Abstract: A method, apparatus and computer program code for automatically planning at least a part of a surgical procedure to be carried out on a body part of a patient are described. A virtual model of the body part is provided, in which the model has data associated with it representing at least a part of a planned surgical procedure. The virtual model is then morphed to the body part using data derived from the patient's real body part thereby also adapting the part of the planned surgical procedure to reflect the anatomy of the patient's real body part.

Abstract: A computer aided surgery system, method, surgical method and instrument for guiding the positioning of an acetabular cup in a pelvis are described. The position of the transverse acetabular ligament of the pelvis and the position of the acetabular labrum of the pelvis are determined. The orientation of an acetabular plane including the acetabular labrum and the transverse acetabular ligament is calculated. A planned position for the acetabular cup is determined, in which an inlet plane of the cup is substantially parallel to the acetabular plane. The instrument comprises a mounting for attaching the instrument to a patient, a support, a guide defining a longitudinal axis, and for receiving a further instrument bearing the acetabular cup implant, and an adjustment mechanism. The adjustment mechanism can allow the angular orientation of the guide to be adjusted about at least two different axes to allow the inclination and version or anteversion of the longitudinal axis to be altered.

Abstract: Methods, systems and data processing apparatus and methods are described for use in planning and carrying out a surgical procedure on a joint of a subject. The joint includes a first component and a second component, the first and second components being relatively movable. Joint data describing the configuration of the joint is captured while the joint is in a functional state wherein the joint is undergoing its usual load bearing functional behaviour. The joint data is analyzed to determine joint component orientation data specifying the relative orientation of the first and second components. The orientation of prosthetic implants to be used in the surgical procedure to recreate the joint is planned using the joint component orientation data. The planned orientation of the prosthetic implants improves the recreation of the functional state of the joint.

Abstract: A computer aided surgery system, method, surgical method and instrument for guiding the positioning of an acetabular cup in a pelvis are described. The position of the transverse acetabular ligament of the pelvis and the position of the acetabular labrum of the pelvis are determined. The orientation of an acetabular plane including the acetabular labrum and the transverse acetabular ligament is calculated. A planned position for the acetabular cup is determined, in which an inlet plane of the cup is substantially parallel to the acetabular plane. The instrument comprises a mounting for attaching the instrument to a patient, a support, a guide defining a longitudinal axis, and for receiving a further instrument bearing the acetabular cup implant, and an adjustment mechanism. The adjustment mechanism can allow the angular orientation of the guide to be adjusted about at least two different axes to allow the inclination and version or anteversion of the longitudinal axis to be altered.

Abstract: A method and apparatus for registering a pelvis of a subject in a lateral position are described. The method includes the position of at least a first point and a second point in a first plane parallel to a first cardinal plane of the pelvis. Then the position of at least a third point and a fourth point in a second plane parallel to a second cardinal plane of the pelvis are determined, in which the second plane is perpendicular to the first plane. Then the position of a third cardinal plane of the pelvis is determined, in which the third cardinal plane is perpendicular to the first cardinal plane and second cardinal plane. The apparatus includes a computer aided surgery system and an instrument trackable by a tracking part of the system.

Abstract: A template for use in a surgical procedure is described. The template comprises a template body, means for fixing the template body to a patient's tissue, a feature on the template body to indicate the appropriate location of the template body relative to an anatomical landmark, a feature on the template body to indicate the required location of a sensor which is to be implanted in the patient during the surgical procedure, and a feature on the template body for indicating the required location of a field generator which can be fixed to the template.