EP1367950A1

EP1367950A1 - Biocompatible material

Info

Publication number: EP1367950A1
Application number: EP02703346A
Authority: EP
Inventors: Charanpreet Bagga; Erik M. Erbe; Antony Koblish; Maarten Persenaire
Original assignee: Vita Licensing Inc
Current assignee: Orthovita Inc
Priority date: 2001-02-20
Filing date: 2002-02-08
Publication date: 2003-12-10
Also published as: AU2002236973B2; WO2002065926A1; MXPA03007491A; IL157486A0; EP1367950A4; CA2438786A1

Abstract

Novel delivery of restorative biocompatible material to intraosseous spaces (64) are provided comprising accessing a space (64), placing a first aliquot (62) of restorative material (46) into the space (64), and after a period of time sufficient for first aliquot (64) to set, placing a second aliquot (71) into the space (64) using kits comprising cannulae (10)for accessing an intraosseous space (64), mandarins (32) insertable into the cannulae (10) and movable therein, one or more catheters(13) and a system for the delivery of aliquots (70,71) of restorative compositions (46) into the space (64) via the catheters(13).

Description

DELIVERY OF BIOCOMPATIBLE MATERIAL FIELD OF THE INVENTION

This invention relates to methods for the restoration of intraosseous spaces as well as methods for the reparation of bony defects, fractures and surgically created defects. The invention relates to methods for restoring intraosseous spaces in percutaneous surgical procedures and in the repair of fractures in procedures requiring screw augmentation. This invention also relates to kits for the delivery of restorative compositions into an intraosseous space, especially kits usable in percutaneous surgical procedures. This invention is directed to systems for the delivery of aliquots of restorative compositions into a desired space especially via catheters and the kits may further comprise needles/cannulae, stylets/mandarins and/or syringes.

BACKGROUND OF THE INVENTION

Percutaneous surgical procedures have come to the forefront of the orthopaedic and neurological surgery fields to limit exposure of tissues, reduce operating time, speed up recovery time and minimize patient scarring. Percutaneous vertebroplasty is currently a procedure by which acrylic cement, typically polymethylmethacrylate OTMMA"), is injected into the vertebral body by a percutaneous route in order to prevent vertebral body collapse and pain in patients with unhealthy vertebral bodies. Percutaneous injection has been indicated as a means of pain relief and restoration in patients with vertebral hemangiomas, painful vertebral body tumors, as well as painful osteoporosis with loss of height and/or compression fractures of the vertebral body. See, e.g., Gangi, A., et al. Percutaneous Vertebroplasty Guided by a Combination of CT and Fluoroscopy, AJNR 15:83-86, Jan 1994 ("Gangi"). Percutaneous injection is also minimally invasive compared to the alternative of exposing the entire soft and hard tissue at the surgical site.

U.S. Patents Nos. 6,033,411 and 6,019,776 to Preissman, et al. disclose methods for controlled approach to the interior of a vertebral body by inserting a threaded or sharp-pointed stylet and cannula percutaneously through the soft tissue of an organism until abutting the soft tissue further inserting the stylet into a predetermined location within the hard tissue ratcheting a pawl mechanism or rotating a camming mechanism to advance the cannula along the stylet to the predetermined location and withdrawing the stylet from the cannula and attaching a source of implantable material for injection of the material into the organism through the cannula. However, these patents do not teach methods of delivering restorative material by percutaneous vertebroplasty in which several doses of material are injected.

U.S. Patent No. 4,838,282 to Strasser, et al. ("Stasser") discloses a bone biopsy needle assembly, which includes a cannula and stylet, for withdrawing samples of bone, bone marrow and other such fluids. The handles of the cannula and stylet are provided with features for mating reception when assembled together. In addition, both the cannula and stylet handles are comprised of two equal generally rectangular halves extending in diametrically opposed directions from the cannula axis.

U.S. Patent No. 4,793,363 to Ausherman, et al. ("Ausherman") discloses a bone marrow biopsy device that includes a cannula member and a stylet member with a Luer-lock connector and handle locking arrangement.

U.S. Patent No. 4,469,109 to Mehl ("Mehl") discloses a bone marrow aspiration needle including a cannula, with a cannula housing that supports the cannula, a partially threaded lower member a stylet with a stylet cap that supports the stylet and a threaded depth stop for engaging over the cannula.

U.S. Patent No. 5,601,559 to Melker, et al. ("Melker") discloses an intraosseous needle having a threaded shaft with two side ports that allows fluids to pass through the needle and a tip having a plurality of cutting edges.

Heini, P.F. et al., Percutaneous Transpedicular Vertebroplasty with PMMA: Operative Technique and Early Results: A Prospective Study for the Treatment of Osteoporotic Compression Fractures, Eur.Spine J. (2000) 9:445-450 ("Heini"), discusses the use of PMMA for percutaneous vertebroplasty and disclose the surgical practice of using four injections (i.e., injecting four vertebrae unipedicularly or two vertebrae bipedicularly) in one session under local anesthesia. The procedure disclosed that within "two minutes into the cement curing, filling is commenced and then the material remains injectable for the following 2 or 3 minutes." Heini further cautions that the flow of cement must be monitored carefully for leakage posteriorly into the spinal canal and anteriorly through the nutritional vessels. Heini also teaches that only low-viscosity PMMA is suitable for injection and that the radio-opaqueness of injectable calcium phosphate makes its use technically difficult to achieve.

Heini further discusses the use of various components for performing percutaneous transpedicular vertebroplasty including a 2.0 mm K-wire for accessing the center of the vertebral body and a bone marrow biopsy needle placed over the K-wire (which is subsequently removed) for positioning the needle. Heini also discloses the use of 2 cc standard syringes for injecting the material through the needle. Gangi describes the percutaneous injection of PMMA into the vertebral body with the aid of CT and/or fluoroscopic guidance using a needle and 2-ml Luer-lock syringe mounted on a pressure regulator to facilitate the injection of the material.

Chiras, J., et al., Percutaneous Vertebroplasty, J NeuroradioL 1997, 24, 45- 59 ("Chiras") discloses cannulae of 10 to 15 cm in length with a beveled edge lumen and diameter of 3 mm as being standard equipment for vertebroplasty.

Deramond, H., et al., Percutaneous Vertebroplasty, Seminars In Musculoskeletal Radiology, Vol.l, No.2, 1997: 285-295 ("Deramond"), Chiras, Jensen, M. E., et al., Percutaneous Polymethylmethacrylate Vertebroplasty in the Treatment of Osteoporotic Vertebral Body Compression Fractures: Technical Aspects, AJNR 18:1897- 1904, Nov 1997 ("Jensen"), and Gangi describe the percutaneous injection of PMMA into the vertebral body with the aid of CT and/or fluoroscopic guidance. Prior to injecting the material, each method describes the step of preparing the injectable acrylic cement material. As described by Gangi, to prevent distal venous migration, the acrylic cement has to be injected during its pasty polymerization phase. Further, since the surgeon is required to wait until the material reaches the pasty polymerization phase, the intervention has to be performed quickly because the glue thicken after 3 minutes and any further injections become impossible. During material injection, the procedure is immediately stopped if an epidural or paravertebral opacification (under strict lateral fluoroscopy) is observed to prevent spinal cord compression. Deramond suggests that a leakage can be avoided by making injections under lateral fluoroscopic control or inserting the needle into the lateral part of the vertebral body. Jensen also teaches that the material should set only if a leak should occur. Deramond discloses the use of various materials for percutaneous vertebroplasty ("PVP") including ten-gauge needles, 10 to 15 cm long with a beveled extremity, fifteen-gauge needles, 5 to 7 cm long with a tapered tip, Luer-lock syringes of 2 or 3 cc, a syringe handle and bone cement. Deramond suggests that leakage can be avoided by making injections under lateral fluoroscopic control or inserting the cannula into the lateral part of the vertebral body.

Jensen further discusses the use of various components for performing vertebroplasty procedures including a disposable 11 -gauge Jamshidi needle, a stylet for accessing a desired space, both 10-ml and 1-ml syringes and an 18-gauge needle for the injection of material through the needle. Jensen teaches that the material should be allowed to set only if a leak should occur.

In the art, if a leak is detected, the operator either stops the procedure altogether, continues with the injection of more material using a different "batch" of material, or allows the material that already has been injected to thicken. Clinically using a different "batch" of material requires the surgeon to open another "batch" of material. This is costly and not desirable or practical in the case of standard restorative materials such as PMMA. Often, in the case of a leak, the surgeon does not allow the material to set but waits until the material reaches a pasty stage (thicken) prior to injecting more material. This approach, however, prevents the surgeon from injecting the desired amount of material since, once the material becomes pasty, he has little time to work and must forcefully inject additional material prior to the material setting in the cannula. If the material hardens in the cannula, the cannula will have to be removed and reinserted for additional doses. Surgeons are very skeptical about doing this because of the extreme difficulty in reinserting another cannula in the same exact place as the one removed. It is the principle object of this invention to provide methods for the restoration of intraosseous spaces. It is a further object of the invention to provide methods of controlled injection of restorative material into a vertebral body to prevent leakage of that material into the venous space. It is yet another object of the invention to provide minimally invasive techniques for the reparation and restoration of bony structures and to provide minimally invasive techniques for the augmentation of procedures requiring screw fixation.

Accordingly, it is the principle object of this invention to provide kits for minimally invasive delivery of restorative composition into an intraosseous space. Additional objects, advantages and novel features of this invention will become apparent to those skilled in the art upon examination of the following descriptions, figures and claims thereof, which are not intended to be limiting.

SUMMARY OF THE INVENTION

This invention relates to methods for restoring an intraosseous space comprising the steps of accessing a space, placing in the space a first aliquot of restorative composition and, after a period of time sufficient for the first aliquot to set, placing in the space a second aliquot of restorative composition. The first aliquot placed into the space to initiate the restorative process can be preselected. There are preferably additional aliquots of restorative composition placed into said space. These additional placements of composition can follow preselected time intervals and be of a preselected amount. The placements within these methods are preferably made using a syringe and catheter via a needle or cannula that is inserted in the intraosseous space. The location of the instrumentation as well as the material in the intraosseous space is easily monitored via fluoroscopy or endoscopy. In one embodiment, the catheter has a distal end and at least one placement orifice disposed proximate to said distal end, said placement orifice being adapted for dispensing the restorative composition radially from the catheter. The space is accessed via drill, knife or needle.

This invention also relates to device combinations and packaged kits for the delivery of a restorative composition into an intraosseous space comprising one or more cannulae adapted for accessing said intraosseous space, one or more stylets/mandarins insertable into the hollow cavity of the cannula and being movable therein to advance the cannula into position and being adapted for accessing said intraosseous space. The kits and systems preferably also have one or more catheters that are insertable into the cannulae and a system for delivery of aliquots of said restorative composition into the intraosseous space via the catheters. The kits can also include a micro-reamer that fits within the hollow cavity of the cannula (after removal of the stylet and before insertion of the catheter) to make a channel for material delivery via the catheter. Fixed to the proximate end of each of the cannulae, stylet and micro-reamer is a substantially lateral surface (flat, solid knob or pedestal) responsive to impact blows. The cannula, micro- reamer and catheter may also include gradations.

The catheters of the present invention have a distal end and at least one placement orifice disposed proximate to the distal end wherein the placement orifice may be adapted for dispensing the restorative composition directly from the distal end or radially therefrom. Catheters used in the kits may comprise stainless steel, polyimide, latex, silicone, vinyl or polymers other than those listed herein. They may be flexible for maneuverability and be long and of such material that they can be cut to size at the time of use. The kits can preferably further comprise a plurality of syringes having an aperture on a distal end providing fluidic passage therethrough from a bore being engageable within said aperture as well as a locking mechanism, such as a Luer-lock type of locking mechanism, for engaging a proximal end of the catheter for dispensing of the material into the space through the catheter. In a preferred embodiment, the kit includes a plurality of syringes including a 1 cc, 3 cc and 5 cc syringes.

This invention also relates to a system for the delivery of a restorative composition to specific intraosseous space wherein the placement of aliquots of said restorative composition is under tactile feedback control of a human operator, such as a surgeon or interventionalist. The restorative composition can comprise a hydrogel, synthetic bone void filler, polymethylmethacrylate or replicated bone marrow.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures la- Id are sectional views showing steps in one embodiment of the present invention method in which a needle/cannula is inserted into a damaged vertebral body to first deliver a dam of material and then deliver a subsequent dose to complete the reparation.

Figures 2a- 2f depict the steps of an alternative embodiment of the present invention in which material is injected percutaneously through a cannulated screw.

Figure 3 depicts a kit of an embodiment of the present invention showing a cannula and stylet, a micro-reamer, and a plurality of catheters and syringes.

Figure 4 depicts a cannula/stylet locking mechanism.

Figure 5 depicts an alternative embodiment stylet tip. Figure 6 depicts a kit of the present invention showing a plurality of catheters and syringes.

Figure 7 depicts the side-opening feature of certain preferred cathetersof the present invention.

Figure 8 depicts a front-opening catheter/cannula having a micro-reamer feature.

Figure 9 depicts a side-opening catheter having a micro-reamer feature. Figure 10 depicts a shape memory embodiment of the catheter/micro- reamer.

Figure 11 depicts certain preferred syringes of the present invention kit.

PREFERRED EMBODIMENTS

This invention provides methods for the delivery of restorative biocompatible material into intraosseous spaces. The methods generally comprise accessing a chosen intraosseous space, such as a damaged area 1 of vertebral body 21 depicted, for example, in Figure la, placing an initial aliquot of the composition into said space and, after a period of time adequate for the first aliquot to set, placing in the space a second aliquot of a more sufficient dosage to restore the intraosseous space. The space can be accessed via a needle or cannula 10 (see, for example, Figure lb), stylet, knife or other sharp instrument depending on the procedure and space. In many embodiments, the space is accessed using a micro-reamer or drill, h other specific embodiments, the space is accessed using a cannulated screw (see Figures 2a through 2f). According to a specific embodiment of the present invention, in cases where the existing bone is soft or porous (e.g., osteoporotic bone), the intraosseous space is accessed either by drilling out existing peripheral bone or by manually using a sharp instrument (such as a needle or cannula having a blunted, diamond or beveled tip). The needle serves as a guide for a stylet or mandarin that fits into the hollow cavity of the needle. More specifically, the stylet is provided with a pedestal on one end, which is impacted to advance the needle into position for delivery. In some embodiments, the stylet has a locking mechanism integral to the pedestal for locking securely to. one end of the needle. In others, the tip of the stylet is beveled to provide steering capabilities or is diamond shaped. Insertion of the instruments is carefully monitored via standard imaging techniques to insure proper positioning and to prevent damage to surrounding structures.

In some preferred embodiments, once the desired position is reached, the stylet is removed with the needle in place and a micro-reamer is inserted into the hollow cavity. Generally, the micro-reamer is provided with a knob for dextrous manipulation and impacting on one end and a sharp cutting tip on the other and serves to make the channel for the catheter 13 and, as such, the eventual delivery of material. Once the channel is created, the catheter 13 is inserted (see, for example, Figure lc). With the use of a syringe 32, material is delivered via the catheter 13 such that a first aliquot of generally between 0.5 - 1.5 cc (and all combinations and subcombinations of ranges and specific volumes therein) is injected to establish a dam 45 and then subsequent aliquots are delivered for reparation.

Typically, once the space is accessed, an operator goes in with a catheter 13 (which sits within the bore of the cannula and extends out the tip of the cannula into the space) and augments the intraosseous space with the first aliquot of a restorative composition. The augmentation generally begins with the creation of an initial dam 45 by a small dosage of composition. The dosage depends upon the osseous space being augmented but may typically be on the order of 0.5-1.5 cc (and all combinations and subcombinations of ranges and specific volumes therein). This dam is created to prevent additional dosages of those materials with a very mobile rheology or high viscosity from "leaking out." In a more typical embodiment, the location of the placement of this initial aliquot is pre-selected to initiate the restorative process and is monitored via standard radiography/fluoroscopy techniques for leakage.

The dam aspect in certain general embodiments of the present invention overcomes the difficulties found in the prior art- including the unexpected step of requiring additional mixing of a new batch of material and the step of waiting for the material to reach a pasty polymerization stage. Many embodiments of this invention include methods that greatly decrease an operator's need to work in haste. Certain embodiments also minimize leakage of the material by providing steps in which a dam of material is first injected into the osseous structure in a controlled manner in order to prevent free flow of the material through openings or pores in the osseous structure. Typically, materials of varying viscosity, but including materials with higher viscosities than PMMA, are injected in a safe and technically proficient manner using the methods disclosed.

In accordance with some preferred forms of this invention such as the embodiment depicted in Figure Id, the dam 45 is allowed to cure and then a second aliquot of the restorative composition 46 is added to the dam 45. Typically, this is done as necessary with a second catheter 47 after removal of the first catheter 13. The dam 45 insures that all openings are closed with the composition 46 for leakage prevention. Typically, once the second aliquot of composition 46 has cured, additional aliquots of composition 46 are injected so that the space or opening is completely filled. It is appreciated that additional aliquots will not be necessary for all forms of this invention and that the number of aliquots may vary. Generally, the additional aliquots are added at preselected time intervals if the composition 46 is known to set within a certain time frame. More generally, the aliquots are added in a pre-selected amount.

To insure that the material is setting, not leaking and/or filling the desired space, it is within the scope of this invention that the location of the catheter 13 within the intraosseous space is monitored. When delivering a composition 46 into an intraosseous cavity such as a vertebra, the catheter's 31 placement is substantially close to, but not in contact with, the anterior wall. Some distance is necessary between the distal end of the catheter 13 and the wall so that the catheter 13 may deliver the compositions into the space. In those embodiments in which catheters are used with a side opening, the composition 46 can be radially dispersed into the space even if the distal end of the catheter is in contact with the anterior wall. During delivery of the composition 46, the catheter 13 may be slowly pulled back while the composition 46 fills the space. During a typical procedure, the catheter 13 can be monitored by a variety of means. More typically, if the catheter is comprised of metal, then it can be monitored by X-ray. The placement made by the catheter can also be monitored due to the radiopaque nature of a restorative composition. In other embodiments, the placement is monitored by fluoroscopy or endoscopy. Using these means, an operator reduces the chance that a composition will flow back in the needle or out of the intraosseous space. If a venous leak is detected, delivery is stopped. Once the aliquots of material are delivered, the screw is advanced slowly into the un-polymerized restorative material the same number of turns minus one half turn used to back the screw out so as to insure that the screw is in its original position and also to insure that the threads of the screw do not displace the restorative material proximally. The restorative material is then allowed to set around the screw (Figure 2d). The method of the present invention can also be employed with a cannulated screw in situations in which the guiding pin penetrates the cortex during repair and the hole needs to be sealed with a dam of material prior to the injection of additional material to repair the site.

The present invention provides kits for the delivery of a restorative composition. Typically, the kits, such as the kit shown, for example, in Figure 11, comprise at least a cannula 10 or needle. More typically, the cannula is adapted for accessing particular intraosseous spaces. In accordance with one embodiment, the cannula 10 is an 8 to 14 gauge, or preferably an 11 to 12-gauge needle having a solid handle 15 for absorbing impact and force upon insertion into bone and a hollow bore 20 component attached thereto. The handle 15 is asymmetrically shaped to accommodate a user's hand and includes a space 16 for receiving the unidirectional stylet/mandarin 11 (or other instruments).

In typical embodiments, the kits of the present invention feature tactile feedback control. When delivering a composition into a vertebra, the cannula 10 is generally inserted substantially close to, but not against, the anterior wall. Some distance is necessary between the cannula 10 and the wall so that the micro-reamer 12 can create a channel. For those embodiments featuring catheters with a side-opening 50, the composition is radially dispersed into the space even if the distal end of the catheter is in contact with the anterior wall. In other embodiments, the syringes of the present invention exemplify the tactile feedback control by allowing the user to apply constant force regardless of volume being inserted.

One or more stylets 11 adapted for accessing an intraosseous space are preferred in some embodiments. Typically, the stylet 11 comprises a solid, impactable knob or head 18 that is tapered for easy insertion and removal into the receiving space 16 of the handle 15 of the cannula 10 and an elongated solid stem 22 with a beveled tip 19 (for steering capabilities) or diamond tip 31 that sits within the bore 20 of the cannula 10 when in use (see, for example, Figure 11). The unidirectional fit allows for a pin 9 within the knob 18 of the stylet 11 to lock within a corresponding recess 17 on the handle 15 of the cannula 10 (see, for example, Figure 10). Specifically, mating occurs when the pin 9 of the stylet 11 is simultaneously displaced in the superior/inferior direction and rotated into the recess 17 of the cannula handle 15. This fit ensures that the stylet is always positioned correctly, thus creating a solid sharp beveled tip 19 or diamond tip 31. The cannula 10 and stylet 11 are used to gain access into the body cavity. Force from either screwing or tapping is used to propel both the cannula 10 and stylet 11 into the osseous space.

Once the space is accessed by the cannula 10 and stylet 11, the stylet 11 can be removed and a micro-reamer 12 is inserted to create room or an opening in the bone for placement of the restorative composition. The micro-reamer 12 conveniently has a knob 8 similar to that of the stylet knob 18 but without a pin being engageable within the cap of the needle. The absence of the pin allows the operator to insert and rotate the micro- reamer 12 about the space. In many forms of this invention, the micro-reamer 12 is used to create a channel that facilitates the insertion of the catheter (and subsequently, material delivery). The rotation of the micro-reamer 12 creates some debris that helps block the venous pathways and thus reduces the potential for leakage. In other forms of this invention, the micro-reamer 12 is fitted with a cutting means 6.

The shaft 7 of the micro-reamer 12 is generally longer than the shaft 20 of the cannula. It can extend from about 1.0 - 3.0 cm (and all combinations and subcombinations of ranges and specific volumes therein) out of the distal tip of the cannula 10 when fully inserted. Typically, the length of the second shaft of the catheter is about equal in length to the length of the micro-reamer 12 when fully inserted into the cannula. Micro-reamers of varying lengths can be used depending on the approach an operator uses to access an intraosseous space. In certain embodiments, when accessing a vertebral space, the tip of the cannula 10 remains in the inner opening of the bone while the elongated micro-reamer 12 accesses the opposite cortex of the vertebral space. In other embodiments, the micro-reamer is shaped, bent, or made from a shape memory material that allows extra bending to create a wider channel space for the catheter.

Once the micro-reamer 12 creates a space for the material, it is removed from the cannula 10 and replaced with a catheter 13. Catheters are used to deliver the restorative composition into the intraosseous space. In one specific embodiment of this invention, a front-opening catheter 43 (see Figure 10) is provided for delivery, and in another embodiment, a side-opening catheter 50 (see Figure 11) is provided for radial delivery of the composition within an osseous space. The front-opening allows direct injection of the material into the site through the opening in the distal tip. The side- opening catheter 50 is useful for radial delivery of the composition within an osseous space since it allows for 360° directional control of the delivery of the restorative materials. In typical embodiments, the catheters also include gradations or gradients 40 along the shaft to further aid in the delivery of the composition. These gradients 40 aid in the determination of the volume of restorative composition being injected and also the depth of the catheter within the space. Typically, the gradients 40 are placed at varying lengths suitable for each procedure and can be internal markings or external protrusions. More typically, these gradients 40 are made 1 cm apart and are external markings. The catheters of the present invention can be of varying volumes and lengths. It is appreciated the distance the micro-reamer 12 extends out of the distal tip of the cannula 10 will vary depending on the nature of the space being accessed.

Generally, the catheters are comprised of metals, such as stainless steel or titanium that are rigid and readily visible by X-Ray, plastic or polyimides that can serve as a flexible element, latex, silicone, vinyl or polymers other than those listed herein or of a ceramic material. In other embodiments of the invention, the catheters are comprised of nitinol, or any other "shape memory" alloy. In tins manner, the shape memory catheter 80 (or shape memory micro-reamer) could be placed through the cannula 10 into a structure, either an implant structure 85 or anatomical structure, with known openings 87, 88, that the shape memory catheter traverses for precise, directional delivery of material (see, for example, Figure 10). In still more embodiments, the catheter is flexible for maneuverability and of such material that it can be cut to size at the time of use.

In accordance with a specific embodiment of this invention, the catheter 13 has a knob 41 which has an adapter 41a for connecting to a syringe tip, such as a Luer-lock and a hollow shaft 42 extending therefrom (see Figure 10). In some preferable embodiments, the catheter can be long (to distance the surgeon or user from any source of radiation that may be used during the surgical process). In other embodiments the catheter has two consecutive shafts with one having a plunger mechanism and the second shaft being engageable to the distal end of the first shaft by means of a Luer lock or other locking means better equipped to ensure non-leakage of the restorative composition. In one specific embodiment such as the embodiment depicted in Figure 10, the catheter is provided with protrusions or cutting elements on its distal end 44. In this manner, the catheter acts both as a micro-reamer and catheter. This feature can be added to both the front-opening catheter 43 (see Figure 10) and side-opening catheter 50 (see Figure 11) embodiments. More specifically, when added to the side-opening catheter 50, the cutting means 60 is attached to the distal end 44 so that the opening 61 (upon removal of the stylet 11) is more proximal to the handle than the cutting means 60. When added to the front- opening catheter 43, the cutting means 60 is more proximal to the handle than the opening 61. While in use, the stylet 11 is kept in place during the micro-reaming aspect of the procedure and then removed for the injection of the material. The cannula of the present invention could also be provided with means for cutting in the same manner as the front opening catheter.

By providing kits with a catheter, the present invention overcomes the situations in which a procedure is halted due to leakage, the material hardens in the cannula and the cannula must be removed and replaced or the material thickens and becomes difficult to inject. In many embodiments, the kits of the present invention are provided with a plurality of catheters that fit through the cannula. Once the material hardens, the first catheter is simply removed with the cannula in place and a new catheter is slipped in place for the next dose. Typically, the cannula never has to be removed and the operator does not run the risk of trying to reinsert the cannula in the same exact place. In one embodiment, such as the embodiment shown in Figure 11, a syringe 14 attaches to the catheter for delivery of the material. Typically, a number of syringes are provided with the kits of the present invention, including standard 1 cc, 3 cc and 5 cc syringes. More typically, the syringes have an aperture 93 on one end for providing fluidic passage therethrough from a bore 95 being engageable within said aperture 93 and a plunger 94 that sits within the barrel 91 of the syringe 14. Material to be injected (not shown) is placed in the barrel 91 of the syringe 14 and then the plunger 94 is placed within the barrel 91 for material extrusion. The aperture 93 can be a Luer-lock type mechanism for engaging the proximal end of a catheter for injecting the restorative material into the space. In a preferred embodiment of the present invention, the 1 cc, 3 cc and 5 cc syringes are specially designed such that the diameters of the respective plungers 94 and the internal diameters of the respective barrels 91 are reduced but are both the same size for each of the syringe sizes- 1 cc, 3 cc and 5 cc syringes. Since the internal diameters of the barrels 91 of each of the different size syringes are the same, the volume differences between the syringes are compensated for by increasing the length of the syringe 14 barrel with increasing syringe size.

The amount of force required to inject material through the present invention syringes is generally reduced in each individual syringe since the cross-sectional area is reduced and the barrel 91 internal diameter and bore 95 diameter are closely matched. To further reduce the force required to move the material through the syringe, in a preferred embodiment, there is a gradual decrease in barrel 91 (internal) diameter at the tip of the syringe toward the bore 95. This gradual decrease better streamlines the material flow through the bore. These syringes differ than those in the prior art in that the plunger/barrel internal diameters (and therefore, cross-sectional areas) of the prior art increase with increasing syringe size. Since the bore diameter does not change with increasing syringe size, increasing force (due to increased resistance) is required to inject the material through the bore as the syringe size/volume increases. When larger syringes (5 cc) are used to inject viscous materials that tend to thicken with time (in order to set) it is not uncommon for syringes of the prior art to break upon the forceful extrusion/injection of the material.

The kits of the present invention are tailored to adequately and precisely deliver a restorative composition into an intraosseous space such as a human vertebra when the composition has a very mobile rheology.

A number of restorative compositions can be used within the systems of the present invention. The type of composition used depends upon which procedure is being performed. In some embodiments, the system includes the injection of a plurality of materials including hydrogels, synthetic bone void fillers, polymethylmethacrylate or replicated bone marrow. In one general embodiment, the system is a syringe filled with material. Specifically, the system is a prefabricated system of material that is directly injected into the syringe or the catheter. In another embodiment, the system for delivery comprises a sole syringe.

Those skilled in the art will appreciate that numerous changes and modifications may be made to the preferred embodiments of the invention and that such changes and modifications may be made without departing from the spirit of the invention. It is therefore intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of the invention. EXAMPLE 1

Once the channel is created, the catheter 13 is filled with restorative material and inserted to the same depth created by the micro-reamer. The catheter 13 is easily visualized under fluoroscopy because of the radiopaque nature of restorative material. A small amount of the restorative material, less than 0.5 cc, is slowly injected under fluoroscopic control while checking for any venous leaks. Should a venous leak occur, the injection is immediately stopped, and the catheter 13 removed from the needle or cannula. In this way the access port to the vertebra remains open. After waiting an appropriate amount of time (between 2 to 4 minutes), a new catheter 47 is inserted and the injection resumed. Should another venous leak occur, the same procedure is repeated. Once there are no (more) venous leaks, the appropriate volume of material is injected. This technique allows one to make optimal use of a mix-on-demand characteristic of a restorative material, place the desired amount of material into the site, and eliminate hurrying of the procedure due to concerns of the material setting in the cannula. However, it can be used with any restorative material.

EXAMPLE 2

As described in accordance with Figures 2a - 2d, one preferred embodiment of the present invention involves the percutaneous injection of restorative material into the femoral head 48 through a cannulated screw 51 that is inserted in a small opening along the lateral aspect of the neck of the femur 52 in the repair of compression hip fractures. The cannulated screw 51 is placed into a final position 53 (Figure 2a) and then backed out from the final position (Figure 2b) to allow room for the cement. A micro-delivery catheter 63 is then inserted through the cannulated screw 51 to allow for injection of the restorative material through the catheter 63 into an open void 64 in front of the screw 51. The tip 54 of the micro-delivery catheter 63 extends beyond the end of the screw 51 to allow for proper dispensing of material. A first aliquot of material 62 of approximately 1 cc is injected into the void 64 to serve as a dam for preventing leakage of the material through pores or openings in the bony structure. The micro-delivery catheter is removed, the first aliquot is allowed to set, and a second micro-delivery catheter 70 is inserted through the screw 51 to allow for injection of a second aliquot of material 71 that complements the first dose in an amount sufficient to allow for screw purchase (approximately 1.5-3 cc) (Figure 2c). Additional aliquots of material may be injected where necessary. It is appreciated that additional aliquots will not be necessary for all procedures. Unlike the prior art, an operator using the present invention can routinely set up a dam of material, allow it to harden, and then inject additional doses of material by replacing the catheter. The systems of the present invention uniquely accommodate for mix on demand delivery systems using a delivery gun and mix-tip.

Claims

WHAT IS CLAIMED IS:

1. A method for restoring an intraosseous space comprising:

(a) accessing said space;

(b) placing in said space a first aliquot of restorative composition; and

(c) after a period of time sufficient for said first aliquot to set, placing in said space a second aliquot of restorative composition.

2. The method of claim 1 wherein the placement of said first aliquot is preselected so as to initiate restorative process.

3. The method of claim 1 wherein said pre-selection is of the location of said placement and said placement isolates said intraosseous space from surrounding tissue.

4. The method of claim 1 further comprising placing additional aliquots of restorative composition in said space.

5. The method of claim 1 wherein the further placements follow preselected time intervals.

6. The method of claim 1 wherein the further placements are of a preselected amount.

7. The method of claim 1 wherein said placement is via a syringe.

8. The method of claim 1 wherein said placement is via a catheter or cannula.

9. The method of claim 8 wherein the location of the catheter or cannula in the intraosseous space is monitored.

10. The method of claim 9 wherein the monitoring is via fluoroscopy.

11. The method of claim 9 wherein the monitoring is via endoscopy .

12. The method of claim 8 wherein the catheter has a distal end and at least one placement orifice disposed proximate to said distal end, said placement orifice being adapted for dispensing the restorative composition radially from the catheter.

13. The method of claim 1 wherein said space is accessed via a drill or micro-reamer.

14. The method of claim 1 wherein said space is accessed via a knife or sharp instrument.

15. The method of claim 1 wherein said space is accessed via a needle or cannula.

16. A kit for delivery of a restorative composition to an intraosseous space or surgically created osseous defect, comprising: at least one cannula for accessing said intraosseous space or defect; at least one stylet insertable into the cannulae and being movable therein; at least one or more catheter that are insertable into the cannulae; and a system for delivery of aliquots of the restorative composition into the intraosseous space via said catheter.

17. The kit of claim 16 wherein said catheter has a distal end and at least one placement orifice disposed proximate to said distal end; said placement orifice being adapted for dispensing the restorative composition radially from the catheter.

18. The kit of claim 16 wherein said cannula is provided with a solid handle affixed to a proximate portion of said cannula and has asymmetric halves extending outward from a bore along the axis of the cannula.

19. The kit of claim 16 further comprising a micro-reamer.

20. The kit of claim 16 further comprising a screw having a bore along the longitudinal axis of said screw.

21. The kit of claim 16 wherein the stylet, micro-reamer, or cannula, all have a proximate end and distal end and is fixed to the proximate end, a lateral surface responsive to impact blows.

22. The kit of claim 16 wherein said catheter comprises stainless steel.

23. The kit of claim 16 wherein said catheter comprises polyimide.

24. The kit of claim 16 wherein said catheter comprises latex.

25. The kit of claim 16 wherein said catheter comprises silicone.

26. The kit of claim 16 wherein said catheter comprises vinyl.

27. The kit of claim 16 wherein said catheter comprises a shape memory material.

28. The kit of claiml6 further comprising one or more syringes having a Luer lock.

29. The kit of claim 16 wherein said cannula is divided into grades, said grades being markings.

30. The kit of claims 16 wherein said micro-reamer is divided into grades, said grades being markings.

31. The kit of claim 16 wherein said catheter is divided into grades, said grades being markings.

32. The kit of claim 16 wherein the restorative composition comprises a hydrogel.

33. The kit of claim 16 wherein the restorative composition comprises a synthetic bone void filler.

34. The kit of claim 16 wherein the restorative composition comprises polymethyl methacrylate.

35. The kit of claim 16 wherein the restorative composition comprises replicated bone marrow.

36. A kit for delivery of a restorative, composition to an intraosseous space, comprising: a plurality of polyimide catheters and a plurality of syringes, the catheters having graded markings on an external surface thereof.

37. The kit of claim 36 further comprising a cannula and stylet having reciprocating mating means, and a micro-reamer for accessing the intraosseous space.

38. The kit of claim 37 wherein the stylet has a diamond or beveled tip.

39. The kit of claim 36 wherein the graded markings are 1 cm apart.

40. A kit for delivery of a restorative composition to an intraosseous space, comprising: a plurality of stainless steel catheters and a plurality of syringes, the catheters having graded markings on an external surface thereof.

41. The kit of claim 40 further comprising a cannula and stylet having reciprocating mating means, and a micro-reamer for accessing the intraosseous space.

42. The kit of claim 41 wherein the stylet has a diamond or beveled tip.

43. The kit of claim 40 wherein the graded markings are 1 cm apart.

44. A kit for delivery of a restorative composition to an intraosseous space, comprising: a plurality of cannulated screws, a plurality of stainless steel catheters and a plurality of syringes, said plurality of stainless steel catheters have graded markings on an external surface thereof.