Patent Publication Number: US-10786273-B2

Title: Rotation knob assemblies for handle assemblies

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/697,418 filed Jul. 13, 2018, the entire disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to handle assemblies for endoscopic surgical instruments. More particularly, the present disclosure relates to rotation knob assemblies for the handle assemblies of the endoscopic surgical instruments. 
     Description of Related Art 
     Surgical clip appliers and other surgical instruments are known in the art and are used for a number of distinct and useful surgical procedures. In the case of a laparoscopic surgical procedure, access to the interior of an abdomen is achieved through narrow tubes or cannulas inserted through a small entrance incision in the skin. Minimally invasive procedures performed elsewhere in the body are often generally referred to as endoscopic procedures. 
     To facilitate orienting an end effector of the surgical instruments relative to the target tissue without rotating an entire handle assembly, an endoscopic portion of surgical instruments is rotatably coupled to the handle assembly by a rotation knob assembly. The rotation knob assembly provides a means for rotating the end effector about a longitudinal axis of the endoscopic portion. 
     SUMMARY 
     A rotation knob assembly for a surgical handle assembly is provided. The rotation knob assembly includes an outer knob, an inner collar disposed within the outer knob, and a plurality of screws received through the outer knob and engaging the inner collar. The outer knob includes a body defining a lumen extending longitudinally therethrough. The lumen includes a proximal lumen portion and a distal lumen portion. The inner collar is disposed within the proximal lumen portion of the outer knob and is rotatably engaged with the outer knob. The inner collar defines an annular groove. The plurality of screws protrude radially inwardly through the body of the outer knob into the proximal lumen portion of the outer knob. Each screw of the plurality of screws includes a ball portion received within the annular groove of the inner collar such that, upon rotation of the outer knob relative to the inner collar, the ball portions slide along the annular groove. 
     In embodiments, the plurality of screws is formed of low friction material. The inner collar may include an annular protrusion for securing the inner collar to a handle assembly. The annular protrusion may be configured to longitudinally fix the inner collar to a handle assembly. The annular protrusion may be configured to rotationally fix the inner collar to a handle assembly. 
     In embodiments, the body of the outer knob defines the distal lumen portion including longitudinal grooves. 
     Another rotation knob assembly for a surgical handle assembly includes an outer knob, an inner collar disposed within the outer knob, and a bearing assembly disposed between the outer knob and the inner collar. The outer knob includes a body defining a lumen extending longitudinally therethrough. The lumen includes a proximal lumen portion and a distal lumen portion. The inner collar is disposed within the proximal lumen portion of the outer knob and is rotatably engaged with the outer knob. The inner collar defines an annular groove. The bearing assembly is disposed within the outer knob and is received about the inner collar. The bearing assembly includes an annular ring received within the annular groove of the inner collar and a plurality of outwardly extending projections extending into the outer knob. The plurality of projections rotationally fixes the bearing assembly to the outer knob. 
     In embodiments, the inner collar includes an annular protrusion for securing the inner collar to a handle assembly. The annular protrusion may be configured to longitudinally fix the inner collar to a handle assembly. The annular protrusion may be configured to rotationally fix the inner collar to a handle assembly. In embodiments, the body of the outer knob defines longitudinal grooves about the distal lumen portion. 
     Still another rotation knob assembly for a surgical handle assembly includes an outer knob, an inner collar disposed with the outer knob, and a snap ring disposed within the outer knob and received about the inner collar. The outer knob includes a body defining a lumen extending longitudinally therethrough and an annular groove. The lumen includes a proximal lumen portion and a distal lumen portion. The inner collar is disposed within the proximal lumen portion of the outer knob and rotatably engages the outer knob. The inner collar defines an annular groove. The snap ring includes a plurality of alternating annular segments and flange segments. The annular segments are received within the annular groove in the inner collar and the flange segments are received within the annular groove of the outer knob. The outer collar is rotatable relative to the inner collar. 
     In embodiments, the snap ring is rotationally fixed relative to the inner collar. The snap ring may be rotationally fixed relative to the outer knob. The inner collar may include an annular protrusion for securing the inner collar to a handle assembly. The annular protrusion may be configured to longitudinally fix the inner collar to a handle assembly. The annular protrusion may be configured to rotationally fix the inner collar to a handle assembly. The body may define longitudinal grooves about the distal lumen portion. 
     Still yet another rotation knob assembly for a surgical instrument is provided. The rotation knob assembly an outer knob, an inner collar disposed within the outer knob, and a bearing assembly disposed between the outer knob and the inner collar. The outer knob includes a body defining a lumen extending longitudinally therethrough. The lumen includes a proximal lumen portion and a distal lumen portion. The inner collar is disposed within the proximal lumen portion of the outer knob and rotatably engages the outer knob. The inner collar includes a bearing surface. The bearing assembly is disposed within the proximal lumen portion of the outer knob between the body of the outer knob and the inner collar. The bearing assembly includes an annular housing and a plurality of paired ball bearings. The annular housing includes an annular protrusion for securing the annular housing to a handle assembly. The inner collar and the outer knob are rotationally fixed relative to each other. 
     In embodiments, the annular housing defines a pair of annular grooves and the bearing surface of the inner collar defines a plurality of paired semi-spherical recesses. The pair of annular grooves and the plurality of paired semi-spherical recesses may define a plurality of paired cavities for receiving the plurality of paired ball bearings. The plurality of paired ball bearings may be rotatably supported within the plurality of paired cavities. The annular housing may include first and second housing halves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects and features of the present disclosure are described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical structural elements and: 
         FIG. 1  is a front, perspective view of a surgical clip applier provided in accordance with the present disclosure including a handle assembly having an elongated assembly engaged therewith; 
         FIG. 2  is front, perspective view of the surgical clip applier shown in  FIG. 1  with the elongated assembly removed from the handle assembly; 
         FIG. 3  is an enlarged, side view of the handle assembly of the surgical clip applier shown in  FIG. 1  with a housing half removed; 
         FIG. 4  is a side, perspective view of a rotation knob assembly of the surgical clip applier shown in  FIG. 1 ; 
         FIG. 5  is a side, perspective view of the rotation knob assembly shown in  FIG. 4  with parts separated; 
         FIG. 6  is a side, perspective view of a screw of the rotation knob assembly shown in  FIG. 4 ; 
         FIG. 7  is a side, cross-sectional view taken along line  7 - 7  shown in  FIG. 4 ; 
         FIG. 8  is a side, perspective view of a rotation knob assembly according to another embodiment of the present disclosure; 
         FIG. 9  is an end, perspective view of an outer knob of the rotation knob assembly shown in  FIG. 8 ; 
         FIG. 10  is a side, perspective view of the rotation knob assembly shown in  FIG. 8  with parts separated; 
         FIG. 11  is a side, cross-sectional view taken along line  11 - 11  shown in  FIG. 8 ; 
         FIG. 12  is an end, cross-sectional view taken along line  12 - 12  shown in  FIG. 11 ; 
         FIG. 13  is a side, perspective view of a rotation knob assembly according to another embodiment of the present disclosure; 
         FIG. 14  is a side, perspective view of the rotation knob assembly shown in  FIG. 13  with parts separated; 
         FIG. 15  is a side, cross-sectional view taken along line  15 - 15  shown in  FIG. 13 ; 
         FIG. 16  is an end, cross-sectional view taken along line  16 - 16  shown in  FIG. 15 ; 
         FIG. 17  is a side, perspective view of a rotation knob assembly according to another embodiment of the present disclosure with parts separated; 
         FIG. 18  is a side, cross-sectional view of the rotation knob assembly shown in  FIG. 17 ; and 
         FIG. 19  is a cross-sectional end view taken along line  19 - 19  shown in  FIG. 18 . 
     
    
    
     DETAILED DESCRIPTION 
     As detailed herein and shown in the drawing figures, as is traditional when referring to relative positioning on a surgical instrument, the term “proximal” refers to the end of the apparatus or component thereof which is closer to the user and the term “distal” refers to the end of the apparatus or component thereof which is further away from the user. Further, to the extent consistent, any or all of the aspects and features detailed herein may be used in conjunction with any or all of the other aspects and features detailed herein. 
     The present disclosure provides rotation knob assemblies for surgical instruments. Although detailed herein as incorporated into a surgical clip applier, the rotation knob assemblies of the present disclosure may alternatively be incorporated into any suitable surgical instrument. 
     Turning to  FIGS. 1 and 2 , a surgical clip applier according to aspects of the present disclosure is shown generally as clip applier  10 . The clip applier  10  generally includes a handle assembly  100  and an adapter assembly  20  selectively connectable to the handle assembly  100 . The handle assembly  100  is configured to operate the adapter assembly  20  upon connection thereto, and may be configured as a sterilizable, reusable component such that handle assembly  100  may be repeatedly used with different and/or additional elongated assemblies (not shown) during the course of one or more surgical procedures. The adapter assembly  20  may be configured as single-use disposable component, limited-use disposable components, or reusable components, depending upon a particular purpose and/or the configuration of the particular elongated assembly. In either configuration, the need for multiple handle assemblies  100  is obviated and, instead, the surgeon need only select an appropriate elongated assembly, and connect that elongated assembly to the handle assembly  100  in preparation for use. 
     The handle assembly  100  includes a housing  110 , an actuation mechanism  120  ( FIG. 3 ) operably disposed within the housing  110 , a latch assembly  130  ( FIG. 3 ) operably disposed within housing  110 , and a rotation knob assembly  140  operably coupled to a distal portion of housing  110 . The housing  110  supports and/or encloses the operating components of handle assembly  100 , the actuation mechanism  120  is configured to enable selective firing of one or more surgical clips (not shown) from the end effector (not shown) of the attached adapter assembly  20 . The latch mechanism  130  is configured to facilitate releasable locking engagement of the adapter assembly  20  with handle assembly  100 . The rotation knob assembly  140  enables the selective rotation of the attached adapter assembly  20  relative to the housing  110 . 
     The handle assembly  100  will only be described to the extent necessary to fully disclose the aspects of the present disclosure. For a detailed description of the operation and function of an exemplary handle assembly, including an exemplary actuation mechanism and an exemplary latch assembly, please refer to commonly owned U.S. Prov. Pat. App. Ser. No. 62/581,144 (“the &#39;144 application”), filed Nov. 3, 2017, the content of which is incorporated herein by reference in its entirety. Other exemplary embodiments of handle assemblies may be found in commonly owned Intl. Pat. App. Nos. PCT/CN2016/096666 and PCT/CN2016/071178, filed on Aug. 26, 2016 and Jan. 18, 2016, respectively, the content of each is hereby incorporated herein by reference in its entirety. 
     Referring to  FIGS. 1 and 2 , the adapter assembly  20  of the clip applier  10  generally includes a proximal hub  22 , an elongated shaft  24  extending distally from the proximal hub  22 , an end effector assembly (not shown) disposed towards a distal end portion of the elongated shaft  24 , and an inner drive assembly (not shown) operably coupled between the handle assembly  100  and the end effector assembly when adapter assembly  20  is engaged with the handle assembly  100 , to enable the sequential firing of at least one surgical clip (not shown) about tissue. The end effector may be integrally formed with the adapter assembly  20 , or may be a separate component releasably secured to the adapter assembly  20 . The end effector assembly may be configured to fire surgical clips similar to those shown and described in U.S. Pat. Nos. 7,819,886 or 7,905,890, the content of each of which is hereby incorporated herein by reference in its entirety. 
     With additional reference to  FIG. 3 , the housing  110  of the handle assembly  100  may be formed from first and second housing halves  110   a ,  110   b  that cooperate to define a body portion  112  and a fixed handle portion  114  depending from the body portion  112 . The body portion  112  of the housing  110  includes a distal nose  116  defining a distal opening  117  ( FIG. 3 ) therethrough. A proximal end portion of the proximal hub  22  of the adapter assembly  20  is configured to extend at least partially through the distal opening  117  of the distal nose  116  of the housing  110  when the adapter assembly  20  is engaged with the handle assembly  100 . 
     The distal nose  116  of the body portion  112  of the housing  110  further includes an annular recess  119  defined on an interior surface thereof surrounding the distal opening  117 . The annular recess  119  is configured to receive an annular protrusion  154  of an inner collar  150  of the rotation knob assembly  140  to secure the rotation knob assembly  140  with the distal nose  116  of the body portion  112  of the housing  110 . To this end, the annular recess  119  and/or the annular protrusion  154  of the inner collar  150  may include one or more keying features to facilitate rotationally lock the inner collar  150  to the distal nose  116  of the housing  110 . In embodiments, and as shown, the inner collar  150  defines an opening  153  ( FIG. 5 ) that receives a tab (not shown) extending from the distal nose  116  of the body portion  112  of the housing  110  for longitudinally and rotationally locking the inner collar  150  relative to the housing  110 . 
     With reference to  FIGS. 3-7 , an outer knob  142  of the rotation knob assembly  140  is rotatably coupled to the distal nose  116  of the body portion  112  of the housing  110  and is configured to receive the proximal hub  22  ( FIG. 1 ) of the adapter assembly  20 . As described below, the outer knob  142  of the rotation knob assembly  140  is coupled to the adapter assembly  20  in fixed rotational engagement therewith to enable selective rotation of the adapter assembly  20  relative to the housing  110  upon rotation of an outer knob  142  relative to housing  110 . The rotation knob assembly  140  includes the outer knob  142 , the inner collar  150 , and a pair of screws  160  rotatably securing the outer knob  142  to the inner collar  150 . 
     The outer knob  142  of the rotation knob assembly  140  may be formed from a polymeric material, e.g., a biocompatible, sterilizable plastic, or other suitable material, and includes a body  144  defining a substantially cone shaped-configuration tapering in diameter from a proximal end portion to a distal end portion thereof, although other suitable configurations are also contemplated. The body  144  defines a plurality of flutes  146  arranged radially about the body  144  to facilitate grasping or gripping of the body  144  by a user at any rotational orientation to enable rotation of the rotation knob assembly  140 . 
     The body  144  of the outer knob  142  of the rotation knob assembly  140  defines a longitudinally-extending lumen  143  therethrough. The longitudinally-extending lumen  143  includes a proximal portion  143   a  and a distal portion  143   b  which may define equal or different diameters, e.g., the proximal portion  143   a  may define a larger diameter as compared to the distal portion  143   b . The proximal portion  143   a  of lumen  143  communicates with the proximal opening of the body  144  of the outer knob  142 . The body  144  of the outer knob  142  defines a pair of threaded transverse apertures  145  ( FIG. 5 , only one shown) that communicate with the proximal portion  143   a  of the lumen  143 . Each of the threaded transverse apertures  145  is configured to receive one of the screws  160  as detailed below. 
     The distal portion  143   b  of the lumen  143  communicates with the distal opening of the body  144  of the outer knob  142  at the distal end thereof and with the proximal portion  143   a  of the lumen  143  at the proximal end thereof. The body  144  includes a plurality of longitudinally-extending grooves  147  arranged annularly on an interior surface thereof and disposed about at least a portion of the distal portion  143   b  of the lumen  143 . The grooves  147  are configured to slidably receive indexing protrusions  22   a  ( FIG. 2 ) of the proximal hub  22  of adapter assembly  20  to rotationally fix the proximal hub  22  relative to the outer knob  142  upon insertion of proximal hub  22  into handle assembly  100 . 
     The inner collar  150  of the rotation knob assembly  140  may be formed from a metal, e.g., stainless steel, or other suitable material, and includes a body  152  defining a longitudinally-extending lumen  151  therethrough. The inner collar  150  further includes an annular protrusion  154  disposed about a proximal end portion thereof and a distal head  156  disposed about a distal end portion thereof. The inner collar  150  defines an annular groove or channel  155  defined within an exterior surface of the inner collar  150 , disposed between the annular protrusion  154  and the distal head  156 . The annular protrusion  154 , as noted above, is configured for receipt within the annular recess  119  of the distal nose  116  of the housing  110  (see  FIG. 3 ) to engage the inner collar  150  with the distal nose  116  of the body portion  112  of the housing  110 , e.g., upon engagement of the first and second housing halves  110   a ,  110   b  ( FIG. 1 ) forming the housing  110  with one another. As noted above, the inner collar  150  defines the opening  154  for receiving a tab (not shown) extending from the distal nose  116  of the housing  110  for rotationally locking the inner collar  150  relative to the housing  110 . 
     The inner collar  150  is configured to be received within the proximal portion  143   a  of the lumen  143  of the body  144  of the outer knob  142 . The inner collar  150  is configured such that the annular groove  155  aligns with the pair of threaded transverse apertures  145  in the body  144  of the outer knob  142  when the outer knob  142  is received about the inner collar  150 . 
     With particular reference to  FIG. 6 , each screw  160  of the rotation knob assembly  140  includes a head portion  162 , a threaded post portion  164  extending from the head  162 , and a ball portion  166  disposed on an end of the threaded post portion  164 . In embodiments, at least the ball portion  166  of the screws  160  is formed from PLASTITE® (a registered trademark of Research Engineering &amp; Manufacturing, Inc., Rhode Island) or other low friction or lubricious material to facilitate rotation of the outer knob  142  of the rotation knob assembly  140  relative to the inner collar  150 . In alternative embodiments, the screws are biased radially inward to facilitate assembly of the rotation knob assembly. 
     Turing to  FIG. 7 , the screws  160  of the rotation knob assembly  140  are received within the transverse apertures  145  defined through the body  144  of the outer knob  142 , and are oriented such that the ball portions  166  of the screws  160  protrude radially inwardly into the proximal portion  143   a  of the lumen  143  of the body  144  of the outer knob  142 . As noted above, the annular groove  155  of the inner collar  150  aligns with the transverse apertures  145  in the outer knob  142  when the outer knob  142  is received about the inner collar  150 . In this manner, the ball portions  166  of the screws  166  extending from the transvers apertures  145  are received within the annular groove  155  of the inner collar  150  to rotatably retain the outer knob  142  relative to the inner collar  150 . The ball portions  166  of the screws  160  are configured to provide minimal friction with inner collar  150  to allow ease of rotation of the outer knob  142  relative to the inner collar  150 . The outer knob  142  may be rotated continuously through an infinite number of positions. 
     With reference now to  FIGS. 8-12 , a rotation knob assembly according to another embodiment of the present disclosure is shown generally as rotation knob assembly  240 . The rotation knob assembly  240  is substantially similar to rotation knob assembly  140  described herein above, and will only be described in detail as relates to the differences therebetween. 
     The rotation knob assembly  240  includes an outer knob  242 , an inner collar  250 , and a bearing assembly  260  rotatable securing the outer knob  242  to the inner collar  250 . The outer knob  242  includes a body  244  defining a longitudinally-extending lumen  243  therethrough. The longitudinally-extending lumen  243  includes a proximal portion  243   a  and a distal portion  243   b . The body  244  of the outer knob  242  defines a plurality of longitudinally extending openings  245  that communicate with the proximal portion  243   a  of the lumen  243 . Each of the longitudinal openings  245  is configured to receive a locking member  270  ( FIG. 10 ) as detailed below. The body  244  of the outer knob  242  also defines a plurality of notches  247  extending radially outward from the proximal portion  243   a  of the longitudinally extending lumen  243 . The notches  247  accommodate protrusions  266  of an annular body  264  of the bearing member  262  of the bearing assembly  260 . 
     The inner collar  250  of the rotation knob assembly  240  includes a body  252 . The inner collar  250  includes an annular protrusion  254  disposed about a proximal end portion thereof, an annular flange  256  disposed about a mid-portion thereof, and a bearing surface  258  disposed between the annular protrusion  254  and the annular flange  256 . As described below, the bearing surface  258  of the inner collar  250  is configured to rotatably support the bearing member  262  of the bearing assembly  260 . 
     The bearing assembly  260  of the rotation knob assembly  240  includes the bearing member  262  and the plurality of fastening members  270 . The bearing member  262  includes an annular body  264  and a plurality of protrusions  266  extending radially outward from the annular body  264 . The annular body  264  of the bearing member  266  is configured to be received about the bearing surface  258  of the inner collar  250  and within the proximal portion  243   a  of the lumen  243  in the outer knob  242  of the rotation knob assembly  240 . The protrusions  266  of the bearing member  262  are configured to be received within the notches  247  in the body  244  of the outer knob  242 . Although shown as having three protrusions  266  with a triangular shape, it is envisioned that the bearing member  262  may include any number of protrusions  266  and the protrusions  266  may include any suitable shape. The number and shape of the notches  247  in the body  244  of the outer knob  242  correspond to the number and shape of the protrusions  266 . Each of the protrusions  266  of the bearing member  262  defines an opening  267  for engaging a proximal end of one of the fastener members  270 . 
     The fastener members  270  of the rotation knob assembly  240  may include a threaded outer surface (not shown) for threading engagement with the protrusions  266  of the bearing member  262 . Alternatively, the fastener members  270  may be received within the openings  267  in the protrusions  266  of the bearing member  262  with a friction fit. The fastener members  270  may be further secured to the protrusions  266  of the bearing member  262  with adhesive. In embodiments, either or both of inner collar  250  and the bearing member  262  are formed from PLASTITE® or other low friction or lubricious material to facilitate rotation of the bearing member  262  relative to the inner collar  250 . Alternatively, either or both of the bearing member  262  and inner collar  250  may include a friction reducing coating to facilitate rotation of the outer knob  242  about the inner collar  250 . 
     With reference now to  FIG. 13-16 , another embodiment of a rotation knob assembly according to the present disclosure is shown generally as rotation knob assembly  340 . The rotation knob assembly  340  is substantially similar to rotation knob assemblies  140 ,  240  described herein above, and will only be described in detail as relates to the differences therebetween. 
     The rotation knob assembly  340  includes an outer knob  342 , an inner collar  350 , and a snap ring  360 . The outer knob  342  includes a body  344  defining a longitudinally-extending lumen  343  therethrough. The longitudinally-extending lumen  343  includes a proximal portion  343   a  and a distal portion  343   b . The body  344  of the outer knob  342  defines an annular groove  345  disposed within the proximal portion  343   a  of the longitudinally extending lumen  343 . The annular groove  345  is configured to receive a plurality of flange portions  364  of the snap ring  360 . Alternatively, the body  344  of the outer knob  342  includes a plurality of cutouts (not shown) for accommodating the plurality of flange portions  364  of the snap ring. 
     The inner collar  350  of the rotation knob assembly  340  includes a body  352 . The inner collar  350  includes an annular protrusion  354  disposed about a proximal end portion thereof and distal head sections  356  disposed about a mid-portion thereof. The inner collar  350  defines an annular groove  355  disposed between the annular protrusion  354  and the annular flange sections  356 . As described below, the annular groove  355  is configured to accept the snap ring  360  of the rotation knob assembly  340 . 
     The snap ring  360  of the rotation knob assembly  340  includes alternating annular segments  362  and flange segments  364 . Together the annular segments  362  define a cylindrical opening  363  configured to be received within the annular groove  355  in the inner collar  350 . The flange segments  364  of the snap ring  360  extend outwardly between the annular segments  362  and are configured to be received within the annular groove  345  in the proximal portion  343   a  of the longitudinally extending lumen  343  of the body  352  of the outer knob  350 . 
     The snap ring  360  may be secured within the annular groove  345  of the outer knob  342  in a rotationally fixed condition such that the snap ring  360  rotates along with the outer knob  342  when the outer knob  342  is rotated relative to the inner collar  350 . In this manner, the snap ring  360  is rotatably received within the annular groove  355  of the inner collar  350  and the snap ring  360  and outer knob  342  rotate relative to the inner collar  350 . Alternatively, the snap ring  360  may be secured within the annular groove  345  of the inner collar  350  in a rotationally fixed condition such that the snap ring  360  does not rotate with the outer knob  342  as the outer knob  342  is rotated relative to the inner collar  350 . In this manner, the snap ring  360  is rotatably received within the annular groove  345  of the outer knob  342  and the outer knob  342  rotates relative to the snap ring  360 . In embodiments the snap ring  360  may be rotationally received within the annular groove  345  of the outer knob  342  and the annular groove  355  of the inner collar  350  such that the snap ring  360  may rotate relative to either or both of the outer knob  342  and inner collar  350  when the outer knob  342  is rotated relative to the inner collar  350 . 
     With reference now to  FIG. 17-19 , still another embodiment of a rotation knob assembly according to the present disclosure is shown generally as rotation knob assembly  440 . The rotation knob assembly  440  is substantially similar to rotation knob assemblies  140 ,  240 ,  340  described herein above, and will only be described in detail as relates to the differences therebetween. 
     The rotation knob assembly  440  includes an outer knob  442 , an inner collar  450 , and a bearing assembly  460 . The outer knob  442  includes a body  444  defining a longitudinally-extending lumen  443  therethrough. The longitudinally-extending lumen  443  includes a proximal portion  443   a  and a distal portion  443   b . The body  444  includes a plurality of longitudinally-extending grooves  447  arranged annularly on an interior surface thereof and disposed about at least a portion of the proximal portion  443   a  of the lumen  443 . The grooves  447  frictionally engage a grooved outer surface  456  of the inner collar  450 . 
     The inner collar  450  of the rotation knob assembly  440  includes a body  452 . The inner collar  450  includes a bearing surface  454  disposed about a proximal end portion thereof and the grooved outer surface  456  about a distal portion thereof. A plurality of paired semi-spherical recesses  453  are defined in the bearing surface  454  of the inner collar  450 . As described below, the semi-spherical recesses  453  support ball bearings  466  of the bearing assembly  460 . The grooved outer surface  456  of the inner collar  450  frictionally engages and rotationally fixes the inner collar  450  to the outer knob  442 . 
     The bearing assembly  460  of the rotation knob assembly  440  includes an annular housing  462  having first and second housing halves  462   a ,  462   b . The annular housing  462  includes proximal and distal annular flanges  464   a ,  464   b . The proximal annular flange  464   a  of the annular housing  462  is configured to be received within the annular recess  119  ( FIG. 3 ) in the distal nose  116  ( FIG. 3 ) of the body portion  114  ( FIG. 3 ) of the housing  110 . The distal annular flange  464   b  of the annular housing  462  is configured to be received within the proximal portion  443   a  of the lumen  443  of the body  444  of the outer knob  442  to support the inner collar  450  within the outer knob  442 . 
     The annular housing  462  of the bearing assembly  460  defines a pair of annular grooves  463  that align with the plurality of paired semi-spherical recesses  453  in the inner collar  450  when the inner collar  450  is received within the outer knob  442 . The annular grooves  463  cooperate with the semi-spherical recesses  453  to support the ball bearings  466 . Receipt of the ball bearings  466  within the semi-spherical recesses  453  and the annular grooves  463  longitudinally fixes the outer knob  442  and the inner collar  450  relative to the housing  112  of the handle assembly  100  and facilitates rotation of the outer knob  442  relative to the housing  110 . 
     It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications and variances. The embodiments described with reference to the attached drawing figures are presented only to demonstrate certain examples of the disclosure. Other elements, steps, methods and techniques that are insubstantially different from those described above and/or in the appended claims are also intended to be within the scope of the disclosure.