Apparatus and method for determining the tension on a ligament graft
First Claim
1. An instrument for determining the variation in tension of a ligament graft extending between first and second fixation sites positioned on first and second articulated bones, respectively, comprising:
- a yoke, said yoke having means for securing said yoke to one of the first and second bones;
a yoke plate rotatably mounted to said yoke;
main housing means, said housing means for connection to said yoke plate;
sled means slidably connected to said main housing, said sled means for connection to the ligament graft and thereby defining one of the first and second fixation sites, respectively;
means for adjusting the position of said sled means relative to said housing means so as to place a desired degree of tension on the ligament graft; and
transducer means associated with said means for adjusting for determining changes in tension from said desired degree as the first and second bones are moved relative to one another.
1 Assignment
0 Petitions
Accused Products
Abstract
An instrument for determining the variation in tension of a ligament graft extending between first and second proposed fixation sites positioned on first and second articulated bones, respectively, comprises a yoke which carries a device for securing the yoke to one of the first and second bones. A yoke plate is rotatably carried by the yoke. A main housing is adapted for connection to the yoke plate. A sled is slidably carried by the main housing. The sled is adapted for connection to the ligament graft. A mechanism is provided for adjusting the position of the sled relative to the housing so as to place a desired degree of tension on the ligament graft. A transducer is associated with the mechanism for adjusting for determining changes in tension, if any, from the desired degree of tension as the first and second bones are moved relative to one another.
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Citations
15 Claims
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1. An instrument for determining the variation in tension of a ligament graft extending between first and second fixation sites positioned on first and second articulated bones, respectively, comprising:
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a yoke, said yoke having means for securing said yoke to one of the first and second bones; a yoke plate rotatably mounted to said yoke; main housing means, said housing means for connection to said yoke plate; sled means slidably connected to said main housing, said sled means for connection to the ligament graft and thereby defining one of the first and second fixation sites, respectively; means for adjusting the position of said sled means relative to said housing means so as to place a desired degree of tension on the ligament graft; and transducer means associated with said means for adjusting for determining changes in tension from said desired degree as the first and second bones are moved relative to one another. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An instrument for measuring the variation in tension of a ligament graft extending from a first fixation site on a patient'"'"'s femur through a tibial tunnel toward a second fixation site on the patient'"'"'s tibia, comprising;
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a yoke, said yoke having means for securing said yoke to the tibia; a main housing; yoke plate means for connection to said main housing, said yoke plate means also for rotatable connection to said yoke such that said main housing is in line with the tibial bore when said yoke plate means is in a first position and is parallel to the tibia when said yoke plate means is in a second position; a sled slidably connected to said main housing; a drill sleeve connected to said sled and having portion means thereof for receiving a loop formed in the end of the ligament graft thereby defining said second fixation site; means for adjusting the position of said sled relative to said housing so as to place a desired degree of tension on the ligament graft; and transducer means associated with said means for adjusting for measuring changes in tension from said desired degree as the tibia is moved relative to the femur.
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10. A method of measuring the variation in tension of a ligament graft extending through a bore between a first and second fixation sites positioned on first and second articulated bones, respectively, comprising the steps of:
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positioning an alignment device on a footplate; using the alignment device to position the footplate relative to the bore; securing said footplate to one of the first and second bones; removing said alignment device and connecting a housing having a sled, means for adjusting the position of said sled relative to said housing, and a transducer to said footplate; connecting the ligament graft to said sled and thereby forming one of the first and second fixation sites, respectively; adjusting the tension on the ligament graft with said adjustment means to place a desired degree of tension on the ligament graft; and measuring changes in tension from said desired degree with said transducer as the first and second bones are moved relative to one another. - View Dependent Claims (11, 12, 13, 14, 15)
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Specification