Anterior Cervical Discectomy and Fusion Using Porous PEEK Implants at Levels Adjacent to a Previous Fusion
Objective: We report the results of a prospective, single center clinical study in which anterior cervical discectomy and fusion (ACDF) was performed using a porous PEEK implant and plate at intervertebral disc spaces in patients who had symptomatic, degenerative cervical disc disease at levels adjacent to a previous ACDF. Methods: Twenty-eight consecutive patients (15 females, 13 males; average age, 54 years) with degenerative cervical disc disease at levels adjacent to a previous fusion underwent anterior cervical discectomy and fusion (ACDF) using a porous PEEK interbody fusion cage and plate. There were 22 single-level and 6 two-level adjacent level fusions between C3 and C7. Patients were assessed at 1.5, 3, 6, 12 and 24 months. Standardized clinical outcome measures were used to evaluate the patient’s condition before and after surgery. Plain radiographs were used to assess fusion, bony ingrowth, sagittal plane angulation, subsidence, and migration of the implant. Results: No patients were lost to follow up; all patients were followed for a minimum of 12 months. Six patients were followed for more than 24 months. At the last follow up, NDI and neck and pain scores showed improvement in all patients. All had previous anterior cervical fusions and 22 had at least 1 additional co-morbidly for an adverse event (diabetes, osteoporosis, smoking, obesity). Following revision surgery, all patients showed radiographic fusion with no motion across the instrumented interspaces on dynamic flexion-extension lateral radiographs. Segmental lordosis at the surgical site improved to an average of 5° (2° to 9°) with no evidence of implant migration or subsidence. Average disc space height increased 4 mm. No patient showed radiographic evidence of a pseudarthrosis. No patient developed any radiolucency at the implant interface with the host bone. Conclusion: This prospective, nonrandomized study shows that porous-surface PEEK is a clinically viable alternative for improving the osseointegration and fusion rates of interbody implants in patients undergoing revision fusion surgery at 1 to 2 levels adjacent to previous surgical fusions.