Abstract:
Systems, methods and devices which may be utilized in surgical treatments that insert a spring-force based separating device configured to maintain separation of two bone portions are provided. In one embodiment, a security device may be provided which is configured to house a spring in a compressed state for insertion into a patient. Upon insertion of the spring, the security device may be configured to release the compression force on the spring to allow the spring provide outward force on bone surfaces of a patient. Additionally, the security device may be configured to release the spring after the spring is deployed in the patient and to allow for removal of the security device. Embodiments may also include an insertion tool configured to utilize a security device to deploy a spring.

Description:
TECHNICAL FIELD 
       [0001]    The present application relates to systems, methods and devices for maintaining separation of bone structures, such as for treating craniosynostosis. 
       BACKGROUND 
       [0002]    Craniosynostosis is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. When such a condition occurs, because the skull cannot expand perpendicular to the fused suture, it may compensate by growing more in the direction parallel to the closed sutures. Sometimes the resulting growth pattern provides the necessary space for the growing brain, but it may result in an abnormal head shape and abnormal facial features. In cases in which the compensation does not effectively provide enough space for the growing brain, craniosynostosis may result in increased intracranial pressure leading possibly to visual impairment, sleeping impairment, eating difficulties, or an impairment of mental development combined with a significant reduction in IQ. 
         [0003]    Many methods for treating craniosynostosis have been implemented. One relatively new method that is gaining acceptance entails creating a strip craniectomy and inserting a device configured to maintain separation of the newly-defined areas of the skull. In such a procedure, a portion of the skull (e.g. a 1 cm wide section) is removed and spring is placed into the void generated by the removal of the skull portion, which then exerts outward force on the skull from within the removed portion in order to facilitate the proper, more anatomical, growth vector in the skull. 
         [0004]    While such a treatment has shown to be a marked improvement over earlier methods, some issues may still arise which are associated with this procedure. For example, a strip craniectomy may be invasive to the patient because of the space required (and corresponding length of incision) to remove the bone, etc. Generally incision length of this size is required because the surgical instruments being employed are general designs and not specifically suited for this procedure. To get proper access using these instruments, larger incisions are made. Further, the placement of the spring may be difficult due to the space needed to compress the spring and to insert the spring into the removed bone area. In fact, in some cases, the placement of the spring may even require multiple surgeons. 
         [0005]    It is also appreciated that there are a number of additional problems which are associated with higher invasiveness of a surgery. For example, additional complexity of a surgery may result in longer anesthesia times for the patient undergoing the surgery. Increased anesthesia doses and time may increase possible adverse effects resulting from the anesthesia drugs. Further, longer surgery times and larger incisions may cause additional blood loss to occur, as well as, increase the time required for patient healing. 
       BRIEF SUMMARY 
       [0006]    The present application provides for systems, methods and devices which may be utilized in surgical treatments that insert a spring-force based separating device configured to maintain separation of two bone portions. In one embodiment, a security device may be provided which is configured to retain a spring in a compressed state for insertion into a patient. Upon insertion of the spring, the security device may be configured to release the compression force on the spring to allow the spring provide outward force on bone surfaces of a patient. Additionally, the security device may be configured to release the spring after the spring is deployed in the patient and to allow for removal of the security device. 
         [0007]    Embodiments may allow for a spring to be deployed from a single incision which is perpendicular with respect to an axis defined by the direction of insertion of the spring. Further, embodiments may allow for a plurality of springs to be deployed from the single incision which is perpendicular with respect to an axis defined by the direction of insertion of the spring, e.g. to allow a spring to be inserted in both perpendicular directions. 
         [0008]    In another embodiment an insertion tool may be provided which attaches to a security device and assists in the insertion of a spring device. The insertion tool may comprise a sliding and/or trigger mechanism which allows a compressed spring to extend out of the end of the security device and to become uncompressed. Such a mechanism may be implemented as a slidably coupled railing system whereupon the inserter may cause the railing system to contract away from the end of the security device while a second portion of the railing system causes the spring to extend from the end of the security device. 
         [0009]    In accordance with one embodiment a system is provided for deploying a spring device into a patient. The system includes a security device having a retaining portion and a sleeve portion. The retaining portion is configured to retain the spring device prior to deployment and is further configured to be slidably disposed within said sleeve portion. Additionally, the sleeve portion is configured to provide compression force on the retaining portion and spring device when the retaining portion is disposed within the sleeve portion. The system further includes an inserter configured to attach to the security device and to slidably retract the sleeve portion of the security device. The inserter further includes an extension portion configured to provide force on the retaining portion to prevent the retaining portion from retracting with the sleeve portion, thereby causing the retaining portion to extend out of the sleeve portion when the sleeve portion is retracted. 
         [0010]    In accordance with another embodiment, a device for deploying a spring force between two bone structures in a patient is provided. The device includes a retaining portion configured to retain a spring device for deployment into a patient. The device further includes a sleeve portion configured to slidably accept the retaining portion, wherein the sleeve portion is configured to provide compression force on the retaining portion and the spring device when the retaining portion is disposed within the sleeve portion. Additionally, the retaining portion is configured to slidably extend from the end of the sleeve portion to release the compression force of the sleeve portion on the spring device. 
         [0011]    In another embodiment a device for deploying a spring force between two bone structures in a patient is provided. This device includes an inserter tool configured to attach to a security device. The inserter tool includes a sliding portion and an extension portion. The sliding portion is configured to transfer a pulling force to a first portion of an attached security device, while the extension portion remains unmoved and provides a stopping force to second portion of the attached security device to prevent pulling on the second portion. 
         [0012]    Another embodiment provides for a method for forming a spring deployment system. The method includes forming a retaining portion configured to retain a spring device for deployment into a patient. Additionally, the method includes forming a sleeve portion configured to slidably accept the retaining portion. The sleeve portion may be configured to provide compression force on the retaining portion and the spring device when the retaining portion is disposed within the sleeve portion. The retaining portion is also configured to slidably extend from the end of the sleeve portion to release the compression force of the sleeve portion on the spring device. In accordance with a more detailed embodiment, the method may also include forming an inserter tool configured to attach to the sleeve portion which is configured to slidably retract the sleeve portion. The inserter is further formed with an extension portion configured to provide force on said retaining portion to prevent the retaining portion from retracting with the sleeve portion, thereby causing the retaining portion to extend out of the sleeve portion when the sleeve portion is retracted. 
         [0013]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter which form the subject of the claims. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present application. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the application as set forth in the appended claims. The novel features which are believed to be characteristic of embodiments described herein, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    For a more complete understanding, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
           [0015]      FIG. 1  illustrates a spring device insertion system in accordance with an embodiment of the present application; 
           [0016]      FIG. 2  illustrates a security device in accordance with an embodiment of the present application; 
           [0017]      FIG. 3  illustrates an assembled security device in accordance with an embodiment of the present application; 
           [0018]      FIG. 4  illustrates a spring insertion device in accordance with an embodiment of the present application; 
           [0019]      FIG. 5  illustrates an exploded view or the spring insertion device of  FIG. 4 ; 
           [0020]      FIG. 6  illustrates spring device insertion system in accordance with an embodiment of the present application; 
           [0021]      FIG. 7  illustrates spring device insertion system in accordance with an embodiment of the present application; and 
           [0022]      FIG. 8  illustrates spring device insertion system in accordance with an embodiment of the present application. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    As an initial matter it is noted that much of the following discussion is made in the context of inserting a spring into a gap in the skull which has been made in the course of a craniectomy. Such discussion is made for the sake of clearly describing the concepts herein. It is noted that the inventive methods may be utilized in other portions of the body where separation between two structures by means of a spring force is implemented. It is further noted that the term “spring” is utilized throughout the present application, and that a spring may entail any device which may function to be compressed in order to facilitate insertion and act to provide an outward force (or spring force) on opposing surfaces when deployed. 
         [0024]      FIG. 1  illustrates a spring device insertion system  100  in accordance with an embodiment of the present invention. Spring device insertion system  100  includes an inserter  110 , a security device  120  and a flexible spring  130 . In some embodiments, spring device insertion system  100  may include a plurality of one or more of components  110 - 130 . For example, in some embodiments multiple flexible springs  103  may be provided for insertion into a patient. In such circumstances, a second spring security device  120  may be utilized for an additional spring  130 . Alternatively, one or more of the devices of system  100  may be configured to be reusable during a single surgery when additional devices are utilized, e.g. inserter  110  may be reused when inserting a second flexible spring  130  within retained within a second security device  120 . System  100  may be provided in this manner as a kit for use by a surgeon in the course of treating a condition such as craniosynostosis. 
         [0025]      FIG. 2  illustrates a security device  200  in accordance with an embodiment of the present application. Security device  200  includes a retainer portion  210  and a sleeve portion  220 . Retainer portion  210  is configured to slidably engage with sleeve portion  220 . 
         [0026]    In the illustrated embodiment, retainer portion  210  comprises first and second arms  211  and a release area  213 . First and second arms  211  may include one or more guide surfaces  214  configured to retain a spring (not shown). Additionally, first and second arms  211  may be configured to be flexible to allow for compression and decompression of a spring which is secured within device  200 . For example, one or more of first and second arms  211  may be configured to pivotably flex at an angle away from axis X in order to facilitate such compression/decompression of a spring device. 
         [0027]    Release area  213  may be configured to retain a spring while the release area  213  of retainer portion  210  is contained within sleeve portion  220 . When retainer portion  210  is allowed to slide such that release area  213  of retainer portion  210  extends out of sleeve portion  220 , the spring may be disengaged from security device  200  for deployment into a patient. 
         [0028]    Retainer portion  210  of security device  200  further includes a cavity  215  configured to accept an extension from an insertion device. Such an extension may be configured to provide force to allow retainer portion  210  to slide within sleeve portion  220 . Accordingly, cavity  215  may be configured to accept the extension in a snap fit configuration or in any other configuration which will allow the extension to transfer force to retainer portion  210  travelling within sleeve portion  220  such as, for example, a force sufficient to slide retainer portion into and/or out of sleeve portion  220  when a compressible spring is retained within retainer portion  210 . 
         [0029]    Sleeve portion  220  of security device  200  is configured to contain retainer portion  210  and configured to provide compression forces for a spring disposed within retainer portion  210 . For example, as retainer portion  210  (including a spring) is drawn into sleeve portion  220 , the outer walls of sleeve portion  220  provide force to compress at least a portion of the spring toward the X axis. Conversely, as retainer portion  210  is extended outside of sleeve portion  220 , the walls of sleeve portion  220  no longer provide force to compress the spring and the spring is allowed to extend outward with respect to the X axis. 
         [0030]    Sleeve portion  220  is further configured to connect to an inserter device such that sleeve portion  220  may remain affixed to the inserter device while an extension received in cavity  215  of retainer portion  210  may be utilized to slidably displace retainer portion  210  within sleeve portion  220  of security device  200 . This connection may be secured using a button device  221  which is configured to engage with at least one surface on the inserter device. Additionally, the connection of sleeve portion  220  to an inserter device may be implemented so as to allow the connection of security device  200  to an inserter to be a releasable connection. It is noted that while a button connection is illustrated, any connection which will reasonably retain the security device while allowing for an inserter to transmit force to retainer portion  210  may be utilized. 
         [0031]      FIG. 3  illustrates an assembled security device  300  in accordance with an embodiment of the present invention. Security device includes a sleeve portion  301 , a spring retainer portion  302 , spring  303  and inserter connection portion  304 . Retainer portion  302  is configured to slide with respect to sleeve portion  301 . As can be seen, in the event that retainer portion  302  were to slide further within sleeve portion  301 , the arms of spring  303  (and retainer portion  302 ) would be drawn in together to be contained within sleeve portion  301 . Such a compression allows for a compact insertion of spring  303  which is advantageous for multiple reasons, e.g. allows the security device and spring to be inserted while not requiring a large incision into a patient, allows for easier access for a surgeon to deploy the spring in an unassisted manner, etc. Security device  300  is configured to affix sleeve portion  301  to an inserter device via inserter connection portion  304  while also allowing the inserter to provide force to retainer portion  302  in order to slidably insert or remove the security device  300  (and to insert spring  303 ) from the patient. 
         [0032]      FIG. 4  illustrates a spring insertion device  400  in accordance with an embodiment of the present application.  FIG. 5  illustrates an exploded view of spring insertion device  400 . Spring insertion device  400  includes an extension portion  401  configured to engage with a security device (e.g. such as within cavity  215  of  FIG. 2 ) and to facilitate slidable motion of a retainer portion of the security device. 
         [0033]    It is noted that while extension portion is shown as having snap fit flanges, any means to connect the extension portion  401  to the security device may be utilized without departing from the concepts of the present invention. It is appreciated that such a connection would be of sufficient strength so as to maintain the connection with the security device (such as with a retainer portion) while being moved with respect to other portions of the security device (such as a sleeve portion). 
         [0034]    Spring insertion device  400  also includes a security device connection portion  402 . In the illustrated embodiment, security device connection portion  402  is an aperture configured to receive a button style device (e.g. button device  221 ) of a security device in order to affix the security device to spring insertion device  400  such that a sleeve portion of the security device may be pulled by spring insertion device  400  without releasing the security device. It is appreciated that any type of connection between a security device and spring insertion device  400  may be utilized which allows for this functionality. The illustrated embodiment offers advantages in terms of simplicity and the ability to be functional while maintaining a low profile. 
         [0035]    It is further noted that this connection may be implemented in a manner that is easily releasable. For example, a button device may be configured such that a user may push on the button to release the security device. Such a configuration may provide for interchanging multiple security devices (e.g. in the event that multiple springs are to be inserted). 
         [0036]    Spring insertion device  400  includes a sliding rail portion  403  where a portion of the inserter may slide with respect to another portion of the inserter. Such sliding may be facilitated by squeezing trigger  404  and/or by manually pulling on a portion of sliding rail portion  403 . It is noted that the portion of spring insertion device  400  that is connected to a security device  402  will slide with respect to extension portion  401 . Such motion allows for the extension and retraction of a retainer portion of the security device and for eventual deployment of a spring as a result of extension portion  401  remaining in a fixed position with respect to sliding portion  403  and providing a force onto a retainer portion while an opposite force is exerted on a sleeve portion of a security device. 
         [0037]      FIGS. 6-8  illustrate a system  600  in various stages of deployment in accordance with an embodiment of the present application. System  600  includes spring insertion device  601 , security device  602  and spring  603 . In  FIG. 6 , spring  603  and retaining portion of security device  602  are drawn into the sleeve portion such that spring  603  is in a compressed form. In this form, a surgeon may create an incision which allows for spring  603  and at least a portion of security device  602  to be inserted within the incision for the deployment of spring  603 . This method provides a substantial improvement over previous methods where more exposure to the skull is needed to deploy spring  603 , and where deployment may require multiple people to implement. 
         [0038]      FIG. 7  illustrates system  600  in the process of an implantation of spring  603  into skull  700 . Spring  603  is navigated to its correct placement using insertion device  601 . Once spring  603  is in its proper place (e.g. when hooks on the end of spring  603  are in contact with the opposing sides of the skull), a user may pull the slide of insertion device  601  which causes sleeve portion of security device  602  to retract with the sliding motion of insertion device  601 , thereby causing retainer portion of security device  602  to extend away from sleeve portion. Upon retainer portion of security device  602  extending away from the sleeve portion, spring  603  will undergo a reduction in compression force and attempt to motion to a relaxed state. In this manner, the hooks on the end of spring  603  which are engaged with the skull will be held in place by the spring force of spring  603 . 
         [0039]    It is appreciated that the present application discusses motion of the retainer portion in terms of the retainer portion extending and the sleeve portion retracting. It is noted that this extension and retraction is generally discussed with respect to each other and it is not intended that the movement be limiting on various placements and motions which will be utilized for insertion of a spring device. For example, the retainer portion may be placed in a desired location whereupon the sleeve portion is retracted without moving the spring portion. Further, the retainer portion may also undergo extension movement during insertion due to the nature of how the spring device may need to be employed. In any event, the retainer portion is extending/retracting with respect to the sleeve portion of a security device. 
         [0040]      FIG. 8  illustrates system  600  after the retainer portion of security device  602  has been fully extended and spring  603  has been deployed. As can be seen, once the retainer portion of security device  602  is extended past a certain point (e.g. where release area  213  is extended outside of the sleeve portion) the spring may be disengaged from security device  602 . After the spring is disengaged, security device  602  may be removed from the patient at the incision area (denoted by  701 ). 
         [0041]    As discussed above, embodiments may allow for multiple springs to be inserted, and in some cases, multiple springs may be deployed from the same incision site. For example, referring to  FIG. 8 , a second spring may be inserted utilizing a same incision area  701  where the spring is deployed to extend toward the back side of skull  700 . 
         [0042]    Although embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the above disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.