Anterior cervical fusion using Caspar plating: analysis of results and review of the literature.

BACKGROUND Ninety-seven patients underwent anterior cervical fusions after discectomy and/or corpectomy. Fibular allograft was used in 13 cases and iliac crest was used in the remaining 84 patients. METHODS Lateral cervical spine X-rays were reviewed for evaluation of fusion and instrumentation failures. RESULTS Solid fusion was achieved in all but two patients (97.91%). Nineteen patients developed instrumentation related failures. Seven patients developed fracture of one screw each (one superior and six inferior). Ten patients developed screw back out (inferior screw) and in one patient the superior screws were found to be 2 mm posterior to the posterior cortex but did not cause any neurological deficits. Seven of these patients underwent revision surgery. No complications related to the instrumentation were encountered in the last 34 cases. There were no infections in this series. Five patients developed temporary dysphagia. Two developed temporary deltoid weakness and three patients developed transient recurrent laryngeal nerve palsy. One developed acute airway obstruction but the patient had a pre-existing epiglottic anomaly and sleep apnea disorder. CONCLUSIONS In selected cases, the Caspar plating system affords an effective means of improving the fusion rate (97.91%) with acceptable instrumentation-related morbidity that improves with experience, (10.7% in the first 38 cases and 1.69% in the last 59 with an overall rate of 7.2%). Temporary neurological deficits seen in this series were probably not related to the Caspar plating procedure itself. Intraoperative fluoroscopic films can be misleading. Therefore regular lateral cervical spine X-rays postplating in the operating room prior to closure are recommended. Lower screws backed out in all failures and this was circumvented by using the bigger (rescue) screws at the inferior end of long constructs.