Abstract: An instrument for locating the cutting plane on the head of a long bone in a surgical procedure, wherein the head of the bone is replaced with a joint prosthesis component, includes an axial reference shaft which can be arranged parallel to the axis of the bone and a cutting guide which can be moved relative to the axial reference shaft. The cutting guide has a reference block for location against the bone relative to the edge of the bone at one side and at least one arm which is shaped so that it can extend from the cutting guide over the face of the head. The arm can be located positively with respect to features on the head so that the location of the reference block along the axis of the bone can be set with reference to features on the head of the bone which are contacted by means of the arm.

Abstract: A trial implant component for use in a surgical procedure for replacement of a joint between a long bone and another bone, comprises a metaphyseal part which can be located so that it extends into a cavity at the resected face of the long bone in contact with the internal wall of the cavity in the metaphyseal region, and a disk which has an essentially flat shape and which can be fitted to the metaphyseal part to provide a gauge as to the appropriate size of a head part which is to be selected according to the location of the axis of the bone relative to the edge of the resected bone.

Abstract: An instrument for locating the cutting plane on the head of a long bone in a surgical procedure, wherein the head of the bone is replaced with a joint prosthesis component, includes an axial reference shaft which can be arranged parallel to the axis of the bone and a cutting guide which can be moved relative to the axial reference shaft. The cutting guide has a reference block for location against the bone relative to the edge of the bone at one side and at least one arm which is shaped so that it can extend from the cutting guide over the face of the head. The arm can be located positively with respect to features on the head so that the location of the reference block along the axis of the bone can be set with reference to features on the head of the bone which are contacted by means of the arm.

Abstract: A trial implant component for use in a surgical procedure for replacement of a joint between a long bone and another bone, comprises a metaphyseal part which can be located so that it extends into a cavity at the resected face of the long bone in contact with the internal wall of the cavity in the metaphyseal region, and a disk which has an essentially flat shape and which can be fitted to the metaphyseal part to provide a gauge as to the appropriate size of a head part which is to be selected according to the location of the axis of the bone relative to the edge of the resected bone.