Device for a ball-and-socket type joint connection of two members

A spinal implant device comprising:

• a bone fixation member having a spherically-shaped head, a fixation section extending from the head and attachable to bone, and a central axis;
• the head having a center lying on the central axis and having a depression in the top of the head, the depression having a spherically-shaped surface having a center lying on the central axis that coincides with the head center;
• a connection member having a central axis, an upper portion, a lower portion, and a bore extending through the upper and lower portions coaxial with the central axis of the connection member, the bore including internal threads within the upper portion;
• the lower portion having a cavity concentric with the central axis of the connection member, the cavity being in communication with the bore, and the lower portion having an opening for the passage therethrough of the fixation section, the cavity having a taper at the opening that forms a spherically-shaped support for the head of the bone fixation member, the spherically-shaped support forming a center;
• the upper portion having a channel formed therein in a peripheral side surface of the connection member for receiving a longitudinal rod, the channel having a channel axis disposed transversely to the central axis of the connection member, an opening of the channel facing radially outward from the peripheral side surface and away from the lower portion, the channel opening being disposed transversely to the central axis of the connection member and transversely to the channel axis;
• a covering cap having a tab parallel to the channel axis for laterally surrounding at least a portion of a longitudinal rod received in the channel, the covering cap being sized and configured to slidably engage an outer surface of the upper portion of the connection member;
• and
• a clamping member extending within the bore and the cavity of the connection member, the clamping member having a front end receivable in the depression and having a back end, the back end including external threads for engaging the threads formed in the bore of the connection member, the clamping member operative to clamp the head of the bone fixation member against the spherically-shaped support to lock the bone fixation member to the connection member;
• wherein the central axis of the connection member and the channel axis are laterally offset from each other by a distance A so that an outer surface of a longitudinal rod received in the channel is separated from an outer surface of the clamping member by the peripheral side surface of the connection member.