Patent ID: 11938038
Assignee: nan
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. An implant device for interbody fusion of lumbar vertebrae comprising:
a unibody cage structure having an enveloping cage volume and a minimized material volume, the cage structure comprising
a first and a second generally planar ring member, each ring member formed from an opposing pair of lengthwise joists and an opposing pair of cross joists, the joists together forming a large opening through the ring member, the large opening not interrupted by a cross-joist,
the ring members fixedly sandwiched on four vertical struts, each of the vertical struts positioned adjacent an intersection between the lengthwise joists and the cross joists to thereby distribute load between the ring members, a central lengthwise portion of the lengthwise joists not supported by an internal strut, the four vertical struts_holding the ring members in a spaced apart relationship to thereby provide a large void volume relative to the enveloping cage volume, to thereby allow for receipt of a large volume of bone graft within the cage structure,
the first ring member on a superior side of the cage and serving as a superior loading surface,
the second ring member on an inferior side of the cage and serving as an inferior loading surface,
wherein a ratio of the void volume to the enveloping cage volume is between about 0.7 to about 0.9.