Intervertebral prosthesis or disk prosthesis

An intervertebral implant system for implantation between an upper vertebra and a lower vertebra, comprising:

• a first spacer, comprising:
• a cavity defined by a body having a first end and an inlet opening for receiving a flowable material to the cavity;
• a second end opposite the first end;
• an upper side for contacting at least a portion of the upper vertebra;
• a lower side for contacting at least a portion of the lower vertebra;
• a first lateral side extending between the upper and lower sides and between the first and second ends;
• and
• a second lateral side extending between the upper and lower sides and between the first and second ends, the second lateral side defining an opening to the cavity;
• a second spacer, comprising:
• a body having a first end and a second end opposite the first end;
• an upper side for contacting at least a portion of the upper vertebra;
• a lower side for contacting at least a portion of the lower vertebra;
• a first lateral side extending between the upper and lower sides and between the first and second ends;
• and
• a second lateral side extending between the upper and lower sides and between the first and second ends;
• wherein the first and second spacers are sized and configured to be positioned in an intervertebral space a distance apart from one another with the second lateral side of the first spacer facing the first lateral side of the second spacer, such that a volume of flowable material delivered to the inlet of the first spacer flows through the cavity of the first spacer, out at least one of the first and second lateral sides, into a central region of the disc space disposed between the first and second spacers, and to the first lateral side of the second spacer,
• wherein the first spacer is configured to have the flowable material emerge asymmetrically from the first spacer such that more of the flowable material emerges from one of the first and second lateral sides of the first spacer than from an opposite one of the first and second lateral sides of the first spacer, and
• wherein at least one of the first and second lateral sides of the first spacer are substantially straight.