Comparison of post-operative lordosis with the PEEK cage and the cervical plate.

OBJECTIVE The maintenance of post-operative lordosis has been shown to be a key factor in decreasing adjacent level disc stress. Previous studies of the PEEK (polyether ketone) cage have used intervertebral bony fusion as the primary measure of surgical success; however, little is known about its effects on spinal curvature. Our objective was to compare the PEEK cage to the cervical plate with respect to the maintenance of cervical lordosis at one year. Secondary outcomes included fusion and complication rates. METHODS We performed a retrospective study of patients who underwent ACDF (anterior cervical discectomy and fusion) by two different methods; 13 patients were treated with the PEEK cage, and 22 with allograft and plating. RESULTS Patient and treatment characteristics were similar in both groups. Average global lordotic curvature (C2-C7) was increased by 1.7 degrees for the PEEK cage and decreased by 1.6 degrees for the plate after an average follow-up of 12.46 and 14.95 months, respectively. Regional lordosis for the PEEK cage and plate was decreased by 2.5 and 2.1 degrees, respectively for the same time period. These differences did not achieve statistical significance. Bony fusion was observed in all patients. One patient in each group developed persistent mild dysphagia. CONCLUSIONS The PEEK cage is comparable to the anterior cervical plate in the maintenance of post-operative cervical lordosis.