Process and device for the preoperative determination of the positioning data endoprosthetic parts
First Claim
1. A method for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising the steps of:
- moving the thigh bone of the knee joint relative to a corresponding hip bone, to determine a first articular point for said thigh bone in the area of the hip joint;
determining a second articular point for said thigh bone in the area of the knee joint;
determining a first characteristic direction for said thigh bone by way of a straight-line connection of the first and second articular points;
moving the lower leg bone of the knee joint relative to a corresponding ankle bone, to determine a third articular point in the area of an ankle joint for said lower leg bone;
determining a fourth articular point in the area of the knee joint for said lower leg bone;
determining a second characteristic direction for said lower leg bone by way of a straight-line connection of the third and fourth articular points; and
determining the orientation of endoprosthetic parts relative to the first and second characteristic directions.
8 Assignments
0 Petitions
Accused Products
Abstract
In order to be able to ascertain the position of the bone in the body without complicated procedures in a process for the preoperative determination of the positioning data of endoprosthetic parts of a central joint relative to the bones forming the central joint, a respective outer articular point is determined by way or movement of the bones about a respective outer joint which is located at the end of the two bones facing away from the central joint. An articular point is determined for each of the two bones in the area of the central joint, and a direction characteristic for each of these bones is determined by way of a straight-line connection of the two articular points obtained in this manner for the two bones. The orientation of the endoprosthetic parts relative to this characteristic direction is then determined. Apparatus for carrying out the process is also provided.
157 Citations
42 Claims
-
1. A method for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising the steps of:
-
moving the thigh bone of the knee joint relative to a corresponding hip bone, to determine a first articular point for said thigh bone in the area of the hip joint; determining a second articular point for said thigh bone in the area of the knee joint; determining a first characteristic direction for said thigh bone by way of a straight-line connection of the first and second articular points; moving the lower leg bone of the knee joint relative to a corresponding ankle bone, to determine a third articular point in the area of an ankle joint for said lower leg bone; determining a fourth articular point in the area of the knee joint for said lower leg bone; determining a second characteristic direction for said lower leg bone by way of a straight-line connection of the third and fourth articular points; and determining the orientation of endoprosthetic parts relative to the first and second characteristic directions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
-
22. A device for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising:
-
at least one marking element securable to each of the thigh bone and a hip bone, said thigh bone and hip bone being connected at a hip joint; at least one marking element securable to each of the lower leg bone and an ankle bone forming an ankle joint; a measuring device for determining the position of the marking elements in space; a data processing system adapted to receive signals corresponding to positioning data of the marking elements from the measuring device; said data processing system being responsive to the signals during movement of the thigh bone relative to the hip joint to determine the point of greatest invariance at the hip joint as a first articular point; and said data processing system being responsive to the signals during the movement of the lower leg bone relative to the ankle joint to determine the point of greatest invariance at the ankle joint as a third articular point; wherein; a second articular point is determined for said thigh bone in the area of the knee joint; a first characteristic direction is determined for the thigh bone from the positions of the first articular point and the second articular point; a fourth articular point is determined for said lower leg bone in the area of the knee joint; and a second characteristic direction is determined for the lower leg bone from the position of the third articular point and the fourth articular point. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40)
-
-
41. A device for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising:
-
at least one marking element securable to each of the thigh bone and a hip bone, said thigh bone and hip bone being connected at a hip joint; a measuring device for determining the position of the marking elements in space; a data processing system adapted to receive signals corresponding to positioning data of the marking elements from the measuring device; said data processing system being responsive to the signals during movement of the thigh bone relative to the hip joint to determine the point of greatest invariance at the hip joint as a first articular point; wherein; a second articular point is determined for said thigh bone in the area of the knee joint; and a first characteristic direction is determined for the thigh bone from the positions of the first articular point and the second articular point; a scanning instrument is associated with the data processing system for supplying signals to the data processing system corresponding to the positioning of the scanning instrument; and the data processing system generates a set of data describing the course of a joint surface of at least one of the bones adjoining the knee joint from a plurality of signals generated by application of the scanning instrument to the joint surface.
-
-
42. A device for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising:
-
at least one marking element securable to each of the thigh bone and a hip bone, said thigh bone and hip bone being connected at a hip joint; a measuring device for determining the position of the marking elements in space; a data processing system adapted to receive signals corresponding to positioning data of the marking elements from the measuring device; said data processing system being responsive to the signals during movement of the thigh bone relative to the hip joint to determine the point of greatest invariance at the hip joint as a first articular point; wherein; a second articular point is determined for said thigh bone in the area of the knee joint; and a first characteristic direction is determined for the thigh bone from the positions of the first articular point and the second articular point; a marking element with an orientation determined by the measuring device is associated with a sawing jig, so that signals corresponding to the orientation are transferred to the data processing system; the data processing system generates difference signals for observing deviation in the orientation of the sawing jig in relation to the characteristic direction; the data processing system indicates the difference signals optically or acoustically; said signals are minimal with a correct orientation; and two separate difference signals are generated for angular deviations in planes extending at right angles to one another.
-
Specification