Hinged Fixation Devices for Combined Upper Jaw Correction

Abstract

Instrumentation and methods are provided for upper jaw correction surgery. The application discloses an orthopedic system and method that can be used to perform both a first distraction (for example a maxillary distraction) and a second distraction (for example a maxillary expansion) within the same surgical procedure. The instrumentation for separating first and second bone segments can include a first footplate; a second footplate; an actuator arranged to vary a distance between the first and second footplates; and a hinge that rotatably attaches the first and second footplates such that the first and second footplates can be angularly adjusted relative to each other about a pivot axis. Additionally, instrumentation and methods are provided for a hinged fixation device capable of securing and adjusting both the linear separation and angular orientation of bone structures.

1 . A fixation device comprising:
 a first footplate including a first footplate body configured to be attached to a first bone portion;   a second footplate including a second footplate body configured to be attached to a second bone portion; and   a joining element coupled between the first and second footplate bodies, the joining element including a hinge that defines a pivot axis about which the first footplate body is passively rotatable with respect to the second footplate body in response to a force applied to the second footplate body.   
     
     
         2 . The fixation device of  claim 1 , wherein the first and second footplates each further comprise an attachment portion that defines a bore and the joining element is configured to fit within each of the bores to connect the first and second footplates. 
     
     
         3 . The fixation device of  claim 1 , wherein the joining element defines a threaded outer surface, and the attachment portion defines a threaded inner surface that at least partially defines the bore, such that when the first and second footplates pivot with respect to one another the corresponding threads of the joining element and the bore mate and cause the first and second footplates to also translate with respect to one another along the first direction. 
     
     
         4 . The fixation device of  claim 1 , wherein the joining element defines an unthreaded outer surface and the attachment portion defines an unthreaded inner surface that at least partially defines the bore, such that when the first and second footplates pivot with respect to one another the corresponding surfaces mate in such a way as to not bias the first and second footplates to translate with respect to one another along the first direction. 
     
     
         5 . The fixation device of  claim 1 , wherein the joining element defines an outer surface and the bore and the outer surface each comprise concentric rings such that when the first and second footplates pivot with respect to one another the first and second footplates are not permitted to translate linearly with respect to one another. 
     
     
         6 . The fixation device of  claim 1 , wherein the joining element is configured as a rivet. 
     
     
         7 . The fixation device of  claim 1 , wherein the joining element is configured as a threaded screw. 
     
     
         8 . The fixation device of  claim 1 , wherein the joining element further comprises an expanded portion comprising a first side wall and a second side wall that are each configured to ensure that the minimum linear separation between the first and second footplates is limited. 
     
     
         9 . The fixation device of  claim 1 , wherein the first and second footplate bodies each comprise a securing portion that is configured to receive at least one fastener to secure the first and second footplate bodies to the first and second bone portions respectively. 
     
     
         10 . The fixation device of  claim 9 , wherein each of the securing portions is configured to be a plate member comprising an upper surface configured to receive a fastener, a lower surface configured to conform to the first or second bone portion, and a side wall extending from the upper surface to the lower surface along an outer circumference of the plate member. 
     
     
         11 . The fixation device of  claim 10 , wherein each of the plate members comprises at least one recess that is configured to receive a fastener to secure the plate member to the underlying bone structure. 
     
     
         12 . The fixation device of  claim 11 , wherein the recess is a threaded bore configured to receive a locking screw. 
     
     
         13 . The fixation device of  claim 1 , further comprising a pair of spacers configured such that when the pair of spacers are each positioned within one of the bores a minimum gap between the first and second footplates is defined. 
     
     
         14 . The fixation device of  claim 1 , wherein the joining element is integrally formed as part of either the first footplate of the second footplate. 
     
     
         15 . The fixation device of  claim 1 , wherein the joining element is coupled between the first and second footplate bodies along a first direction, and the joining element defines a variable spacer, such that at least one or both of the first and second footplate bodies can be actuated to move along the variable spacer from a first position spaced from the other of the first and second footplate bodies a first distance along the first direction to a second position spaced from the other of the first and second footplate bodies a second distance along the first direction, such that the second distance is different from the first distance. 
     
     
         16 . The fixation device of  claim 1 , wherein the device is configured to be attached to a maxilla and a remaining portion of a skull after the maxilla has been separated from the remaining portion of the skull; and wherein:
 the first footplate body is configured to be attached to the remaining portion of the skull;   the second footplate body is configured to be attached to the separated maxilla; and   wherein the hinge defines a pivot axis about which the at least one of the first and second footplate bodies are rotatable with respect the other of the first and second footplate bodies, such that when a sagittal split separates the maxilla into first and second segments, at least one of the first and second segments is angularly adjustable with respect to the other of the first and second segments about the pivot axis after the first and second footplate bodies have been attached to the remaining portion of the skull and the maxilla, respectively.   
     
     
         17 . The fixation device of  claim 16 , wherein the joining element is coupled between the first and second footplate bodies along a first direction, and the fixation device further comprises an actuator configured to vary a distance between the first and second footplates along the first direction so as to advance the separated maxilla with respect to the remaining portion of the skull after the first and second footplate bodies have been attached to the remaining portion of the skull and the maxilla, respectively. 
     
     
         18 . The fixation device of  claim 17 , wherein joining element includes a variable spacer, such that at least one or both of the first and second footplate bodies can be actuated to move along the variable spacer from a first position spaced from the other of the first and second footplate bodies a first distance along the first direction to a second position spaced from the other of the first and second footplate bodies a second distance along the first direction, such that the second distance is different from the first distance. 
     
     
         19 . The fixation device of  claim 17 , wherein the actuator comprises:
 a sleeve having a body with an outer surface, the body defining a bore extending through the body; and   a screw connected to and disposed at least partially within the bore of the sleeve such that the screw can rotate relative to the sleeve but cannot translate relative to the sleeve;   wherein rotation of the screw causes the first and second footplates to translate with respect to the each other along a second direction that is substantially perpendicular to the first direction.   
     
     
         20 . The fixation device of  claim 19 , wherein the first footplate further comprises:
 a first actuator portion defining an inner bore that is configured to be threadedly secured to the screw.   
     
     
         21 . The fixation device of  claim 17 , wherein the second footplate further comprises an actuator attachment portion that is removably attached to the actuator. 
     
     
         22 . The fixation device of  claim 21 , wherein the actuator attachment portion is removably attached to the outer surface of the sleeve. 
     
     
         23 . The fixation device of  claim 19 , wherein the sleeve is externally threaded so as to mate with an alignment member that aligns the first and second footplates with the separated maxilla and the remaining portion of the skull, respectively, prior to attaching the first and second footplates to the separated maxilla and the remaining portion of the skull, respectively 
     
     
         24 . The fixation device of  claim 23 , wherein the sleeve is keyed so as to mate with the alignment member in a predetermined relative orientation. 
     
     
         25 . The fixation device of  claim 17 , wherein at least one of the first and second footplates is made of a bioresorbable material, and the actuator is made of a non-bioresorbable material. 
     
     
         26 . The fixation device of  claim 17 , wherein the angularly adjusting of at least one of the first and second segments with respect to the other of the first and second segments causes at least one of the first and second footplates to translate along the pivot axis relative to the other of the first and second footplates. 
     
     
         27 . The fixation device of  claim 26 , wherein the first and second footplates translate relative to each other a maximum distance of about 1 mm to about 2 mm. 
     
     
         28 . The fixation device of  claim 17 , wherein the hinge comprises a post coupled to one of the first and second footplates, and the hinge further comprises a receiving sleeve coupled to the other of the first and second footplates, wherein the receiving sleeve is rotatably attached to the post. 
     
     
         29 . The fixation device of  claim 28 , wherein the hinge and post define threads such that the hinge and the sleeve are configured to be threadedly coupled. 
     
     
         30 . The fixation device of  claim 17 , wherein the hinge is movable between a first position and a second position about the pivot axis so as to angularly adjust the first and second footplates from a corresponding first relative angular position to a second corresponding angular position. 
     
     
         31 . The fixation device of  claim 30 , wherein the hinge is configured to maintain the first and second footplates in the second relative angular position during fixation of the fixation device to an underlying bone. 
     
     
         32 . The fixation device of  claim 17 , wherein the hinge comprises a hinge body that connects the first and second footplates, the hinge body defining one or more gaps positioned and dimensioned within the body so as to define a pair of spaced legs, at least one of the legs being deformable so as to adjust the angular orientation of the first and second bone attachment portions. 
     
     
         33 . The fixation device of  claim 17 , wherein the pivot axis is substantially parallel to the first direction. 
     
     
         34 . The fixation device of  claim 19 , wherein the actuator is arranged to vary a linear distance between the first and second footplates along a second direction, and the pivot axis is offset from the first direction. 
     
     
         35 . The fixation device of  claim 34 , wherein the actuator is arranged to vary the linear distance between the first and second footplates along the first direction, and the pivot axis is angularly offset with respect to the first direction. 
     
     
         36 . The fixation device of  claim 35 , wherein the pivot axis is substantially perpendicular to the first direction. 
     
     
         37 . The fixation device of  claim 17 , wherein at least one of the first and second footplates is deformable to substantially follow a contour of underlying bone. 
     
     
         38 . The fixation device of  claim 17 , wherein at least a portion of at least one of the first and second footplates is made of a bioresorbable material. 
     
     
         39 . The fixation device of  claim 38 , wherein the at least one of the first and second footplates is attached to a respective bone segment by at least one bioresorbable fastener. 
     
     
         40 . The fixation device of  claim 17 , wherein the first footplate is configured and adapted to attach to a construct, the construct being mechanically coupled to a patient's teeth. 
     
     
         41 . The fixation device of  claim 17 , further comprising a fastener to removably fix the second footplate to the actuator. 
     
     
         42 . The fixation device of  claim 17 , wherein the bone-facing surfaces of the first and second footplates are substantially perpendicular prior to implantation of the fixation device. 
     
     
         43 . The fixation device of  claim 17 , wherein at least a portion of the first footplate is configured to attach to a maxilla and at least a portion of the second footplate is configured to attach to a zygoma of the remaining portion of the skull. 
     
     
         44 . The fixation device of  claim 17 , wherein the first and second bone-facing surfaces substantially define first and second respective planes, and the actuator is arranged to translate at least one of the first and second footplates relative to the other along the respective first and second plane. 
     
     
         45 . The fixation device of  claim 44 , wherein the first and second bone-facing surfaces substantially lie in initial first and second planes, and the hinge moves at least one of the first and second bone-facing surfaces out of the corresponding initial plane. 
     
     
         46 . The fixation device of  claim 17 , wherein the hinge further comprises a first hinge member configured to be secured to the actuator, and a second hinge member configured to be secured to the first footplate body and rotationally attached to the first hinge member such that the first and second hinge members can rotate about the pivot axis relative to one another. 
     
     
         47 . The fixation device of  claim 46 , wherein the hinge further comprises an axial locking mechanism that is configured to axially secure the first and second hinge members relative to each other such that relative translation of the first and second hinge members is prevented. 
     
     
         48 . The fixation device of  claim 47 , wherein the first hinge member comprises a pivot shaft having a necked portion and the axial locking mechanism comprises a pin hole and a locking pin; wherein upon alignment of the necked portion and the pin hole the locking pin can be inserted through the pin hole and at least partially into the necked portion to axially lock the first and second pivot members. 
     
     
         49 . The fixation device of  claim 46 , wherein the hinge further comprises a rotational locking mechanism configured to rotationally secure the first and second hinge members relative to each other such that the first and second hinge members cannot rotate relative to one another about the pivot axis. 
     
     
         50 . The fixation device of  claim 49 , wherein the rotational locking mechanism comprises a set screw configured to abut the pivot shaft such that a force is applied against the pivot shaft that is sufficient to rotationally secure the first and second hinge members relative to each other. 
     
     
         51 . The fixation device of  claim 46 , wherein the first and second hinge members comprise a ball and socket joint that enables the first and second hinge members to rotate relative to each other about the pivot axis, as well as limited universal adjustability about other axes offset from the pivot axis. 
     
     
         52 . The fixation device of  claim 51 , wherein the hinge further comprises an axial locking mechanism that is configured to axially secure the first and second hinge members relative to each other such that relative translation of the first and second hinge members is prevented. 
     
     
         53 . The fixation device of  claim 51 , wherein the hinge further comprises a rotational locking mechanism configured to rotationally secure the first and second hinge members relative to each other such that the first and second hinge members cannot rotate relative to one another about the pivot axis. 
     
     
         54 . The fixation device of  claim 53 , wherein the rotational locking mechanism comprises a set screw configured to abut the pivot shaft such that a force is applied against the pivot shaft that is sufficient to rotationally secure the first and second hinge members relative to each other. 
     
     
         55 . The fixation device of  claim 51 , wherein the actuator is elongate along a central axis and the pivot axis is substantially perpendicular to the central axis. 
     
     
         56 . The fixation device of  claim 51 , wherein the actuator is elongate along a central axis and the pivot axis is substantially parallel to the central axis. 
     
     
         57 . The fixation device of  claim 17 , wherein the hinge comprises:
 a hinge spacer member having an actuator attachment portion configured to secure the hinge spacer member to the actuator and a first footplate attachment portion configured to be received within an inner bore of the first footplate, the first footplate attachment portion including a collet member that defines an inner bore; and   a pin configured to be inserted into the inner bore of the collet member;   wherein when the collet member is positioned within the inner bore of the first footplate the pin can be inserted into the inner bore of the collet member such that the collet member expands from an unlocked configuration wherein the collet member and the first footplate can translate relative to one another, to a locked configuration wherein the collet member and the first footplate are prevented from translating relative to one another.   
     
     
         58 . The fixation device of  claim 57 , wherein the hinge spacer member defines a height such that the first footplate is offset from the second footplate. 
     
     
         59 . The fixation device of  claim 57 , wherein the hinge spacer member is monolithic with the actuator. 
     
     
         60 . The fixation device of  claim 57 , further comprising a locking mechanism that is configured to secure the pin relative to the collet member such that the pin cannot be removed from the inner bore of the collet member. 
     
     
         61 . The fixation device of  claim 57 , further comprising a second hinge that defines a second pivot axis such that the second footplate body is angularly adjustable with respect to the first footplate body about the second pivot axis. 
     
     
         62 . The fixation device of  claim 61 , wherein the second hinge comprises:
 a second hinge spacer member having an actuator attachment portion configured to secure the second hinge spacer member to the actuator and a second footplate attachment portion configured to be received within an inner bore of the second footplate, the second footplate attachment portion including a second collet member that defines an inner bore; and   a second pin configured to be inserted into the inner bore of the second collet member;   wherein when the second collet member is positioned within the inner bore of the second footplate the second pin can be inserted into the inner bore of the second collet member such that the second collet member expands from an unlocked configuration wherein the second collet member and the second footplate can translate relative to one another, to a locked configuration wherein the second collet member and the second footplate are prevented from translating relative to one another.   
     
     
         63 . The fixation device of  claim 62 , further comprising at least one locking mechanism that is configured to secure the first or second pin relative to the respective collet member such that the first or second pin cannot be removed from the respective inner bore of the respective collet member. 
     
     
         64 . The fixation device of  claim 17 , wherein the hinge comprises:
 a hinge body having an actuator attachment portion configured to secure the hinge body to the actuator and a first footplate attachment portion configured secure the hinge body to the first footplate, the first footplate and the first footplate attachment portion each including a pin hole; and   a pin configured to be inserted into the pin hole of the first footplate and the first footplate attachment portion;   wherein when the pin hole of the first footplate and the first footplate attachment portion are aligned, the pin can be inserted through the pin hole of the first footplate and the first footplate attachment portion such that the first footplate can rotate with respect to the hinge body about the pin and about the pivot axis.   
     
     
         65 . The fixation device of  claim 64 , further comprising a second hinge, wherein the second hinge includes:
 a second hinge body having an actuator attachment portion configured to secure the second hinge body to the actuator and a second footplate attachment portion configured secure the second hinge body to the second footplate, the second footplate and the second footplate attachment portion each including a pin hole; and   a second pin configured to be inserted into the pin hole of the second footplate and the second footplate attachment portion;   wherein when the pin hole of the second footplate and the second footplate attachment portion are aligned, the pin can be inserted through the pin hole of the second footplate and the second footplate attachment portion such that the second footplate can rotate with respect to the hinge body about the second pin and about a second pivot axis.   
     
     
         66 . The fixation device of  claim 17 , further comprising a retention mechanism rotationally coupled to the first footplate, the retention mechanism configured to allow rotation of the first footplate  1060  about the pivot axis in one direction, while preventing rotation about the pivot axis in the opposite direction. 
     
     
         67 . The fixation device of  claim 66 , wherein the retention mechanism includes a one way ratchet system. 
     
     
         68 . The fixation device of  claim 67 , wherein the one way ratchet system includes:
 a gear rotationally coupled to the first footplate, the gear having a plurality of teeth that each define a front side and a back side; and   a pawl that is configured to engage the gear, the pawl including an arm that is attached to the distractor and a tip having a front surface, an opposed back surface, and a bottom surface the extends from the front surface to the back surface that is configured to engage the gear;   wherein the gear can rotate about the pivot axis in a first direction but rotation of the gear in a second direction is blocked by interference between the front surface of the tip of the pawl and the back side of one of the teeth of the gear.   
     
     
         69 . The fixation device of  claim 1 , wherein the joining element releasably couples together the first and second footplate bodies. 
     
     
         70 . The fixation device of  claim 1 , wherein the joining element comprises a flexible pin configured to secure the hinge and to releasably couple the first and second footplate bodies. 
     
     
         71 . A method to perform both a first distraction and a second distraction within the same surgical procedure, the method comprising the steps of:
 performing a first osteotomy to separate a first bone segment from a second bone segment;   performing a second osteotomy to separate the first bone segment into a first bone segment and a second bone segment;   attaching a first footplate of a first distractor to the first bone segment and attaching a second footplate of the first distractor to the second bone segment;   actuating the first distractor to move the first bone segment in a first direction relative to the second bone segment; and   moving the first bone segment in a second direction relative to the second bone segment, the second direction different than the first direction;   wherein movement of the first bone segment in the second direction causes the second footplate of the first distractor to rotate relative to the first footplate.   
     
     
         72 . The method of  claim 69 , further comprising, before the first performing step, identifying a starting position of the first bone segment and the second bone segment. 
     
     
         73 . The method of  claim 71 , further comprising attaching a first footplate of a second distractor to the second bone segment and attaching a second footplate of the second distractor to the second bone segment. 
     
     
         74 . The method of  claim 73 , further comprising actuating the second distractor to move the second bone segment in the first direction relative to the second bone segment. 
     
     
         75 . The method of  claim 73 , further comprising attaching a third distractor to the first and second bone segments across the second osteotomy such that in a first configuration the first, second, and third distractors retain the first and second bone segments and the second bone segment in the starting position. 
     
     
         76 . The method of  claim 75 , wherein movement in the second direction is caused by actuation of the third distractor. 
     
     
         77 . The method of  claim 76 , wherein movement in the second direction also causes the second footplate of the second distractor to rotate as the first and second bone segments are separated. 
     
     
         78 . The method of  claim 71 , further comprising repeating the actuating step so as to incrementally move the first bone segment in the first direction. 
     
     
         79 . The method of  claim 71 , further comprising the step of repeating the moving step so as to incrementally move the first bone segment in the second direction relative to the second bone segment. 
     
     
         80 . The method of  claim 71 , wherein rotation of the second footplate relative to the first footplate is about a pivot axis, and the rotation causes the second footplate to translate relative to the first footplate along the pivot axis. 
     
     
         81 . The method of  claim 80 , further comprising the step of rotating the second footplate relative to the first footplate so as to translate the second footplate relative to the first footplate along the pivot axis prior to the attaching step. 
     
     
         82 . The method of  claim 81 , further comprising retaining the first and second footplates in a relative rotatable position during the attaching step. 
     
     
         83 . The method of  claim 71 , wherein the first distraction is a maxillary distraction and the second distraction is a maxillary expansion. 
     
     
         84 . The method of  claim 83 , wherein the first bone segment is a maxilla and the second bone segment is a zygoma. 
     
     
         85 . The method of  claim 84 , wherein the first osteotomy is a Lefort I osteotomy. 
     
     
         86 . The method of  claim 85 , wherein the second osteotomy is a sagittal split osteotomy. 
     
     
         87 . A kit comprising:
 at least a pair of distractors each configured to be coupled to bone across an osteotomy, each of the distractors comprising;   a first footplate and a second footplate coupled to the first footplate and spaced from the first footplate along a first direction, each of the first and second footplates including a bone attachment portion that defines a respective bone-facing surface configured to contact bone on opposite sides of the osteotomy;   an actuator arranged to vary a distance between the first and second footplates of each of the respective distractors along the first direction; and   a hinge that rotatably attaches the first and second footplates such that the first and second footplate can be angularly adjusted relative to each other about a pivot axis.   
     
     
         88 . The kit of  claim 87 , further comprising a third distractor configured to attach to first and second bone segments across a second osteotomy, the third distractor configured to move the first bone segment relative to the second bone segment. 
     
     
         89 . The kit of  claim 87 , wherein the second footplate of each of the first and second distractors is configured to angularly adjust with respect to the corresponding first footplate about the pivot axis. 
     
     
         90 . The kit of  claim 89 , wherein the angular adjustment of the second footplate further causes the second footplate to translate relative to the first footplate along the pivot axis. 
     
     
         91 . The kit of  claim 89 , wherein the hinge comprises a flexible pin configured to rotatably attach the first and second footplates together. 
     
     
         92 . A method of performing both a maxillary advancement and a maxillary expansion within the same surgery, the method including the steps:
 performing an osteotomy to separate a maxilla from a remaining portion of a skull;   advancing the maxilla to a desired position in an anterior-posterior direction;   securing a pair of the fixation devices to the posterior region of the maxilla and the remaining portion of the skull on each side of the skull;   performing a sagittal split osteotomy to split the maxilla into two segments;   expanding the maxilla to a desired orientation by expanding the distance between the two segments of the maxilla in the medial lateral direction; and   
       securing the segments of the maxilla to each other and the skull in the desired orientation. 
     
     
         93 . A method to perform a distraction, the method comprising the steps of:
 performing a first osteotomy to separate a first bone segment from a second bone segment;   attaching a first footplate of a first distractor to the first bone segment and attaching a second footplate of the first distractor to the second bone segment;   attaching a third footplate of a second distractor to the first bone segment and attaching a fourth footplate of the second distractor to the second bone segment;   actuating the first and second distractors to move the first bone segment in a first direction relative to the second bone segment; and   wherein movement of the first bone segment in the first direction causes the second and fourth footplates of the first and second distractors to rotate relative to the first and third footplates, respectively.