Abstract:
A surgical kit for inserting a biological material into a portion of the skeletal bone by a minimally invasive technique has several components which are manually operated using a universal tool. The kit includes a docking needle used as a guide for placing a cannula in a bone. The tool has a spring loaded hinged connection for temporarily attaching to the other components and which locks upon release of compression. An ultrasonic probe is inserted through the cannula for forming a cavity within the soft tissue of the bone. Treatment or support material is placed in the cannula and a plunger is inserted in the cannula. The universal tool is connected to the plunger and the material is expelled by telescopic movement of the plunger.

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 10/190,044 now U.S. Pat. No. 6,780,191 filed Jul. 5, 2002, the entire contents of which are herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to orthopedic surgery and to an ultrasonic apparatus and process for minimal invasion of skeletal bones in the body for treatment and support. 
     BACKGROUND OF THE INVENTION 
     The use of cannulas to gain access to the interior regions of a patient&#39;s body is very old. In recent history, the use of the cannula in all types of surgery has gained wide acceptance. Heart catheterization and delivery of stints contributed to the increased popularity, as well as laproscopic surgery of all kinds. These techniques have reduced patient trauma, incidence of infection and hospital stays. These procedures have in common gaining access to the interior of the body by a small stab wound through which is inserted a cannula for maintaining a passageway. All sorts of other surgical implements may then traverse this passageway depending on the specific procedure to be performed on the patient. 
     Vertebroplasty was recently introduced to the medical arts as a percutaneous technique for repairing spinal compression fractures by injecting bone cement into the vertebral body. However, the technique quickly expanded to osteoporotic individuals that had been treated with narcotics and immobilization. The bone cement is used to shore up the collapsing vertebrae for support which relieves the pain associated with undue pressure on the nerves. This procedure rapidly gained acceptance as a substitute for open spinal surgery and vertebral microsurgery. 
     Radiologists and surgeons are involved in the procedure since the process is monitored by fluoroscopy and has the potential for leakage of the cement into the local blood stream. Some of the critical parameters of the procedure involve the mixing of the cement to an appropriate viscosity, ensuring that the cement is radio-dense for viewing, properly placing the injector inside the cancellous portion of a vertebra, and rigorously controlling injection pressure and quantity. See “Vertebroplasty: Dangerous Learning Curve,”  START - UP , June 2001. 
     DESCRIPTION OF THE PRIOR ART 
     U.S. Pat. No. 6,273,916 to Murphy describes vertebroplasty, generally, as performed on a prepped and draped prone patient who has been injected with a local anaesthetic. A skin incision is made over the selected vertebrae and a needle is inserted in a posterior approach to engage the vertebral body. A suitable cement is prepared using a contrast medium, such as barium powder, mixed with methylmethacrylate powder, and a monomer liquid. The cement (PMMA) becomes unworkable within 4 to 11 minutes from mixing. 
     Cement is injected into the vertebrae, while visualized by lateral and anterior-posterior X-ray projection fluoroscopy imaging. The injection is halted if the cement starts to extend into unwanted locations, such as the disc space or towards the posterior quarter of the vertebral body where the risk of epidural venous filling and spinal cord compression is greatest. If no unwanted migration is detected, the injection continues until the vertebrae is adequately filled. The amount of cement injected may vary considerably, e.g. from 4 to 36 cc. 
     Reiley et al, U.S. Pat. No. 6,048,346, teach a posterior-lateral approach for accessing the interior of the vertebrae for injecting bone cement or treatment substances or a combination of both. The bone cement is injected using a caulking gun-like device with a ram rod in the barrel. 
     In this procedure, the cement follows the cracks and crevices pre-existing in the vertebrae which may result in weak structural areas with little or no cement support between bony outcrops and/or migration of the cement outside the desired boundary through larger fissures before other areas are adequately filled. 
     Scribner et al, U.S. Pat. No. 6,241,734, teach the use of a balloon inflated within the intra-vertebral space to create a regular shaped void for application of a well shaped charge of cement with greater supporting characteristics. There are attendant risks of rupture of the inflated balloon while it is within the vertebrae. Scribner et al also teach the use of multiple components for gaining access to the intra-vertebral space. 
     Wuchinich, U.S. Pat. No. 5,167,619 discloses an ultrasonic handpiece used for reaming cement from a long bone preparatory to replacement of a prosthesis. Wuchinich recognizes that incidental contact between the ultrasonic probe and the interior of the bone surface is not injurious to the bone. 
     The use of an ultrasonic probe in the intervertebral disk is shown by Marcove et al, U.S. Pat. No. 5,976,105. The probe is not inserted within the vertebra body but is applied to the exterior tissues. The Marcove ultrasonic tip is vibrated longitudinally in the frequency range of 25 Khz to 60 Khz which is considered sufficient to soften body tissue. The energy is transmitted to the tip from a handpiece having an ultrasonic transducer connected to a wire extending through a cannula. 
     The use of an ultrasonic probe for treatment of blood clots is disclosed by U.S. Pat. No. 5,725,494 to Brisken. The vascular probe must be extremely flexible to follow the twists and turns of the blood vessels through which it traverses. The ultrasonic transducer is located at the leading end of the flexible probe. 
     What is needed in the art is a simple apparatus having several components operated by the same handle to perform cannulazation of skeletal bone including the formation, by ultrasound, of a defined intra-bone cavity for treatment deposits 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an objective of this invention to teach a percutaneous system for surgery using ultrasonic vibration to shape or destroy tissue. 
     Also, it is an objective of the instant invention to teach a kit having a guide needle, cannulas, ultrasonic probe, several different cannula tips, a plunger, a clearing tool, a connector and a universal handle. 
     It is another objective of the instant invention to teach the formation of a cavity within bone or soft tissue, by ultrasonic energy, as well as, modulating and directing the ultrasonic energy to shape the cavity and to visualize the cavity. 
     It is yet another objective to teach a kit with several interchangeable tips to be fitted on the leading end of the cannula for different penetrations of the body. 
     It is a still further objective of the invention to teach a kit for orthopedic use to perform bone biopsy and to deliver a biological material to the cancellous portion of bone. 
     It is a further objective of the invention to teach manipulation of a biological material within the bone to change position, as well as, physical form 
     It is yet another objective to teach a kit in which the universal tool has plural elements spring biased together and forms a temporary connection with the other components of the kit by operation of the spring bias. 
     Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     FIG. 1 is a schematic and partial perspective of the ultrasonic surgical system of this invention; 
     FIG. 2 is a perspective of the docking needle and a cannula removably telescoped together; 
     FIG. 3 is a cross section of the telescoped docking needle and cannula taken along line A—A of FIG. 1; 
     FIG. 4 is a longitudinal cross section of a cannula and a plunger; 
     FIG. 5 is an exploded top view of the universal tool of this invention; 
     FIG. 6 is an enlarged view of the connector of this invention; 
     FIG. 7 is a side view of a flexible ultrasonic probe with the cannula and connector of this invention; and 
     FIG. 8 is a perspective, partially in section, of a vertebra with and rigid ultrasonic probe therein. 
    
    
     DESCRIPTION OF THE INVENTION 
     The ultrasonic surgical system, shown in FIG. 1, may have different utilitarian features, eg., the entire system may be housed in a free standing cabinet, either fixed or mobile. The system may be enclosed in a wall mounted or a table top cabinet. Or the different components could be separate and connected only by the various leads and tubes necessary for functional operation. Depending on the particular surgery to be performed and/or the anatomical location of the surgery, the system may be operated with less than all the components or some components inactive. 
     The leading end  91  of the tubular surgical implement is equipped to deliver ultrasonic energy, inject biological material, aspirate, and view the surgical field. Of course, these functions could be done sequentially through a single lumen in a catheter or the catheter can have multiple channels for simultaneous functions. As shown in FIG. 1, the ultrasonic energy is delivered by a transducer  100 , the delivery of biological material is through lumen  101 , the aspiration is through lumen  102 , and visualization is through lumen  103 . Each lumen of the catheter is connected to a controllable power unit for the respective function, for example, an ultrasonic transducer  107 , a pressure pump  108 , a suction pump  109 , and camera and light source  110 . Further, the visualization of the field may be by direct viewing by fiber optics and camera or computer enhanced imaging derived from ultrasound or sonar or similar devices. 
     The system may be operated by a control unit  104  in the form of a personal computer (PC) with a central processing unit (CPU); a memory; programming; an input device  105 , such as a keyboard, joystick, touch screen; a display  106 , such as a cathode ray tube (CRT), liquid crystal, etc.; and an output transmitting appropriate signals to the components. The control unit  104  of the system can modulate and aim the ultrasonic energy to destroy different density tissue and shape or limit the surgical field by controlling the ultrasonic transducer  105 . The ultrasonic energy may be in the form of a directed beam which can be aimed by the control unit. 
     The introduction of biological material through lumen  101  results by direction of the pump through the control unit. Of course, the biological substance may be manually introduced through the lumen, if desired. 
     The cannula system of this invention is in the form of a kit which, in one embodiment, includes a docking needle  10  with an elongated shaft  11 , shown in FIGS. 2-4, having an insertion point  12  for penetration through the cutaneous layer of a patient. The point  12  passes through the skin, muscle and the hard shell of a bone into the softer cancellous bone material. The point  12  forms a tapered end portion with the base of the taper  13  smoothly merging into the shaft  11 . The shaft may have a central bore  14  extending through the length of the needle. The bore may be eccentric in another embodiment (not shown). 
     The needle is of a size and material to withstand the compression required for insertion without deformation. The needle may be made of stainless steel, other metals, or suitable polymers. Normally, the insertion is performed manually by axial pressure at the trailing end of the needle to include striking the needle with a surgical hammer. 
     The tool or handle  50 , shown in FIG. 5 is designed to fit on the trailing end of the needle for translating the manual axial pressure to the needle  10 . The handle  50  is a universal tool for use with all the components of the kit. The needles and cannulas of the kit have a shaped tailing end that will fit into one of the blind bores on the handle or they will have a connector, as shown in FIG. 6, which cooperates with the eccentric lock of the handle  50 . 
     Preferably, in vertebroplasty, the needle  10 , as shown in FIG. 8, is inserted on a posterior-lateral tract, using X-ray fluoroscopy, to dock in a vertebrae anteriorly of the lateral process. Other approaches may be chosen by the surgeon. Regardless, of the orthopedic surgical procedure involved, the docked needle serves as a guide for the subsequent insertion of the cannulas of the system. Of course, in some applications, the needle and cannula may be inserted simultaneously. 
     In operation, a cannula  15  is telescoped over the docking needle  10  to provide a pathway for removal or delivery of material from the bone. The surgeon removes the handle  50  from the trailing end of the docking needle and connects the handle with the trailing end of the cannula. The leading end of the cannula is then placed over the trailing end of the needle. Axial pressure is applied to the cannula to slide the cannula along the needle to the desired location. Using fluoroscopy, the surgeon telescopes the cannula over the docking needle until the leading end of cannula and the leading end of the docking needle are flush or superimposed within the bone site thereby designating proper placement of the delivery cannula. 
     The trailing end  18  of the cannula has a connector  80 , shown in FIG. 6, either removably affixed by internal threads  82 , in the nature of a Leur-type fitting, or permanently connected to the shaft. The connector  80  has external planar surfaces  81  which provide a gripping surface for manipulating the cannula. In one embodiment, the connector has a hex-nut outer surface to prevent rotation within handle  50  although other configurations are a matter of choice. The connector  80  has a reduced diameter portion  83  between a shoulder  84  and a flange  85  to prevent longitudinal movement within the handle  50 . 
     As shown in FIG. 5, the hinged eccentric lock  60  has a hinge  70  displaced laterally from the opening  61 . The hinge post  70  formed on the R section of the handle is inserted into bore  71  on the L section. Both the bore  71  and the hinge post  70  are rectangularly shaped to provide an stabilized axis of rotation. As shown, the hinge post is bifurcated with two resiliently separated legs  72  and  73 . The hinge post may be solid. The legs carry a circumferential slot  74  about their free ends. Upon assembly, the hinge post  70  is inserted into aperture  71  which has a smaller diameter than that of the hinge post. The aperture has a circular protrusion  75  about the interior wall. The protrusion  75  fits into the slot  74  to prevent the sections from separating after assembly. Of course, the R and L sections of the handle may be permanently fixed together forming an integral spring biased handle, eg., the hinge post and the bore may be autogenously bonded. 
     In the embodiment shown in FIG. 5, the R section of the universal tool  50  has a opening  61  therethrough surrounded by a columnar wall which ends in an extension  69 . In another embodiment, (not shown) the extension  69  is omitted. The columnar wall has a circumferential slot into which the flange  68  is inserted. The flange  68  on the L section has an eccentric opening, a portion of which forms a part of the opening  61 . Becasue the hinge is displaced from the flange, the flange has a lateral vector, as well as a rotational movement upon compression of the handle. When the R and L sections are assembled and the eccentric hinge is formed, a portion of the flange  68  obstructs the opening  61 . 
     By compressing the universal handle, the jaws of the slit are forced closer together. The portion of the flange obstructing the bore  61  slides into registry with the columnar wall of the R section. This allows the connector  80  to telescope into the opening  61  and through the flange  68 . When the manual compression is relieved, the flange  68  moves into the opening  61  and engages the reduced portion  83  of the connector  80  locking the cannula into the handle  50 . 
     Once the cannula is telescoped over the needle to the desired location within the body, the handle is removed from the trailing end of the cannula and re-attached to the trailing end of the needle which extends beyond the trailing end of the cannula. Axial force is then applied in the opposite direction to remove the needle from the bone and the cannula. After the needle has been removed, the cannula bore  19  is open for either removing material for biopsy, for creating a space, or for dispensing a biological material for treatment. 
     Of course, the leading end  16  of the delivery cannula  15  may be modified to enhance the ability to cut through bone, particularly if a biopsy is necessary. Once the biopsy cannula  20  has been manipulated either rotationally or longitudinally or both by the handle  50  engaged with the connector  80 , the handle is used to withdraw the cannula from the patient&#39;s body. A clearing tool is inserted into the bore  23 . The clearing tool is advanced through the bore to push the tissue sample from the cannula. 
     If a biopsy is not required or after removal of the biopsy cannula, a delivery cannula  15  is telescoped over the docking needle, as described above. The delivery cannula is provided with a connector  80  at its trailing end. The longitudinal dimension of the connector is such that it fits within hinged eccentric lock  61  in the handle  50 . 
     The tool or handle  50  is made from surgical stainless steel, liquid metal, or other magnetizable or non-magnetizable metals, or, preferably, molded or machined from a high impact polymer, such as polyethylene, polypropylene, NYLON or similar compositions capable of withstanding repeated sterilizations. The handle  50  has two elements, R and L, respectively, separated along a longitudinal center line  54 . The handle is flexible and, preferably, resilient. The handle has a top surface  51 , a bottom surface  52  and side walls defining a periphery  53 . The left and right elements, R and L, of the handle are eccentrically hinged together at eccentric lock  60 . The slit  54  has opposing jaws  55  and  56  which pivot about the spring biased center portion. The jaws  55  and  56  each have a bore  63  and  64 , respectively, oriented in the same plane in which each jaw pivots. 
     Slit  54  extends through the side walls from the periphery toward the center portion with opposing jaws  58  and  59  which pivot about the spring biased eccentric lock  60 . 
     By applying pressure on the opposing pairs of jaws of each slit, the jaws may approach with each other. When pressure is released, the respective pairs of jaws resiliently move away from each other. As illustrated, the slits are arranged to oppose each other. 
     A blind bore  62  is formed in the periphery of the handle for the purpose of engaging the trailing end of the docking needle. The shaft of the blind bore  62  is shaped to cooperate with the trailing end of the needle to provide rotation of the needle upon rotation of the handle. The surgeon manually grips the handle and applies longitudinal and/or rotational force through the handle to the needle to penetrate the soft tissue and bone of the patient. The handle may also provide a striking plate for receiving blows from a surgical hammer for driving the needle into the bone. Once the needle is properly docked in the bone, the handle is removed from the needle. 
     Blind bore  65  is of suitable size to accommodate the trailing end of the cannula fitted with a connector  80 . The blind bore  65  has a larger diameter terminating with a shoulder  66  which will engage and stop the connector  80 . A smaller diameter portion  67  of the bore continues above the shoulder to allow the trailing end of the docking needle to extend beyond the trailing end of the connector  80 . Because the cannula is somewhat larger than the docking needle, the tip of the cannula may be sharpened to cut through the bone. A surgical hammer may be used to drive the delivery cannula, at least, through the hard outer shell of the bone. Once the cannula is located in the cancellous portion of the bone, the cannula may be removed from the blind bore  65 . 
     The cannula with an attached connector  80  may then placed in the opening  61 , of the handle. The connector  80  is engaged with the eccentric flange  68  to prevent longitudinal or rotational movement of the cannula within the handle. The surgeon telescopes the leading end of the cannula over the trailing end of the needle and again applies longitudinal force through the handle to the cannula to force the cannula through soft tissue and into the bone. As the cannula approaches the proper position in the bone, the trailing end  14  of the telescoped docking needle emerges from the trailing end of the cannula. When the trailing end of the needle  14  is level with the top surface  51  of the handle, the leading end  16  of the cannula is flush with the end of the needle. The top surface  51  of the handle and the trailing end  14  of the needle serve as a visual and tactile gauge, in the surgeon&#39;s hand, for properly placing the leading end of the cannula in the bone. 
     The handle  50  is then removed from the cannula and the jaws of slit  54  are pivoted to place the bores  63  and  64  in parallel. The trailing end of the needle is then inserted through bores  63  and  64 . The pivoting pressure on jaws  55  and  56  is then released causing the bores to resiliently intersect engaging the shaft of the needle. Of course, the tool  50  may operate in reverse, with the pivoting pressure causing the jaws to close, in another embodiment. The needle is then removed from the cannula by use of the handle  50 . After the needle is removed from the cannula the jaws are pivoted to release the shaft of the needle and free the handle. 
     The ultrasonic apparatus  90  may now be introduced into the body through the cannula  15  which has penetrated the hard exterior of the bone, as shown in FIGS. 7-8. The probe  91  extends from the ultrasonic pulse generator  92  into the soft tissue inside the bone. The probe  91  is protected by the cannula with only the vibratory tip  93  exposed to the tissue. The probe, which is rigid in the longitudinal axis but may be transversely flexible, provides a degree of control of the ultrasonic tip by transmitting pressure from the surgeon directly to the tissue. Of course, the probe may be flexible with an ultrasonic transducer only on the vibrating tip, as shown in FIG.  7 . The intensity and frequency of the ultrasonic pulses may be regulated by the pulse generator  92  to further control the effect of the tip upon the tissue. The ultrasonic probe may be modulated by suction in a multilumen catheter. The operation of the tip macerates or liquefies the soft tissue inside the hard bone thereby removing diseased or damaged tissue and leaving a void or pocket for receiving various treatment and/or reinforcement agents. Once the desired amount of tissue is destroyed, the ultrasonic probe  91  is withdrawn from the cannula. Because of the porous nature of the marrow and the fissures within structure, a cavity is formed within the soft tissue. As shown, the ultrasonic probe is used in vertebroplasty however, the device may be used in other procedures in other skeletal bones of the body. In one modification, the ultrasonic probe is separated from the pulse generator. In such case, the trailing end of the probe may have a fitting  94  to cooperate with the universal tool to aid in the withdrawal. Further, irrigation and aspiration catheters may be inserted through the cannula  15 , if desired. A multilumen catheter may be used with separate lumen for the ultrasonic probe, irrigation, aspiration, illumination, and visualization. 
     The delivery cannula is now positioned to transmit or withdraw the biological material to/from the bone. In general, the biological substance may be either structural or a treating agent or a combination of both. 
     For example, the material may be selected from such groups of substances as BMP, bone morphogenic proteins, DBM, demineralized bone matrix, BOTOX and other viral vectors, any bone marrow aspirate, platelet rich plasma, composite ceramic hydroxyapatite, tricalcium phosphate, glass resin mixtures, resorbable highly purified polylacttides/polylactides-co-glycolides and others. The treating agent may include hormonal, antibiotic, anti-cancer, or growth factor substances, among others. The material may be liquid, powder, crystals, granules, paste, gel or other forms. In vertebroplasty, polymethylmethacrylate (PMMA) is the customary bone cement though other compounds may be used. 
     Regardless of the chemical make-up of the biological substance, this system preferably uses a high viscosity biological material delivered through the cannula at a low pressure. To accomplish this objective, after the delivery cannula is properly placed in the bone, it is filled with a biological material having a viscosity allowing it to flow into the cannula. The viscosity of some of the materials continues to increase within the cannula to reach a consistency acceptable to the surgeon. Other materials may be ready for use, when loaded in the cannula. 
     The surgeon inserts a plunger into the cannula  15  to express the biological substance into the cancellous portion of the bone. The plunger is fitted with a connector  80  and manipulated by handle  50 . Both the plunger and the cannula  15  are telescoped together and the plunger is sized to substantially co-terminate with the leading end of the delivery cannula when both the connectors  80  are in contact. The diameter of the plunger is slightly less than the diameter of the cannula to provide telescoping movement for the system. The viscosity of the biological material will be such that the entire amount of the material will be expressed from the cannula. In this instance, the amount of biological material delivered is precisely measured to be the corresponding volume of the delivery cannula, for example, 4 cc. 
     Of course, the amount of biological material may be adjusted to a particular patient. This is accomplished through the continued fluoroscopic observance of the procedure. If more material is necessary in a particular procedure, the syringe used to load the delivery cannula may be utilized to pre-load the bone cavity before the plunger is inserted into the delivery cannula. 
     When the appropriate amount of biological material has been injected into the bone, the handle  50  is used to rotate and withdraw the plunger. Once the biological substance has begun to solidify, the handle is placed on the delivery cannula and twisted to rotate the cannula thereby separating the cannula from the substance. However, some substances will not harden or solidify. The ultrasonic probe may be re-introduced to manipulate the substance, in situ. For example, the biological substance may be injected as a powder or granules and subsequently transformed into a liquid within the bone. The cannula is subsequently withdrawn from the bone. 
     The kit of this invention may be produced in various sizes and combinations depending on the size of the patients and the procedures to be accomplished. For example, the kit may be used to deliver and remove balloons, stents and cages; pedicle screws and hardware, including laproscopic surgery; pouches and solutions for tissue augmentation; radioactive pellets, micro robots and chips; tracking and identification devices; medications; wires; laser systems; and the like. 
     It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings.