Patent Publication Number: US-2021186527-A1

Title: Adapter device for surgical instruments

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     The present application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/951,566, filed Dec. 20, 2019, the contents of which are hereby incorporated by reference in their entirety, and claims priority from European Patent Application EP 19 219 144.3, filed Dec. 20, 2019, the contents of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Field 
     The application relates to an adapter device for surgical instruments and to a system including such an adapter device and a surgical instrument. The adapter device may be employed in particular in connection with surgical instruments that have an elongate shaft. 
     Description of Related Art 
     Adapter devices that carry instrument parts used in computer guided surgery are known in the prior art. For example, US 2005/0154296 A1 describes an instrument for use in computer guided surgery that includes a shaft and a reference element adapter, wherein the reference element adapter is directly couplable to the shaft and rotatable about the shaft. A selectively operable mechanical retainer provides retention of the reference element adapter to an instrument shaft adapting interface of the instrument shaft. 
     U.S. Pat. No. 6,021,343 describes a trackable medical instrument for use in a computer assisted image guided medical and surgical navigation system, which includes a guide member having an emitter array for being tracked by the system and a drive shaft contained within the guide member. The drive shaft is rotatable within the guide member and fixable axially inside the guide member. A proximal end of the drive shaft has a first connector for interchangeably receiving at least one drive source, and a distal end has a second connector for interchangeably receiving at least one instrument tip. 
     SUMMARY 
     The known adapters and instruments usually are specifically adapted to each other. Thus, a variety of systems are provided by the prior art, wherein parts of one system may not normally be combined with parts of another system. 
     It is therefore an object of the invention to provide an improved and/or alternative adapter device for a surgical instrument and a system including such an adapter device and the surgical instrument that is easy to handle and provides for a greater variety of applications. 
     The adapter device for surgical instruments includes an adapter member for coupling to an end portion of a surgical instrument and a mounting member, wherein the mounting member is an exchangeable part that is configured to interchangeably connect an additional instrument to the adapter member. In particular, the mounting member is configured to interchangeably connect at least one of at least two additional instruments to the adapter member. 
     With the adapter device it is possible to interchangeably attach a variety of different additional instruments to a surgical instrument. Such other instruments can be instruments for navigation assisted surgery, instruments for robotic assisted surgery, simple holding devices, or many other additional instruments that are used in connection with the surgical instrument. 
     Moreover, the adapter device can be employed in a universal manner, as it is connectable to surgical instruments which have a standard connection portion, such as, for example, a ¼ inch coupling. Because of this, the adapter device can be used with already existing surgical instruments having such a standard connection. Hence, with the adapter device, the costs of providing a system including the adapter device and one or more surgical instruments can be reduced. Such surgical instruments may be drills, thread cutters, awls, shank inserters, shank drivers, and many others. 
     In addition, the adapter device can be used to easily extend or lengthen existing instruments. 
     As the connection between the surgical instrument and the adapter device is designed substantially free of play in the radial and/or axial directions, any surgical instrument with a shaft and/or an overall cylindrical shape can be held in position by the aid of the adapter device. 
     In an embodiment, the mounting member includes an arm or outrigger extending at an angle to the longitudinal axis of the adapter member, and an attachment portion provided at the arm. 
     In a further embodiment, the attachment portion is configured to permit mounting of the additional instrument in various positions and/or orientations. This allows in some applications for gripping of the adapter instead of the handle, to prevent the hand of the surgeon from interfering, for example, with a fluoroscopy area. 
     As a connection between the adapter member and the arm is substantially free of play, the instrument can be more precisely held in position, and/or a positional relationship between the surgical instrument and the additional instrument can be held or maintained very precisely. 
     The adapter device can be used with a surgical instrument in a manner such that the adapter device is mounted between the surgical instrument and a handle, and the surgical instrument can be held in position by gripping, for example, an arm of the mounting member with one hand while the instrument is operated via the handle with the other hand. 
     In one embodiment, at least two mounting members are provided, each being connected to an additional instrument, where the mounting members are exchangeably or interchangeably connectable to the adapter member. 
     In an embodiment, the arm is detachably mounted to the mounting member. Hence, a plurality of different arms for various functions can be attached and exchanged with one another. Also, when the arm is detachable, the arm can more easily be cleaned. In addition, the adapter device may be cannulated. This permits use of the adapter device in procedures using needles, for example. 
     Furthermore, a need for using a large number of specific additional instruments, for example, instruments specifically designed for working under fluoroscopy or for computer based navigation assisted surgery, can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will become apparent from the detailed description of embodiments by means of the accompanying drawings. In the drawings: 
         FIG. 1  shows an embodiment of a system including a surgical instrument and an embodiment of the adapter device connected to a navigation instrument when applied in spinal surgery. 
         FIG. 2  shows a perspective exploded view of a system including the adapter device of  FIG. 1  and various different surgical devices, various different handles, and various additional instruments attachable to the adapter device. 
         FIG. 3  shows another perspective view of the system of  FIG. 1 . 
         FIG. 4  shows a perspective exploded view of the system of  FIGS. 1 and 3 . 
         FIG. 5  shows an enlarged perspective view of the embodiment of the adapter device shown in  FIGS. 1 to 4 . 
         FIG. 6  shows a cross-sectional view of the adapter device of  FIG. 5 , the cross-section being taken in a plane including a longitudinal axis of an adapter member and a longitudinal axis of an arm of the adapter device. 
         FIG. 7  shows a perspective view from above of the adapter member of the adapter device of  FIGS. 5 and 6 . 
         FIG. 8  shows a perspective view from the bottom of the adapter member of  FIG. 7 . 
         FIG. 9  shows a side-view of the adapter member of  FIGS. 7 and 8 . 
         FIG. 10  shows a cross-sectional view of the adapter member of  FIGS. 7 to 9 , the cross-section being taken along line A-A in  FIG. 9 . 
         FIG. 11  shows a perspective view from a top of a mounting member of the adapter device of  FIGS. 5 and 6 . 
         FIG. 12  shows a perspective view from a bottom of the mounting member of  FIG. 11 . 
         FIG. 13  shows a top view of the mounting member of  FIGS. 11 and 12 . 
         FIG. 14  shows a cross-sectional view of the mounting member of  FIGS. 11 to 13 , the cross-section being taken along line B-B in  FIG. 13 . 
         FIG. 15  shows a perspective view of an axial play adjustment member of the adapter device of  FIGS. 5 and 6 . 
         FIG. 16  shows a perspective view of a portion of the arm of the adapter device of  FIGS. 5 and 6 , with a navigation star attached to the arm. 
         FIG. 17  shows a perspective view of the arm and the navigation star of  FIG. 16 , attached in another position. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an embodiment of a system including a surgical instrument  10  and an adapter device  20  coupled thereto. The surgical instrument  10  is preferably an elongate instrument having a shaft  11  defining a longitudinal axis L, and is configured to perform a function along the longitudinal axis, such as drilling, thread cutting, screw-driving, pushing, or one or more other functions. The specific surgical instrument shown is, for example, a thread cutter for cutting a thread in a prepared hole in a vertebra  500 . The adapter device  20  according to an embodiment is at one end fixedly connectable to the surgical instrument  10 . At the other end, the adapter device may be fixedly connectable to a handle  60 . The handle portion  60  optionally may also be part of the system. Moreover, an additional instrument  50  may be mounted to the adapter device  20  and optionally may also be part of the system. The additional instrument  50  is, for example, a navigation instrument, such as a navigation star. 
     As shown in greater detail in  FIG. 2 , the surgical instrument  10  may be one of a plurality of elongate instruments with shaft. Such different shafts may be, for example, a thread cutter  11 , a head placer  11 ′, a screw-driver  11 ″, an awl, or any other shaft-based instrument. Some additional instruments  50  may be, for example, a navigation star  51  that carries transmitters or receivers for electromagnetic radiation including light, pliers  51 ′, a simple holder  51 ″, a radiolucent holder, a navigation clamp, pliers, a counterholder, and/or many other instruments. Hence, in the following, the surgical instrument  10  is also called a main instrument and the additional instrument  50  is also called a secondary instrument. The handle  60  may be one of different handle portions, such as a cylindrical handle  61 , a T-handle  61 ′, a L-handle, or any other type of handle. The handle  60  may also include a further instrument or tool such as, for example, an electric drive device. One or more main instruments and/or one or more handles and/or one or more secondary instruments together with the adapter device  20  forms a modular system. In the modular system, the main instruments  10  and the secondary instruments  50 , as well as the handles  60 , are each interchangeable. 
     Referring now additionally to  FIGS. 3 and 4 , the surgical instrument  10  includes the shaft  11 , a tip portion  12  at one end of the shaft  11 , and a connection portion  13  at the opposite end of the shaft  11 . The tip portion  12  is configured to perform the function of the instrument. The shaft  11  may have various shapes according to the specific instrument. The connection portion  13  in the embodiment may be designed as a male connection portion with a polygonal outer contour, such as a square-end. In a specific embodiment, the connection portion  13  may be a ¼ inch connection portion as used in many standard couplings. The shaft  11  may further include, adjacent to the connection portion  13 , a cylindrical portion  15  with a small circumferential groove  14 . 
     As shown in greater detail in  FIGS. 5 to 14 , the adapter device  20  includes an adapter member  30  and a mounting member  40  rotatably supported on the adapter member  30 . The mounting member  40  may be connected to the secondary instrument  50 . 
     The adapter member  30  is a substantially elongate part with a first end  30   a  and an opposite second end  30   b , and a longitudinal axis L extending through the first end  30   a  and the second end  30   b . When the adapter member  30  is mounted to the surgical instrument  10 , the longitudinal axes L of the adapter member  30  and of the surgical instrument  10  are coincident or coaxial. A channel  31  which is coaxial with the longitudinal axis L may extend through the adapter member  30  from the first end to the second end. Hence, the adapter member  30  may be cannulated. In a region at the first end  30   a , a first connection structure  32  is formed that is configured to cooperate with the mating connection portion at the surgical instrument  10 . In greater detail, the first connection structure  32  includes a female socket connection portion  32   a  configured to cooperate with the male connection portion  13  of the surgical instrument  10 . For example, the female socket connection portion  32   a  may be shaped as a polygonal recess, such as a square-recess, for example, as the female part of a ¼ inch connection. The first connection structure  32  may also have a guiding portion  32   b  that extends between the end surface of the first end  30   a  and the female connection portion  32   a . The size of the female socket portion  32   a  is such that the male connection portion  13  of the instrument can be received therein, substantially free of play. The guiding portion  32   b  is configured to accommodate at least a part of the cylindrical portion  15  of the shaft  11  which includes the groove  14 . A cross-section of the guiding portion  32   b  may also be polygonal, for example, square-shaped with a slightly greater width and longitudinal grooves in the corners. 
     In the region of the second end, a second connection structure  33  is provided that is configured to cooperate with a mating connection structure  62  at the handle  60 . In the embodiment, the second connection structure  33  is shaped identically to the connection structure of the instrument, including a male connection portion  33   a , such as a polygonal structure, and more particularly a square-end such as a ¼ inch male connection portion. The male connection portion  33   a  is followed by a cylindrical portion  33   c  in which a circumferential groove  33   b  is formed. The mating connection structure  62  at the handle is identical to the first connection structure  32  of the adapter member. 
     The first connection structure  32  is provided in a first portion  34  of the adapter member adjacent to the first end  30   a . The first portion  34  of the adapter member  30  may have a substantially cylindrical outer shape that may slightly taper and narrow towards the first end  30   a . The first connection structure  32  is arranged in a coaxial manner therein and extends to a distance away from the first end  30   a  that is sufficient to receive the connection structure of the instrument  10  to a sufficient length. 
     Two opposite transverse threaded holes  35  may be formed at a distance from the first end  30   a  in the first portion  34 , and may extend through the wall of the first portion  34  into the guiding portion  32   b . The axial position of the threaded holes  35  corresponds to the position of the groove  14  of the connection portion of the main instrument  10  when the connection portion  13  is received in the connection structure  32  of the adapter member  30 . The threaded holes are configured to receive threaded pins  70  therein. The threaded pins  70  have a rounded, preferably a spherical, front end  70   a  that is configured to press into the groove  14  of the mating connection structure at the surgical instrument  10 . Thereby, the connection portion of the instrument can be centered within the adapter member and firmly clamped therein. A length of the pins  70  is such that when the pins  70  are screwed into the threaded holes  35 , the rear end of the pins  70  does not protrude out of the adapter member  30 . For achieving this, a circumferential groove  36  may be provided in the outer surface of the first portion  34  at the axial position of the threaded holes  35 . The circumferential groove  36  has an axial width such that the threaded holes  35  are located therein. 
     Adjacent to the first portion  34 , there is a second portion  37  which has a cylindrical outer diameter and forms a support for the mounting member  40 . The second portion  37  has a smaller diameter than the first portion  34 , thereby forming a shoulder  34   a  between the portions. A length of the second portion  37  in the axial direction is such that it corresponds substantially to an axial length of the mounting member  40 . Between the second portion  37  and the cylindrical portion  33   c  of the second connection structure  33 , a third portion  38  with an external thread may be provided that receives an adjustment member  300  which will be explained in greater detail below. The third portion  38  slightly tapers and narrows towards the second portion  37 , so that a step  37   a  is formed between the second portion  37  and the third portion  38 . Moreover, an outer diameter of the third portion  38  may be slightly smaller than an outer diameter of the second portion  37 . 
     Referring now in greater detail to  FIGS. 3 to 6 and 11 to 14 , the mounting member  40  will be described. 
     The mounting member  40  is a separate part from the adapter member  30  and is configured to be detachably connectable to the adapter member. 
     The mounting member  40  includes a sleeve-shaped part  41  with a cylindrical inner surface  42  that has an inner diameter which may only be slightly greater than an outer diameter of the second portion  37  of the adapter member  30 , such that the sleeve-shaped part  41  can be mounted onto the second portion  37  and rotate thereon. In particular, the mounting member can rotate smoothly, i.e., in a stepless manner 360° around the adapter member. A length of the sleeve-shaped part in the axial direction corresponds to a length of the second portion  37 . Hence, when the mounting member  40  is mounted onto the adapter member  30 , and more specifically onto the second portion  37  of the adapter member  30 , one end of the sleeve-shaped part  41  is confined by or abuts against the step  37   a , while the other end is substantially flush with the corresponding end of the second portion  37 , as shown in  FIG. 6 . An outer surface of the sleeve-shaped part  41  may be substantially cylindrical. Longitudinal flat portions or shallow grooves  43   a  may be formed in the outer surface that extend substantially parallel with one another and are arranged substantially equidistantly in the circumferential direction. Furthermore, in the outer surface  43  of the sleeve-shaped part  41 , a mounting portion  44 , such as a mounting recess, is formed that facilitates attachment of an arm  45  to the sleeve-shaped part  41 . The mounting recess may be cylindrical and sized so as to receive a mating first connection portion  46  provided at one end of the arm  45 . The connection between the first attachment portion  46  and the mounting recess  44  may be, for example, a press-fit connection. The arm  45  may be detachably mounted to the sleeve-shaped part  41  or may be permanently mounted thereto. In an alternative embodiment, the arm  45  may be formed monolithically with the sleeve-shaped part  41 . 
     The arm  45  may be substantially cylindrical, and the connection between the mounting portion and the first connection portion  46  may be such that the longitudinal axis of the arm  45  is substantially perpendicular to the sleeve axis of sleeve-shaped part  41  of the mounting member  40 . Hence, when the arm  45  is mounted to the sleeve-shaped part  41 , the arm  45  extends radially from the longitudinal axis L of the adapter member  30 . At the end opposite to the first connection portion  46 , the arm  45  includes a second connection portion  47  that is configured to connect to an attachment member or attachment portion  48  for attaching a secondary instrument  50 . An outer diameter of the arm  45  may taper and narrow towards the second connection portion  47 . The second connection portion  47  may be, for example, a cylindrical end portion with a smaller diameter than the rest of the arm  45 , which fits into a mounting recess  49  at a lower side of the attachment member  48 . 
     The attachment member  48  may have a shape that resembles a prism with a base  48   a  that includes the second mounting recess  49 , a roof  48   b  opposite to the base  48   a , and rounded edges between the base  48   a  and the roof  48   b . Recesses  48   c  may be formed on opposite long sides of the attachment portion  48  between the base  48   a  and the roof  48   b , which may be arranged to sequentially provide vertical and angled surfaces  48   d ,  48   e  between the roof  48   b  and the base  48   a . Hence, the roof  48   b , together with the vertical surface  48   d , the angled surface  48   e , and the base  48   a  provide a clamping surface in the form of an irregular polygon that allows for adjusting of a clamping member mounted thereon to various different positions. The attachment member  48  may be detachable from the arm  45  or may be fixedly connected to the arm  45 . In an alternative embodiment, the attachment member  48  is monolithically formed with the arm  45 . 
     Several mounting members with different additional instruments connected thereto can be provided and used interchangeably. Such mounting members can differ in shape. 
     It shall be noted that the additional instrument can also be fixed to the mounting member and can even be formed monolithically with the mounting member, for example, the additional instrument can be monolithically formed with the arm. 
     Referring in particular to  FIGS. 6 and 15 , the adjustment member  300  is formed as a nut member that is configured to be screwed onto the threaded third portion  38  of the adapter member  30 . An axial length of the adjustment member  300  is such that it extends substantially along the third portion  38  and abuts with its front face  300   a  against the step  37   a . An outer diameter of the adjustment member  300  may be the same or smaller than an outer diameter of the sleeve-shaped portion  41  of the mounting member  40 . The adjustment member  300  is configured to adjust and confine the axial length of the region in which the mounting member can rotate, and is more specifically configured to adjust the axial play of the mounting member relative to the adapter member. In a case in which different mounting members can be connected selectively to the adapter member, the adjustment member is able to adjust the axial play for each of the mounting members, for example, if the respective axial lengths of the different mounting members are different. 
     The adapter device  20  may be preassembled with the mounting member  40  mounted onto the second portion  37  of the adapter member  30 . When the adjustment member  300  is screwed onto the third portion  38  until its front end  300   a  abuts against the step  37   a , the mounting member  40 , or more specifically the sleeve-shaped part  41 , is mounted to the adapter member  30  substantially free of play. Simultaneously, the mounting member  40  is rotatably supported on the adapter member  30 . Hence, a rotation of the adapter member  30  relative to the mounting member  40  maintains an exact position between the arm  45  and the longitudinal axis L of the adapter member  30 . As a result, any secondary instrument  50  mounted to the attachment member  48  can be maintained at a constant axial positional relationship relative to the adapter member  30 . 
     In use, the adapter device  20  with the mounting member  40  including the arm  45  and the attachment member  48  is coupled to the connection portion  13  of a main instrument via the first connection structure  32  of the adapter member. The connection between the main instrument  10  and the adapter member  30  can be centered, and in addition made substantially free of play, by screwing the pins  70  into the threaded holes  35  until they press into the groove  14  of the main instrument  10 . By means of this, an orientation of the secondary instrument  50  relative to the main instrument  10  is precise and does not change during actuating of the main instrument. The second connection portion  33  of the adapter member may be coupled to the mating connection portion  61  of a handle  60 . A secondary instrument may be attached to the attachment member  48 . 
     An example for attaching a secondary instrument in the form of the navigation star  51  is shown in  FIGS. 16 and 17 . As shown in  FIG. 16 , the navigation star  51  may be connected via a clamp  400  onto the attachment portion  48 . The clamp  400  has substantially mating inner surfaces that are configured to cooperate with the surfaces formed by the recess  48   c  of the attachment portion  48 . Flexible arms  401  of the clamp  400  may snap around the roof  48   b  and the vertical side surfaces  48   d  within the recess  48   c . Hence, with the manner of attachment shown in  FIG. 16 , arms  52  of the navigation star  51  can be oriented substantially perpendicular to the axis of the arm  45 . In  FIG. 17 , an inclined attachment of the navigation star  51  is shown. In this case, the clamp  400  engages the attachment portion  48  in a configuration where the arms  52  of the navigation star  51  extend at an angle to the axis of the arm  45 , and therefore also at an angle to the longitudinal axis L of the adapter device  20 . As shown by the arrows in  FIG. 17 , various angled positions of the navigation star  51  can be selected by rotating the clamp  400 . 
     Depending of the field of application, one method of use can include actuating the main instrument  10  through the handle  60  with one hand, for example rotating the handle, wherein the rotational movement of the handle is transmitted via the adapter member  30  to the main instrument. Simultaneously, the secondary instrument  50  can be kept stationary by gripping it with the other hand. Thereby, the orientation of the secondary instrument to the tip portion  12  of the main instrument is substantially maintained. In the case of navigation assisted surgery, for example, when the secondary instrument is a navigation star, the navigation star maintains its position relative to the navigation system. In another method of use, the handle can be omitted. 
     Various other modifications of the embodiments described are also conceivable. The parts are not limited to their detailed shape as depicted in the embodiments. In particular, the shapes of the adapter member and the mounting member are not limited to the specific shapes shown. The adapter member does not need to be cannulated. The arrangement of male/female connection portions is also not limited to the arrangement shown, but can be interchanged. The arm can also be mounted such that it extends at an angle different than 90° relative to the longitudinal axis of the adapter member. The instruments are also not limited to the specific instruments shown in the figures or mentioned as examples. 
     While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is instead intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof.