Abstract
BACKGROUND: Carbon-fiber-reinforced polyether ether ketone (CF-PEEK) is a radiolucent, non-metallic implant material used for instrumented lumbar spondylodesis. Clinical studies of pedicle screw systems employing this material, especially for degenerative indications, are scant. METHODS: We conducted a multicenter, prospective clinical study to assess clinical and radiographic outcomes in patients with symptomatic degenerative lumbar disk disease, including degenerative spondylolisthesis treated with a CF-PEEK pedicle screw and a transforaminal lumbar interbody fusion (TLIF) cage system. We followed up the participants for two years postoperatively to collect clinical data (via the Oswestry Disability Index, Core Outcome Measures Index, and Visual Analog Scale), radiographic parameters (functional X-rays) to assess fusion status, and any complications. RESULTS: In total, 86 patients were recruited. During the study, 21 patients (24.4%) dropped out, including 5 (5.8%) who underwent explantation of the study device(s). At the final follow-up, the fusion rate was 98.6% (95% confidence interval, 92.7-100.0%). All clinical parameters improved significantly. There were no complications potentially attributed to the implant material. CONCLUSIONS: The results demonstrate a fusion rate similar to that of metallic implant systems with the use of a CF-PEEK pedicle screw and a TLIF cage system. Further studies with larger samples are needed to substantiate this finding. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (NCT02087267). Date of registration: March 12, 2014.