Biocompatibility And Osseointegration Of Porous Titanium Alloy By Electron Beam Melting:Experimental Studies In Swine

Objective:(1)To investigate the biocompatibility of Electron Beam Melting fabricated porous Titanium alloy implants in vitro.(2) To study thefeasibility of the Electron Beam Melting fabricated porous Titanium alloy implants in Bama minipigs.Methods:(1) Extraction fluid wasperformed byElectron Beam Melting porous implants, peek cages, ordinary titanium cages,and then the cytotoxicity analysis and the cell proliferation were performed based onISO 10993-5. (2)An Electron Beam Melting fabricated porous Titanium alloy implants (P group) and an ordinaryTitanium alloy cage (C group) were randomly implanted into L2-3 or L4-5 lumbar intervertebral disc of a Bama minipig. The height of the fusion segments,bone ingrowth were measured by radiological methods, and histological of the fusion segments and the heart, liver and kind were performed. The blood routine measurement and serum chemistry were tested.Results:(1)There were no significant differences of cytotoxicity and cell proliferation among the extraction fluids ofElectron Beam Melting porous implants, peek cages, ordinary titanium cages(p>0.05). (2)A11 surgeries were successful,and all minipigs were in good condition after operation. At one month, three month and six month after operations significant differences (p<0.05) of the subsidence height between Electron Beam Melting fabricated Titanium alloy implants group and ordinaryTitanium alloy cages group were noted.A better interface osseointegration ratio was observed in Electron Beam Melting fabricated Titanium alloy implants group. Bone ingrowth was observed from cages in two groups, bone grow of the EBM cages were better. At one month postoperative WBC count increased, a significant diffidence (p<0.05) in WBC count between the one month group and the preoperative groups was noted. At one month postoperative Bcr increase was found, a significant diffidence (p<0.05) in Bcr between the one month group and the preoperative groups was noted. There was no abnormality observed in histological sections of heart, liver,kidney.Conclusions:Electron Beam Melting fabricated porous Titanium alloy implants show satisfactory biocompatibility and Young modulus. Porous implants facilitated osseointegrated effectively. The additional benefits of these results justify further clinical studies.