Failure of a Carbon Fiber Implant

STUDY DESIGN: Case report. OBJECTIVES: Failure of a carbon fiber implant. SUMMARY OF BACKGROUND DATA: To simplify the procedure of posterior lumbar interbody fusion, a carbon-fiber-reinforced polymer implant has been developed. The implant has ridges to resist retropulsion, struts to support weight, and a hollow area to allow packing of autologous bone graft. So far, no complications have been reported from the use of carbon implant as a fusion aid in spine surgery. METHODS: A patient with postoperative infection has been followed with computed tomography images and histologic examination from a reoperation. RESULTS: An entire nonunion across the width of the disc space and a clearly broken cage was visualized with computed tomography. The spinal canal was explored during a reoperation and the tissue surrounding the dura and nerves were all black. Microscopic examination showed a large quantity of carbon particulate debris. The authors have operated on approximately 100 patients so far and no other carbon cage has broken, to their knowledge. CONCLUSIONS: Carbon cages can break if a nonunion occurs and as a result free carbon particles move out to the spinal canal.