Abstract:
The disclosure illustrates a dual driver for surgical reamers in which either of a crossbridge and crossbar style reamers are axially inserted in the distal end of a central shaft for the reamer driver. A pair of L shaped grips are adapted to connect and disconnect the different style of reamers by the movement of an external sleeve biased towards the connection position. Movement of the sleeve away from the distal end allows an internal plunger to cam the grips to an open position and urge the appropriate reamer from the tool driver directly in an axial direction.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of U.S. patent application Ser. No. 12/233,149, entitled “DUAL REAMER DRIVER”, filed Sep. 18, 2008, which is incorporated herein by reference. U.S. patent application Ser. No. 12/233,149 is a non-provisional application based upon U.S. provisional patent application Ser. No. 60/973,919, entitled “AUTOMATIC DUAL CONNECTION REAMER DRIVE”, filed Sep. 20, 2007, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present invention relates to orthopedic surgical reamers and more specifically to drivers for such tools. 
         [0003]    In the field of orthopaedic surgery, it is often necessary to remove bone material to enable implantation of prosthesis to repair joints in the human body. Patella cutters and acetabular reamer cups and glenoid reamers are surgical tools which are used in surgery for the insertion of artificial joints. Acetabular reamer cups are used to cut hemispherical cavities in pelvis bones for the insertion of artificial hip joints. Patella cutters are used to shape the underside of the patella or knee cap during knee replacement surgery. Glenoid reamers are used to cut hemispherical cavities in shoulder bones for the insertion of artificial shoulder joints. Patella cutters have a complex arrangement of precisely shaped cutting edges arranged around an axis of rotation for cutting the patella. Acetabular reamer cups and glenoid reamers have a complex arrangement of cutting edges arranged on a spherical surface around the axis of rotation of the cup. 
         [0004]    A number of tools have been developed for this purpose and include reamers having generally semi-hemispherical configuration with cutting elements on them so that a corresponding semi-hemispherical hollow can be formed in the bone material for providing a foundation for the repair of the joint. 
         [0005]    There are two major driver styles in the field, one of which is for the Othy style manufactured by Symmetry Medical, Inc. and the other style manufactured by Precimed SA of L&#39;Echelette, Switzerland. Although these both have semi-hemispherical cutting heads, they have different interfaces between driving tools with which they are associated. The Othy style has a crossbridge element. This element is a bar extending between the circumference of the hemisphere and having a circular expanded section in the middle. Numerous arrangements are available for securing this device as exemplified by U.S. Pat. No. 6,854,742. Alternatively, the Precimed reamer has a crossbar shape in which two circular cross section bars intersect at the center and extend to the walls of the hemisphere. An example of a driver for this type is found in U.S. Pat. No. 5,658,290 in which a bayonet interconnection is provided between the reamer and the driver. 
         [0006]    Typically, surgeons use specialized drivers for each of the reamers. The drivers connect to a source of power and have appropriate handles for guiding the operation of the reamer by a surgeon. If a surgeon has one of the adaptors, it is difficult to utilize the other type of reamer since it requires a specialized driver for that reamer. It has been proposed in U.S. Pat. No. 7,115,119 to provide a dual adapter that accommodates both the Othy and the Precimed reamers. However, this style of dual reamer requires a bayonet interconnection in which the assemblies are inserted axially and then a rotational movement, in accordance with a bayonet connection, is provided to lock the elements in place. This type of action slows the process of utilizing a new reamer because of the additional movement, But, more than that, the release of the device, after it has been in the surgical environment, is more difficult because it requires holding the reamer to reverse the rotational movement and then axial movement to finally free the reamer. 
         [0007]    What is needed in the art, therefore, is a tool driver for surgical reamers that enables rapid and immediate connection and disconnection of the reamers. 
       SUMMARY OF THE INVENTION 
       [0008]    In one form, the invention is a tool driver for multiple styles of surgical reamers. The driver includes a central shaft rotatable about a longitudinal axis and having a proximal driven end and a distal end. A reamer receiver is carried by the distal end of the shaft and the receiver has axially facing sets of recesses for receiving at least two different styles of surgical reamers. A gripping device is provided for releasably holding the surgical reamer assemblies in place, the releasable holding device permitting axial removal of the different styles of surgical reamers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0010]      FIG. 1  is an exploded perspective view of a tool driver in accordance with the present invention; 
           [0011]      FIG. 2  is a longitudinal section view of the tool driver shown in  FIG. 1 ; 
           [0012]      FIG. 3  is an expanded detailed view of a portion of the tool driver in  FIGS. 1 and 2  taken in the same plane as  FIG. 2 ; 
           [0013]      FIG. 4  is an enlarged detailed view of a portion of the tool driver shown in  FIG. 2  taken on a plane at 90 degrees to the plane of  FIG. 2 ; 
           [0014]      FIG. 5  is a side view of an element of the tool driver shown in  FIGS. 1-4 ; and 
           [0015]      FIG. 6  is a top view of the element shown in  FIG. 5 . 
       
    
    
       [0016]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0017]      FIG. 1  shows an exploded view of a reamer driver  10  in accordance with the present invention. Reamer driver  10  has a central shaft  12  rotatable about a longitudinal axis A at an RPM that is appropriate for removal of material during a surgical procedure. Shaft  12  has a proximal end  14  with an interface having an appropriate to receive a power element to produce the correct torque and RPM to perform the surgical removal of material. 
         [0018]    Central shaft  12  has a distal end  16  for receiving one of a plurality of different styles of surgical reamers. As shown particularly in  FIGS. 3 and 4 , distal end  16  has a plurality of recesses integrally formed with the end of shaft  12 . It should be apparent, however, to those skilled in the art that the recesses may be formed in a separate element that is affixed to the end of shaft  12 . A pair of recesses  18  are semicircular in cross section as shown in  FIG. 3 . Recesses  18  are formed in portions of the distal end  16  offset from the central axis A and permit movement directly in an axial direction as shown in  FIG. 3 .  FIG. 4  shows a pair of recesses  20  including a base  22  and a shoulder  24  connecting to sidewalls  26 . Recesses  20  are positioned at  90  degrees relative to recesses  18 . 
         [0019]    As stated previously there are two major styles of reamers in the surgical field, one of which is a crossbar and the other of which is a crossbridge. The crossbar interface is illustrated by dashed lines  28 , shown in  FIG. 3  and  FIG. 4 . It is to be noted that the base of semicircular recess  18  and recess base  22  are in the same plane so that the interface for the crossbar reamer  28  is positioned in a common plane to stabilize it. The other surgical reamer is an Othy crossbridge reamer having a circular center and two radially extending bars illustrated by dashed line  30 . The crossbridge reamer  30  rests on the shoulder  24 . The crossbridge reamer is also moveable into and out of the recesses  20  in an axial direction as illustrated in  FIG. 4 . 
         [0020]    The different styles of reamers  28  and  30  are retained within the recesses  18  and  24  by grips  32  and  34  shown in  FIGS. 2 and 3  and in detail in  FIGS. 5 and 6 . The grips  32  and  34  are identical so that reference characters used in  FIGS. 5 and 6  are applicable for both grips. Grips  32 - 34  comprise base elements  36  and  37  having central aligned bores  40  to provide a pivotal mounting on central shaft  12 . Bases  36  extend to integral gripping elements  38  having an L-shaped extension  41  so that the grips  32 - 34  form an L-shape with a pivotal mounting at one end of the L. The extension  41  has a gripping surface  42  with a contour that provides a negative angle with respect to the center of bore  40  so as to accommodate varying thicknesses of reamers. Generally speaking the surface  44  has approximately a 4 degree angle with respect to a plane at right angles to a line extending through bore  40 . An intermediate section  46  has a camming surface  48  projecting downward as shown in  FIGS. 5 and 6  to interact with elements of the reamer driver  10  disclosed below. 
         [0021]    The grips  32  and  34  are pivotally connected to shaft  12  at surfaces  50  with a through hole  52  by a pin  54  extending through bore  40  and through hole  52 . Thus, the grips  32  and  34  are mounted so as to grip or release the respective reamers  28  and  30  in an axial direction.  FIG. 2  shows the grips  32  and  34  in the retention position. 
         [0022]    Grips  32  and  34  are biased to the open position permitting removal of the reamers  28  or  30 . As shown in  FIGS. 1 and 2 , this is done by a central plunger  56  received in an axial bore  58  of central shaft  12 . Plunger  56  is retained within the bore  58  by a removable ring  60  and is biases towards the left by a spring  62  retained within bore  58 . Plunger  56  has a shoulder  64  that acts as a camming surface for the corresponding camming surface  48  on grips  32 - 34  so as to displace them in a radially outward direction upon axial movement of plunger  56  towards the distal end of shaft  12 . Thus, in the absence of any restraining element, the grips  32  and  34  are urged to their open position. 
         [0023]    The grips  32 - 34  are urged to the closed position illustrated in  FIG. 2  by a sleeve  66  telescoped over shaft  12 . Sleeve  66  has an inwardly facing shoulder  68  which abuts a corresponding outwardly facing shoulder  70  on shaft  12  to limit the left most position of sleeve  66 . Sleeve  66  has a suitable serrated gripping surface  67  to enable manual manipulation. Sleeve  66  is urged to the leftmost position by a spring  74  retained over shaft  12  and abutting a protective sleeve  76 , also telescoped over shaft  12 . 
         [0024]    Protective sleeve  76  is retained on shaft  12  by a pin  78  received in a cross bore  80  of shaft  12  and yieldably urged to the position shown in  FIG. 2  by a spring  82 . An appropriate cap  84  retains spring  82  within the bore  80 . A retention sleeve  86  is appropriately affixed to the proximal end  14  of shaft  12  so as to limit the rightmost movement of protective sleeve  76 . 
         [0025]    In order to facilitate cleaning of the reamer driver, radial passages  88  are provided from recess  58  to the exterior and a central passage  90  is provided in plunger  56 . In addition, plunger  56  has cross semicircular recesses  92  at 90 degrees to one another to abut the crossbars of reamer style  28  so as to further stabilize it. 
         [0026]    The reamer driver  10  is operated by pulling sleeve  66  to the right as viewed in  FIG. 2  so as to free the grips  32  and  34  and permit the spring  62  to displace the plunger  56  axially so that shoulder  64  urges the camming surface  48  radially outward. The arc of movement is sufficient to permit the surfaces  42  of grips  32 - 34  to provide axial clearance permitting removal or installation of the reamer driver styles  28  and  30  in an axial direction only. While the sleeve  66  is retracted, either reamer driver style  28  or  30  is axially inserted into the appropriate recesses and the plunger  56  is displaced to the right as shown in  FIG. 2 . In the case of reamer style  28 , the semicircular recesses  92  embrace the crossbars so as to stabilize the reamer. In the case of reamer style  30 , the end of plunger  56  abuts the undersurface of the crossbridge reamer  30 . The displacement of the plunger  56  to the right permits the grips  32  and  34  to be acted on by sleeve  66  as urged by spring  74 . This action holds the drivers in place for a surgical procedure. When the surgical procedure is completed, the sleeve  66  is simply displaced axially to the right as shown in  FIG. 2  and the plunger  56  automatically urges either driver style from the driver assembly, thus eliminating multiple movements during a surgical procedure. 
         [0027]    In addition to providing a simplified axial movement for connection and removal, the displacement of pin  78  permits the protective sleeve  76  to be moved to the right against retention sleeve  86 , thus allowing total expansion of the grips  32  and  34  for cleaning. The radial passages provided in plunger  66  and in the sidewall of recess  58  also facilitate the cleaning of the assembly. 
         [0028]    The angle provided on surface  44  of grip  32 - 34  enables the retention of a range of thicknesses for the reamers  28  and  30 . 
         [0029]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.