title: Experimental lumbar spine fusion with novel tantalum-coated carbon fiber implant.
abstract: Implants of carbon fiber composite have been widely used in orthopedic and spinal surgeries. However, studies using carbon fiber-reinforced cages demonstrate frequent appearance of fibrous layer interposed between the implant and the surrounding bone. The aim of the present study was to test the possibility of coating a biocompatible metal layer on top of the carbon fiber material, to improve its biological performance. Tantalum was chosen because of its bone compatibility, based on our previous studies. A novel spinal fusion cage was fabricated by applying a thin tantalum coating on the surface of carbon-carbon composite material through chemical vapor deposition. Mechanical and biological performance was tested in vitro and in vivo. Compress strength was found to be 4.9 kN (SD, 0.2). Fatigue test with 500,000 cycles was passed. In vitro radiological evaluation demonstrated good compatibility with X-ray and CT scan examinations. In vivo test employed eight pigs weighing 50 kg each. Instrumented lumbar spine fusion of L3/4 and L4/5 with these cages was performed on each pig. After 3 months, excellent bone integration property was demonstrated by direct contact of the cage with the host bone and newly formed bone. No inflammatory cells were found around the implant. Cages packed with two different graft materials (autograft and COLLOSS) achieved the same new bone formation. The present study proved that coating tantalum on top of the carbon-based implant is feasible, and good bone integration could be achieved.
authors.affiliation: Orthopaedic Research Laboratory, Orthopaedic Department E, Aarhus University Hospital,Noerrebrogade 44, 8000 Aarhus C, Denmark. haisheng.li@ki.au.dk
authors.forename: Haisheng
authors.initials: H
authors.lastname: Li
authors.forename: Xuenong
authors.initials: X
authors.lastname: Zou
authors.forename: Charlotte
authors.initials: C
authors.lastname: Woo
authors.forename: Ming
authors.initials: M
authors.lastname: Ding
authors.forename: Martin
authors.initials: M
authors.lastname: Lind
authors.forename: Cody
authors.initials: C
authors.lastname: Bünger
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D020099:Coated Materials, Biocompatible; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000166:cytology / Q000000981:diagnostic imaging / Q000601:surgery*; D019736:Prostheses and Implants; D013552:Swine; D013635:Tantalum / Q000737:chemistry*; D014057:Tomography, X-Ray Computed
chemical_list: D000077482:Carbon Fiber; D020099:Coated Materials, Biocompatible; D013635:Tantalum; D002244:Carbon