Patent ID: 8162992

Claim:
An interbody spinal fusion method, comprising providing surgical access to an interbody space between first and second adjacent vertebral bodies, said access including at least one opening in a wall of a disc annulus defining the interbody space; introducing a first loadbearing spinal spacer and a second loadbearing spinal spacer into the interbody space through said at least one opening, wherein the first and second loadbearing spacers comprise bone or metal; delivering an osteogenic substance to said interbody space through said opening so as to promote bone growth to fuse said first and second adjacent vertebral bodies to one another, wherein said osteogenic substance is delivered in a carrier material containing osteogenic protein to a space in and around said first loadbearing spinal spacer and said second loadbearing spinal spacer; and delivering a flowable, biodegradable barrier material by flow through a tubular delivery device so as to inhibit migration of said osteogenic substance from said opening, wherein the barrier material (i) extends at least 50% along the dimension of either a posterior or anterior wall of the disc and (ii) contacts a portion of said osteogenic substance to inhibit migration but does not surround all of said osteogenic substance, wherein the biodegradable barrier material comprises a ceramic material, and wherein during delivery the barrier material has a first state and after delivery the barrier material has a second state, wherein said first state is more flowable than said second state.