Hinged fixation devices for combined upper jaw correction
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 method of moving a first bone fragment relative to a second bone fragment using a distractor, the method comprising the steps of:
pivoting a first footplate of the distractor about a first hinge relative to an actuator of the distractor about a first axis, wherein the actuator is elongate along a longitudinal direction and the first axis is oriented in a perpendicular direction that is perpendicular to the longitudinal direction;
attaching the first footplate to the first bone fragment;
pivoting a second footplate of the distractor about a second hinge relative to the actuator of the distractor about a second axis that is both parallel to the first axis and aligned with the first axis with respect to the longitudinal direction;
attaching the second footplate to the second bone fragment;
rotating a screw of the actuator relative to a sleeve of the actuator about a central axis that is oriented along the longitudinal direction wherein the rotating step causes the second footplate to translate along the actuator relative to the first footplate,
wherein the second axis intersects the sleeve, and the second hinge overlaps opposed ends of the actuator along the perpendicular direction at two opposed regions of overlap, such that the actuator is received between the two regions of overlap.
2. The method of claim 1 , wherein the step of pivoting the first footplate is performed before the step of attaching the first footplate.
3. The method of claim 1 , wherein the step of attaching the second footplate is performed before the step of attaching the first footplate.
4. The method of claim 1 , wherein the first attaching step includes the step of inserting a plurality of fasteners through respective holes defined by the first footplate and into the first bone fragment, and the second attaching step includes the step of inserting a plurality of fasteners through respective holes defined by the second footplate and into the second bone fragment.
5. The method of claim 1 , wherein during the rotating step, a bone attachment portion of the first footplate is angularly offset with respect to a bone attachment portion of the second footplate.
6. The method of claim 1 , wherein the rotating step includes the step of: 1) rotating the screw relative to the sleeve about the central axis in a first direction which causes the second footplate to translate along the actuator away from the first footplate; 2) rotating the screw relative to the sleeve about the central axis in a second direction, opposite the first direction, which causes the second footplate to translate along the actuator toward the first footplate; or 3) both.
7. The method of claim 1 , wherein during the rotating step a pawl of a retention mechanism of the distractor rides along a tooth of a gear of the retention mechanism.
8. The method of claim 1 , wherein the actuator includes a first end and a second end, the second end opposite the first end with respect to the longitudinal direction such that the actuator terminates at each of the first end and the second end with respect to the longitudinal direction, and the rotating step includes the step of maintaining a distance as measured from the first end to the second end along the longitudinal direction.