Modified Inside-outside Occipito-Cervical Plate System: Preliminary Results

Internal rigid fixation provides immediate stability of the occipito-cervical (OC) junction for treatment of instability; however, in current practice, the optimal OC junction stabilization method is debatable.

The aim of this study to test the safety and efficacy of a newly designed modified inside-outside occipito-cervical (MIOOC) plate system for the treatment of instability.

This was a feasibility study of MIOCC plate system.

Five male and four female patients with OC instability were treated using MIOOC plate system. Stabilization rate, safety, and efficacy were evaluated radiologically and clinically.

Mean age of the patients was 35 ± 11 (range: 22-58) years. Etiology of OC instability included trauma, neoplasm, congenital abnormalities, and iatrogenic. The fusion levels ranged from occiput-C3 to occiput-C6. Mean follow-up duration was 22 ± 10 (range: 6-46) months. There were neither complication nor was there any need for plate revision or screw pullout. Mortality occurred in one patient due to primary malignancy at 6 months; otherwise, no morbidity was observed. During the follow-up, no recurrent subluxation or newly developed instability at adjacent levels occurred. All patients showed a satisfactory union at the most recent follow-up examination.

These preliminary results suggest that the MIOCC plate system is a useful and safe method for providing immediate internal stability of the OC junction. Using a multi-piece plate design in this plate system provided easy implantation and a better interface between plate and OC bones. Further, clinical studies and long-term results are needed to determine the reliability of the MIOOC plate system.