# Occipito-Cervical Fusion Using Screw Rod Plate System in Craniocervical Pathologies: A Prospective Cohort Analysis of Long-Term Functional and Radiological Outcome With Minimum Two Years of Follow-Up

## TL;DR

This study shows that a modern surgical technique for occipito-cervical fusion leads to high success rates and improved patient outcomes over the long term.

## Contribution

The study introduces a posterior-only surgical technique that avoids facet joint exposure and uses enabling technologies for occipito-cervical fusion.

## Key findings

- 18 out of 19 patients achieved radiological fusion with bony trabeculae forming around the rods.
- Clinical scores like VAS, NDI, Nurick grade, and mJOA showed significant improvement post-surgery.
- Radiological parameters such as McGregor slope and POCA improved, indicating better spinal alignment.

## Abstract

Introduction: Occipito-cervical fusion is a standard treatment for craniovertebral junction (CVJ) instability and myelopathy. The technique has evolved from onlay bone grafting with halo immobilisation to rigid internal fixation with pedicle screws and rods construct, allowing early mobilisation and improving fusion rates. We describe our experience with the posterior-only surgical technique using enabling technologies, avoiding facet joint exposure and its associated complications.

Methodology: A total of 19 patients who underwent occipito-cervical fusion for CVJ pathologies were evaluated. These patients were followed up for a minimum of 24 months. Clinical assessment included Visual Analog Scale (VAS), Neck Disability Index (NDI), Nurick grade, and modified Japanese Orthopaedic Association (mJOA) scores. Radiological parameters, McGregor slope, occiput-C2 angle (O-C2), C2-C7 lordosis, and posterior occipito-cervical angle (POCA), were evaluated on lateral radiographs. Fusion was confirmed via CT scan by the presence of bony trabeculae between the occiput and C2 lamina.

Results: Of the 19 patients, 18 (94.7%) achieved radiological fusion on follow-up CT scan, showing bony trabeculae often forming around the rods. Clinically, mean VAS improved from 7.4 to 1.8, NDI from 38.6 to 15.8, Nurick grade from 3.2 to 0.9, and mJOA from 10.6 to 15.4. Radiologically, the McGregor slope, O-C2 angle, and POCA showed significant improvement postoperatively, indicating better alignment.

Conclusion: Posterior-only occipito-cervical fusion using modern technologies results in high fusion rates, clinical improvement, and radiological correction, while avoiding the morbidity associated with anterior approaches and facet joint exposure.