Abstract: The invention relates to a hydraulic traction apparatus for surgery, in particular for knee surgery, having at least one pair of working sections which can be adjusted relative to one another and at least one exchangeable piston in cylinder arrangement made of plastic whose piston is releasably coupled to the one working section and whose cylinder is releasably connected to the other working section and which is stiffened by an outer support mount supporting the cylinder from the outside and by at least one inner reinforcement insert which can be inserted into the cylinder together with the piston.

Abstract: The invention relates to a hydraulic traction apparatus for surgery, in particular for knee surgery, having at least one pair of working sections which can be adjusted relative to one another and at least one exchangeable piston in cylinder arrangement made of plastic whose piston is releasably coupled to the one working section and whose cylinder is releasably connected to the other working section and which is stiffened by an outer support mount supporting the cylinder from the outside and by at least one inner reinforcement insert which can be inserted into the cylinder together with the piston.

Abstract: The invention relates to a drilling jig for the determination of the axis of a femur head prosthesis. A guide tube (6), around whose longitudinal axis (14) a sensing probe can be rotated, has a rounded head (7) which is supported in a housing (3) pivotable in all directions and fixable by first clamping elements (5), in order to fix its longitudinal axis in a desired angle. The housing (3) is displaceable in all directions transversely to its longitudinal axis with respect to a base part (1) which can be anchored to the femur head (10) and fixable by two clamping elements (4) in order to define the position of the longitudinal axis (14) of the guide tube (6) by rotation of a sensing probe around this longitudinal axis (14) relative to the cross-section of the femur neck (16).

Abstract: The invention relates to a drilling jig for the determination of the axis of a femur head prosthesis. A guide tube (6), around whose longitudinal axis (14) a sensing probe can be rotated, has a rounded head (7) which is supported in a housing (3) pivotable in all directions and fixable by first clamping elements (5), in order to fix its longitudinal axis in a desired angle. The housing (3) is displaceable in all directions transversely to its longitudinal axis with respect to a base part (1) which can be anchored to the femur head (10) and fixable by two clamping elements (4) in order to define the position of the longitudinal axis (14) of the guide tube (6) by rotation of a sensing probe around this longitudinal axis (14) relative to the cross-section of the femur neck (16).

Abstract: The acetabulum (1) comprises a semispherical support shell (2d) whose inner surface (20) has at least three retaining means (2b) which protrude into the interior. Furthermore, the acetabulum (1) comprises a semispherical inner shell (3) which can be inserted into the correspondingly dimensioned semispherical support shell (2d). The outer surface (30) of the inner shell (3) has at least one recess (3b) extending in a helical manner, in such a way that the inner shell (3) can be rotated into the support shell (2d) with a screw motion, thereby resulting in operative connection between the protruding retaining means (2b) of the support shell (2d) and the recess (3b) extending in a helical manner of the inner shell (3), so that the inner shell (3) is retained in the support shell (2d).