Patent Publication Number: US-9889415-B2

Title: Vacuum indicator system that avoid release without the proper vacuum level

Description:
PRIORITY APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/371,592, filed Dec. 7, 2016, now U.S. Pat. No. 9,724,661 issued on Aug. 8, 2017, which application is a continuation of U.S. patent application Ser. No. 14/050,983, filed Oct. 10, 2013, now U.S. Pat. No. 9,549,770, filed Jan. 24, 2017. 
    
    
     FIELD 
     The present disclosure relates to a vacuum indicator for a bone cement storage and mixing device that restricts operation when predetermined vacuum level has not been reached. 
     BACKGROUND 
     This section provides background information related to the present disclosure, which is not necessarily prior art. 
     Bone cement can be used for artificial joint fixation and in a variety of surgical procedures to repair damaged bone, such as by filling bone defects. Bone cement is often made from a powder component and a liquid component, which are mixed just prior to or during the surgical procedure. To maintain the sterility of the bone cement and facilitate handling during the surgery, the liquid and powder components are stored and mixed within a single device. To enhance the quality of the bone cement, the liquid and powder components are mixed under a vacuum below a predetermined pressure, typically by surgical staff. To help surgical staff identify when the predetermined pressure has been reached, it would be advantageous for the device to have a visual indicator, as well as a feature to prevent mixture of the liquid and powder components unless the predetermined pressure has been reached. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     The present teachings provide for a device for storing and mixing bone cement components. The device includes a housing, a safety device, and a vacuum indicator. The housing defines a mixing chamber configured to store a first bone cement component therein. The safety device is movable between a first safety position and a second safety position. In the first safety position, the safety device prevents contact between the first bone cement component and a second bone cement component in the mixing chamber. In the second safety position, the safety device permits contact between the first and second bone cement components in the mixing chamber. The vacuum indicator is configured to move from a first vacuum indicator position to a second vacuum indicator position when pressure within the mixing chamber falls below a threshold value. The vacuum indicator restricts movement of the safety device from the first safety position to the second safety position when in the first vacuum indicator position. The vacuum indicator permits movement of the safety device from the first safety position to the second safety position when in the second vacuum indicator position. 
     The present teachings further provide for a device for storing and mixing bone cement components. The device includes a housing defining a mixing chamber configured to store a powder bone cement component therein. A first container support is slidably mounted to an exterior of the housing and movable from a first position to a second position in which the first container support is closer to the housing than in the first position. A first container configured to be mounted to the first container support. The first container is configured to store a liquid bone cement component therein. A first piercing cannula is in communication with the mixing chamber and extends from the housing. The first piercing cannula is proximate to the first container support. A safety insert is removably coupled to the housing and includes a first arm. The first arm is configured to extend between the first container support and the housing to restrict movement of the first container support from the first position to the second position. A vacuum indicator is movable from an extended position in which the vacuum indicator is configured to couple with the safety insert to restrict removal of the safety insert from cooperation with the housing, to a retracted position in which the vacuum indicator is not configured to couple with the safety insert in response to a reduction in pressure of the mixing chamber. 
     The present teachings also provide for a method for storing and mixing bone cement components. The method includes creating a vacuum within a mixing chamber containing a first bone cement component to decrease pressure therein below a threshold level, thereby causing a vacuum indicator to move from a first indicator position to a second indicator position, in the first indicator position the vacuum indicator restricts movement of a safety device from a first safety position to a second safety position, in the first safety position the safety device restricts contact between the first bone cement component and a second bone cement component in the mixing chamber, in the second position the vacuum indicator permits movement of the safety device to the second safety position in which the safety device does not obstruct contact between the first bone cement component and the second bone cement component in the mixing chamber; moving the safety device from the first safety position to the second safety position; mixing the first and second bone cement components together in the mixing chamber to form a bone cement mixture; and dispensing the bone cement mixture from within the mixing chamber. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a perspective view of a device for storing and mixing bone cement components according to the present teachings; 
         FIG. 2  is a exploded view of the device of  FIG. 1 ; 
         FIG. 3  is a perspective view of a container support of the device of  FIG. 1 ; 
         FIG. 4  is a perspective view of a safety insert of the device of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of the device of  FIG. 1  taken along line  5 - 5  of  FIG. 1 ; 
         FIG. 6  illustrates the device of  FIG. 1  coupled to a vacuum source to provide the device with a reduced internal pressure and a safety insert removed from cooperation with the device; 
         FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 6  of a vacuum indicator of the device having been moved from a first position ( FIG. 5 ) to a second position as illustrated; 
         FIG. 8  is a side view of the device of  FIG. 1 , with first and second supports having been moved from a first position ( FIG. 6 ) to a second position as illustrated; 
         FIG. 9  is a cross-sectional view of the device of  FIG. 1  with the first and second container supports illustrated in the second position; and 
         FIG. 10  is a cross-sectional view of the device of  FIG. 1  including an additional vacuum indicator according to the present teachings, the view is taken along a line similar to line  5 - 5  of  FIG. 1 . 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     With initial reference to  FIGS. 1 and 2 , a device for storing and mixing bone cement components, such as liquid and powder components, is generally illustrated at reference numeral  10 . The device  10  can be used with any suitable bone cement. The powder component can be of a variety of different materials in a variety of different forms. For example, the powder can be a poly (methyl methacrylate) or methyl methacrylate-styrene homo- or copolymer. The powder component can also include various other forms or morphologies, such as spherical beads that can be obtained by any conventional suspension polymerization process. The beads can be sieved to comply with particular size specifications. The powder component can also include particles that have been milled or crushed, such as benzoyle peroxide at about 1% to about 5% and radiopacifiers, such as barium sulfate and zircronum dioxide. Furthermore, the powder component can include particles of antibiotics, such as Gentamicyn, Clindamicyn. The liquid component can be a variety of different materials in a variety of different forms. For example, the liquid component can be a methyl methacrylate monomer liquid. In addition, a polymerization accelerator, such as about 0.5% to about 4% dimethyl-para-toluidine, and/or a stabilizer in monomer hydro-quinone at 10-100 ppm can be used. 
     The device  10  includes a housing having a first housing portion  12  and a second housing portion  14 . With reference to  FIG. 2  for example, the first housing portion  12  includes a proximal end  16  and a distal end  18 , which is opposite to the proximal end  16 . At the proximal end  16  is a proximal coupling member  20 . The proximal coupling member  20  can be any suitable coupling member, such as external threads as illustrated. A distal end coupling member  22  is at the distal end  18 . The distal end coupling member  22  can be any suitable coupling member, such as an internally threaded coupling member, as illustrated in  FIG. 5  for example. The first housing portion  12  defines a first mixing chamber portion  24  of the device  10 . 
     The second housing portion  14  includes a proximal end  30  and a distal end  32 , which is opposite to the proximal end  30 . At the proximal end  30  is a proximal coupling member  34 . The proximal coupling member  34  can be any suitable coupling member, such as external threads as illustrated. The second housing portion  14  defines a second mixing chamber portion  36  of the device  10 . The first and second mixing chamber portions  24  and  36  together define a mixing chamber of the device  10 , which can include the powder component of bone cement. An outlet  38  of the second mixing chamber portion  36  is at the distal end  32  of the second housing portion  14 . The second housing portion  14  is coupled to the first housing portion  12  through cooperation between the distal end coupling member  22  of the first housing portion  12  and the proximal coupling member  34  of the second housing portion  14 , as illustrated in  FIG. 5 , for example. 
     The second housing portion  14  includes a first radially extending piercing cannula  40  extending therefrom. The first piercing cannula  40  is in cooperation with the second mixing chamber portion  36 . The first piercing cannula  40  includes a pointed distal tip configured to pierce and penetrate a container including a liquid bone cement component as described herein to permit the liquid bone cement to be extracted therefrom as described herein. The first piercing cannula  40  is surrounded by a first cannula housing  42  extending from the second housing portion  14 . As illustrated in  FIG. 9  for example, a second piercing cannula  44  extends from the second housing portion  14  in a direction opposite to the first piercing cannula  40 . The second piercing cannula  44  is surrounded by a second cannula housing  46 . The second piercing cannula  44  is similar to the first piercing cannula  40 , and the second cannula housing  46  is similar to the first cannula housing  42 . The first piercing cannula  40  and the second piercing cannula  44  are generally on opposite sides of the second housing portion  14  and extend perpendicular to a longitudinal axis of the housing  42 . The second piercing cannula  44  is optional and need not be included. 
     An indicator housing  50  extends radially from the second housing portion  14 . Seated within the indicator housing  50  is a spring  52  and a vacuum indicator, which can be a piston  54  for example, as illustrated. As illustrated in  FIG. 2  and  FIG. 5 , the piston  54  includes a body  56  with an outer surface  58 . The body  56  defines an inner cavity  60 , which the spring  52  is seated within (see  FIG. 5 ). The spring  52  also abuts an outer surface  62  of the second housing portion  14  surrounded by the indicator housing  50 . The indicator housing  50  is in communication with the second mixing chamber portion  36  by way of a passageway  64  defined by the outer surface  62  and extending to the second mixing chamber portion  36 . A washer or any suitable seal  66  surrounds the body  56 . The spring  52  biases the piston  54  in the outward or first configuration of  FIG. 5 . As further described herein, the piston  54  is movable to a second or retracted position in response to pressure of the first and second mixing chamber portions  24  and  36  being reduced below a predetermined threshold, as illustrated in  FIG. 7  for example. In the first configuration of  FIG. 5 , the outer surface  58  of the piston  54  extends out from within the indicator housing  50 . In the second position of  FIG. 7 , the outer surface  58  is recessed within the indicator housing. 
     The second housing portion  14  further includes a first retention member  70  and a second retention member  72 . The first and second retention members  70  and  72  are generally on opposite sides of the second housing portion  14 . The first and second piercing cannulas  40  and  44  are between the first and second retention members  70  and  72 . The first retention member  70  includes a proximal rail  74   a  and a distal rail  76   a . The proximal and distal rails  74   a  and  76   a  extend generally spaced apart and parallel to one another. The second retention member  72  is substantially similar to the first retention member  70 , and thus includes a proximal rail  74   b  and a distal rail  76   b . The proximal rail  74   b  and the distal rail  76   b  extend generally parallel to one another and are spaced apart. 
     An insert for the second housing portion  14  is illustrated at reference numeral  80 . Extending from an outer periphery of the insert  80  is a proximal rim  84 , an intermediate rim  86 , and a distal rim  88 . A plurality of spaced apart locking flanges  90  extend from the insert  80  proximate to the distal rim  88 . As illustrated in  FIG. 5 , the insert  80  is seated within the second housing portion  14  at the distal end  32  thereof such that the distal rim  88  is seated on an inner distal flange  92  defined at an interior of the second housing portion  14  to support the insert  80  therein. The locking flanges  90  couple with corresponding recesses  94  of the second housing portion  14  to secure the insert  80  at the distal end  32  of the second housing portion  14 . 
     The device  10  further includes a cap  102  and a plunger rod  104  extending through a plunger aperture  106  defined by the cap  102 . At a first end of the plunger rod  104  is a handle  108 , and at a second end of the plunger rod  104  opposite to the handle  108  is a mixer  110 . The mixer  110  includes a center portion  112  to which the plunger rod  104  is mounted. Extending from the plunger rod  104  is a plurality of spaced apart mixing fins  114 . The cap  102  defines a first port  116 , which is illustrated as covered by cap  118 , and a second port  120 . Contents of the first and second housing portions  12  and  14  can be extracted through the first port  116  after removal of the cap  118 . The second port  120  can be connected to a vacuum source, such as the vacuum source  210  described herein, with any suitable connector, such as connection tube  212 . At an interior of the cap  102  are threads  122  ( FIG. 9 , for example), which are configured to couple with the proximal coupling member  20  of the first housing portion  12  to secure the cap  102  to the first housing portion  12 . The threads  122  can be any suitable coupling member to connect the cap  102  to the first housing portion  12 . 
     Coupled to the first and second retention members  70  and  72  is a first container support  130   a  and a second container support  130   b . The second container support  130   b  is optional and need not be included. With continued reference to  FIG. 2  and additional reference to  FIG. 3 , the first container support  130   a  includes a first flange  132   a  and a second flange  134   a . The first container support  130   a  defines a first slot  136   a  and a first cannula receptacle  138   a  configured to receive the first piercing cannula  40  therein. A first outer surface  140   a  of the first container support  130   a  is opposite to a first inner surface  142   a . The first slot  136   a  is between the first outer surface  140   a  and the first inner surface  142   a . Extending from the first inner surface  142   a  is a first cannula boss  144   a , which surrounds the first cannula receptacle  138   a . The first cannula receptacle  138   a  extends through the first inner surface  142   a  to provide a passageway to the first slot  136   a . The first cannula boss  144   a  is sized and shaped to receive the first cannula housing  42  therein. The second container support  130   b  is substantially similar to the first container support  130   a . Therefore, the description of the first container support  130   a  also applies to the second container support  130   b . Features in common between the first and second container supports  130   a  and  130   b  are referenced in the figures with respect to second container support  130   b  using the same reference numbers, but with the letter “b” instead of the letter “a.” 
     With respect to the first container support  130   a , the first flange  132   a  is slidably coupled to the first retention member  70  and the second flange  134   a  is slidably coupled to the second retention member  72 . With respect to the second container support  130   b , the first flange  132   b  is slidably coupled to the first retention member  70  and the second flange  134   b  is slidably coupled to the second retention member  72 . 
     A first container  160   a  is seated within the first slot  136   a  of the first container support  130   a . The first container  160   a  defines a receptacle  162   a  configured to store a liquid component of bone cement therein. The first container  160   a  defines a tapered portion  164   a  and retention members  166   a . A tapered portion  164   a  is seated within the first slot  136   a , and secured therein through cooperation between retention members  166   a  and corresponding retention members within the first slot  136   a . The first container  160   a  can be any suitable container for storing the liquid component of bone cement therein, such as a flexible polymeric container. 
     A second container  160   b  is substantially similar to the first container  160   a . The second container  160   b  is optional and need not be included, such as when the second container support  130   b  is not included. Features of the second container  160   b  are identified in the drawings with in the same reference numbers used to identify features in common with the first container  160   a , but include the letter “b” instead of the letter “a.” The second container  160   b  is seated within the second slot  136   b  defined by the second container support  130   b.    
     A safety insert for the device  10  is illustrated at reference number  170 . The safety insert  170  includes a main body  172  and a flange  174  extending therefrom. The flange  174  defines an aperture  176 , which is sized and shaped to receive the piston  54  therein. A tab  178  extends from an end of the main body  172  opposite to the flange  174 . The tab  178  can be configured in any suitable manner to facilitate removal of the safety insert  170  from cooperation with the first and second housing portions  12  and  14  as described herein. Extending from opposite ends of the main body  172  are a first arm  180   a  and a second arm  180   b . The first and second arms  180   a  and  180   b  extend from the same side of the main body  172 . The first arm  180   a  includes a first stop  184   a , which extends from the first arm  180   a  in the same direction that the flange  174  does, and defines an aperture  186   a . The second arm  180   b  includes a similar second stop  184   b  and aperture  186   b.    
     An exemplary operation of the device  10  will now be described. With reference to  FIG. 6 , upon activation of vacuum source  210  with line  212  connected to the second port  120 , air will be drawn from within the first and second mixing chamber portions  24  and  36  to lower the air pressure therein. The pressure within the first and second mixing chamber portions  24  and  36  can be lowered to any suitable level, such as 0.78 Bar for example, which can be a predetermined threshold pressure. Upon reaching this threshold pressure, or any other suitable predetermined pressure, the vacuum indicator or piston  54  moves from the first position of  FIG. 5  to the second position of  FIGS. 6 and 7 . More specifically, reduction of air pressure within the second mixing chamber portion  36  draws air out from within the indicator housing  50  through the passageway  64  and into the second mixing chamber portion  36 . As air is drawn out from the within the indicator housing  50 , the piston  54  is drawn radially inward towards the outer surface  62  in the passageway  64  in a direction generally perpendicular to the longitudinal axis of the housing  50 . 
     In the first position, the piston  54  is arranged such that a portion of the body  56  adjacent to the outer surface  58  extends through the aperture  176  defined by the flange  174  of the safety insert  170 , as illustrated in  FIG. 5 . With the piston  54  arranged in this first position, the safety insert  170  cannot be removed from cooperation with the first and second housing portions  12  and  14 , as illustrated in  FIGS. 1 and 5  for example. The safety insert  170  is further coupled to the second housing portion  14  through cooperation with the proximal rail  74   a  and the distal rail  76   a  of the first retention member  70 , as illustrated in  FIG. 5  for example. More specifically, the proximal rail  74   a  is seated within a proximal recess  188   a  of the main body  172  at the safety insert  170 , and the distal rail  76   a  is seated within distal recess  188   b  of the main body  172 . 
     With the safety insert  170  coupled to the second housing portion  14  as illustrated in  FIG. 1 , for example, the first and second container supports  130   a  and  130   b  are retained in the expanded or deactivated position of  FIG. 1 . More specifically, the first arm  180   a  of the safety insert  170  is positioned between the first container support  130   a  and the second housing portion  14  with the first stop  184   a  arranged such that the first cannula housing  42  is seated within the aperture  186   a . Similarly, the second arm  180   b  is arranged between the second container support  130   b  and the second housing portion  14  such that the second cannula housing  46  is seated within the second aperture  186   b.    
     With reference to  FIGS. 6 and 7 , when the piston  54  moves to the second position of  FIGS. 6 and 7  in response to the predetermined pressure being reached within the first and second mixing chamber portions  24  and  36 , the body  56  will not extend through the aperture  176  of the safety insert  170 , thereby permitting removal of the safety insert  170  from cooperation with the second housing portion  14 . With the safety insert  170  removed, it no longer impedes movement of the first and second container supports  130   a  and  130   b  together along the first and second retention members  70  and  72 . Therefore, the first and second container supports  130   a  and  130   b  can be moved together to a retracted or activated position, as illustrated in  FIG. 8 . The first piercing cannula  40  pierces and penetrates the liquid component receptacle  162   a  as the first container  160   a  is pushed onto the first piercing cannula  40  in response to movement of the first container support  130   a  to the active position of  FIGS. 8 and 9 . Similarly, the second piercing cannula  44  pierces and penetrates the liquid component receptacle  162   b  of the second container  160   b  when the second container support  130   b  is moved to the activated position of  FIGS. 8 and 9 . 
     Due to the decreased pressure within the first and second mixing chambers  24  and  36 , the liquid component of bone cement stored within the liquid component receptacles  162   a  and  162   b  is drawn out from within the liquid component receptacles  162   a  and  162   b  through the first and second piercing cannulas  40  and  44  respectively and into the second mixing chamber portion  36 , where the liquid component of bone cement mixes with the powder component of bone cement stored therein. To further mix and prepare the bone cement, the mixer  110  can be rotated and/or moved longitudinally through the first and second mixing chamber portions  24  and  36  using the handle  108  coupled to the plunger rod  104 . After the liquid and powder bone cement components have been sufficiently mixed, they can be extracted out from within the first and second mixing chamber portions  24  and  36  through the first port  116  for delivery to a desired area. 
     The present teachings therefore provide a device and method to ensure that surgical staff mixes the bone cement under the proper vacuum, which ensures that the mixed bone cement does not include excessive amounts of air therein. For example, if the air pressure within the first and second mixing chamber portions  24  and  36  is not at or lower than the predetermined threshold, the piston  54  will not move to the second position, and thus will prevent removal of the safety insert  170  from cooperation with the second housing portion  14  in which the first and second arms  180   a  and  180   b  prevent movement of the first and second container supports  130   a  and  130   b  together to the activated position of  FIGS. 8 and 9 . During use of the device  10 , if the pressure within the first and second mixing chamber portions  24  and  36  rises back above the predetermined threshold, the spring  52  of the piston  54  will force the piston back outward to the first position, which will give the operator a visual indicator that the pressure is no longer at or below the predetermined threshold. 
     With reference to  FIG. 10 , the piston  54  need not include the spring  52 , and thus the piston  54  can be retained in the first position by a friction fit with an interior of the indicator housing  50 . The washer or seal  66  can enhance the friction fit with the indicator housing  50 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.