. Thus, the inserter and stabilization device may be packaged sterile, or may be sterilizable. In some variations, a reusable handle is provided that may be used with a pre-packaged inserter stabilization device assembly. In some variations the handle is single-use or disposable. The handle may be made of any appropriate material. For example, the handle may be made of a polymer such as polycarbonate.
By securing the proximal end of the inserter in the handle, the handle can then be used to controllably actuate the inserter, as illustrated in
As mentioned above, in the delivery configuration the struts of the stabilization device are typically closer to the long axis of the body of the stabilization device. Thus, the device may be inserted into the body for delivery into a bone region. This may be accomplished with the help of an access cannula (which may also be referred to as an introducer). As shown in
Any of the devices (stabilization devices) and applicators (including handles) may be included as part of a system or kit for correcting a bone defect or injury.
A bone drill, such as the hand drill shown in
Any of the devices shown and described herein may also be used with a bone cement. For example, a bone cement may be applied after inserting the stabilization device into the bone, positioning and expanding the device (or allowing it to expand and distract the bone) and removing the inserter, leaving the device within the bone. Bone cement may be used to provide long-term support for the repaired bone region.
Any appropriate bone cement or filler may be used, including PMMA, bone filler or allograft material. Suitable bone filler material include bone material derived from demineralized allogenic or xenogenic bone, and can contain additional substances, including active substance such as bone morphogenic protein (which induce bone regeneration at a defect site). Thus materials suitable for use as synthetic, non-biologic or biologic material may be used in conjunction with the devices described herein, and may be part of a system includes these devices. For example, polymers, cement (including cements which comprise in their main phase of microcrystalline magnesium ammonium phosphate, biologically degradable cement, calcium phosphate cements, and any material that is suitable for application in tooth cements) may be used as bone replacement, as bone filler, as bone cement or as bone adhesive with these devices or systems. Also included are calcium phosphate cements based on hydroxylapatite (HA) and calcium phosphate cements based on deficient calcium hydroxylapatites (CDHA, calcium deficient hydroxylapatites). See, e.g., U.S. Pat. No. 5,405,390 to O'Leary et al.; U.S. Pat. No. 5,314,476 to Prewett et al.; U.S. Pat. No. 5,284,655 to Bogdansky et al.; U.S. Pat. No. 5,510,396 to Prewett et al.; U.S. Pat. No. 4,394,370 to Jeffries; and U.S. Pat. No. 4,472,840 to Jeffries, which describe compositions containing demineralized bone powder. See also U.S. Pat. No. 6,340,477 to Anderson which describes a bone matrix composition. Each of these references is herein incorporated in their entirely.
As mentioned above, any of the devices described herein may be used to repair a bone. A method of treating a bone using the devices describe herein typically involves delivering a stabilization device (e.g., a self-expanding stabilization device as described herein) within a cancellous bone region, and allowing the device to expand within the cancellous bone region so that a cutting surface of the device cuts through the cancellous bone.
For example, the stabilization devices described herein may be used to repair a compression fracture in spinal bone. This is illustrated schematically in
As mentioned above, an introducer (or access cannula) and a trocar, such as those shown in
In
Once in position within the vertebra, the stabilization device is allowed to expand (by self-expansion) within the cancellous bone of the vertebra, as shown in
Once the stabilization device has been positioned and is expanded, it may be released from the inserter. In some variations, it may be desirable to move or redeploy the stabilization device, or to replace it with a larger or smaller device. If the device has been separated from the inserter (e.g., by detaching the removable attachments on the stabilization device from the cooperating attachments on the inserter), then it may be reattached to the inserter. Thus, the distal end of the inserter can be coupled to the stabilization device after implantation. The inserter can then be used to collapse the stabilization device back down to the delivery configuration (e.g., by compressing the handle in the variation shown in
As mentioned above, a cement or additional supporting material may also be used to help secure the stabilization device in position and repair the bone. For example, bone cement may be used to cement a stabilization device in position.
For example, in
While preferred embodiments of the present invention have been shown and described herein, such embodiments are provided by way of example only. Numerous variations, changes, and substitutions are possible without departing from the invention. Thus, alternatives to the embodiments of the invention described herein may be employed in practicing the invention. The exemplary claims that follow help further define the scope of the systems, devices and methods (and equivalents thereof).
The devices and methods for treating vertebral bodies describes above in detail may be used for the implantation of a self-reshaping device through a pedicle into the cancellous bone interior of a vertebral body, as mentioned. The self-reshaping of embodiments of the device includes a coincident longitudinally shortening of the device as a whole, and a radial expansion of struts. Following implantation and release from constraints that maintain the linear configuration, the struts of device self-expand, and while expanding, they cut through cancellous bone so as to arrive at the inner surface of the surrounding cortical bone of the superior (or cephalad) and inferior (or caudal) endplates of the vertebral body. The device may be sized and configured such that self-expansion takes the device to an appropriate dimension for the vertebral body. Thus, as the device approaches its final expanded dimension, it presses the surface outwardly so as to restore the height and volume of the vertebral body toward the dimensions of the vertebral body prior to the fracture.
Methods of using the implants, applicators and systems including them may include a step of selecting devices appropriate in form, shape, and size for each implantation site. Thus, in some variations the applicator or inserter devices described herein may be configured so that they may be used with implants of different sizes (both length and/or widths). For example, the devices may be configured so that the relative movement and separation of the inner and outer members spans a variety of sizes (e.g., lengths) of the bone stabilization implants from expanded to collapsed lengths. In some variations the handles include a limiter that prevents overexpansion of the applicator when coupled to an implant.
In general, these handles include a capture mechanism for connecting to the elongate member (e.g., inserter) that connects to the implant. As mentioned, an elongate member may be referred to as a delivery device or an elongate linkage member of the applicator. The elongate member typically includes a first elongate member (e.g., an outer member or cannula) that is configured to removably secure or couple with one region of an implant (e.g., the proximal end of the implant), and a second elongate member (e.g., an inner member, cannula or rod) that is configured to removably secure or couple with a second region of the implant (e.g., the distal end of the implant). The first and second members of the elongate member may be configured to couple and uncouple from the implant by rotating in opposite directions. The proximal end of the elongate member may include a proximal grips or couplers for grasping and/or manipulating the inner and outer members to control the expansion or contraction of the implant. The linkage portion of the applicator connects distally to the proximal and distal regions of the implant, and the handle engages the proximal end of the linkage portion of the applicator by connecting to and controlling these proximal couplers.
For example, the
The diameter of the drive shaft, as well as the threads per inch, can be configured to control the mapping of the lateral movement and rotation of the adjustment knob based on implant size. For example, a typical implant may require a lateral change of approximately 1.4 mm to change from a collapsed (delivery) configuration to an expanded (deployed) configuration. The movement of the inner member relative to the outer member may be geared by adjustment of the dimensions so that an exact and convenient movement between the adjustment knob and the implant can be created.
In some variations the delivery device (also referred to herein as the elongate linkage portion 2001), including an outer member (e.g., cannula) and an inner member (e.g., rod or cannula), that couples to the implant distally and the handle proximally, may also include a bias 2005 that maintains a load on the implant when it is connected. For example,
The exemplary handle 2101 shown in
In some variations the handle is permanently affixed to the elongate linkage member (e.g., forming a unitary applicator); in other variations the elongate linkage member of the inserter is separate from the handle.
In use, a handle that is detachably coupleable to an elongate linkage member may be attached within the handle, e.g., by removing a handle cover (see
In some variations, the handle may be configured as a ratcheting handle. A ratcheting handle may include a lever arm can engage the rotatable region of the handle and allow it to be rotated. The lever arm may provide a further mechanical advantage for collapsing or expanding a stabilization device. In some variations (not pictured), a portion of the handle may be removable so that he handle can be ratcheted from different angles or directions. In some variations, the handle may include a directional control for the ratchet mechanism, such as a button, lever, etc. Changing the setting on the directional control may allow the direction rotation to be changed, while the applied direction of rotation (e.g., pushing or pulling the level arm) is the same.
In some variations, the distal end of the stabilization device is connected to an inner member of the inserter. For example, the inner member of the inserter may be a rod that is relatively fixed as an outer rod or cannula may be moved around it (or along it). Thus, the shaft (e.g., the hollow outer part) moves to expand/contract the stabilization device.
In addition to the inserters (e.g., handles and elongate linkage members) described and illustrated above, other variations of inserters may also be used. An inserter may include a threaded outer member that is configured to secure to the proximal end of the stabilization device. In this example, a handle may be configured to mate with the threaded outer portion of the inserter, For example, this may eliminate the threading in the handle. This threading may be keyed to prevent rotation of the inserter. Preventing rotation, particularly unnecessary rotation, may prevent the device from unthreading prematurely at the distal end. In some variations the keying may be a channel, etc.
In any of the variations described herein, the handles (or other portions of the inserter) may be marked or coded to indicate the size of the implant. For example, the handle (which may mate with a generic handle, regardless of the size of the attached stabilization device) may be marked with numbering/lettering to indicate the size, and/or color coated. In some variations the handle is marked to indicate the orientation of the implant (e.g., the self-expanding struts) relative to the inserter.
The handle 2601 shown in
The handle shown in
In some variations the handle may also include an indicator of the size of the implant to be used (e.g., 10 mm, 12 mm, 16 mm, 18 mm, etc.). In some variations the system includes one or more sensors or connections to sensors. For example, the handle may include a connector to a temperature sensor or other sensor (including visualization devices) for sensing data from the implant or the region of implantation.
In operation, the applicator may be connected to the proximal and distal ends of an implant by connecting to the elongate linkage member, as mentioned above. The proximal end of the implant may connect to the outer member, while the distal end of the implant connects to the inner member (e.g., rod). Both ends may include counter-directional threads. The threads may be on the outer surface of the proximal end and on the inner surface of the distal end. The implant may be connected to the elongate linkage member either before or after it has been coupled to the handle. In some variations the elongate linkage member is pre-packaged coupled to the implant, so that it may be opened from a sterile packaging for use. The same handle may be re-used for different implants, typically within the same patient.
A self-expanding implant, connected to the applicator as described above, may be inserted into a patient by manipulating the handle and shaft of the applicator. Once it is positioned as desired (which may be visualized by florosocopy), it may be allowed to controllably self-expand using the applicator. As mentioned, the applicator may include an indicator of the orientation of the self-expanding struts. Thus, the handle and shaft of the applicator may be manipulated (e.g., rotated) orient the implant so that the struts will be positioned as desired.
The elongate linkage member may be connected to the handle by engaging the keyed engagement member (shaft stabilizer) on the surface of the elongate linkage member. Inserting the shaft stabilizer into the handle also engages the inner and outer members of the elongate linkage member. Thereafter, rotation of the ratcheting handle will move the outer member, and therefore the proximate end of the implant, relative to the inner member. The direction of motion may depend on the ratchet switch, which moves the pawl member to select the engaged motion of the ratchet mechanism.
In some variations it is helpful that the proximal end of the implant is moving relative to the length of the implant. By moving the proximal end, the implant may be inserted into a desired location and controllable allowed to self-expand into a position without extending from the distal implantation location. Thus, the implant will not shift position relative to the distal insertion site by foreshortening as the implant is controllably self-expanded into a deployed configuration.
The ratchet direction may be selected and switched using the ratcheting switch as indicated. In some variations, an indicator (e.g., a symbol, color, text, etc.) may indicate the direction of movement enabled (e.g., expansion/deployment or contraction/retraction of the implant).
Once the implant has been inserted and allowed to self-expand, the applicator (handle and shat of the elongate linkage member) may be removed. The force applied to the implant by the handle may be released by pushing the release button (switch), on the handle, so that the shaft of the elongate linkage member may be removed from the handle. The handle may be removed from the elongate linkage member and the elongate linkage member may then be removed from the implant by the proximal and distal ends. In some variations the implant may be removed from the elongate linkage member while still attached to the handle. In other variations the handle is removed first. The elongate linkage member may be decoupled from the proximal and distal ends of the implant by rotating the inner and outer members (e.g., counter clockwise at the distal end and clockwise at the proximal end) in threaded variations.
If the position of the implant is not optimal, the position may be re-adjusted using the handle as indicated above, e.g., by collapsing the implant using the handle and moving the implant.
The methods, devices and systems described herein provide only some variations described herein, and additional variations may be included and are contemplated. While embodiments of the present invention have been shown and described herein, such embodiments are provided by way of example only. Thus, alternatives to the embodiments of the invention described herein may be employed in practicing the invention. The exemplary claims that follow help further define the scope of the systems, devices and methods (and equivalents thereof).
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/058,157, filed on Jun. 2, 2008, entitled “CONTROLLED DEPLOYMENT HANDLE FOR BONE STABILIZATION DEVICES”, and U.S. Provisional Patent Application Ser. No. 61/142,552, filed on Jan. 5, 2009, entitled “CONTROLLED DEPLOYMENT HANDLE FOR BONE STABILIZATION DEVICES.” This application is related to U.S. patent application Ser. No. 11/468,759, filed on Aug. 30,2006, entitled “IMPLANTABLE DEVICES AND METHODS FOR TREATING MICRO-ARCHITECTURE DETERIORATION OF BONE TISSUE”, which claims the benefit of U.S. Provisional Application Ser. No. 60/713,259, filed on Aug. 31, 2005, entitled “IMPLANTABLE DEVICE FOR TREATING VCF, TOOLS AND METHODS”. This application is also related to U.S. patent application Ser. No. 12/041,607 filed on Mar. 3, 2008, entitled “FRACTURE FIXATION SYSTEM AND METHOD”; U.S. patent application Ser. No. 12/044,884 filed on Mar. 7, 2008, entitled “TRANSDISCAL INTERBODY FUSION DEVICE AND METHOD”; U.S. patent application Ser. No. 12/044,880 filed on Mar. 7, 2008, entitled “SYSTEMS, METHODS AND DEVICES FOR SOFT TISSUE ATTACHMENT TO BONE”; U.S. patent application Ser. No. 12/024,938 filed on Feb. 1, 2008, entitled “SYSTEMS, DEVICES AND METHODS FOR STABILIZING BONE”; and U.S. patent application Ser. No. 12/025,537 filed on Feb. 4, 2008, entitled “METHODS AND DEVICES FOR STABILIZING BONE COMPATIBLE FOR USE WITH BONE SCREWS”. All of these patent applications are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61058157 | Jun 2008 | US | |
| 61142552 | Jan 2009 | US |
