Patent Publication Number: US-2023135907-A1

Title: Expanadable spinal jack for installation between upper and lower succeeding superior articular processes

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional of U.S. Ser. No. 17/516,885 filed Nov. 2, 2021. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to spinal jacks for providing inter-vertebral support. More specifically, the present invention teaches an adjustable spinal jack for installation between superior articular processes of upper and lower succeeding vertebrae. 
     BACKGROUND OF THE INVENTION 
     Spinal jacks designs are known in the prior art for providing adjusted and secure positioning support between succeeding spinal vertebra. An examples of this is depicted in Linares U.S. Pat. No. 8,623,056. 
     SUMMARY OF THE PRESENT INVENTION 
     The present invention discloses a spinal jack adapted for installation between first and second vertebral processes, including first and second inter-expandable jack halves arranged between retracted and expanded positions. Each of the jack halves further includes gripping portions adapted for engaging the vertebral processes. A geared mechanism provides for expanding or retracting the jack halves in order to establish a corrected adjusted orientation between the processes. 
     In a first variant, a hex key rotatable driver actuates, via a bevel gear arrangement, a pair of laterally expandable slave gears supported upon a stationary shaft. A pair of extending support stems associated with one of the jack halves are provided and include inwardly stepped ratchet locations which abut the opposite outward faces of the slave gears in order to adjust a lateral separation between the jack halves. The spinal jack halves are further biased in an outward expanding direction. 
     In a second variant, a central body supports the outwardly displaceable spinal jack halves and includes a rotatable worm gear which in turn actuates a disk gear having both outer and inner coaxial arranged threads. These in turn mesh with threads configured in support stems associated with each of the jack halves and so that, upon actuating the worm gear to drive the disk gear, the spinal jack halves are caused to inter-displace in an outwardly expanding configuration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which: 
         FIG.  1    is perspective view of a spinal jack according to one non-limiting variant and having first and second spinal jack halves shown in a retracted position prior to being installed between succeeding superior articular processes associated with upper and lower consecutive spinal vertebra; 
         FIG.  2    is a succeeding illustration to  FIG.  1    and depicting the spinal jack in an expanded position and further illustrating an expandable rubberized skirt located between the outwardly inter-displacing jack halves; 
         FIG.  3    is a cutaway view taken along line  3 - 3  of  FIG.  1    and showing the pair of slave gears supported upon a width extending shaft in the retracted position; 
         FIG.  4    is a cutaway view taken along line  4 - 4  of  FIG.  2    and showing the adjusted position of the slave gears relative to the inwardly stepped ratchet stems to the outward-most expanded position; 
         FIG.  5    is a cutaway taken along line  5 - 5  of  FIG.  1    and showing bevel gear arrangement established between the drive gear and slave gears corresponding to the lowermost retracted position of  FIG.  3   ; 
         FIG.  6    is a perspective view of a spinal jack according to a further non-limiting variant and including a central body supports the outwardly displaceable spinal jack halves in a retracted position; 
         FIG.  7    is a further view to  FIG.  6    and illustrating the spinal jack halves in an inter-outward expanded position; 
         FIG.  8    is a cutaway view taken along line  8 - 8  of  FIG.  6    and illustrating the rotatable worm gear which in turn actuates a disk gear having both outer and inner coaxial arranged teeth, these in turn meshing with opposing teeth configured in the support stems associated with each of the jack halves; and 
         FIG.  9    is a corresponding cutaway view to  FIG.  8    and depicting the spinal jack halves being caused to inter-displace in the outwardly expanding configuration. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the attached illustrations, the present invention discloses a number of variants of an adjustable spinal jack for installation between superior articular processes of upper and lower succeeding vertebrae. A general representation of a selected jack is depicted generally at  10  in the perspective view of  FIG.  1    and is understood to be positioned between upper and lower  4  successive superior articular processes (not shown) corresponding to upper and lower vertebrae. 
     As will be described in further detail with reference to the succeeding embodiments, the present invention provides an expandable spinal jack which overcomes many of the disadvantages of the prior art and provides an effective solution for stabilizing and fixing in position a given orientation established between the succeeding vertebrae. As will be further described, the spinal jack designs described herein further permit adjustment, at any future time following initial surgical implantation, in a minimally invasive fashion and in order to re-adjust the spatial positioning established between the upper and lower halves of each variant of the spinal jack, such as in order to compensate and correct for downstream vertebral complications following the initial implantation of the spinal jack. 
     Referring again to  FIG.  1   , the perspective view of the spinal jack according to one non-limiting variant includes first  12  and second  14  bodies, also hereinafter referred to as spinal jack halves, which are shown in a retracted position prior to being installed between succeeding superior articular processes associated with upper and lower consecutive spinal vertebra. Each of the spinal jack halves can be constructed of a suitable medical grade sanitary metal, plastic or composite and can incorporate opposite and outwardly facing gripping portions, these as further shown exhibiting a substantially “U” shape with aligning apertures configured in spaced apart and extending legs (see pairs  16 / 18  for each of first or upper jack half  12  and further at  20 / 22  for second or lower half  14 ). 
     Aligning apertures are further defined by spaced apart pairs of inner perimeter extending edges (at  24 / 26  for upper gripping portion legs  16 / 18  and at  28 / 30  for lower gripping portion legs  20 / 22 ). As understood, the spaced apart pairs of legs  16 / 18  and  20 / 22  of the opposite extending gripping portions are adapted to seat the upper and lower consecutive superior articular processes, The inner “U” shaped surface profile of each of the gripping portions is further exhibited by any type of textured or ribbed profile (see at inner base surface  32  and inner side surfaces  34 / 36  for the upper spinal jack gripping portion as well as inner base surface  38  and inner side surfaces  40 / 42  for the lower spinal jack gripping portion) the purpose of which is to provide additional resistive engagement against the facet surfaces of the vertebral processes and. 
     Also shown are screw type fasteners  44  and  46  (see  FIG.  1   ) which, upon positioning and the gripping portions and drilling through the vertebral processes, anchor the spinal jack halves  12 / 14  to the respective vertebrae. Alternatively, the gripping portions can be crimped into engagement with the vertebral processes without the use of separate screws. 
       FIG.  2    is a succeeding illustration to  FIG.  1    and depicts the spinal jack in an expanded position and further illustrating an expandable rubberized skirt  48  located between the outwardly inter-displacing jack halves  12 / 14 . Without limitation, the skirt can be constructed of any suitable flexible and FDA (Food and Drug Administration) approved material. 
     As further best shown in the cutaway views of  FIGS.  3 - 4   , the skirt  48  is initially wound into a circumferential extending roll ( FIG.  3   ) and seated within a likewise circumferentially extending pocket  50  extending within a base circumference of the upper spinal jack half  12 . An opposite end of the skirt is anchored (at  52 ) to an opposing perimeter end face location of the lower spinal jack half  14  such that, and upon expanding the jack halves  12 / 14  as shown in  FIG.  4   , the skirt  48  unrolls to the position depicted in  FIGS.  2 - 4    in which it provides a barrier between the exterior environment and the inner gear mechanism (to be described below) of the vertebral jack assembly. Additionally, the skirt  48  can be tensioned to the rolled up position of  FIG.  3    (such as through the use of additional torsional springs, bands or the like) in order to maintain a tensioned and taut arrangement of the skirt at any expanded adjusted position established between the jack halves  12 / 14 . 
     A rotatable driver component (see at  53  in  FIG.  5   ) is depicted and includes an integrated hex head or other suitable bit receiving opening (further at  54 ). The driver component is further seated within a closed rim surface defining aperture  56  (see  FIGS.  1 ,  2  and  5   ) associated with the first or upper jack half  12 . A pair of laterally expandable slave gears  58  and  60  (see again  FIGS.  3 - 5   ) are supported upon a width supported shaft  62 , this in turn being secured in extending fashion through a lower interior projection  64  of the upper jack half  12 . 
     As best shown in  FIG.  5   , a bevel gear arrangement is established between the driver component  53  and the slave gears  58 / 60 . The slave gears  58 / 60  are stationary and each in turn further includes an interior and laterally displacing inner component (see at  59 / 61 ) which is threaded and inter-displaceable relative to the outer driving slave gears  58 / 60 . The inner components  59 / 61  are further seated, as shown, over opposite ends of the stationary shaft  62  between the positions of  FIG.  3    (retracted) and  FIG.  4    (expanded). 
       FIG.  5    best shows bevel engaging tooth  66  (associated with selected slave gear  58 ) and corresponding outer bevel tooth  68  (associated with driver component  53 ), such that rotation of the hex head driver opening  54  (via the inserted bit) results in threaded engagement between interior threads  70  and  72  associated with each of the slave gears  58 / 60  and opposing exterior threaded locations  74  and  76  associated with each of the inner displacing components  59 / 61 . The inner components  59 / 61  each further define interior channels (see as best shown at  78 / 80  in each of  FIGS.  3  and  5   ) within which is seated the width supported and stationary shaft  62 . 
     A pair of extending support stems  82  and  84  are associated with one of the jack halves, and which is shown in the  FIGS.  3 - 4    cutaway views being anchored into the lower jack half  14  so that the stems  82 / 84  (best shown in  FIG.  3   ) project upwardly within interior tracks or pockets  86 / 88  defined in the upper jack half  12 . Each of the stems  82 / 84  include an individual plurality of opposing and progressively inwardly stepped ratchet locations (see at  86  for stem  82  and at  88  for stem  84  and which, without limitation, can be spaced at any desired incremental distance such as  2 mm per step) which abut the opposite outward faces of the laterally displacing inner components  59 / 61  and to assist in adjusting a lateral separation between the jack halves. One or more springs (see first pair  90  and second pair  92 ) are seated within the pocket shaped tracks or pockets  82 / 84  so that they are compressed/obscured in the retracted view of  FIG.  3    (these can without limitation seat within upper end recessed locations defined in the ratchet stems  82 / 84 ). 
     In use, the inner displacing components  59 / 61  are depicted in the outermost displaced locations along the shaft  62  in the retracted position of  FIG.  3   . At this point, the spinal jack  10  is position in relation to a pair of succeeding superior articular processes and, upon actuating the rotary driving (e.g. hex key) component  53  in a first selected direction, the inter-threaded relationship with the slave gears  58 / 60  causes the inner components  59 / 61  to retract inwardly, to the point at which it unseats/inwardly clears in succession from each inwardly facing and opposing pair of progressively inwardly stepped ratchet locations  86 / 88 . As each inward facing pair of stepped locations is cleared, the springs  90 / 92  progressively and outwardly expand the spinal jack halves  12 / 14  to each succeeding pair of stepped ratchet locations, and which can occur up to the last and inwardly-most stepped pair of opposing ratchets as shown in  FIG.  4   . 
     Once the spinal jack halves  12 / 14  are progressively expanded to the desired separation distance, the rotary driver component  53  is reverse rotated in a second direction to outwardly expand the inner components  59 / 61  in order to engage the desired pair of ratchet. Given the inwardly stepped nature of the ratchets, the desired expansion position between the spinal jack halves is maintained via the shoulder interfaces (see by example at  94 / 96 ) established between each succeeding pair of ratchets  86 / 88  so that, and upon outwardly tightening the inner components  59 / 61  of the slave gears  58 / 60  at the desired ratchet locations  86 / 86 , the adjoining shoulders  94 / 96  corresponding to the next inwardly stepped ratchet location provide a secure engagement profile and prevent further inter expansion of the spinal jack halves  12 / 14 . 
     Proceeding now to  FIG.  6    is a perspective view of a spinal jack is generally shown at  100  according to a further non-limiting variant in a retracted position and includes a central body  102  which supports a pair of outwardly displaceable spinal jack halves  104  and  106 , each of which again including any medical grade metal, plastic or composite material. 
     The central body  12  (as best shown in the spinal jack expanded position of  FIG.  7   ) depicts a three dimensional modified puck shape with top  108  and bottom  110  facing surfaces, against which are seated (in the retracted positions of  FIGS.  6  and  8   ) base surfaces  112  and  114  associated with gripping portions configured into each of the upper  102  and lower  104  jack halves. 
     Similar to the preceding embodiment  10  of  FIG.  1   , the gripping portions each further exhibit a substantially “U” shape with aligning apertures configured in spaced apart and extending legs (see upper pairs  116 / 118  and  120 / 122  for each gripping portion associated with the upper  102  and lower  104  spinal jack halves). The aligning apertures are further defined by spaced apart pairs of inner perimeter extending edges (at  124 / 126  for upper spaced apart legs  116 / 118  and further at  128 / 130  for lower spaced apart legs  120 / 122 ). 
     With reference again to  FIG.  1   , the spaced apart pairs of legs  116 / 118  and  120 / 122  of the opposite extending gripping portions are adapted to seat the upper and lower consecutive superior articular processes, The inner “U” shaped surface profile of each of the gripping portions is further exhibited by any type of textured or ribbed profile (see at inner base surface  132  and inner side surfaces  134 / 136  for the upper gripping portion as well as inner base surface  138  and inner side surfaces  140 / 142  for the lower gripping portion) the purpose of which is to provide additional resistive engagement against the facet surfaces of the processes. As shown at  44  and  46  in  FIG.  1   , any type of screw fasteners can be employed and which, upon pre-positioning the gripping portions and drilling through the processes, anchor the jack halves  12 / 14  to the respective vertebrae. Alternatively, and as previously stated, the gripping portions can be crimped into engagement with the vertebral processes without the use of separate screws. 
       FIG.  7    is a further view to  FIG.  6    and illustrating the spinal jack halves  12 / 14  in an inter-outward expanded position.  FIG.  8    further provides a cutaway view taken along line  8 - 8  of  FIG.  6    and illustrating the rotatable worm gear which in turn actuates a disk gear having both outer and inner coaxial arranged threads, these in turn meshing with threads configured in support stems associated with each of the jack halves.  FIG.  9    is a cutaway view similar to  FIG.  8    and depicting the spinal jack halves  12 / 14  being caused to inter-displace in the outwardly expanding configuration. 
     As best shown in  FIGS.  8 - 9   , the central body  102  includes a rotatable worm gear  144  having exterior spiral arrayed teeth  145  and which, in turn, actuates a disk gear  146 , this further exhibiting a multi-sided profile as depicted in cutaway and having both outer most facing annular threads or spiral teeth  148 , along with each of first  150  and second  152  coaxially arranged inner threads or teeth. These in turn mesh with opposing coaxial threads or teeth  154  and  156  (see further as best shown in  FIG.  9   ) configured in in each of support stems  158  (lower spinal jack  14 ) and  160  (upper spinal jack  12 ) and so that, upon actuating the worm gear  144  to drive the disk gear  146 , the spinal jack halves are caused to inter-displace in an outwardly expanding configuration. 
     Similar to the first variant, a hex or other bit shaped key insert portion  162  is shown which is seated within a closed rim  164  defining an access passageway through the central body  12 . Although not shown, the bit portion  162  can be integrated into the worm gear  144  for inter-displacing the spinal jack halves  12 / 14  in the manner shown between  FIGS.  8 - 9   . 
     Owing further to the inter-engaging geared relationship established between the worm gear  144 , rotatably engaged disk gear  146  and opposing threaded gears  154 / 156  associated with the inner support stems  158  and  160  of the jack halves  14 / 12 , adjustment of the spinal jack halves is provided in a secured fashion (such as during either of initial implantation or in response to a subsequent change in the patient&#39;s condition in which the spinal jack is further adjusted in-situ and without removing from the vertebral superior processes). Additional structural features can include an inner-most stem  164 , shown integrated into the lower support stem  158  of the lower jack half  106 , which seats within an aligning inner-most pocket  166  (see  FIG.  9   ) defined in the upper support stem  160  of the upper jack half  104  and in use provides secure support to the jack halves in their inter-expanded outer configuration of  FIGS.  7  and  9   . 
     Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims. The detailed description and drawings are further understood to be supportive of the disclosure, the scope of which being defined by the claims. While some of the best modes and other embodiments for carrying out the claimed teachings have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. 
     The foregoing disclosure is further understood as not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims. 
     In the foregoing specification, the disclosure has been described with reference to specific embodiments. However, as one skilled in the art will appreciate, various embodiments disclosed herein can be modified or otherwise implemented in various other ways without departing from the spirit and scope of the disclosure. Accordingly, this description is to be considered as illustrative and is for the purpose of teaching those skilled in the art the manner of making and using various embodiments of the disclosure. It is to be understood that the forms of disclosure herein shown and described are to be taken as representative embodiments. Equivalent elements, materials, processes or steps may be substituted for those representatively illustrated and described herein. Moreover, certain features of the disclosure may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the disclosure. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. 
     Further, various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and should in no way be construed as limiting of the present disclosure. All joinder references (e.g., attached, affixed, coupled, connected, and the like) are only used to aid the reader&#39;s understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the systems and/or methods disclosed herein. Therefore, joinder references, if any, are to be construed broadly. Moreover, such joinder references do not necessarily infer that two elements are directly connected to each other. 
     Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, “primary”, “secondary”, “main” or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader&#39;s understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or modification. 
     It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Additionally, any signal hatches in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically specified.