Head center instrument and method of using the same
First Claim
1. An orthopaedic instrument for establishing reference markings relating to the position of a ball in a ball joint, and for evaluating the positioning of a prosthetic implant replacing said ball, said instrument comprising:
- an instrument head chuck;
a plurality of locator devices adjustably received by said head chuck and adapted to at least partially engage the ball;
adjustment means associated with said head chuck and said plurality of locator devices for bringing each one of said plurality of locator devices into engagement with the ball, and for securing the position of said head chuck relative to the ball; and
an orientation arm extending outwardly from said head chuck, said orientation arm including reference indicia for establishing and comparing bone markings.
3 Assignments
0 Petitions
Accused Products
Abstract
An orthopaedic instrument for comparing post-surgical joint geometry to pre-surgical joint geometry. The instrument has a head chuck which can be secured to the ball of a ball joint, and an arm having reference indicia thereon. Markings indicative of the pre-surgical joint geometry are made on the bone with reference to the center of the ball. After replacement with a prosthetic ball, the post-operative geometry is verified by securing the head chuck to the prosthetic ball, and comparing the location of the bone markings against the reference indicia on the arm. As needed, adjustments are made in the prosthetic components.
279 Citations
23 Claims
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1. An orthopaedic instrument for establishing reference markings relating to the position of a ball in a ball joint, and for evaluating the positioning of a prosthetic implant replacing said ball, said instrument comprising:
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an instrument head chuck;
a plurality of locator devices adjustably received by said head chuck and adapted to at least partially engage the ball;
adjustment means associated with said head chuck and said plurality of locator devices for bringing each one of said plurality of locator devices into engagement with the ball, and for securing the position of said head chuck relative to the ball; and
an orientation arm extending outwardly from said head chuck, said orientation arm including reference indicia for establishing and comparing bone markings. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for comparing the neck angle and length of a prosthetic ball component of a ball joint to the neck angle and length of the natural ball, comprising:
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providing an instrument having a head chuck adapted to be secured in position relative to the ball of a ball joint and of a prosthetic implant;
providing an arm on said instrument extending from said head, said arm being of a length to reach a surface area of the bone remaining after surgical reduction;
providing a plurality of reference indicia on said arm of said instrument;
exposing the natural ball component of the ball joint;
affixing said arm relative to the center point of the ball component;
establishing bone markings relative to specific ones of said plurality of indicia on the orientation arm;
removing the arm;
replacing, surgically, the natural ball component with a prosthetic ball component;
securing the orientation arm relative to the center point of the prosthetic ball;
comparing the bone markings to the indicia on the orientation arm; and
adjusting, as necessary, the neck length and angle of the prosthetic ball to match said bone markings against said specific ones of said plurality of indicia against which said bone markings were made. - View Dependent Claims (12, 13, 14, 15, 16)
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17. An orthopaedic instrument comprising:
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a head chuck for engaging a ball of a ball joint, said head chuck including a cylindrical body and a cap rotatably secured in said body;
an orientation arm extending radially outwardly from said body;
a plurality of locator devices associated with said head chuck for securing said head chuck relative to the center point of a ball component in a ball joint; and
indicia on said orientation arm having reference points for making markings. - View Dependent Claims (18, 19, 20)
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21. A method for replacing a femoral head, comprising;
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exposing the femoral head surgically;
securing a reference gauge against the posterior femur relative to the femoral head center;
creating reference bone markings on the posterior femur;
removing the reference gauge;
replacing the femoral head with a prosthetic femoral head;
re-securing the reference gauge against the posterior femur relative to the center of the prosthetic femoral head;
comparing the bone markings against the reference gauge; and
adjusting the prosthetic femoral head to achieve a relationship between the and the reference gauge similar to the relationship when said bone markings were made. - View Dependent Claims (22, 23)
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Specification