Aspirating Implants and Method of Bony Regeneration

Abstract

Devices and methods for in situ drawing, filtering and seeding cells from the marrow of surrounding bone into a fusion cage without any of the challenges mentioned above. Various implants and devices with aspiration ports that enable in-situ harvesting and mixing of stem cells. These devices may include spinal fusion cages, long bone spacers, lateral grafts and joint replacement devices. Each device utilizes at least one aspiration port for harvesting of stem cell-containing marrow via aspiration from adjacent bony elements.

We claim: 
     
         1 . A method of treating a bone defect with a fusion cage comprising:
 i) a proximal surface comprising a first throughole therethrough,   ii) a distal surface comprising a second throughole therethrough,   iii) a peripheral sidewall connecting the proximal and distal surfaces and comprising at least a third throughhole,   
       comprising the steps of: 
       a) inserting the fusion cage into the bone defect whereby the proximal surface faces away from the bone defect, 
       b) covering the first throughhole with a cell-impermeable porous sheath, 
       c) attaching an aspirator to the cell-impermeable porous sheath, and 
       d) actuating the aspirator to apply suction through the sheath and draw bone marrow through the sidewall and into the cage. 
     
     
         2 . A method of charging a fusion cage having an aspiration port with bone marrow aspirate, comprising the steps of:
 a) inserting the fusion cage into an interbody space defined by opposing bones,   b) fluidly connecting the aspirator to the aspiration port, and   c) creating suction in the aspirator to draw bone marrow from at least one of the bones into the fusion device.   
     
     
         3 . The method of  claim 2  wherein the opposing bones have opposing endplates that have been rasped. 
     
     
         4 . The method of  claim 2  wherein the aspiration port and the aspirator have mating lock fittings. 
     
     
         5 . The method of  claim 2  wherein the aspirator is a syringe. 
     
     
         6 . The method of  claim 2  wherein a sidewall of the cage has at least one throughhole. 
     
     
         7 . The method of  claim 6  wherein the cage further comprises a fluid-tight jacket wrapped around the sidewall to occlude the throughhole. 
     
     
         8 . The method of  claim 2  wherein bone marrow substantially fills the fusion cage. 
     
     
         9 . The method of  claim 2  wherein an excess of bone marrow is drawn through the cage to concentrate stem cells in the cage.