Vario-head endoprosthesis

Claim 2

A vario-head endoprosthesis comprising a ball-shaft prosthesis, for example a femur prosthesis, and a vario-head prosthesis having an outer shell and an inner insert which provides a socket for the prosthesis ball having an aperture forming a constriction providing a positive safeguard against removal of the prosthesis ball from the socket, characterized in that the insert has a collar with an inwardly facing annular groove (8) surrounding and opening into the aperture region of the socket (1,2), and the constriction is formed by a split ring (11) mounted within the annular groove and retained therein against expansion to engage and positively retain the prosthesis ball within the socket, the split ring being flexible so as to be adapted to be inserted circumferentially into the annular groove (8) and the opening side of the socket collar having cut-out means (10) to enable the split ring (11) to be inserted into or withdrawn from the annular groove in the circumferential direction.

Claim 3

Vario-head endoprosthesis according to claim 1, characterised in that a means for applying a withdrawal tool (14) is formed on at least one end of the split ring (11).

Claim 4

Vario-head endoprosthesis according to claim 2, characterised in that both ends of the split ring have a hole (13).

Claim 5

Vario-head endoprosthesis according to claim 1, charcterised in that, in the aperture region, the insert additionally has a constriction (6) which elastically yields on insertion of the prosthesis ball.

Claim 6

A vario-head endoprosthesis comprising a ball-shaft prosthesis, for example a femur prosthesis, and a vario-head socket having an aperture forming a constriction providing a positive safeguard against removal of the prosthesis ball from the socket, characterized in that the vario-head socket has a collar which delimits an inwardly facing annular groove (8) surrounding the aperture region of the socket (1, 2), and the constriction is formed by a split ring (11) adapted to be inserted circumferentially into the annular groove (8) and the opening side of the socket collar has cut-out means (10) to enable the split ring (11) to be inserted into or withdrawn from the annular groove in the circumferential direction, the split ring (11) having grooves (12) at least on its side intended to face outwardly for aiding circumferential displacement of the ring (11) within said annular groove (8).

Claim 7

A vario-head endoprosthesis comprising a ball-shaft prosthesis, for example a femur prosthesis, and a vario-head socket having an aperture forming a constriction providing a positive safeguard against removal of the prosthesis ball from the socket, characterized in that the vario-head socket has a collar which delimits an inwardly facing annular groove (8) surrounding the aperture region of the socket (1, 2), and the constriction is formed by a split ring (11) adapted to be inserted circumferentially into the annular groove (8) and the opening side of the socket collar has cut-out means (10) to enable the split ring (11) to be inserted into or withdrawn from the annular groove in the circumferential direction, the split ring (11) having grooves (12) at least on its side intended to face outwardly for aiding circumferential displacement of the ring (11) within said annular groove (8).

Claim 8

A vario-head endoprosthesis comprising a ball-shaft prosthesis, for example a femur prosthesis, and a vario-head socket having an aperture forming a constriction providing a positive safeguard against removal of the prosthesis ball from the socket, characterized in that the vario-head socket has a collar which delimits an inwardly facing annular groove (8) surrounding the aperture region of the socket (1, 2), and the constriction is formed by a split ring (11) adapted to be inserted circumferentially into the annular groove (8) and the opening side of the socket collar has cut-out means (10) to enable the split ring (11) to be inserted into or withdrawn from the annular groove in the circumferential direction, the split ring (11) having means formed on at least one end thereof for applying a withdrawal tool (14) for withdrawing the split ring (11) from the said annular groove (8), and the split ring (11) having grooves (12) on at least its one side which is intended to face outwardly for aiding circumferential displacement of the split ring (11) within said annular groove (8).

Claim 9

A vario-head endoprosthesis comprising a ball-shaft prosthesis, for example a femur prosthesis, and a vario-head socket having an aperture forming a constriction providing a positive safeguard against removal of the prosthesis ball from the socket, characterized in that the vario-head socket has a collar which delimits an inwardly facing annular groove (8) surrounding the aperture region of the socket (1, 2), and the constriction is formed by a split ring (11) adapted to be inserted circumferentially into the annular groove (8) and the opening side of the socket collar has cut-out means (10) to enable the split ring (11) to be inserted into or withdrawn from the annular groove in the circumferential direction, the split ring (11) having means formed on at least one end thereof for applying a withdrawal tool (14) for withdrawing the split ring (11) from the said annular groove (8), and the split ring (11) having grooves (12) on at least its one side which is intended to face outwardly for aiding circumferential displacement of the split ring (11) within said annular groove (8).