SPINE DISTRACTION IMPLANT AND METHOD
A spine distraction implant alleviates pain associated with spinal stenosis and facet arthropathy by expanding the volume in the spine canal and/or neural foramen. The implant provides a spinal extension stop while allowing freedom of spinal flexion.
1 . An apparatus, comprising:
a first implant member having a first portion and a second portion, the second portion configured to be disposed between a first spinous process and a second spinous process; and
a second implant member having a first portion and a second portion, the first portion of the second implant member configured to be slidably disposed within the first portion of the first implant member, the second portion of the second implant member configured to limit movement of the first implant member relative to the first spinous process and the second spinous process.
2 . The apparatus of claim 1 , wherein the first portion of the second implant member is configured to move within the first portion of the first implant member in a direction substantially normal to a longitudinal axis of the second portion of the first implant member.
3 . The apparatus of claim 1 , wherein the first portion of the second implant member is configured to move within the first portion of the first implant member when the second portion of the first implant member is disposed between the first spinous process and the second spinous process.
4 . The apparatus of claim 1 , wherein the second portion of the first implant member has an outer surface that is curved about a longitudinal axis of the second portion of the first implant member.
5 . The apparatus of claim 1 , wherein the second portion of the first implant member has an outer surface that is curved about a longitudinal axis of the second portion of the first implant member, a portion of the outer surface configured to contact an inferior surface of the first spinous process.
6 . The apparatus of claim 1 , wherein the second portion of the second implant member is configured to contact a side surface of the second spinous process.
7 . The apparatus of claim 1 , wherein:
the second portion of the first implant member is configured to contact an inferior surface of the first spinous process; and
the second portion of the second implant member is configured to contact a side surface of the second spinous process.
8 . The apparatus of claim 1 , wherein the first portion of the first implant member includes a locking member to maintain a position of the second implant member relative to the first implant member.
9 . The apparatus of claim 1 , further comprising:
a set screw disposed within an opening defined by the first portion of the first implant member, the set screw configured to engage the first portion of the second implant member to maintain a position of the second implant member relative to the first implant member.
10 . The apparatus of claim 1 , wherein:
the first portion of the first implant member defines an opening having a rectangular cross-sectional area; and
the first portion of the second implant member includes a shaft configured to be disposed within the opening, the shaft having a rectangular cross-sectional area.
11 . The apparatus of claim 1 , wherein the second portion of the first implant member includes a tapered end portion configured to displace a bodily tissue.
12 . The apparatus of claim 1 , wherein the second portion of the first implant member is configured to rotate relative to the first portion of the first implant member about a longitudinal axis of the second portion of the first implant member.
13 . An apparatus, comprising:
a first implant member configured to be disposed within a space between a first spinous process and a second spinous process such that a longitudinal axis of the first implant member is substantially parallel to a lateral axis defined by the space between the first spinous process and the second spinous process; and
a second implant member coupled to the first implant member, the second implant member configured to limit movement of the first implant member relative to the first spinous process and the second spinous process, the second implant member configured to translate relative to the first implant member along an axis substantially normal to the longitudinal axis of the first implant member.
14 . The apparatus of claim 13 , wherein:
a first portion of the second implant member is configured to be slidably disposed within an opening defined by the first implant member; and
a second portion of the second implant member is configured to contact a side surface of the first spinous process.
15 . The apparatus of claim 13 , wherein a portion of the second implant member is configured to rotate relative to the first implant member.
16 . The apparatus of claim 13 , wherein a portion of the first implant member has an outer surface that is curved about the longitudinal axis of the first implant member.
17 . The apparatus of claim 13 , wherein:
a portion of the first implant member is configured to contact an inferior surface of the first spinous process; and
a portion of the second implant member is configured to contact a side surface of the second spinous process.
18 . The apparatus of claim 13 , wherein the first implant member includes a locking member to maintain a position of the second implant member relative to the first implant member.
19 . The apparatus of claim 13 , further comprising:
a set screw disposed within an opening defined by the first implant member, the set screw configured to engage a portion of the second implant member to maintain a position of the second implant member relative to the first implant member.
20 . The apparatus of claim 13 , wherein the second portion of the first implant member includes a tapered end portion configured to displace a bodily tissue.
21 . An apparatus, comprising:
a first implant member having a first portion and a second portion, the first portion of the first implant member configured to contact a first spinous process; and
a second implant member having a first portion and a second portion, the first portion of the second implant member to contact a second spinous process,
the second portion of the second implant member configured to be slidably disposed within the second portion of the first implant member such that the second implant member can translate relative to the first implant member to adjust a size of a space between the first spinous process and the second spinous process.
22 . The apparatus of claim 21 , wherein the second portion of the second implant member is configured to move within the second portion of the first implant member when the first portion of the first implant member is in contact with the first spinous process.
23 . The apparatus of claim 21 , wherein the second portion of the first implant member includes a locking member to maintain a position of the second implant member relative to the first implant member.
24 . The apparatus of claim 21 , further comprising:
a set screw disposed within an opening defined by the second portion of the first implant member, the set screw configured to engage the second portion of the second implant member to maintain a position of the second implant member relative to the first implant member.
25 . The apparatus of claim 21 , wherein the second portion of the first implant member is configured to rotate relative to the second portion of the second implant member.
26 . The apparatus of claim 21 , further comprising:
a third implant member coupled to the first implant member, the third implant member configured to be disposed within the space between the first spinous process and the second spinous process.
27 . The apparatus of claim 21 , further comprising:
a third implant member coupled to the first implant member, the third implant member configured to be disposed within the space between the first spinous process and the second spinous process,
the third implant member including a tapered end portion configured to adjust the size of the space between the first spinous process and the second spinous process.
28 . A method, comprising:
inserting an implant having a first implant member and a second implant member such that a portion of the first implant member contacts a first spinous process and a portion of the second implant member contacts the a second spinous process;
translating the second implant member relative to the first implant member to adjust a distance between the first spinous process and the second spinous process.
29 . The method of claim 28 , wherein the inserting includes inserting the implant via a lateral access passageway.
30 . The method of claim 28 , wherein the inserting is performed such that the portion of the first implant member contacts at least a side surface of the first spinous process and the portion of the second implant member contacts at least a side surface of the second implant member.
31 . The method of claim 28 , wherein:
the portion of the first implant member is a first portion;
the portion of the second implant member is a second portion; and
the translating includes sliding a second portion of the second implant member within a second portion of the first implant member.
32 . The method of claim 28 , further comprising:
locking temporarily a position of the second implant member relative to the first implant member.
33 . The method of claim 28 , further comprising:
actuating a set screw within an opening defined by the first implant member to maintain a position of the second implant member relative to the first implant member.