SUPPLEMENTAL SPINE FIXATION DEVICE AND METHOD
A supplemental spine fixation device and method is used in association with a primary spine fixation device. The supplemental spine fixation device includes a guide and spacer for distracting apart adjacent spinous processes and the device has hook members which hook about the first and second spinous processes. With the spinous processes distracted and the hook members about the spinous processes, the hook members can be rigidly secured to a hub in order to rigidly affix the spinous processes about the spacer. The rigidity between the spinous processes assures that the vertebral bodies will be held rigidly in place in order to promote bone growth and fusion. Further additional freedom of movement between the spacer and hub is accomplished with the spacer being pivotably mounted relative to the hub. The hooks have a tissue distracting lead-in guide for allowing the hooks to be easily urged between spinous processes.
1 . An apparatus, comprising:
an interspinous-process spacer having a proximal portion, a distal portion and a body portion between the proximal portion and the distal portion, the proximal portion having a cross-sectional size greater than a cross-sectional size of the body portion, the body portion being rotatably coupled to the proximal portion.
2 . The apparatus of claim 1 , wherein a proximal end of the distal portion of the interspinous-process spacer has a cross-sectional size substantially corresponding to the cross-sectional size of the body portion.
3 . The apparatus of claim 1 , wherein:
the interspinous-process spacer has an insertion configuration and a rotated configuration,
the body portion being at a first rotational orientation relative to the proximal portion when the interspinous-process spacer is in the insertion configuration,
the body portion being at a second rotational orientation relative to the proximal portion and different from the first rotational orientation when the interspinous-process spacer is in the rotated configuration.
4 . The apparatus of claim 1 , wherein:
the interspinous-process spacer has an insertion configuration and a rotated configuration,
the body portion is at a first distance from an instantaneous axis of rotation of a spinal column when the interspinous-process spacer is in the insertion configuration,
the body portion is at a second distance from the instantaneous axis of rotation and different from the first distance when the interspinous-process spacer is in the rotated configuration.
5 . The apparatus of claim 1 , wherein:
the interspinous-process spacer is configured to be inserted into a space between a pair of adjacent spinous processes,
a distance across the cross-sectional size of the proximal portion along an axis is greater than a distance across the space between the pair of adjacent spinous processes along the axis.
6 . The apparatus of claim 1 , wherein the distal portion of the interspinous-process spacer is configured to distract a pair of adjacent spinous processes when inserted between the pair of adjacent spinous processes.
7 . The apparatus of claim 1 , wherein the interspinous-process spacer is configured to be inserted into a space between a pair of adjacent spinous processes from a lateral direction and from a first side of the pair of adjacent spinous processes such that the distal portion of the interspinous-process spacer is disposed on a second side of the pair of adjacent spinous process opposite the first side.
8 . The apparatus of claim 1 , wherein the proximal portion of the interspinous-process spacer includes a first wing, the apparatus further comprising:
a second wing disposed distal to a proximal end of the body portion, the second wing having a cross-sectional size greater than the cross-sectional size of the body portion.
9 . The apparatus of claim 1 , wherein the body portion is rotably coupled to the proximal portion about a longituindal axis of the body portion.
10 . An apparatus, comprising:
an interspinous-process spacer having a proximal portion, a distal portion and a body portion between the proximal portion and the distal portion, the cross section of the body portion being non-circular, the body portion being rotatably coupled to the proximal portion.
11 . The apparatus of claim 10 , wherein the interspinous-process spacer defines a longitudinal axis, the cross section of the body portion being defined within a plane substantially orthogonal to the longitudinal axis.
12 . The apparatus of claim 10 , wherein:
the interspinous-process spacer has an insertion configuration and a rotated configuration,
the body portion being at a first rotational orientation relative to the proximal portion when the interspinous-process spacer is in the insertion configuration,
the body portion being at a second rotational orientation relative to the proximal portion and different from the first rotational orientation when the interspinous-process spacer is in the rotated configuration.
13 . The apparatus of claim 10 , wherein:
the interspinous-process spacer has an insertion configuration and a rotated configuration,
the body portion being at a first distance from an instantaneous axis of rotation of a spinal column when the interspinous-process spacer is in the insertion configuration,
the body portion being at a second distance from the instantaneous axis of rotation and different from the first distance when the interspinous-process spacer is in the rotated configuration.
14 . The apparatus of claim 10 , wherein:
the interspinous-process spacer is configured to be inserted into a space between a pair of adjacent spinous processes,
a distance across the cross-sectional size of the proximal portion along an axis is greater than a distance across the space between the pair of adjacent spinous processes along the axis.
15 . The apparatus of claim 10 , wherein the body portion is configured to be rotated relative to the proximal portion when the body portion is disposed between the pair of adjacent spinous processes.
16 . An apparatus, comprising:
an interspinous-process spacer having a body portion with a non-circular cross-sectional size,
the interspinous-process spacer having a first configuration associated with a rotational orientation of the body portion relative to a proximal portion of the interspinous-process spacer,
the interspinous-process spacer having a second configuration associated with a rotational orientation of the body portion relative to the proximal portion different from the rotational orientation associated with the first configuration.
17 . The apparatus of claim 16 , wherein the body portion is disposed between the proximal portion and a distal portion of the interspinous-process spacer, a proximal end of the distal portion of the interspinous-process spacer has a cross-sectional size substantially corresponding to the non-circular cross-sectional size of the body portion.
18 . The apparatus of claim 16 , wherein:
the body portion is at a first distance from an instantaneous axis of rotation of a spinal column when the interspinous-process spacer is in the first configuration,
the body portion is at a second distance from the instantaneous axis of rotation and different from the first distance when the interspinous-process spacer is in the second configuration.
19 . The apparatus of claim 16 , wherein the interspinous-process spacer defines a longitudinal axis, the non-circular cross-sectional size of the body portion being defined within a plane substantially orthogonal to the longitudinal axis, the proximal portion having a cross-sectional size different from the non-circular cross-sectional size of the body portion.
20 . The apparatus of claim 16 , wherein the proximal portion of the interspinous-process spacer includes a first wing, the apparatus further comprising:
a second wing disposed distal to a proximal end of the body portion, the second wing having a cross-sectional size greater than the non-circular cross-sectional size of the body portion,
the first wing having a cross-sectional size greater than the non-circular cross-sectional size of the body portion.
21 . An apparatus, comprising:
an interspinous-process spacer having a body portion with a non-circular cross sectional size,
the interspinous-process spacer having a first configuration associated with a distance of the body portion from an instantaneous axis of rotation of a spinal column,
the interspinous-process spacer having a second configuration associated with a distance of the body portion from the instantaneous axis of rotation different from the distance associated with the first configuration.
22 . The apparatus of claim 21 , wherein the body portion is disposed between the proximal portion and a distal portion of the interspinous-process spacer, a proximal end of the distal portion of the interspinous-process spacer has a cross-sectional size substantially corresponding to the non-circular cross-sectional size of the body portion.
23 . The apparatus of claim 21 , wherein:
the body portion has a first rotational orientation relative to the proximal portion when the interspinous-process spacer is in the first configuration,
the body portion has a second rotational orientation relative to the proximal portion and different from the first rotational orientation when the interspinous-process spacer is in the second configuration.
24 . The apparatus of claim 21 , wherein the interspinous-process spacer is configured to be inserted into a space between a pair of adjacent spinous processes from a lateral direction and from a first side of the pair of adjacent spinous processes such that the distal portion of the interspinous-process spacer is disposed on a second side of the pair of adjacent spinous process opposite the first side.
25 . The apparatus of claim 21 , wherein the proximal portion of the interspinous-process spacer includes a first wing, the apparatus further comprising:
a second wing disposed distal to a proximal end of the body portion, the second wing having a cross-sectional size greater than the non-circular cross-sectional size of the body portion,
the first wing having a cross-sectional size greater than the non-circular cross-sectional size of the body portion.