Modular interbody spacer

An intervertebral spinal spacer comprising:

• (a) a first portion of a modular spacer, the first portion being selectable from a plurality of spacer elements having different sizes, the first portion having an upper surface, a lower surface, an outer surface, and a first attachment member;
• (b) a second portion of the modular spacer, the second portion being selectable from the plurality of spacer elements having different sizes, the second portion having an upper surface a lower surface, an outer surface, and a second attachment member, wherein the first attachment member is engaged with the second attachment member to interlock the first portion and the second portion, wherein at least one of the first portion or the second portion of the modular spacer defines one or more internal cavities;
• and
• (c) at least one fluid passage defined by the first portion or the second portion, the at least one fluid passage being curved and being in fluid communication with at least one of the one or more internal cavities.

A kit for an intervertebral spacer comprising:

• (a) a plurality of anterior portions for a modular spacer, each of the plurality of anterior portions for the modular spacer having a different size;
• (b) a plurality of posterior portions for a modular spacer, each of the plurality of posterior portions for the modular spacer having a different size, wherein at least one of the first portion or the second portion of the modular spacer defines one or more internal cavities;
• and
• (c) a plurality of fluid passages defined by at least one of the plurality of anterior portions or plurality of posterior portions, the plurality of fluid passages being curved and being in fluid communication with at least one of the one or more internal cavities,
• wherein at least one of the plurality of anterior portions is interlocked with at least one of the plurality of posterior portions.