Cervical foraminal area and intervertebral height changes after titanium ring cage placement: Preliminary results

Objective: To investigate the effect of titanium ring cage implantation on cervical foraminal area and intervertebral height. Methods: Twenty-two patients with single level cervical disc herniation were enrolled in this study. All patients underwent a standard anterior cervical discectomy followed by titanium ring cage implantation. Radiographs were used for evaluation of the cervical foraminal area and intervertebral height in the pre- and postoperative periods. Results: Mean intervertebral heights were 0.7 +/- 0.1 cm (preoperative), 1.1 +/- 0.2 cm (early postoperative) and 0.9 +/- 0.2 (final measurement). Increase in intervertebral height at final follow-up was 0.2 0.1 cm (22.6 +/- 8.5%). Mean cervical foraminal areas were 0.4 +/- 0.1 cm 2 (preoperative), 0.5 +/- 0.2 cm(2) (early postoperative) and 0.5 +/- 0.1 cm(2) (final measurement). Increase in cervical foraminal area at the final follow-up was 0.1 +/- 0.1 cm(2). Conclusion: Our study demonstrates that cervical intervertebral height and cervical foraminal area significantly increased after cervical ring cage placement but subsidence during the follow-up period negatively affects foraminal area. However, overall, there was a relative increase of foraminal area and intervertebral height when compared with preoperative values. Long-term follow-up is required to further assess the subsidence rate. (c) 2005 Elsevier Ltd. All rights reserved.