Allograft tissue material for filling spinal fusion cages or related surgical spaces

Claim 1

A method for filling a surgical site with bone material, comprising the steps of: placing a mass of lyophilized bone chips of predetermined mixed size ranging from 100 microns to 2.0 mm, said mass of chips including a packing of the interstitial spaces between the larger granular tissue particles of particulate cortical bone powder ranging from about 100 to about 300 microns and larger sized granular tissue particles in a straight-walled barrel of a syringe having a circular opening at the distal end thereof, ranging from about 8 mm to about 15 mm in diameter; tamping the mass of bone chips to fill air pockets in the syringe; adding a volume of sterile fluid ranging from about 3 to about 6 times the bulk of the volume of the mass of bone chips to provide adequate wetting; allowing the fluid to flow through said mass of bone chip to filly hydrate the bone chips for a period of time hydrating the bone chips until the mass is fully reconstituted from its initial lyophilized state and obtains chip self-adherence conforming to the shape of the lumen of the barrel of the syringe and retain such shape and geometric integrity; draining sterile fluid from the syringe; and depressing a plunger of the syringe and extruding the shaped bone material in a semi-solid mass which retains its shape and integrity in a surgical site.

Claim 2

A method for filling a surgical site with bone material, comprising the steps of: placing a mass of lyophilized bone chips of predetermined mixed size ranging from 100 microns to 2.0 mm, said mass of chips including a packing of the interstitial spaces between the larger granular tissue particles of particulate cortical bone powder ranging from about 100 to about 300 microns and larger sized granular tissue particles in a straight-walled barrel of a syringe having a circular opening at the distal end thereof, ranging from about 8 mm to about 15 mm in diameter; tamping the mass of bone chips to fill air pockets in the syringe; adding a volume of sterile fluid ranging from about 3 to about 6 times the bulk of the volume of the mass of bone chips to provide adequate wetting; allowing the fluid to flow through said mass of bone chip to filly hydrate the bone chips for a period of time hydrating the bone chips until the mass is fully reconstituted from its initial lyophilized state and obtains chip self-adherence conforming to the shape of the lumen of the barrel of the syringe and retain such shape and geometric integrity; draining sterile fluid from the syringe; and depressing a plunger of the syringe and extruding the shaped bone material in a semi-solid mass which retains its shape and integrity in a surgical site.

Claim 5

A method of filling a surgical site with a shape-retaining, semi-solid bone composition, comprising the steps of: placing a plurality of lyophilized bone particles of mixed sizes ranging from a particulate powder mixed with larger granular tissue particles, said lyophilized bone particles comprising a mixture containing about 75% by volume of lyophilized, demineralized cortical/cancellous bone powder ranging from 0.5 to 2 mm particle size and about 25% by volume of lyophilized, demineralized cortical bone powder ranging from 100 to 300 micron particle size to provide a bone composition with a packing of the interstitial spaces between the larger granular tissue particle with particulate powder or other granular tissue particles in a straight-walled extrusion vessel having an opening at the distal end thereof which opening has substantially the same dimensions as the interior of a spinal fusion chamber; pouring a volume of hydrating solution into an open proximal end of said extrusion vessel and allowing the solution to flow through said mass of bone particles to fully hydrate same; removing the air bubbles from the hydrating solution which adhere to said plurality of bone particles; allowing the bone particles to hydrate for at least 20 minutes in said solution so that said bone particles become an extrudable, shape-retaining semi-solid mass; and extruding said bone particle composition from said extrusion vessel into said surgical site in a semi-solid shape which substantially retains the shape of the interior of said extrusion vessel.

Claim 6

A method of filling a surgical site with a shape-retaining, semi-solid bone composition, comprising the steps of: placing a plurality of lyophilized bone particles of mixed sizes ranging from a particulate powder mixed with larger granular tissue particles, said lyophilized bone particles comprising a mixture containing about 75% by volume of lyophilized, demineralized cortical/cancellous bone powder ranging from 0.5 to 2 mm particle size and about 25% by volume of lyophilized, demineralized cortical bone powder ranging from 100 to 300 micron particle size to provide a bone composition with a packing of the interstitial spaces between the larger granular tissue particle with particulate powder or other granular tissue particles in a straight-walled extrusion vessel having an opening at the distal end thereof which opening has substantially the same dimensions as the interior of a spinal fusion chamber; pouring a volume of hydrating solution into an open proximal end of said extrusion vessel and allowing the solution to flow through said mass of bone particles to fully hydrate same; removing the air bubbles from the hydrating solution which adhere to said plurality of bone particles; allowing the bone particles to hydrate for at least 20 minutes in said solution so that said bone particles become an extrudable, shape-retaining semi-solid mass; and extruding said bone particle composition from said extrusion vessel into said surgical site in a semi-solid shape which substantially retains the shape of the interior of said extrusion vessel.