Surgical distraction device and procedure
A surgical procedure for distracting two anatomical structures, according to which one or more cams are rotatably mounted on a body member and are inserted between the structures and rotated to distract the structures.
1 . A surgical distraction device adapted to distract two anatomical structures comprising:
a body member;
at least one cam rotatably mounted on the body member and having a relatively large dimension and a relatively small dimension, and
means mounted on the body member for rotating the cam,
the cam adapted to be inserted between the structures with its relatively small dimension extending between the structures and rotated towards a position whereby its relatively large dimension extends between the structures to distract the structures.
2 . The device of claim 1 wherein the means comprises a knob rotatably mounted on the body member, and a link connecting the knob to the cam so that rotation of the knob causes corresponding rotation of the cam.
3 . The device of claim 1 further comprising indicia on the knob for indicating the amount of rotation of the knob and therefore the amount of rotation of the cam.
4 . The device of claim 1 wherein the body member comprises two spaced arms one of which engages one of the structures, at least one cam being rotatably mounted on the other arm and engaging the other structure.
5 . The device of claim 4 wherein two spaced dimples are mounted on the one arm for receiving the one structure.
6 . The device of claim 4 wherein there are two cams rotatably mounted on the other arm and adapted to rotate in opposite directions.
7 . The device of claim 5 wherein one cam is axially offset from the other, and each cam engages the corresponding structure during the rotation to distract the structures.
8 . The device of claim 1 wherein the body member comprises two spaced arms that respectively engage the structures, and wherein the cam is rotatably mounted on one of the arms.
9 . The device of claim 8 wherein two spaced dimples are mounted on each arm for receiving the structures.
10 . The device of claim 8 further comprising a pin extending from the one arm and into a slot in the one cam so that rotation of the cam drives the one arm into engagement with its corresponding structure to distract the structures.
11 . The device of claim 1 wherein the body member comprises two spaced arms one of which engages one of the structures, and where there are at least two cams rotatably mounted on the other arm and adapted to engage the other structure.
12 . The device of claim 11 wherein there are at least three cams rotatably mounted on the other arm.
13 . The device of claim 11 wherein the sizes of the cams vary.
14 . The device of claim 11 wherein the relatively angular positions of the cams vary.
15 . The device of claim 11 further comprising a shaft extending from the arm, at least one of the cams being eccentrically mounted on the shaft with variable degrees of eccentricity.
16 . A surgical procedure for distracting two anatomical structures, the procedure comprising:
providing a cam having a relatively large dimension and a relatively small dimension;
rotatably mounting the cam on a body member;
grasping the body member and inserting the cam between the structures with its relatively small dimension extending between the structures; and
rotating the cam relative to the body member towards a position whereby its relatively large dimension extends between the structures to distract the structures.
17 . The procedure of claim 16 wherein the step of rotating comprises rotatably mounting a knob on the body member, connecting the knob to the cam, and rotating the knob to cause corresponding rotation of the cam.
18 . The procedure of claim 17 further comprising indicating the amount of rotation of the knob and therefore the amount of rotation of the cam.
19 . The procedure of claim 16 wherein the step of rotating comprises rotatably mounting two cams on the body member so that they rotate in opposite directions.
20 . The procedure of claim 19 further comprising axially offsetting one cam from the other, and engaging each cam with the corresponding structure during the rotation to distract the structures.
21 . The procedure of claim 16 wherein the step of rotating comprises driving part of the body member into engagement with its corresponding structure to distract the structures.
22 . The procedure of claim 16 wherein there are at least three cams rotatably mounted on the body member and adapted to engage a structure.
23 . The procedure of claim 16 further comprising varying the angular position of the cams relative to the body member.
24 . The procedure of claim 16 further comprising eccentrically mounting the cams on a shaft of the body member with variable degrees of eccentricity.