Abstract: An orthopaedic surgical instrument includes a patella trial and drill guide that may be used to both perform a surgical trial of the patellofemoral joint and guide the surgeon in drilling a number of anchor holes in the patella of the patient.

Abstract: A method of calibrating a contact probe having a contact element includes measuring with the contact probe a first geometric property of a calibrated artifact and a second geometric property of the or a further calibrated artifact. The first and second geometric properties are such that a deviation between a measured value and the expected value, resulting from a difference between an effective diameter of the contact element and an assumed diameter used for determining the measured value, has the opposite sign for each of the first and second geometric properties. The method further includes identifying a difference in the effective diameter of the contact element from the assumed diameter including comparing deviations of the measured value to the expected value for each of the first and second geometric properties to determine whether there is a difference in the deviations.

Abstract: A method of calibrating a contact probe having a contact element includes measuring with the contact probe a first geometric property of a calibrated artefact and a second geometric property of the or a further calibrated artefact. The first and second geometric properties are such that a deviation between a measured value and the expected value, resulting from a difference between an effective diameter of the contact element and an assumed diameter used for determining the measured value, has the opposite sign for each of the first and second geometric properties. The method further includes identifying a difference in the effective diameter of the contact element from the assumed diameter including comparing deviations of the measured value to the expected value for each of the first and second geometric properties to determine whether there is a difference in the deviations.

Abstract: Disclosed is a method of moving an articulating mechanism (22,410) for a measuring device, comprising the steps of: releasing two bodies (14,16, 410a,410b) which form the articulating mechanism allowing relative movement thereof; moving one of the bodies with respect to the other until a desired position is reached; and re-constraining the two bodies so they are relatively fixed, perhaps as part of a locking process, characterised in that relative movement prior to re-constraining at the desired position occurs under particular conditions. The particular conditions including moving from the same direction; and stopping, slowing down or maintaining the condition at a position adjacent to the desired position. Also disclosed is a method of positioning an articulating mechanism (22,410) for a measuring device which is controlled by a potentiometer and a controller (11) for a measuring device.

Abstract: Disclosed is a method of moving an articulating mechanism (22,410) for a measuring device, comprising the steps of: releasing two bodies (14,16, 410a,410b) which form the articulating mechanism allowing relative movement thereof; moving one of the bodies with respect to the other until a desired position is reached; and re-constraining the two bodies so they are relatively fixed, perhaps as part of a locking process, characterised in that relative movement prior to re-constraining at the desired position occurs under particular conditions. The particular conditions including moving from the same direction; and stopping, slowing down or maintaining the condition at a position adjacent to the desired position. Also disclosed is a method of positioning an articulating mechanism (22,410) for a measuring device which is controlled by a potentiometer and a controller (11) for a measuring device.