Abstract:
A radially ported bone graft needle, particularly useful in minimally invasive procedures, is provided. The bone graft needle delivers bone graft material to a bone defect area by extruding the bone graft material both axially and radially simultaneously.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority to U.S. Provisional Patent Application Serial No. 60/415,503, filed Oct. 3, 2003.  
         [0002]    This application is related to Assignee&#39;s co-pending U.S patent application [720.112.2], filed the same day as this patent application. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    The present invention generally pertains to the use of graft materials for promoting bone growth and, more particularly, to ported needles for delivering bone graft materials to metaphyseal compression fractures, other bone voids or other bone defect areas.  
           [0005]    2. Discussion of the Prior Art  
           [0006]    In the past, bone graft materials have been delivered to bone defect areas, such as metaphyseal compression fractures or bone voids as well as other areas of bone structures having discontinuities, cavities, recesses or the like (hereinafter referred to as bone defect areas). Minimally invasive bone graft procedures are preferred in many cases, and the delivery or injection of bone graft material to the bone defect areas has been accomplished using a needle having an open distal end forming an axial port for delivering the bone graft material to the bone defect areas from a syringe coupled with the proximal end of the needle. Since the only opening for delivery of the bone graft material is the axial port, the prior art needle has the disadvantages of: (1) being unable to deliver bone graft material when the axial port abuts bone or other tissue, (2) not being able to radially inject bone graft material, and (3) requiring undesirable excessive force to eject bone graft material through the axial port.  
         SUMMARY OF THE INVENTION  
         [0007]    Accordingly, it is an object of the present invention to overcome the above mentioned disadvantages of the prior art by providing a radially ported bone graft needle particularly useful in minimally invasive procedures. Another object of the present invention is to deliver bone graft material to a bone defect area by extruding the bone graft material both axially and radially simultaneously.  
           [0008]    A further object of the present invention is to fill a bone defect area by radial, multiaxial and/or multidirectional delivery of bone graft material. The present invention is generally characterized in a bone graft needle having at least one radial opening or port for delivering bone graft material radially to a bone defect area.  
           [0009]    The needle preferably has an axial opening or port allowing simultaneous axial and radial delivery of bone graft material. Preferably, equally spaced radial ports are arranged around the axial port; however, the size, arrangement and configuration of the radial ports can be varied dependent upon particular situations.  
           [0010]    The present invention is further generally characterized in a method of delivering bone graft material to a bone defect area including the steps of placing the distal end of an elongate tubular delivery member of a bone graft needle adjacent the bone defect area and flowing the bone graft material through the delivery member to exit both radially and axially of the delivery member.  
           [0011]    Some of the advantages of the present invention over the prior art are that both axial and radial delivery of bone graft material at a bone defect area can be achieved, radial delivery of bone graft material at a bone defect area can be achieved producing a more even distribution of bone graft material, bone graft material can be delivered even when the axial distal end opening of the needle is blocked, and reduced pressure is required to deliver bone graft material to a bone defect area. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    FIG. I is a perspective view of an instrument assembly incorporating a bone graft needle according to the present invention.  
         [0013]    [0013]FIG. 2 is an exploded side view of the instrument assembly including a side view of the bone graft needle of the present invention.  
         [0014]    [0014]FIG. 3 is a sectional view of a delivery member of the bone graft needle taken along line A-A of FIG. 2.  
         [0015]    [0015]FIG. 4 is an exploded side view of an alternative instrument assembly incorporating an alternative bone graft needle according to the present invention.  
         [0016]    [0016]FIG. 5 is a sectional view of the delivery member of the alternative bone graft needle taken along lines B-B of FIG. 4.  
         [0017]    [0017]FIG. 6 is a side view of another alternative bone graft needle according to the present invention.  
         [0018]    [0018]FIG. 7 is a side view of a further alternative bone graft needle according to the present invention. 
     
    
       [0019]    Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, wherein like parts in each of the several figures are identified by the same reference characters.  
       DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]    The present invention relates to a bone graft needle used to deliver bone graft material to a bone defect area in a patient&#39;s body in a minimally invasive procedure in which the bone defect area is accessed via a minimal portal or incision. FIGS. I and  2  illustrate an instrument assembly  10  comprising a bone graft needle  12  and a penetrating member  14 , such as a trocar. The bone graft needle  12  comprises an elongate tubular delivery member  16  extending distally from a handle  18 . The delivery member  16  has an open distal end  20  communicating with a longitudinal passage  22  extending entirely through the delivery member  16  and the handle  18 . A hollow coupling  24  having open distal and proximal ends is disposed at a proximal end of passage  22  with the interior of the coupling  24  in communication with the passage  22 . The coupling  24  is designed for releasable attachment to a standard syringe and may be designed as a conventional luer lock coupling. The handle  18  can have various configurations to facilitate grasping. A proximal end of the delivery member  16  can be attached to the handle  18  via a hub  26  or in any desired manner. The proximal end of the delivery member  16  can extend any desired distance into a passage of the handle  18  or can extend entirely through the handle. The coupling  24  can be attached to the handle  18  in various ways or may be formed integrally, unitarily with the handle. The distal end of the coupling  24  can extend any desired amount into the passage of the handle  18 . Accordingly, it should be appreciated that the longitudinal passage  22  can be formed in its entirety by the lumen of delivery member  16 , can be formed in part by the lumen of the delivery member  16  and by a passage in handle  18 , or can be formed in part by the lumen of delivery member  16 , a passage in the handle  18  and the interior of the coupling  24 .  
         [0021]    The delivery member  16 , as best shown in FIGS. 2 and 3, has an external cross sectional diameter or size for insertion through a minimally invasive portal or incision formed in the patient&#39;s body to access a bone defect area. The delivery member  16  has an internal cross-sectional diameter or size to receive the penetrating member  14  therethrough. As shown in FIGS. I and  2 , the penetrating member  14  includes an elongate shaft  28  having a tissue penetrating distal end  30  and having a proximal end attached to a hub  32 . The shaft  28  is insertable in the passage  22  extending entirely through the bone graft needle and, when the hub  32  is in abutment with the handle  18 , the tissue penetrating distal end  30  protrudes distally from the open distal end  20  of the delivery member  16  as shown in FIG. 1. The instrument assembly  10  formed when the penetrating member  14  is inserted in the delivery member  16  can be utilized to form a minimally invasive portal in anatomical tissue of a patient to establish access to a bone defect area. The exposed tissue penetrating distal end  30  of the penetrating member is used to penetrate the anatomical tissue to introduce the distal end  20  of delivery member  16  at or near the bone defect area. Thereafter, the penetrating member  14  can be removed from the bone graft needle  12  leaving the bone graft needle in place to maintain the thusly formed portal with the handle  18  disposed externally of the patient&#39;s body. It should be appreciated, however, that the bone graft needle  12  can be used independently of a penetrating member and that the bone graft needle can be introduced at or near a bone defect area via a pre-established portal.  
         [0022]    The open distal end  20  of delivery member  16  is circumscribed by a circumferential edge  34  that is provided with one or more proximally curving indentations as best shown in FIG. 2. Accordingly, the circumferential edge  34  comprises one or more distal most edge segments or points and one or more proximal most edge segments or points spaced proximally from the one or more distal most edge segments or points. A plurality of radial ports or openings  36  are formed through delivery member  16  proximally of circumferential edge  34 . As shown in FIG. 3, four radial ports  36  are formed through the wall of delivery member  16  at spaced locations about a central longitudinal axis  38  of delivery member  16 . The ports  36  are shown as being equally spaced about the central longitudinal axis  38  at 90 degree spaced locations about the central longitudinal axis  38 . It should be appreciated, however, that the ports  36  can be equally spaced or variably spaced about the central longitudinal axis. The ports  36  are shown as having a circular perimetrical configuration, but the ports can have other perimetrical configurations including oval, elliptical and various longitudinally elongated perimetrical configurations. Each port  36  has a longitudinal dimension in a direction parallel to the central longitudinal axis  38 . In the case of ports  36 , the longitudinal dimension corresponds to the diameter of the ports. Each port  36  begins a distance D proximally of the proximal most edge segment or point of circumferential edge  34  as shown in FIG. 2. Where the circumferential edge is disposed in its entirety in a plane perpendicular to the central longitudinal axis  38 , the proximal most edge segment or point will be disposed in the plane perpendicular to the central longitudinal axis  38  as described below for FIGS. 6 and 7. Distance D may be in the range of 0.020 inch to 0.275 inch. For delivery member  16  having ports  36  that are 0.063 inch in diameter, the longitudinal dimension for ports  36  is also 0.063 inch and a preferred range for distance D is 0.0505 inch to 0.0805 inch. FIG. 2 illustrates a removable tubular sheath  40  that may be disposed over the delivery member  16  prior to use.  
         [0023]    In a preferred embodiment for bone graft needle  12 , the needle is a 4 inch needle with delivery member  16  made of  304  stainless steel or other rigid biocompatible material and having a J-type cannulated distal end or tip; the delivery member is 0.185 inch in diameter; the radial ports  36  are 0.063 inch in diameter with centers at 90° (+ or −2.0°) spaced locations about the central longitudinal axis; and the centers of ports  36  are located 0.082 inch (+0.030 inch, −0.000 inch) proximally of the proximal most edge segment or point of circumferential edge  34 . The needle  12  may be a JAMSHIDI—type needle with a luer-lock coupling or connector.  
         [0024]    The open distal end  20  defines an axial or longitudinal port for delivery member  16  from which a bone graft material is discharged from delivery member  16  in an axial or longitudinal direction. The radial ports  36  permit bone graft material to be discharged from delivery member  16  in a direction radial to the central longitudinal axis  38  so that bone graft material is discharged radially simultaneously with the axial discharge.  
         [0025]    In a method according to the present invention, the distal end  20  of delivery member  16  is introduced at or near a bone defect area in a patient&#39;s body via a minimally invasive portal providing access to the bone defect area from externally of the patient&#39;s body. As discussed above, the bone graft needle  12  may be assembled with a penetrating member to form an instrument assembly that may be used to form the portal. Visualization of the bone defect area may be accomplished using a remote viewing device, such as a fluoroscope or x-ray device, as conventionally utilized in minimally invasive procedures. FIG. 2 illustrates a bone segment  42  having a bone defect area  44  to be supplied with a bone graft material delivered via the bone graft needle  12 . The bone defect area  44  may include metaphyseal compression fractures, bone voids, discontinuities, cavities, recesses, non-unions or the like. The bone graft material to be delivered to the bone defect area may be any synthetic or tissue-based material that promotes bone growth and may be provided in paste form. Representative bone graft materials include calcium sulfate, as represented by the OSTEOSET® bone graft substitute of Wright Medical Technology, Inc., Allomatrix® and MIIG™ 115 of Wright Medical Technology, Inc., and demineralized bone matrix. The bone graft material is supplied to the bone graft needle  12  via a conventional syringe coupled with the coupling  24 . With the handle  18  disposed externally of the patient&#39;s body, the syringe containing the bone graft material is coupled with coupling  24 . The distal end  20  of delivery member  16  is positioned at or adjacent the bone defect area  44  and, depending on the size of the bone defect area, the distal end  20  may be positioned within the bone defect area. With the distal end  20  properly positioned, a plunger of the syringe is depressed to fill the passage  22  with the bone graft material. Depressing the plunger of the syringe pressurizes the bone graft material in passage  22  causing the bone graft material to be simultaneously discharged axially through distal end  20  and radially through the ports  36  to fill the bone defect area  44 . In the case of delivery member  16 , the bone graft material is discharged simultaneously in five directions, i.e. in a first direction axially or longitudinally through distal end  20  and in second, third, fourth and fifth radial directions through ports  36 , respectively. In the event that the distal end  20  is in abutment with bone or other anatomical tissue, plugging or clogging of the delivery member  16  is avoided since discharge of the bone graft material continues through ports  36 . In addition, back pressure is reduced for easier injection of the bone graft material since resistance to injection is reduced due to the multi-directional discharge provided by opening  20  and ports  36 . The arrangement of ports  36  along the circumference of delivery member  16  permits radial discharge and distribution of the bone graft material and allows the bone defect area to be filled radially as well as from the distal end  20  of the delivery member. The distribution of ports  36  along the circumference of the delivery member allows the bone defect area to be filled in a range of 360 degrees around the delivery member. Also, the circumferential distribution of the ports  36  provides a more even and more balanced distribution of bone graft material to the bone defect area. Once the bone defect area  44  has been sufficiently supplied or filled with the bone graft material, the needle  12  is removed from the patient&#39;s body through the portal. The bone graft material remains in the patient&#39;s body to promote bone growth or regeneration.  
         [0026]    [0026]FIG. 4 illustrates an alternative instrument assembly  110  comprising a bone graft needle  112  and a penetrating member  114 . The instrument assembly  110  is similar to instrument assembly  10  except that the bone graft needle  112  and the penetrating member  114  are shorter in length than the bone graft needle  12  and penetrating member  14 . Accordingly, it should be appreciated that the bone graft needle, as well as the penetrating member, can be provided in different lengths depending on the length needed to access the bone defect area. The bone graft needle  112  also differs from the bone graft needle  12  in that the delivery member  116  is of smaller external diameter than the delivery member  16 . It should be appreciated, therefore, that the delivery members of the bone graft needles can be provided in various diametric sizes. Of course, the shafts of the penetrating members can also be provided in various diametric sizes depending on the anatomical tissue to be penetrated. The radial ports  136  for delivery member  116  differ from the ports  36  in that the ports  136  are smaller in diameter.  
         [0027]    In a preferred embodiment for bone graft needle  112 , the external diameter of delivery member  116  is 0.115 inch; the ports  136  have a diameter of 0.047 inch with centers at 90° (+ or −2.0°) spaced locations about the central longitudinal axis  138 ; distance D may be in the range of 0.020 inch to 0.275 inch and is preferably in the range of 0.082 inch to 0.112 inch; the needle  112  is a 6 cm needle with delivery member  116  made of 304 stainless steel or other rigid biocompatible material and having a J-type cannulated distal end or tip; and the centers of ports  136  are located 0.082 (+0.030 inch, −0.000 inch) proximally of the proximal most edge segment or point of circumferential edge  134 . The needle  112  may be a JAMSHIDI-type needle with a luer-lock coupling or connector.  
         [0028]    [0028]FIG. 6 is illustrative of a bone graft needle  212  in which the delivery member  216  has a distal end  220  with a circumferential edge  234  disposed in a plane perpendicular to the central longitudinal axis  238 . Distance D for delivery member  216  is defined from the plane of edge  234  to where the ports  236  begin proximally of edge  234 .  
         [0029]    The bone graft needle  312  illustrated in FIG. 7 is representative of a delivery member  316  having radial ports  336  that are not circular in perimetrical configuration. The radial ports  336  are formed as elongate slots in delivery member  316 , and the slots begin a distance D proximally of the circumferential edge  334 , which is disposed in a plane perpendicular to central longitudinal axis  338 .  
         [0030]    Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all subject matter discussed above or shown in the accompanying drawings be interpreted as illustrative only and not be taken in a limiting sense.