Abstract: A tool (2) for forming a cavity within a bone (6) comprises a shaft (10) and a blade (12) which is pivotally mounted on the shaft towards one end thereof. A rod is fastened to the blade, and can slide within the shaft, to change the pivotal position of the blade relative to the shaft. The tool can include an incremental drive to cause the rod to translate along the shaft when the shaft and rod are rotated.

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 tool (2) for forming a cavity within a bone (6) comprises a shaft (10) and a blade (12) which is pivotally mounted on the shaft towards one end thereof. A rod is fastened to the blade, and can slide within the shaft, to change the pivotal position of the blade relative to the shaft. The tool can include an incremental drive to cause the rod to translate along the shaft when the shaft and rod are rotated.

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 surgical guide and computer aided surgery method of use thereof are described. The guide is mounted on a body part to guide a device along a guide axis. The body has a channel in it which defines the guide axis and which receives the device in use. A base engages the surface of the body part when mounted on it in use, and supports the body over an entry point for the body part with the guide axis passing through the entry point. A pivot mechanism attaches the body to the base. The body can move relative to the base by pivoting only. The guide is configured such that the entry point is a centre of motion about which the body pivots.

Abstract: A vertebral-column device that is suitable to be received in an intervertebral space between two dorsal vertebrae, the prosthesis comprising a curved strip of biocompatible material. The width of the strip being such that after placement, the strip makes contact with the vertebrae. The strip is manufactured from a material that can undergo great deformations before permanent deformation arises. The strip is curved in a shape in which the extremities are situated apart from one another and the radius of the curved parts and the thickness of the strip are chosen in such a way that when the strip is bent out into an approximately straight strip, scarcely any permanent deformation arises. Thus, the strip which has been bent out into an approximately straight strip is capable of being introduced into an intervertebral space where the strip assumes its original curved shape.