Abstract: A technique for locating an axis of a bone, which extends through the center of rotation of the bone around a joint between that bone and another bone, involves a. moving the bone in a plane about the said joint, between a first point and a second point, b. locating a third point which is equidistant from the first and second points, and c. locating the axis which passes through the third point, perpendicular to a line which connects the first and second points. The invention provides an instrument for performing this technique.

Abstract: A method for locating the mechanical axis of a long bone involves generating an image of the long bone and determining the angle between the mechanical axis of the bone and a reference axis, which contains at least two reference points towards one end of the bone. A reference arm is positioned relative to the at least two predetermined reference points, and the mechanical axis is located relative to the reference arm with reference to the previously determined angle.

Abstract: An orthopaedic surgical device for determining the joint force of a patient's joint includes a sensor housing and a handle. The sensor housing is shaped to be positioned in a patient's joint and includes a sensor array positioned therein and configured to generate sensor signals indicative of the joint force of the patient's joint. The handle includes a circuit positioned therein and configured to control a display located on the handle to provide a visual indication of the joint force of the patient's joint. The handle may be physically secured to the sensor housing or may be coupled thereto via a wire to facilitate communications between the sensor array and the circuit.

Abstract: A method for performing an orthopaedic surgical procedure on a knee joint of a patient includes resecting a proximal end of a patient's tibia to create a resected surface of the patient's tibia and positioning a tibial paddle of a sensor module on the proximal end of the patient's tibia. The tibial paddle includes a sensor array generating sensor signals indicative of the joint force of the patient's knee joint. The method also includes performing a number of orthopaedic surgical steps while monitoring a display of the sensor module that provides a visual indication of the medial-lateral balance of the joint force of the patient's knee joint.

Abstract: A computer assisted orthopaedic system includes a sensor module, a display, and a computer coupled to the display. The sensor module is configured to be positioned in a knee joint of a patient and transmit joint force data indicative of a joint force of the patient's knee joint. The computer includes a receiver circuit to receive the joint force data. The computer is configured to determine position data indicative of a position of a patient's femur and a patient's tibia and display an image of the patient's femur and the patient's tibia based on the position data. The computer is also configured to determine a medial force value and a lateral force value based on the joint force data and display the medial and lateral force values on the display.

Abstract: A hand-held display module includes a housing, a display coupled to the housing, and a circuit positioned in the housing and coupled to the display. The circuit includes a receiver circuit configured to communicate with a sensor module positioned in a knee joint of a patient to receive joint force data indicative of the joint force of the patient's knee joint. In one mode, the circuit is configured to display a visual indication of the medial-lateral balance of the joint force based on the joint force data. In a second mode, the circuit is configured to display a visual indication of the medial-lateral and the anterior-posterior balance of the joint force.

Abstract: An orthopaedic surgical device for determining the joint force of a patient's knee joint includes a tibial paddle shaped to be positioned in the patient's knee joint and a handle extending from the tibial paddle. The tibial paddle includes a sensor array positioned therein and configured to generate sensor signals indicative of the joint force of the patient's knee joint. The orthopaedic surgical device also includes a control circuit configured to control a display located on the handle to provide a visual indication of the medial and lateral balance of the joint force.

Abstract: An orthopaedic surgical device for determining the joint force of a patient's knee joint includes a tibial paddle shaped to be positioned in the patient's knee joint and a handle extending from the tibial paddle. The tibial paddle includes a sensor array positioned therein and configured to generate sensor signals indicative of the joint force of the patient's knee joint. The orthopaedic surgical device also includes a control circuit configured to control a display located on the handle to provide a visual indication of the medial and lateral balance of the joint force.

Abstract: A computer assisted orthopaedic system includes a sensor module, a display, and a computer coupled to the display. The sensor module is configured to be positioned in a knee joint of a patient and transmit joint force data indicative of a joint force of the patient's knee joint. The computer includes a receiver circuit to receive the joint force data. The computer is configured to determine position data indicative of a position of a patient's femur and a patient's tibia and display an image of the patient's femur and the patient's tibia based on the position data. The computer is also configured to determine a medial force value and a lateral force value based on the joint force data and display the medial and lateral force values on the display.

Abstract: A method for performing an orthopaedic surgical procedure on a knee joint of a patient includes resecting a proximal end of a patient's tibia to create a resected surface of the patient's tibia and positioning a tibial paddle of a sensor module on the proximal end of the patient's tibia. The tibial paddle includes a sensor array generating sensor signals indicative of the joint force of the patient's knee joint. The method also includes performing a number of orthopaedic surgical steps while monitoring a display of the sensor module that provides a visual indication of the medial-lateral balance of the joint force of the patient's knee joint.

Abstract: An orthopaedic surgical device for determining the joint force of a patient's joint includes a sensor housing and a handle. The sensor housing is shaped to be positioned in a patient's joint and includes a sensor array positioned therein and configured to generate sensor signals indicative of the joint force of the patient's joint. The handle includes a circuit positioned therein and configured to control a display located on the handle to provide a visual indication of the joint force of the patient's joint. The handle may be physically secured to the sensor housing or may be coupled thereto via a wire to facilitate communications between the sensor array and the circuit.

Abstract: A hand-held display module includes a housing, a display coupled to the housing, and a circuit positioned in the housing and coupled to the display. The circuit includes a receiver circuit configured to communicate with a sensor module positioned in a knee joint of a patient to receive joint force data indicative of the joint force of the patient's knee joint. In one mode, the circuit is configured to display a visual indication of the medial-lateral balance of the joint force based on the joint force data. In a second mode, the circuit is configured to display a visual indication of the medial-lateral and the anterior-posterior balance of the joint force.

Abstract: A technique for locating an axis of a bone, which extends through the centre of rotation of the bone around a joint between that bone and another bone, involves a. moving the bone in a plane about the said joint, between a first point and a second point, b. locating a third point which is equidistant from the first and second points, and c. locating the axis which passes through the third point, perpendicular to a line which connects the first and second points. The invention provides an instrument for performing this technique.

Abstract: A method for locating the mechanical axis of a long bone involves generating an image of the long bone and determining the angle between the mechanical axis of the bone and a reference axis, which contains at least two reference points towards one end of the bone. A reference arm is positioned relative to the at least two predetermined reference points, and the mechanical axis is located relative to the reference arm with reference to the previously determined angle.

Abstract: A reamer guide is described for reaming a cavity within a tibia. The reamer guide comprises: a plate having a circular aperture there through and defining a plane; and a disc rotatably mounted in the aperture, the disc having a bushing therein defining a reamer axis offset from the center of the disc for receiving a reamer in use and in which the disc is rotatable about an axis transverse to the plane of the plate. Thus a cavity larger than the reamer can be accurately and easily formed.