Abstract:
A rotary abrader allowing for improved visibility during surgery and improved aspiration of waste material. This is accomplished by providing a hood or sheath formed of a clear material and is available in various shapes and sizes. Slots are provided on the cannulated tube to provide aspiration of waste material and used to attach the hood to the cannulated tube.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application No. 60/715,615, filed Sep. 12, 2005, the entire disclosure of which is incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to rotary abraders used in surgery and, more particularly to an abrader which gives the surgeon an improved view of the surgical site during arthroscopic procedures.  
       BACKGROUND OF THE INVENTION  
       [0003]     Least invasive surgical techniques have gained significant popularity because of their ability to accomplish outcomes with reduced patient pain and accelerated return of the patient to normal activities. Arthroscopic surgery, in which the intra-articular space is filled with fluid, allows orthopedists to efficiently perform procedures using special purpose instruments designed specifically for arthroscopists. Among these special purpose tools are various manual graspers and biters, electrosurgical devices, and powered shaver blades and rotary abraders. Shaver blades having hollow bores are typically removably coupled to a shaver handpiece and are used for cutting, resecting, boring, and abrading both soft and hard tissue at the surgical site. An arthroscopic abrader (also known as a burr) generally includes a rotatable inner tube having an abrading head at its distal end and fixed outer tube for rotatably receiving the inner tube. Abraders are used for abrading or shaping both soft and hard tissue as bone, cartilage, ligaments, etc. by use of the rotating abrading head. As the tissue is being abraded, debris and fluid are generally drawn or sucked through the rotatable inner shaft which supports the burr.  
         [0004]     Requirements for a rotary abrader for arthroscopy include a compact size so as to fit through small cannulae, a means for removal of debris, and a configuration which allows the surgeon to access, while retaining good visibility, structures within a joint. One requirement for good visibility is the effective removal of debris as it is generated. Another is that the instrument be configured so that the view of the active portion of the abrader in contact with the tissue and the view of the tissue being abraded are not obscured by the instrument.  
         [0005]     Rotary abraders for arthroscopy generally have a shield, also called a “hood,” on one side of the distal end of the outer tube to prevent inadvertent damage to tissue in close proximity to the tissue being abraded. The distal end of this hood is angled with respect to the tube axis so as to expose only one side of the burr head. During use, the burr head (the abrading element at the distal end of the rotating inner member) is subjected to significant lateral forces. Although rotary abraders typically have a bearing near the distal end of the instrument to support the inner member, lateral deflection of the burr head occurs to some degree. Contact between the burr head and the hood is undesirable since the burr will abrade metal from the hood and deposit metallic debris in the joint. Accordingly, it is necessary to leave adequate clearance between the hood and the burr head. Further, hoods are usually opaque, which hinder visibility of the surgical site during surgery.  
         [0006]     Removal of debris from the field is accomplished by aspirating the material from the joint via a lumen in the inner, rotating member which is connected through a means in the handpiece to an external vacuum source. The aspiration of material through the inner member is desirable as this allows easy transfer of the materials from the proximal end of the instrument to the aspiration passage of the handpiece. The manner in which material and fluid enter the lumen at the distal end of the instrument has a large effect on the volume of flow through the instrument and on the frequency with which the instrument clogs. Insufficient flow causes decreased visibility because of residual debris suspended in the intra-articular fluid. Clogging requires that the instrument be removed from the joint and “de-clogged.” The degree of difficulty of clog removal is determined by the instrument design. Even if clog removal is easily accomplished, removing, de-clogging and reinserting the instrument is a nuisance and causes increased procedure times. Aspiration effectiveness, and therefore instrument design, have a large effect on burr efficiency.  
         [0007]     There is a need for an improved rotary abrader that provides a clear hood to improve visibility during surgery.  
         [0008]     It is accordingly an object of this invention to produce a rotary abrader with a hood or sheath or guard that is available in various shapes to improve the procedure of abrading tissue.  
         [0009]     Further, there is a need for an abrading instrument having rigidity, and an aspiration means which effectively removes debris without clogging and which can be readily cleared of clogs without disassembly, and which enhances surgeon visibility in procedures where visibility is crucial, such as SLAP repair.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is a rotary abrader having a clear sheath or hood over the abrading element or burr. Slots provided on the cannulated shaft supporting the burr provide aspiration and are used to attach the hood to the cannulated shaft.  
         [0011]     Several hoods in various shapes are provided to cover the burr at the distal end of the abrader. The hoods are formed of a clear material, such as polycarbonate. The clear material of the hoods provide visibility of the burr during the procedures.  
         [0012]     Other features and advantages of the present invention will become apparent from the following detailed description of the invention, which is provided with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a plan view of the outer tube of a rotary abrader in accordance with an embodiment of the invention.  
         [0014]      FIG. 2  is a side elevational view of an outer tube of the rotary abrader of  FIG. 1 .  
         [0015]      FIG. 3  is a side elevational view of the hood of an outer tube assembly of the rotary abrader of  FIG. 1 .  
         [0016]      FIG. 4  is a plan view of the hood of an outer tube assembly of the rotary abrader of  FIG. 1 .  
         [0017]      FIG. 5  is a perspective view of the hood of the outer tube assembly of the rotary abrader of  FIG. 1 .  
         [0018]      FIG. 6  is a plan view of the outer tube of the rotary abrader of  FIG. 1 .  
         [0019]      FIG. 7  is a plan view of the outer tube of the rotary abrader of  FIG. 1 .  
         [0020]      FIG. 8  is a plan view of the outer tube of the rotary abrader of  FIG. 1 .  
         [0021]      FIG. 9  is an expanded axial view of the objects at location A-A of  FIG. 6 .  
         [0022]      FIG. 10  is a plan view of the inner tube assembly of the rotary abrader.  
         [0023]      FIG. 11  is an expanded plan view of the distal end of the inner tube assembly of the rotary abrader.  
         [0024]      FIG. 12  is a perspective view of the distal end of the inner tube assembly of the rotary abrader.  
         [0025]      FIG. 13  is an expanded plan view of the distal end of the inner tube assembly of a rotary abrader in accordance with another embodiment of the invention.  
         [0026]      FIG. 14  is an expanded plan view of the distal end of the inner tube assembly of a rotary abrader in accordance with another embodiment of the invention.  
         [0027]      FIG. 15  is a perspective view of the distal end of the inner tube assembly of a rotary abrader in accordance with another embodiment of the invention.  
         [0028]      FIG. 16  is a plan view of the inner tube of a rotary abrader.  
         [0029]      FIG. 17  is a plan view of the assembled rotary abrader.  
         [0030]      FIG. 18  is a side elevational view of an assembled rotary abrader.  
         [0031]      FIG. 19  is a plan view of an outer tube assembly of a rotary abrader in accordance with another embodiment of the invention.  
         [0032]      FIG. 20  is a side elevational view of an outer tube assembly of the rotary abrader of  FIG. 19 .  
         [0033]      FIG. 21  is a plan view of an inner tube assembly of a rotary abrader.  
         [0034]      FIG. 22  is a plan view of an outer tube assembly of the rotary abrader of  FIG. 19 .  
         [0035]      FIG. 23  is a plan view of a hood of the rotary abrader of  FIG. 19 .  
         [0036]      FIG. 24  is a side elevational view of the hood of a rotary abrader of  FIG. 19 .  
         [0037]      FIG. 25  is a perspective view of a hood of the rotary abrader of  FIG. 19 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]     In the following detailed description, reference is made to various specific embodiments in which the invention may be practiced. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be employed, and that structural and logical changes may be made without departing from the spirit or scope of the present invention.  
         [0039]     Referring now to the drawings, where like elements are designated by like reference numerals,  FIGS. 1 through 5  illustrate the outer tubular portion  50  of a rotary abrader formed in accordance with the first embodiment of the invention. Outer tube  52  has a proximal end  54  and a distal end  56 . Tube  52  has a lumen  53  of diameter  60  and an outer diameter  62 . Distal end  56  has a first portion  64  with an inner diameter  66  formed therein, and a second portion  68  of length  70  with a diameter  72  formed therein. Diameter  72  decreases slightly and varies at slope  45  at distal end  56 . Diameter  72  is slightly larger than diameter  60 . Diameter  66  is slightly larger than diameter  72 . Beveled surfaces  75  and  77  together with outer surfaces  55  define a hood (or guard)  79 .  
         [0040]     The hood  79  may be formed of any material, but in an exemplary embodiment, at least a portion of hood  79  is made of a clear polymer plastic material, such as polycarbonate. The polycarbonate hood  79  enhances visualization of the operational site. The hood  79  also is provided to enhance aspiration and to protect tissue surrounding the operational site.  
         [0041]     The outer tube  52 , as illustrated in  FIGS. 6 through 9 , is preferably about 5.15 inches long and has a diameter of about 0.171 inches. Further, elongated slots  73  and  74  extend from the lumen  53  to the tube outer surface  55  ( FIG. 3 ). Two elongated slots  73  are used to attach hood  79  to the outer tube  52 . As shown in  FIG. 9 , slots  73  have inward bevels for insert molding, created by laser cutting, to allow the plastic from hood  79  to fill the space  75 . Also, the slots  73 , having a dovetail configuration, prevent the hood  79  from becoming dislodged. A core pin is inserted into the lumen of the outer tube  52  to prevent plastic from obstructing the pathway for inner tube  102  ( FIG. 10 ). Slot  74  provides aspiration of debris and waste without clogging. A raised diamond knurl  49  at the proximal end  54  of the outer tube  52  is a point of attachment for the outer tube  52  with the inner tube  102  ( FIG. 10 ).  
         [0042]     Referring now to  FIGS. 10 through 12 , inner tube assembly  102  of a rotary abrader constructed in accordance with the principles of the invention has an elongated tubular portion  104  with a proximal end  106  and a distal end  108 . Distal end  108  has affixed thereto portion  110  having a diameter  114 , and a distal portion  116  forming an abrading element (or burr head) of diameter  117 . In addition, a Teflon (FEP) shrink tubing covers the elongated tubular portion of inner tube assembly  102  to prevent wear and keep the inner and outer tubes more concentric. Near distal end  108  of tubular portion  104  aspiration port  111   a  extends from lumen  112  to outer surface  113 . Aspiration port  111   b  extends from the distal portion  116  to a distance immediately before  111   a . The suction pathways  111   a  and  111   b  enhance aspiration of waste and debris. An example of a surgical abrader that provides a suction port proximal to the bearing to enhance aspiration is disclosed in U.S. Pat. No. 7,077,845, which is incorporated herein by reference in its entirety. In another preferred embodiment, as illustrated in  FIGS. 13 through 15 ,,the burr head and portion  112  extends about 1 inch without aspiration ports at the distal portion  116 . The aspiration ports may be disposed on the inner tube a distance away from the burr head. In addition, as best seen in  FIG. 16 , the inner tube  102  has an elongated tubular portion  104  that extends about 5.4 inches. A raised diamond knurl  48  at the proximal end  106  of the inner tube  102  is a point of attachment for the inner tube  102  with the outer tube  52  ( FIG. 1 ).  
         [0043]     Referring now to  FIGS. 17 and 18 , an assembled rotary abrader  200  is shown. To assemble, an inner tube assembly  100  is inserted into the outer tube  52  of outer assembly  50 . Inner hub  122  is inserted into the outer hub  120 , which is held secure by a retaining ring  118 . The inner hub  122  of inner tube assembly  100 , includes a spring  125 , spring retainer  126 , and thrust washer  127 . Also, the clear tip hood  79  covers the burr blade.  
         [0044]     In another embodiment, the clear tip hood is removably interchangeable with other hoods, which are provided in various shapes. U.S. patent application Ser. No. 11/365,939, which is incorporated herein by reference in its entirety, provides another embodiment of an endoscopic rotary abrader with an abrader and an outer assembly portion having flush ends and a removable hood.  
         [0045]     In another preferred embodiment, as illustrated in  FIGS. 19 through 25 , a rotary abrader has an outer assembly  310  and inner assembly  320 . A hood  311  is insert molded onto the outer tube  315 . The hood  311  covers the burr blade  312 . This abrader is known as a SLAP burr. In this embodiment, the inner tube  314  is removable from the outer tube  315 . The outer assembly  310  has a proximal end  316  with a hub  317  affixed to the proximal end  316  of outer tube  315 . The inner assembly  320  has a proximal end  318  with a hub  319  affixed to the proximal end  318  of inner tube  314 . As discussed above, to assemble the rotary abrader, the inner tube assembly  320  is inserted into the outer tube  315  of outer assembly  310 . Inner hub  319  is inserted into the outer hub  317 , which is held secure by a retaining ring  321 . The inner hub  319  of inner tube assembly  320 , includes a spring  325 , spring retainer  326 , and thrust washer  327 .  
         [0046]     As best seen in  FIGS. 23 through 25 , the hood  311  has a different shape than the embodiment discussed above. This shape provides better protection for the surrounding tissue as the burr blade abrades the tissue. The hood is preferably made of a polycarbonate or other clear material to enhance visibility of the surgical site. Although the hood is shaped differently than the embodiments described above, the abrader still maintains the required minimum clearance between the burr head and the hood and does not obstruct the surgeon&#39;s view. In a preferred embodiment, the hood is enlarged as compared to the diameter of the outer tube. In this embodiment, the diameter of the abrading element can be increased and still maintain the minimum clearance required between the element and the hood.  
         [0047]     Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention is to be limited not by the specific disclosure herein, but only by the appended claims.