Use of Screw-Rod System in Occipitocervical Fixation

Background: This study retrospectively reviewed 9 patients who underwent occipitocervical fixation with a newly developed screw-rod fixation system between April 2004 and November 2005. The objective was to evaluate the clinical result of occipitocervical fixation with the screw-rod fixation system, including symptom relief, fusion rate and complications. Methods: All 9 patients received occipitocervical fixation surgery with screw-rod fixation system and autologous bone grafts for fusion. Fusion was assessed by plain cervical X-ray films, and the myelopathy by Nurick scale. Results: Four males and 5 females were enrolled into this study. Mean age was 58.8 years, and mean follow-up period was 15 months. One female patient experienced surgical site infection with instrument pullout 20 months after surgery; she received a second operation for instrument revision. The overall fusion rate was 100%. The mean Nurick scores were 3 preoperatively and 2.1 postoperatively, with advancement of 0.9 points on average. Seven of 9 patients experienced pain or myelopathy improvement. There were no complications except for the 1 infection mentioned above. Conclusion: The fusion rate, complication rate and improvement in neurological function of occipitocervical fixation surgery using the screw-rod system were comparable to those of the widely used wire-rod system and screw-plate system. [J Chin Med Assoc 2009;72(1):20-28]